Effects of age and weaning conditions on blood indicators of oxidative status in pigs

Effects of microbe-derived antioxidants on growth performance, hepatic oxidative stress, mitochondrial function and cell apoptosis in weaning piglets

BACKGROUND

Weaning causes redox dyshomeostasis in piglets, which leads to hepatic oxidative damage. Microbe-derived antioxidants (MA) have great potential for anti-oxidation. This study aimed to investigate changes in hepatic redox system, mitochondrial function and apoptosis after weaning, and effects of MA on growth performance and liver health in weaning piglets.

METHODS

This study consisted of 2 experiments. In the both experiments, piglets were weaned at 21 days of age. In Exp. 1, at 21 (W0), 22 (W1), 25 (W4), 28 (W7), and 35 (W14) days of age, 6 piglets were slaughtered at each timepoint. In Exp. 2, piglets were divided into 2 groups: one received MA gavage (MA) and the other received saline gavage (CON). At 25 days of age, 6 piglets from each group were sacrificed.

RESULTS

In Exp. 1, weaning caused growth inhibition and liver developmental retardation from W0 to W4. The mRNA sequencing between W0 and W4 revealed that pathways related to "regulation of apoptotic process" and "reactive oxygen species metabolic process" were enriched. Further study showed that weaning led to higher hepatic content of reactive oxygen species (ROS), H2O2 and O2-. Weaning enhanced mitochondrial fission and suppressed their fusion, activated mitophagy, thus triggering cell apoptosis. In Exp. 2, MA improved growth performance of piglets with higher average daily gain (ADG) and average daily feed intake (ADFI). The hepatic ROS, as well as products of oxidative damage malonaldehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the MA group decreased significantly than that of the CON group. The MA elevated mitochondrial membrane potential, increased activity of mitochondrial respiratory chain complexes (MRC) I and IV, enhanced mitochondrial fusion and reduced mitophagy, thus decreasing cell apoptosis.

CONCLUSIONS

The present study showed that MA improved the growth performance of weaning piglets and reversed weaning-induced oxidative damage, mitochondrial dysfunction, and apoptosis. Our results suggested that MA had promising prospects for maintaining liver health in weaning piglets and provided a reference for studies of liver diseases in humans.

The Effect of Vitamins on the Immune Systems of Pigs

In modern pig farming, there are many environmental, physiological or social stresses that weaken the immune response and increase susceptibility to disease. Nutritional management has a significant impact on the efficiency of the immune system in pigs. Among the various nutrients, vitamins have been shown to have specific effects on immune system activity. However, the needs of modern genetic types are not met by the dietary recommendations for vitamins in pig diets. The present study therefore summarises the data on dietary integration with supranutritional doses of vitamins in gestating and lactating sows and post-weaning piglets in terms of the immune response. The present data highlight that high doses of dietary vitamins are an effective way to improve the immune system, antioxidant status and gut health. Further studies are needed to deepen the understanding of the role of dietary supplementation with vitamins in pigs on immune system and gut functionality.

Improved Antioxidant Blood Parameters in Piglets Fed Diets Containing Solid-State Fermented Mixture of Olive Mill Stone Waste and Lathyrus clymenum Husks

Solid-state fermentation represents a sustainable approach for the conversion of agro-industrial wastes into high-added-value feed ingredients. The present study aimed to evaluate the effects of the dietary addition of a solid-state-fermented mixture of olive mill stone waste (OMSW) and Lathyrus clymenum husks (LP) on the antioxidant blood parameters of weaned piglets. Two hundred 35-day-old weaned piglets were allotted into two groups and fed either a control (C) diet or a diet containing 50 g of OMSW-LP per kg (OMSW-LP) for 40 days. Blood samples were collected at 35 and 75 days of age to assess the free radical scavenging activity (FRSA), reduced glutathione (GSH) levels, catalase activity (CAT), protein carbonyls (CARBs), and thiobarbituric acid reactive species (TBARS). The OMSW-LP diet reduced the TBARS (p = 0.049) and CARB contents (p = 0.012) and increased the levels of FRSA (p = 0.005), GSH (p = 0.040), and CAT activity (p = 0.012) in the piglets' blood, likely due to the synergistic action of the antioxidants and bioactive compounds present in the OMSW-LP mixture. Overall, the dietary inclusion of solid-state-fermented OMSW-LP at 50 g/kg could potentially serve a bio-functional purpose since it enhanced the antioxidant blood parameters in this study, a crucial factor for the health and growth of piglets post-weaning.

Increased Dietary Trp, Thr, and Met Supplementation Improves Performance, Health, and Protein Metabolism of Weaned Piglets under Mixed Management and Poor Housing Conditions

A sanitary challenge was carried out to induce suboptimal herd health while investigating the effect of amino acids supplementation on piglet responses. Weaned piglets of high sanitary status (6.33 ± 0.91 kg of BW) were distributed in a 2 × 2 factorial arrangement into two similar facilities with contrasting sanitary conditions and two different diets. Our results suggest that increased Trp, Thr, and Met dietary supplementation could support the immune systems of piglets under a sanitary challenge. In this manner, AA+ supplementation improved the performance and metabolism of piglets under mixed management and poor sanitary conditions. No major temporal microbiome changes were associated with differences in performance regardless of sanitary conditions or diets. Since piglets often become mixed in multiple-site production systems and facility hygiene is also often neglected, this study suggests that increased Trp, Thr, and Met (AA+) dietary supplementation could contribute to mitigating the side effects of these harmful risk factors in modern pig farms.

Porcine ear necrosis is associated with social behaviours in weaned piglets

BACKGROUND

Porcine ear necrosis (PEN) is a worldwide health issue and its aetiology is still unclear. The aim of this study was to describe the prevalence and the severity of PEN in a commercial farm, associated with pig behaviour and health biomarkers measures. On two consecutive batches, PEN prevalence was determined at the pen level. PEN scores, blood haptoglobin concentration and oxidative status were measured on two pigs per pen (n = 48 pens) 9, 30 and 50 days (D) after arrival to the post-weaning unit. Social nosing, oral manipulation and aggression of pen mates and exploration of enrichment materials were observed on two to three pigs per pen twice a week from D9 to D50.

RESULTS

At the pen level, the higher the time spent nosing pen mates, the lower the percentage of pigs affected by PEN during both the early and the late post-weaning periods (P < 0.002) and, in the opposite, the higher the time spent orally manipulating pen mates during the late post-weaning period, the higher the percentage of affected pigs (P = 0.03). At the pig level, the higher the increase in hydroperoxides and haptoglobin during the early post-weaning period, the higher the PEN scores on D30 (P < 0.001).

CONCLUSIONS

This study suggests that a high incidence of social nosing, which can be an indicator of good social cohesion in a group, was significantly associated with less frequent lesions of PEN. In opposite, high incidence of oral manipulation of pen mates may increase the percentage of PEN-affected pigs. According to these observations, PEN is a multifactorial condition which may have social causes among others.

Verbascoside-Rich Plant Extracts in Animal Nutrition

In recent years, the search for dietary intervention with natural products able to sustain animal health and decrease environmental impact, has raised the number of studies pertaining to the use of plants' secondary metabolites. In fact, in livestock, there is a clear relationship between the animals' antioxidant status and the onset of some diseases that negatively affect animal welfare, health, and productive performance. An interesting compound that belongs to the secondary metabolites family of plants, named phenylpropanoids, is verbascoside. The genus Verbascum, which includes more than 233 plant species, is the genus in which this compound was first identified, but it has also been found in other plant extracts. Verbascoside exhibits several properties such as antioxidant, anti-inflammatory, chemopreventive, and neuroprotective properties, that have been evaluated mainly in in vitro studies for human health. The present work reviews the literature on the dietary integration of plant extracts containing verbascoside in livestock. The effects of dietary plant extracts containing verbascoside on the productive performance, antioxidant status, blood parameters, and meat quality in several animal species were evaluated. The present data point out that dietary plant extracts containing verbascoside appear to be a favorable dietary intervention to enhance health, antioxidant status, and product quality in livestock.

Targeting mitochondria with antioxidant nutrients for the prevention and treatment of postweaning diarrhea in piglets

Post-weaning diarrhea (PWD) in piglets poses a significant challenge and presents a grave threat to the global swine industry, resulting in considerable financial losses and compromising the welfare of animals. PWD is commonly associated with gut homeostatic imbalance, including oxidative stress, excessive inflammation, and microbiota dysbiosis. Antibiotic use has historically been a common initiative to combat PWD, but concerns about the development of antibiotic resistance have led to increased interest in alternative strategies. Mitochondria are key players in maintaining cellular homeostasis, and their dysfunction is intricately linked to the onset and progression of PWD. Accumulating evidence suggests that targeting mitochondrial function using antioxidant nutrients, such as vitamins, minerals and polyphenolic compounds, may represent a promising approach for preventing and treating PWD. Moreover, nutrients based on antioxidant strategies have been shown to improve mitochondrial function, restore intestinal redox balance, and reduce oxidative damage, which is a key driver of PWD. The present review begins with an overview of the potential interplay between mitochondria and gut homeostasis in the pathogenesis of PWD in piglets. Subsequently, alternative strategies to prevent and treat PWD using antioxidant nutrients to target mitochondria are described and discussed. Ultimately, we delve into potential limitations and suggest future research directions in this field for further advancement. Overall, targeting mitochondria using antioxidant nutrients may be a promising approach to combat PWD and provides a potential nutrition intervention strategy for regulating gut homeostasis of weaned piglets.

Lactobacillus johnsonii N5 from heat stress-resistant pigs improves gut mucosal immunity and barrier in dextran sodium sulfate-induced colitis

Developing effective strategies to prevent diarrhea and associated-gut disorders in mammals has gained great significance. Owing to the many health benefits provided by the commensal microbiota of the intestinal tract, such as against environmental perturbation, we explored the host phenotype-associated microbes and their probiotic potential. Based on the observations that the chronic heat stress-exposed weaned piglets present as heat stress-susceptible (HS-SUS) or heat stress-resistant (HS-RES) individuals, we confirmed the phenotypic difference between the two on growth performance (P < 0.05), diarrhea index (P < 0.001), intestinal heat shock protein 70 (HSP70) regulation (P < 0.01), and inflammatory responses (P < 0.01). By comparing the gut microbiome using 16S rRNA gene sequencing and KEGG functional analysis, we found that Lactobacillus johnsonii exhibited significantly higher relative abundance in the HS-RES piglets than in the HS-SUS ones (P < 0.05). Further experiments using a mouse model for chemical-induced inflammation and intestinal injury demonstrated that oral administration of a representative L. johnsonii N5 (isolated from the HS-RES piglets) ameliorated the clinical and histological signs of colitis while suppressing intestinal pro-inflammatory cytokines TNF-α and IL-6 production (P < 0.05). We found that N5 treatment enhanced tight junction proteins ZO-1 and occludin and cytoprotective HSP70 levels under physiological condition and restored their mucosal expressions in colitis (P < 0.05). In support of the high production of the anti-inflammatory cytokine IL-10, N5 promoted the intestinal Peyer's patches MHCII+ and CD103+ dendritic cell populations (P < 0.05), increased the regulatory T (Treg) cell numbers (P < 0.05), and decreased the Th17 population and its IL-17a production under physiological condition and during colitis (P < 0.01). Our results shed light on understanding the interaction between commensal Lactobacillus and the host health, and provide L. johnsonii N5 as an alternative to antibiotics for preventing diarrhea and intestinal diseases.

Influence of the circadian cycle, sex and production stage on the reference values of parameters related to stress and pathology in porcine saliva

BACKGROUND

The concentration of biomarkers in saliva could be influenced by several factors not related to the specific condition under analyses, which should be considered for proper clinical interpretation. In the present study, the circadian rhythm of C-reactive protein (CRP), haptoglobin (Hp), Pig-MAP, S100A12, Cu, Zn, Adenosine deaminase (ADA), total protein (TP), total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), cortisol and α-amylase in saliva of 20 female and 20 male pigs was investigated. Moreover, the influence of sex and production phase (post-weaning, fattening and finishing) on the concentrations of biomarkers in a total of 414 healthy pigs was studied and the reference intervals for all salivary biomarkers were calculated accordingly.

RESULTS

All parameters except Pig-MAP, OSI and α-amylase varied significantly along the daytime, and most of them peak around early afternoon (13-15 h). The cosinor analysis described the temporal dynamics of circadian rhythms for all parameters. The range values showed differences between male and female pigs in 8 out of the 13 biomarkers, with higher concentrations in females in comparison to male pigs. The influence of the production phase on the salivary concentrations was observed for all the biomarkers. The highest concentrations were observed for Pig-MAP, S100A12 and α-amylase in post-weaning animals, for TP in growing pigs and for OSI in finishing animals. Most of the sex-influenced biomarkers showed the highest concentrations at growing stages with some exceptions such as ADA or Hp that showed the peak at finishing and post-weaning stages respectively.

CONCLUSIONS

It is necessary to establish the optimal daytime for routine saliva sampling to avoid circadian variations and for that end, the time interval between 10:00 a.m. to 12:00 a.m. is highly recommended. The factors sex and production phase influence the concentration of biomarkers and should be considered for proper biomarker interpretation. The reference intervals presented here for each salivary biomarker will help to correctly interpret the results of these analytes and contribute to the use of saliva as a non-invasive sample for the diagnosis and monitoring of the health status of swine farms.

Influence of body lesion severity on oxidative status and gut microbiota of weaned pigs

Body lesions in pigs are a common welfare concern, particularly during the weaning period. These lesions can lead to pain, infection, and impaired mobility, resulting in reduced growth performance and increased mortality. Moreover, weaning stress can affect gut microbiota, immune response and increase the oxidative stress of piglets during this transition period. It has been hypothesised that social stress and body lesions could contribute to affect the gut microbiota, physiological and immune response of piglets. The study aims to evaluate the impact of the body lesions due to social stress on microbial profile, immune response, and oxidative status of weaned piglets. Lesion score (LS) on skin, tail, ear, neck, middle trunk, and hind quarters was measured 1 week (28 days of age, T1) and 7 weeks postweaning (T2) on 45 tail-docked pigs according to the method suggested from the Walfer Quality® (2009) on a scale from 0 to 2. Based on the LS, at T1, piglets were classified as High LS (n = 16), when LS was >1 in at least two of the areas considered, or Low LS (n = 29). At T2, based on the same scoring system and to the LS observed at T1, piglets were divided into four groups: High to Low LS (H-L, n = 11), High to High LS (H-H, n = 5), Low to Low LS (L-L, n = 21) and Low to High LS (L-H, n = 8). Blood and faecal samples were collected at T1 and T2. At T1, pigs with a high LS had a lower biological antioxidant potential compared with the L group (P < 0.02). At T2, the L-H group had a lower Reactive Oxygen Metabolites concentration compared with the H-H group (P = 0.03) while the L-L group had a lower concentration of Immunoglobulin A compared with H-H and L-H groups (P = 0.02 and P = 0.04, respectively). At T1, piglets with high LS had a different microbiota compared to piglets with low LS (R² = 0.04, P < 0.01). Low LS pigs were characterised by a higher abundance of Firmicutes, Blautia, Eubacterium coprostanoligenes, Faecalibacterium, Megasphaera, Subdoligranulum (P.adj < 0.05), while pigs with high LS were characterised by higher abundance of Bacteroidota, Rikenellaceae RC9, Prevotellaceae UCG-003, uncultured-Lachnospiraceae and uncultured-Oscillospiraceae (P.adj < 0.05). At T2, the H-H group were characterised by Oscillospirales-UCG-010, H-L by Agatobachter and L-L by Alloprevotella (P.adj < 0.05). Overall, this study provides valuable insights into the relationship between body lesions, oxidative stress, and gut microbiota in weaned pigs.

A blend of functional amino acids and grape polyphenols improves the pig capacity to cope with an inflammatory challenge caused by poor hygiene of housing conditions

BACKGROUND

Dietary supplementation with a blend of functional amino acids (AA) and grape extract polyphenols contributes to preserve intestinal health and growth performance of piglets during the post-weaning period. In the present experiment, we assessed if a supplementation with a mix of AA and grape extract polyphenols during the post-weaning period would persist to improve the pig capacity to cope with a subsequent challenge caused by poor hygiene of housing conditions. Eighty pigs weaned at 28 days of age were fed a standard diet supplemented (AAP) or not (CNT) with 0.2% of a blend of AA (glutamine, arginine, cystine, valine, isoleucine, and leucine) and grape extract polyphenols during the post-weaning period (from week 0 to 6). At week 6, pigs were transferred to a growing unit where 50% of pigs previously fed AAP and CNT diets were housed in good and the other 50% in poor hygiene conditions for 3 weeks (from week 7 to 9; challenge period). All pigs were fed a standard growing diet that was not supplemented with AAP. We measured pig growth performance, plasma indicators of inflammation, digestive integrity, and oxidative status, and scored fecal consistency. Differences were considered significant at P ≤ 0.05.

RESULTS

One week post-weaning, pigs fed AAP had lower plasma concentrations of haptoglobin than CNT pigs (P = 0.03). Six weeks post-weaning, plasma concentrations of diamine oxidase (DAO) were lower (P = 0.03) whereas those of vitamin E and A were greater (P ≤ 0.05) in pigs fed AAP compared to CNT pigs. The prevalence of diarrhea was higher in CNT pigs compared to AAP pigs (P < 0.01). During the challenge period, only pigs previously fed CNT diet had lower growth rate in poor than good conditions (P ≤ 0.05). They had also greater plasma concentrations of haptoglobin and oxidative stress index (OSI) and lower plasma concentrations of vitamin E in poor than good hygiene conditions (P ≤ 0.05).

CONCLUSIONS

Pigs fed AAP diet during post-weaning had less diarrhea and plasma concentrations of a digestive integrity marker, as well as greater plasma concentrations of antioxidant indicators during the post-weaning period. The beneficial effects of AAP supplementation persisted after the post-weaning period as evidenced by the absence of effects of the hygiene challenge on growth and health indicators in pigs previously fed APP. This clearly indicated a greater ability of pigs fed AAP to cope with the poor hygiene conditions.

Plasma protein levels of young healthy pigs as indicators of disease resilience

Selection for disease resilience, which refers to the ability of an animal to maintain performance when exposed to disease, can reduce the impact of infectious diseases. However, direct selection for disease resilience is challenging because nucleus herds must maintain a high health status. A possible solution is indirect selection of indicators of disease resilience. To search for such indicators, we conducted phenotypic and genetic quantitative analyses of the abundances of 377 proteins in plasma samples from 912 young and visually healthy pigs and their relationships with performance and subsequent disease resilience after natural exposure to a polymicrobial disease challenge. Abundances of 100 proteins were significantly heritable (false discovery rate (FDR) <0.10). The abundance of some proteins was or tended to be genetically correlated (rg) with disease resilience, including complement system proteins (rg = -0.24, FDR = 0.001) and IgG heavy chain proteins (rg = -0.68, FDR = 0.22). Gene set enrichment analyses (FDR < 0.2) based on phenotypic and genetic associations of protein abundances with subsequent disease resilience revealed many pathways related to the immune system that were unfavorably associated with subsequent disease resilience, especially the innate immune system. It was not possible to determine whether the observed levels of these proteins reflected baseline levels in these young and visually healthy pigs or were the result of a response to environmental disturbances that the pigs were exposed to before sample collection. Nevertheless, results show that, under these conditions, the abundance of proteins in some immune-related pathways can be used as phenotypic and genetic predictors of disease resilience and have the potential for use in pig breeding and management.

Effects of different processing techniques of broken rice on processing quality of pellet feed, nutrient digestibility, and gut microbiota of weaned piglets

The present study was conducted to assess the effect of different processing techniques of broken rice on processing quality of pellet feed, growth performance, nutrient digestibility, blood biochemical parameters, and fecal microbiota of weaned piglets. A total of 400 crossbred piglets (Duroc × Landrace × Yorkshire) with a mean initial body weight (BW) of 7.24 ± 0.52 kg were used in a 28-d experiment. Piglets were randomly distributed to one of 4 treatment and 10 replicate pens per treatment, with 10 piglets per pen. The dietary treatments were as follows: CON, corn as the main cereal type in the dietary; BR, 70% of the corn replaced by broken rice; ETBR, 70% of the corn replaced by extruded broken rice; EPBR, 70% of the corn replaced by expanded broken rice. Extruded broken rice and expanded broken rice supplementation significantly (P < 0.05) increased hardness, pellet durability index, crispness, and starch gelatinization degree. Extruded broken rice and expanded broken rice generated a higher (P < 0.05) average daily feed intake, increased (P < 0.05) average daily gain, decreased (P < 0.05) feed conversion ratio, and lowered (P < 0.05) the diarrhea rate. Piglets fed extruded broken rice displayed high apparent total tract digestibility levels of dry matter (P < 0.05), gross energy (P < 0.05), crude protein (P < 0.05), and organic matter (P < 0.05). In addition, extruded broken rice and expanded broken rice supplementation had increased Lactobacillus and Bifidobacterium levels in gut, whereas a lower abundance of the potential pathogens Clostridium_sensu_strictio_1 and Streptococcus was observed. Dietary supplementation of extruded broken rice and expanded broken rice failed to show significant effects on blood biochemical parameters. Combined, 70% corn substituted with broken rice failed to show significant effects. Collectively, extruded broken rice and expanded broken rice supplementation had positively enhanced the pellet quality, growth performance, nutrient digestibility, and gut microbiota of weaned piglets.

Effect of the supplementation with a combination of plant extracts on sow and piglet performance and physiology during lactation and around weaning

Weaning is a critical period for pigs. Some plant extracts showing antioxidant, anti-inflammatory or antibacterial properties, provided to piglets and/or their dam, may improve piglets' robustness at weaning, thus reducing the need for antobiotics. This study investigated the effects of a maternal and/or a direct supplementation of piglets with a combination of plant extracts on sow and piglet performance and their metabolic, immune, inflammatory, and oxidative status during lactation and around weaning. Sixty-four sows were assigned to the control or treated group. Treated sows were supplemented with a powdered plant extracts supplement daily top-dressed on feed from day of gestation (DG) 106 to day of lactation (DL) 28 and a liquid solution top-dressed on feed on DG109. Within each sow group, litters were divided into two groups: a control piglet group and a treated piglet group. A single dose of a liquid solution was orally given to piglets in the treated piglet group. Piglets were weaned on DL28. Blood samples were collected from sows on DG94, DG112, and DL26 and from 2 piglets per litter on DL3, DL14, DL25, and 5 d postweaning to analyze indicators of metabolic, immune, inflammatory, and oxidative status. Colostrum and milk samples were collected at farrowing, DL6, and 26. Maternal supplementation had no effect on sow metabolic, immune, inflammatory, and oxidative status except for fewer lymphocytes on DG112 (P < 0.05) and a lower plasma concentration of non-esterified fatty acids on DL26 (P < 0.05). Maternal supplementation tended to decrease dry matter and gross energy (P < 0.10) and reduced fat and haptoglobin concentrations (P < 0.01) in milk on DL26. Maternal supplementation had no effect on piglets' growth performance and blood indicators during lactation and around weaning. On DL25, the direct supplementation of piglets decreased their neutrophils proportion (P < 0.05), increased the expression of genes encoding pro- and anti-inflammatory cytokines in whole blood culture in response to lipopolysaccharide (P < 0.05) and tended to decrease the oxidative stress index (P = 0.06). After weaning, these beneficial effects were no longer observed but the supplementation improved piglets' growth performance during the postweaning period (P < 0.05). Plant extract supplementation could thus modify the composition of mammary secretions and improve postweaning performance of piglets potentially related to the modification of their immune and oxidative status before weaning.

Spraying compound probiotics improves growth performance and immunity and modulates gut microbiota and blood metabolites of suckling piglets

One factor that shapes the establishment of early neonatal intestinal microbiota is environmental microbial exposure, and probiotic application has been shown to promote health and growth of piglets. Thus, this study hypothesized that environmental probiotic application in early days of life would be beneficial to newborn piglets. This study aimed to investigate the effect of spraying a compound probiotic fermented liquid (CPFL) into the living environment of piglets on their early growth performance and immunity. This work included 68 piglets, which were randomized into probiotic and control groups. Blood and fecal samples were collected at 0, 3, 7, 14, and 21 days of age. Spraying CPFL significantly reshaped the microbiota composition of the delivery room environment, increased piglets' daily weight gain and weaning weight (P<0.001), and modulated piglets' serum cytokine levels (increases in IgA, IgG, and IL-10; decrease in IFN-γ; P<0.05 in each case) in piglets. Additionally, spraying CPFL during early days of life modified piglets' gut microbiota structure and diversity, increased the abundance of some potentially beneficial bacteria (such as Bacteroides uniformis, Butyricimonas virosa, Parabacteroides distasonis, and Phascolarctobacterium succinatutens) and decreased the abundance of Escherichia coli (P<0.05). Interestingly, CPFL application also significantly enhanced the gut microbial bioactive potential and levels of several serum metabolites involved in the metabolism of vitamins (B2, B3, B6, and E), medium/long-chain fatty acids (caproic, tetradecanoic, and peptadecanoic acids), and dicarboxylic acids (azelaic and sebacic acids). Our study demonstrated that spraying CPFL significantly could improve piglets' growth performance and immunity, and the beneficial effects are associated with changes in the gut microbiota and host metabolism. Our study has provided novel data for future development of probiotic-based health-promoting strategies and expanded our knowledge of probiotic application in animal husbandry.

Ultra-early weaning alters growth performance, hematology parameters, and fecal microbiota in piglets with same genetic background

Piglets with the same genetic background were used to investigate the effects of different lengths of suckling period on growth performance, hematology parameters, and fecal microbiota. All piglets were born by a sow (Landrace×Yorkshire). On day 14 postpartum, a total of 16 piglets [Duroc×(Landrace×Yorkshire)] with a similar initial body weight (2.48 ± 0.25 kg) were randomly assigned into two groups with four replicates per group, two pigs per replicate pen (one barrow and one gilt). On day 14 of age, experiment started, piglets from the first group were weaned (14W), whereas the others continued to receive milk until day 28 of age (28W). The experiment completed on day 70 of age, last 56 days. Growth performance parameters including body weight, average daily gain, feed intake, feed efficiency, and growth rate and hematology parameters including immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), albumin, globulin, and total protein were measured in this study. Additionally, a technique of 16S rRNA gene sequencing was used to analyze fecal microbiota for revealing how the changes in the lengths of suckling period on intestinal microbiota. We found that ultra-early weaning impaired growth performance of piglets, whose worse body weight, average daily gain, feed intake, feed efficiency, and growth rate were observed in 14W group at all measured timepoints in comparison with those in 28W group (P < 0.05). Moreover, higher contents of serum IgA (P = 0.028), IgG (P = 0.041), and IgM (P = 0.047), as well as lower contents of serum albumin (P = 0.002), albumin-to-globulin ratio (P = 0.003), and total protein (P = 0.004), were observed in 14W group in comparison with those in 28W group on day 28 of age, but not on day 70 of age. High-throughput pyrosequencing of 16S rRNA indicated that the intestinal microbiota richness in 14W group was lower than that in 28W group (P < 0.05); moreover, in comparison with 28W group at all sampling timepoints, fecal microbiota in 14W group showed more beneficial bacteria and fewer pathogenic bacteria (P < 0.05). Therefore, we considered that ultra-early weaning had positive effects on immune status and fecal microbiota composition in piglets, but negative effects on growth performance and fecal microbiota abundance.

The Connection Between Stress and Immune Status in Pigs: A First Salivary Analytical Panel for Disease Differentiation

This paper analyzes the association between stress and immune response activations in different diseases, based on the salivary analytics. Moreover, a first attempt to discriminate between diseases was performed by principal component analysis. The salivary analytics consisted of the measurement of psychosocial stress (cortisol and salivary alpha-amylase) indicators, innate (acute phase proteins: C-reactive protein and haptoglobin), and adaptive immune (adenosine deaminase, Cu and Zn) markers and oxidative stress parameters (antioxidant capacity and oxidative status). A total of 107 commercial growing pigs in the field were divided into six groups according to the signs of disease after proper veterinary clinical examination, especially, healthy pigs, pigs with rectal prolapse, tail-biting lesions, diarrhea, lameness, or dyspnea. Associations between stress and immune markers were observed with different intensities. High associations (r = 0.61) were observed between oxidative stress markers and adaptive immune markers. On the other hand, moderate associations (r = 0.31–0.48) between psychosocial stress markers with both innate and adaptive immune markers were observed. All pathological conditions showed statistically significant differences in at least 4 out of the 11 salivary markers studied, with no individual marker dysregulated in all the diseases. Moreover, each disease condition showed differences in the degree of activation of the analyzed systems which could be used to create different salivary profiles. A total of two dimensions were selected through the principal component analysis to explain the 48.3% of the variance of our data. Lameness and rectal prolapse were the two pathological conditions most distant from the healthy condition followed by dyspnea. Tail-biting lesions and diarrhea were also far from the other diseases but near to healthy animals. There is still room for improvements, but these preliminary results displayed a great potential for disease detection and characterization using salivary biomarkers profiling in the near future.

Effect of live yeast supplementation in sow diet during gestation and lactation on sow and piglet fecal microbiota, health and performance

Feeding probiotics like live yeast Saccharomyces cerevisiae var. boulardii (SB) in pig diets has been suggested to preserve health and reduce antibiotic use during critical periods like weaning. This study was conducted to determine whether SB added in the diet of sows during the last 2 mo of gestation and the 4 wk of lactation may contribute to supporting health and performance of piglets before and after weaning through changes in sow physiology, milk composition and fecal microbiota. Crossbred sows (n=45) from parity 1 to 9 were allocated to two dietary treatments, Control (n=23) and SB (n=22). Sows in the SB group were fed the same standard gestation then lactation diet as the Control sows but with the addition of SB at 1x10 9 colony forming units/kg of feed. Piglets were weaned under challenging conditions consisting in mixing of litters, no pen cleaning and a 2-h period of non-optimal temperature exposure. Blood and feces were collected from sows on d 28 and 113 of gestation and d 6 (feces only) and 28 of lactation, and from piglets on d 6 (feces) and 28 of lactation and d 5 after weaning. Colostrum was collected during parturition and milk on d 6 of lactation. Supplementation of sow diets with SB influenced the fecal microbiota of the sows and their piglets. Five days after weaning, the alpha-diversity was lower (P < 0.05) in piglets from SB sows than in piglets from Control sows. Analysis of microbiota with Partial Least Square Discriminant Analysis discriminated feces from SB sows from that of Control sows at 110 d of gestation (29.4% error rate). Piglet feces could also be discriminated according to the diet of their mother, with a better discrimination early after birth (d 6 of lactation) than after weaning (d 5 post-weaning, 3.4% vs 12.7% error rate). Five d after weaning, piglets had greater white blood cell count, plasma haptoglobin concentration, and oxidative stress than before weaning (P <0.001). Nevertheless, SB supplementation in sow diets had no effect (P > 0.05) on most of health criteria measured in blood and growth performance of piglets during lactation and the post-weaning period. Moreover, dietary supplementation of SB to sows did not elicit any changes (P > 0.05) in their reproductive performance, metabolic and health status, nor in the immunoglobulin and nutrient concentration of colostrum and milk. In the present experimental conditions, feeding SB to sows influenced sow and piglet microbiota with no consequences on their health and performance.

Antioxidant potential of Pediococcus pentosaceus strains from the sow milk bacterial collection in weaned piglets

BACKGROUND

In modern animal husbandry, breeders pay increasing attention to improving sow nutrition during pregnancy and lactation to favor the health of neonates. Sow milk is a main food source for piglets during their first three weeks of life, which is not only a rich repository of essential nutrients and a broad range of bioactive compounds, but also an indispensable source of commensal bacteria. Maternal milk microorganisms are important sources of commensal bacteria for the neonatal gut. Bacteria from maternal milk may confer a health benefit on the host.

METHODS

Sow milk bacteria were isolated using culturomics followed by identification using 16S rRNA gene sequencing. To screen isolates for potential probiotic activity, the functional evaluation was conducted to assess their antagonistic activity against pathogens in vitro and evaluate their resistance against oxidative stress in damaged Drosophila induced by paraquat. In a piglet feeding trial, a total of 54 newborn suckling piglets were chosen from nine sows and randomly assigned to three treatments with different concentrations of a candidate strain. Multiple approaches were carried out to verify its antioxidant function including western blotting, enzyme activity analysis, metabolomics and 16S rRNA gene amplicon sequencing.

RESULTS

The 1240 isolates were screened out from the sow milk microbiota and grouped into 271 bacterial taxa based on a nonredundant set of 16S rRNA gene sequencing. Among 80 Pediococcus isolates, a new Pediococcus pentosaceus strain (SMM914) showed the best performance in inhibition ability against swine pathogens and in a Drosophila model challenged by paraquat. Pretreatment of piglets with SMM914 induced the Nrf2-Keap1 antioxidant signaling pathway and greatly affected the pathways of amino acid metabolism and lipid metabolism in plasma. In the colon, the relative abundance of Lactobacillus was significantly increased in the high dose SMM914 group compared with the control group.

CONCLUSION

P. pentosaceus SMM914 is a promising probiotic conferring antioxidant capacity by activating the Nrf2-Keap1 antioxidant signaling pathway in piglets. Our study provided useful resources for better understanding the relationships between the maternal microbiota and offspring. Video Abstract.

Metabolic Profile of Sow Blood Serum after Weaning

The aim of our research was to determine the content of protein, carbohydrate, lipid, and mineral metabolites, as well as an antioxidant status of the sow's blood after weaning and to calculate the correlation between these parameters. The experiment was carried out on twenty clinically healthy crossbred sows (Yorkshire × Landrace). Twenty sows were allocated to one of two groups: (1) 1 day after weaning (group 1, n = 10) and (2) 8 days after weaning (group 2, n = 10). The basis of the sow diet was SK-1 compound feed, balanced in terms of nutrients and energy in accordance with modern standards and the recommended feeding regimen. Sows blood samples were taken and analyzed for the metabolites of nitrogenous, carbohydrate-lipid, and mineral metabolism and indicators of antioxidant status. The results showed that, in group 2, the total protein content was 89.07 g/l, which is 10.2% higher than that in group 1 (p < 0.05); it was mainly achieved due to the globulin fraction. The urea increased by 19.1% (p < 0.05), but the concentrations of magnesium and chlorides decreased by 20.2% (p < 0.01) and 5.43% (p < 0.05), as well as the alkaline phosphatase and ALT activities decreased by 42.5% (p < 0.05). Strong positive correlations of the ceruloplasmin with total protein (0.672) and very strong with globulins (0.780) were observed. There was a strong negative correlation between the AST activity and the TBA-AP content, as well as the values of phospholipids and TAWSA. There are moderate negative correlations of the TBA-AP with magnesium, TAWSA and ALT activity, and moderate positive correlations of the TBA-AP with total protein, albumin, triglycerides, and cholesterol. The revealed tendencies and dependencies will serve as the theoretical basis for the development of practical methods for regulating the level of free-radical reactions.

Review: Implication of redox imbalance in animal health and performance at critical periods, insights from different farm species

The process of oxidative stress occurs all over the production chain of animals and food products. This review summarises insights obtained in different farm species (pigs, ruminants, poultry, and fishes) to underpin the most critical periods for the venue of oxidative stress, namely birth/hatching and weaning/start-feeding phase. Common responses between species are also unravelled in periods of high physiological demands when animals are facing dietary deficiencies in specific nutrients, suggesting that nutritional recommendations must consider the modulation of responses to oxidative stress for optimising production performance and quality of food products. These conditions concern challenges such as heat stress, social stress, and inflammation. The magnitude of the responses is partly dependent on the prior experience of the animals before the challenge, reinforcing the importance of nutrition and other management practices during early periods to promote the development of antioxidant reserves in the animal. When these practices also improved the performance and health of the animal, this further confirms the central role played by oxidative stress in physiologically and environmentally induced perturbations. Difficulties in interpreting responses to oxidative stress arise from the fact that the indicators are only partly shared between studies, and their modulations may also be challenge-specific. A consensus about the best indicators to assess pro-oxidative and antioxidant pathways is of huge demand to propose a synthetic index measurable in a non-invasive way and interpretable along the productive life of the animals.

Improving maternal welfare during gestation has positive outcomes on neonatal survival and modulates offspring immune response in pigs

Improving the housing of pregnant sows by giving them more space and access to deep straw had positive effects on their welfare, influenced their maternal behavior and improved the survival of their offspring. The present study aimed at determining whether these effects were actually due to environmental enrichment and whether the provision of straw pellets and wood can partly mimic the effects of straw bedding during gestation. Three graded levels of enrichment were used, that were, collective conventional pens on slatted floor (C, n = 26), the same pens with manipulable wood materials and distribution of straw pellets after the meals (CE, n = 30), and larger pens on deep straw litter (E, n = 27). Sows were then housed in identical farrowing crates from 105 days of gestation until weaning. Decreased stereotypies, blood neutrophils, and salivary cortisol, and increased behavioral investigation indicated that health and welfare of sows during gestation were improved in the E environment compared with the C environment. The CE sows responded as C or E sows depending on the trait. Piglet mortality rate in the first 12 h after birth was lower in E and CE litters than in C litters, but enrichment level during gestation had only small effects on lactating sow behavior and milk composition postpartum. On days 2 and 3 of lactation, E sows interrupted less often their nursing sequences than C and CE sows. On day 2, milk from both E and CE sows contained more minerals than that from C sows. In one-day-old piglets, the expression levels of genes encoding toll-like receptors (TLR2, TLR4) and cytokines (interleukin-1, -6 and -10) in whole blood after 20-h culture, were greater in E piglets than in CE or C piglets. In conclusion, housing sows in an enriched environment during gestation improved early neonatal survival, probably via moderate and cumulative positive effects on sow behavior, milk composition, and offspring innate immune response. The gradation in the effects observed in C, CE and E housing environment reinforced the hypothesis of a causal relationship between maternal environmental enrichment, sow welfare and postnatal piglet traits.

The Effect of Lithium Salt with Ascorbic Acid on the Antioxidant Status and Productivity of Gestating Sows

This research is aimed at the influence of different doses of lithium ascorbate on pigs’ diet estimation, at farrowing sows’ antioxidant status increase, and at lipid peroxidation product level decrease. The research was conducted in farrowing sows of the Irish landrace breed during the second farrow. Three groups of animals were formed, with ten livestock units in each. Thirty days after successful insemination, the sows of the E10, E5 and E2 experimental groups started receiving lithium ascorbate powder together with feed stuff in dosages of 10, 5 and 2 mg/kg of body weight, respectively. Their weighing and biochemical examinations were performed before the substance introduction as well as on the 60th and 110th days of pregnancy. The following were detected in sows’ blood plasma: malondialdehyde, reduced glutathione, oxidized glutathione, SH/SS ratio, superoxide dismutase and glutathione peroxidase activity. Lithium ascorbate usage during sows’ breeding cycle caused a significant increase in SH (reduced glutathione) level by 21% (p < 0.05), SS (oxidized glutathione) level decrease by 17% (p < 0.05), and malondialdehyde level decrease by 60% (p < 0.05). These data outline antioxidant defense system activization, reducing the risk of oxidative stress under the influence of feeding with lithium ascorbate. Lithium ascorbate in dosages of 10 mg/kg per body weight given together with feed stuff shows prominent adaptogene and stress protective features in the most effective way. The research conducted regarding lithium ascorbate usage for farrowing sows can reduce the negative consequences of oxidative stress, increase sows’ health preservation level, and contribute to fertility boost.

Impact of Enrichment and Repeated Mixing on Resilience in Pigs

Resilience, the capacity of animals to be minimally affected by a disturbance or to rapidly bounce back to the state before the challenge, may be improved by enrichment, but negatively impacted by a high allostatic load from stressful management procedures in pigs. We investigated the combined effects of diverging environmental conditions from weaning and repeated mixing to create high allostatic load on resilience of pigs. Pigs were either exposed to barren housing conditions (B) from weaning onwards or provided with sawdust, extra toys, regular access to a “play arena” and daily positive human contact (E). Half of the pigs were exposed to repeated mixing (RM) and the other half to one mixing only at weaning (minimal mixing, MM). To assess their resilience, the response to and recovery from a lipopolysaccharide (LPS) sickness challenge and a Frustration challenge were studied. In addition, potential long-term resilience indicators, i.e. natural antibodies, hair cortisol and growth were measured. Some indications of more favorable responses to the challenges in E pigs were found, such as lower serum reactive oxygen metabolite (dROM) concentrations and a smaller area under the curve of dROM after LPS injection. In the Frustration challenge, E pigs showed less standing alert, escape behaviors and other negative behaviors, a tendency for a smaller area under the curve of salivary cortisol and a lower plasma cortisol level at 1 h after the challenge. Aggression did not decrease over mixings in RM pigs and was higher in B pigs than in E pigs. Repeated mixing did not seem to reduce resilience. Contrary to expectations, RM pigs showed a higher relative growth than MM pigs during the experiment, especially in the week of the challenges. Barren RM pigs showed a lower plasma cortisol concentration than barren MM pigs after the LPS challenge, which may suggest that those RM pigs responded less detrimentally than MM pigs. Enriched RM pigs showed a higher level of IgM antibodies binding keyhole limpet hemocyanin (KLH) than enriched MM and barren RM pigs, and RM pigs showed a sharper decline in IgG antibodies binding Bovine Serum Albumin (PC-BSA) over time than MM pigs. Hair cortisol concentrations were not affected by enrichment or mixing. To conclude, enrichment did not enhance the speed of recovery from challenges in pigs, although there were indications of reduced stress. Repeated as opposed to single mixing did not seem to aggravate the negative effects of barren housing on resilience and for some parameters even seemed to reduce the negative effects of barren housing.

Antioxidants in Animal Nutrition

Oxidative stress is an imbalance between the production of free radicals and their neutralization by the antioxidants' defenses [...].

Mixed organic acids as an alternative to antibiotics improve serum biochemical parameters and intestinal health of weaned piglets

The primary aim of this experiment was to critically explore the relationship between the different levels of mixed organic acids (MOA) and growth performance, serum antioxidant status and intestinal health of weaned piglets, as well as to investigate the potential possibility of MOA alternative to antibiotics growth promoters (AGP). A total of 180 healthy piglets (Duroc × [Landrace × Yorkshire]; weighing 7.81 ± 1.51 kg each, weaned at d 28) were randomly divided into 5 treatments: 1) basal diet (CON); 2) CON + chlorinomycin (75 mg/kg) + virginiamycin (15 mg/kg) + guitaromycin (50 mg/kg) (AGP); 3) CON + MOA (3,000 mg/kg) (OA1); 4) CON + MOA (5,000 mg/kg) (OA2); 5) CON + MOA (7,000 mg/kg) (OA3). This study design included 6 replicates per treatment with 6 piglets per pen (barrow:gilt = 1:1) and the experiment was separated into phase 1 (d 1 to 14) and phase 2 (d 15 to 28). In phases 1, 2 and overall, compared with the CON, the feed conversion ratio (FCR) was reduced (P < 0.01) and the average daily gain (ADG) was increased (P < 0.05) in piglets supplemented with AGP, OA1 and OA2. The concentration of serum immunoglobulins G (IgG) was improved (P < 0.05) in piglets supplemented with OA2 in phase 2. In the jejunum and ileum, the villus height:crypt depth ratio was significantly increased (P < 0.01) in piglets fed AGP and OA1. The mRNA expression level of claudin-1 and zonula occludens-1 (ZO-1) (P < 0.01) was up-regulated in piglets supplemented with OA1 and OA2. The piglets fed AGP, OA1 and OA2 showed an increase (P < 0.05) in the content of acetate acid and total volatile fatty acids (TVFA) in the cecum, and butyric acid and TVFA in the colon compared with CON. Also, OA1 lowered (P < 0.05) the content of Lachnospiraceae in piglets. These results demonstrated that MOA at 3,000 or 5,000 mg/kg could be an alternative to antibiotics due to the positive effects on performance, immune parameters, and intestinal health of weaned piglets. However, from the results of the quadratic fitting curve, it is inferred that MOA at a dose of 4,000 mg/kg may produce a better effect.

Physiological response to the weaning in two pig lines divergently selected for residual feed intake

Breeding efficient pigs is a way to reduce dietary costs and environmental waste. However, optimization of feed efficiency must not be linked to a decrease of the ability of animals to cope with stress, such as the weaning. This study characterizes the response after weaning of pigs from two lines divergently selected for residual feed intake (RFI) during growth. Animals of the low (L) RFI line are more efficient than animals from the high (H) RFI line. Thirty-six piglets from each line weaned at 28 days of age were individually housed and fed a conventional dietary sequence. Their performance, behaviour, health and oxidative status, immune and nutritional parameters were followed during three weeks. Daily feed intake and growth rate of pigs from the LRFI line were 35% and 40% lower compared with HRFI (p < 0.001). Pigs from the LRFI-line had lower total tract apparent digestibility (-6% for OM) and suffered more from undernutrition with a 167 and 55% higher plasmatic concentration of NEFA and urea compared with HRFI (p < 0.01). In the first week after the weaning, they had more diarrhoea and had a higher inflammatory status with concentration of haptoglobin 52% higher (p < 0.001). These piglets then seemed to adapt to the weaning conditions and to recover during the second and third weeks. Both lines had similar zootechnical performance and physiological characteristics at the end of the post-weaning period. To conclude, the physiological responses to the weaning differed between lines. Pigs from the LRFI line, selected for greater feed efficiency, were more sensitive to the weaning stress. They were also more resilient as they finally adapted to the new condition and recovered to show similar performance results as pigs of the HRFI line.

Effects of Weaning Age at 21 and 28 Days on Growth Performance, Intestinal Morphology and Redox Status in Piglets

The study objective was to assess effects of different weaning ages on growth performance, intestinal morphology and redox status in Duroc × Landrace × Large White piglets (n = 96) fed diets without antibiotic growth promoters. Piglets were selected from 24 litters based on similar body weight at 14 d of age. All piglets were allocated to two groups in a completely random design with six replicates and eight pigs per replicate (four barrows and four gilts), which were weaned at 21 (n = 48; BW = 6.87 ± 0.33 kg) and 28 (n = 48; BW = 8.49 ± 0.41 kg) days of age. After weaning, pigs were fed a corn-soybean meal-based diet. Average daily gain (ADG), average daily feed intake (ADFI), feed conversion (F:G), diarrhea incidence, gastrointestinal pH, intestinal morphology and redox status were determined. Pigs weaned at 28 d displayed increased ADG from d 8 to 14 (p < 0.01) compared with pigs weaned at 21 d. Pigs weaned at 28 d had a higher ADFI from d 0 to 7 (p < 0.01), d 8 to 14 (p < 0.01), d 15 to 28 (p < 0.05) and during the entire experimental period (p < 0.01) compared with pigs weaned at 21 d. Pigs weaned at 21 d had an improved F:G from d 15 to 28 (p < 0.05) compared with pigs weaned at 28 d. Pigs weaned at 28 d had decreased diarrhea incidence from d 8 to 14 (p < 0.01) and the entire experimental period (p < 0.01) compared with pigs weaned at 21 d. On d 28, the pH of the stomach contents in pigs weaned at 21 d was significantly higher compared with pigs weaned at 28 d (p < 0.01). On d 14, the morphology of the duodenum, jejunum and ileum in pigs weaned at 28 d was improved compared with pigs weaned at 21 d. During the experiment period, the antioxidant abilities of pigs weaned at 28 d of the heart, liver, kidney, intestinal and serum were better than pigs weaned at 21 d. In conclusion, intestinal morphology, pH of the stomach and antioxidant status of pigs weaned at 28 d were better than pigs weaned at 21 d. These factors supported better growth performance and decreased diarrhea incidence.

Effect of dietary crude protein level on growth performance, blood characteristics, and indicators of intestinal health in weanling pigs

An experiment was conducted to test the hypothesis that reducing crude protein (CP) in starter diets for pigs reduces post-weaning diarrhea and improves intestinal health. In total, 180 weanling pigs were allotted to 3 diets containing 22, 19, or 16% CP. Fecal scores were visually assessed every other day. Blood samples were collected from 1 pig per pen on days 1, 6, 13, 20, and 27, and 1 pig per pen was euthanized on day 12. Results indicated that reducing dietary CP reduced (P < 0.01) overall average daily gain, gain to feed ratio, final body weight, and fecal scores of pigs. Pigs fed the 16% CP diet had reduced (P < 0.01) serum albumin compared with pigs fed other diets. Blood urea nitrogen, haptoglobin, interleukin-1β, and interleukin-6 concentrations in serum were greatest (P < 0.01) on day 13, whereas tumor necrosis factor-α and interleukin-10 concentrations were greatest (P < 0.01) on day 6. Villus height in the jejunum increased (P < 0.05) and crypt depth in the ileum was reduced (P < 0.01) if the 19% CP diet was fed to pigs compared with the 22% CP diet. A reduction (P < 0.05) in mRNA abundance of interferon-γ, chemokine ligand 10, occludin, trefoil factor-2, trefoil factor-3, and mucin 2 was observed when pigs were fed diets with 16% CP. In conclusion, reducing CP in diets for weanling pigs reduces fecal score and expression of genes associated with inflammation.

Dietary Plant Extracts Improve the Antioxidant Reserves in Weaned Piglets

Reducing the use of antibiotics in livestock in order to contain antibiotic resistance and studying natural substance additives are key to sustainability. Among the various biological activities of plant extracts, antioxidant activity plays an important role. The present study assesses the total antioxidant activity and antioxidant reserves using the Kit Radicaux Libres test (KRL™ Kirial International, Couternon, France). One hundred and sixty piglets (Topics × Tempo) weaned at 28 days of age were divided into four dietary treatment groups that were fed a commercial diet (the control group, C); 500 mg/kg Boswellia extract (BOS); 200 and 50 mg/kg Uncaria and Tanacetum extracts (UT) respectively; and 225 mg/kg of an antioxidant plant extract mixture (AOX). The blood antioxidant activity of the piglets was measured using the KRL test and the reserves were analyzed on whole blood samples after hydrolysis with glucosidase, sulfatase and glucuronidase. No significant differences were observed in growth performance. The delta KRL values of the whole blood showed a significantly higher total antioxidant status of the piglets from the BOS and AOX groups than the UT and C groups (+30.7 BOS; +27.7 AOX vs. +17.81 UT +13.30 C; p = 0.002) between 18 and 28 days post-weaning. The delta KRL values of red blood cells (RBCs) showed a significantly higher total antioxidant status of the piglets from the AOX groups than the UT and BOS groups (+22.2 AOX; vs. +9.90 UT +9.4 BOS; p = 0.016) between the two sampling times. Reserves of UT and AOX were higher than C and BOS for all enzymes, glucosides, sulphates, and glucuronides. The biological KRL test proved to be an extremely sensitive tool to evaluate the piglets' antioxidant status. Determining the antioxidant reserve also provides a better understanding of the real antioxidant status of pigs.

Identification of blood immune and metabolic indicators explaining the variability of growth of pigs under contrasted sanitary conditions

Background

Health and growth of pigs are affected by the hygiene of housing. Lower growth performance observed in poor hygiene of housing conditions is explained by reduced feed intake and metabolic changes caused by the activation of body defences. In a previous experiment, we reported contrasted average values of body weight gain, concentrations of circulating metabolites, redox and immune indicators in blood of pigs housed in good or poor hygiene conditions during the growing period. This study addressed inter-individual variability in these responses to determine whether a particular blood profile explains average daily gain (ADG) of the pig.

Results

The data originated from 160 growing pigs, half of which subjected to a hygiene challenge for 6 weeks (W0 to W6) and the others housed in good hygiene conditions. Pigs originated from two lines divergently selected for residual feed intake (RFI). Individual body weights were recorded during this period, and relative ADG (rADG_W0-W6) was calculated as the ADG corrected by the initial body weight measured at W0. Blood samples were taken before (W0) and 3 weeks (W3) after the beginning of the challenge. The analysed dataset consisted of 51 metabolites and indicators of immune and inflammatory responses measured on 136 pigs having no missing value for any variables, when calculated as the differences W3 minus W0 in circulating concentrations. An algorithm tested all possible linear regression models and then selected the best ones to explain rADG_W0-W6. Six variables were identified across the best models and correlated with rADG_W0-W6 with a goodness of fit (adjusted R²) of about 67%. They were changes in haptoglobin, global antioxidant capacity of plasma (Biological Antioxidant Power or BAP), free fatty acids, and 3 amino acids: leucine, tryptophan, and 1-methylhistidine. The effects of housing conditions and RFI lines were comprised in the variables of the selected models and none of these conditions improved accuracy of the predictive models, leading to genericity of the pinpointed metabolic changes in relation to variability of ADG.

Conclusions

This approach allows us to identify blood variables, whose changes in blood concentrations correlated to ADG under contrasted sanitary conditions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-02872-3.

The impact of the oxidative status on the reproduction of cows and the calves’ health – a review

The profitability of cattle farming is largely determined by ensuring high-quality breeding animals for replacement and longevity in production. The provision of breeding animals requires adequate fertility of the cowherd and then intensive weight gain in the calf rearing period. For ensuring these demands, many management aspects must be considered. Continuous monitoring of the herd’s health status, including redox status, is essential. This review aims to provide a summary of relevant scientific data published in the last few decades regarding the role of oxidative stress (OS) in infertility of dairy cows and developmental diseases in calves, the major predisposing factors, and possible prevention.

Dietary Oxidative Distress: A Review of Nutritional Challenges as Models for Poultry, Swine and Fish

The redox system is essential for maintaining cellular homeostasis. When redox homeostasis is disrupted through an increase of reactive oxygen species or a decrease of antioxidants, oxidative distress occurs resulting in multiple tissue and systemic responses and damage. Poultry, swine and fish, raised in commercial conditions, are exposed to different stressors that can affect their productivity. Some dietary stressors can generate oxidative distress and alter the health status and subsequent productive performance of commercial farm animals. For several years, researchers used different dietary stressors to describe the multiple and detrimental effects of oxidative distress in animals. Some of these dietary challenge models, including oxidized fats and oils, exposure to excess heavy metals, soybean meal, protein or amino acids, and feeding diets contaminated with mycotoxins are discussed in this review. A better understanding of the oxidative distress mechanisms associated with dietary stressors allows for improved understanding and evaluation of feed additives as mitigators of oxidative distress.

Weaning differentially affects mitochondrial function, oxidative stress, inflammation and apoptosis in normal and low birth weight piglets

Weaning is associated with increased occurrence of infections and diseases in piglets. Recent findings indicate that weaning induces mitochondrial dysfunction and oxidative stress conditions that more severely impact smaller piglets. The objective of this study was to characterize the molecular mechanisms underlying these physiological consequences and the relation with systemic inflammatory status in both normal and low birth weight (NBW and LBW) piglets throughout the peri-weaning period. To conduct the study, 30 sows were inseminated, and specific piglets from their litters were assigned to one of two experimental groups: NBW (n = 60, 1.73 ± 0.01 kg,) and LBW piglets weighing less than 1.2 kg (n = 60, 1.01 ± 0.01 kg). Then, 10 piglets from each group were selected at 14, 21 (weaning), 23, 25, 29 and 35 days of age to collect organ and plasma samples. Specific porcine RT2 Profiler™ PCR Arrays related to mitochondrial function, oxidative stress, inflammation and apoptosis processes were first used to target genes that are modulated after weaning in NBW piglets (d 23 and d 35 vs. d 14). Expression of selected genes was evaluated by quantitative PCR. These analyses revealed that expression of inflammatory genes CXCL10 and CCL19 increased after weaning in intestinal mucosa, while expression of genes encoding subunits of the mitochondrial respiratory chain was downregulated in liver and kidney of both groups. Interestingly, major modulators of mitophagy (BNIP3), cell survival (BCL2A1) and antioxidant defense system (TXNRD2, GPx3, HMOX1) were found to be highly expressed in NBW piglets. The systemic levels of TNF-α and IL1-β significantly increased following weaning and were higher in NBW piglets. These results provide novel information about the molecular origin of mitochondrial dysfunction and oxidative stress observed in weaned piglets and suggest that clearance of dysfunctional mitochondria, antioxidant defenses and inflammatory response are compromised in LBW piglets.

Effects of Commercial Antioxidants in Feed on Growth Performance and Oxidative Stress Status of Weaned Piglets

This work aimed to evaluate the effect of adding two different commercial antioxidants (AOX) products to pre-starter and starter diets using low vitamin E (Vit E as DL-α-tocopheryl acetate) levels on the growth performance and oxidative stress of piglets for the first six weeks post-weaning (PW). They were sorted by initial body weight (BW: 6.175 ± 0.931 kg) and randomly allotted to four dietary treatments (with six replicates per treatment): a positive control (PC) and a negative control (NC) diet, with normal and low dose of vitamin E (80 and 15 mg kg^-1, respectively), both without AOX; the other two experimental diets with a low dose of vitamin E (LVE) plus LOXIDAN VD100 (LVE + AOX1) or LOXIDAN E Ros (LVE + AOX2). Growth data were recorded, and blood samples were taken, at the beginning (day 0) and at the end of each feeding period: pre-starter and starter (at days 14 and 42, respectively). No differences among dietary treatments were found with respect to growth performance in the pre-starter period (p ≥ 0.05). However, at the end of the starter period, a lower BW was found in piglets fed the NC diet compared to the other dietary treatments. Differences in daily gain and feed conversion ratio were also found either for the starter period or when the whole period was considered (p < 0.05), whereby piglets fed PC or LVE diets supplemented with AOX showed better growth performance compared to piglets fed the NC diet. Regarding Vit E (α-tocopherol) serum levels, there were no differences among treatments at day 0; but the serum values of this vitamin decreased in LVE diets at 14 and 42 days, but not in the PC. On day 42, the highest levels of α-tocopherol in liver were also found in piglets fed PC (p < 0.05). Nevertheless, in general, from a metabolic point of view and after checking the serum biochemical profile of piglets, there were no differences in other oxidative stress markers (p ≥ 0.05). The results showed that the AOX products used were able to compensate for the lower Vit E supply with respect to growth performance in the starter phase. The use of AOXs or usual levels of Vit E in feed constitutes a key factor in achieving optimal growth performance of piglets in the PW period.

Effects of Dietary Supplementation of Garlic and Oregano Essential Oil on Biomarkers of Oxidative Status, Stress and Inflammation in Postweaning Piglets

The effects of two different concentrations of micro capsuled oregano essential oil (OEO) and purple garlic powder on biomarkers of oxidative status, stress, and inflammation, as well as on average daily gain (ADG) and feed conversion ratio (FCR), were evaluated in piglets during the postweaning period. The trial was carried out with 300 crossbred pigs of 21 days of age fed with different concentrations of OEO and purple garlic powder and ZnO. Saliva and serum samples were taken to evaluate a panel of biomarkers of oxidative status, stress, and inflammation. OEO and garlic powder at 0.4% did not produce significant changes in C-reactive protein (CRP) and cortisol and yielded higher levels of the antioxidant biomarker CUPRAC in serum than higher doses (p < 0.01); they yielded a better ADG than the control and ZnO diets. OEO and garlic powder at higher concentrations than 0.4% showed higher concentrations of CRP (p < 0.05). Overall, doses of OEO and garlic powder at 0.4% did not lead to inflammation, stress, or negative changes in oxidative biomarkers in piglets during the postweaning period and gave better productive performance than the control and ZnO diets. High doses of OEO and garlic powder were ineffective and could negatively affect the animals. Therefore, our results highlight the importance of the dose used when OEO or garlic are supplemented to piglets.

Changes in cecal morphology, cell proliferation, antioxidant enzyme, volatile fatty acids, lipopolysaccharide, and cytokines in piglets during the postweaning period

Weaning stresses often induce markedly structural and functional changes in the small intestine. However, little data are available on the changes of the morphology, function, and health in the cecum of piglets post-weaning. This study was conducted to measure the effects of weaning on the cecum in piglets. Forty piglets were weaned at 21 d and samples were collected at different time points (days 0, 1, 3, 7, and 14) post-weaning. The crypt depth, crypt width, and total epithelial cell numbers increased on days 7 and 14, compared with days 0, 1, and 3 (P < 0.001). The value of Ki67/total epithelial cells was highest on day 0 compared with all other days (P < 0.05). Besides, a higher concentration of malondialdehyde was observed on day 3 (P < 0.001). The activity of CuZn-superoxide dismutase (P < 0.05) enhanced from day 0 to 1 and the activity of catalase increased from day 1 to 3 (P < 0.001). In addition, days 3, 7, and 14 had greater acetic, propanoic, and butyric acid contents than on day 1 (P < 0.001). The pH and monocarboxylate transporter 1 (MCT1) expression increased from day 0 to 1 and from day 3 to 7 and decreased between days 1 and 3 (P < 0.001). The mRNA expression of solute carrier family 9 member A3 (SLC9A3) decreased on day 1 compared to all other postweaning days (P < 0.05). The abundance of toll-like receptor 4 (TLR4) and interferon-γ (IFN-γ) mRNA expression increased (P < 0.05) during the first 24 h after weaning. The concentration of lipopolysaccharide increased from day 3 to 7, then decreased on day 14 (P < 0.05). The mRNA expression of tumor necrosis factor-α (TNF-α) enhanced from day 7 to 14 (P < 0.05). The abundance of phosphorylated mammalian target of rapamycin protein was lower on day 14 than day 0 (P < 0.05). Taken together, these results show that weaning in piglets influences intestinal morphology, function, and health in the cecum.

Suplementação com óleos ricos em ácidos graxos poli-insaturados na dieta de leitões na fase de creche: efeitos no desempenho, na resposta inflamatória, no perfil lipídico e no “status” oxidativo

RESUMO Nos sistemas de produção, os produtos naturais vêm se destacando na substituição a produtos sintéticos, dentre eles podemos ressaltar os óleos vegetais ricos em ácido graxos poli-insaturados (PUFA), que são conhecidos, popularmente, por seus efeitos benéficos. Dessa forma, o objetivo com este trabalho foi avaliar os efeitos da suplementação dos óleos de pequi (Caryocar brasiliense) e girassol (Helianthus annus) sobre parâmetros fisiológicos em leitões na fase de creche. Foram utilizados 180 leitões alojados em granja comercial, distribuídos em três grupos (n=60) conforme suplementação alimentar: óleo de pequi, óleo de girassol e controle negativo. Amostras de sangue e o peso dos animais foram obtidos nos intervalos de quatro trocas de rações da fase de creche para avaliação do desempenho, da resposta inflamatória, do perfil lipídico e do “status” oxidativo. Os parâmetros fisiológicos mensurados demonstraram que os óleos interferiram positivamente na resposta inflamatória sistêmica, por meio dos leucócitos totais e da relação neutrófilo/linfócito (P<0,05); no equilíbrio oxidante-antioxidante, por mensuração de óxido nítrico e do malondialdeído (P<0,05); e no metabolismo lipídico, com a avaliação de colesterol total e triglicérides (P<0,05). Por outro lado, esses óleos vegetais interferiram no ganho de peso e no consumo de ração (P<0,05). Assim, concluí-se que a suplementação com óleos de pequi e girassol melhora a saúde dos animais, mas tem impacto negativo no desempenho zootécnico de leitões na fase de creche.

Changes of the glutathione redox system during the weaning transition in piglets, in relation to small intestinal morphology and barrier function

Background

Weaning is known to result in barrier dysfunction and villus atrophy in the immediate post-weaning phase, and the magnitude of these responses is hypothesized to correlate with changes in the glutathione (GSH) redox system. Therefore, these parameters were simultaneously measured throughout the weaning phase, in piglets differing in birth weight category and weaning age, as these pre-weaning factors are important determinants for the weaning transition. Low birth weight (LBW) and normal birth weight (NBW) littermates were assigned to one of three weaning treatments; i.e. weaning at 3 weeks of age (3w), weaning at 4 weeks of age (4w) and removal from the sow at 3 d of age and fed a milk replacer until weaning at 3 weeks of age (3d3w). For each of these treatments, six LBW and six NBW piglets were euthanized at 0, 2, 5, 12 or 28 d post-weaning piglets, adding up 180 piglets.

Results

Weaning increased the glutathione peroxidase activity on d 5 post-weaning in plasma, and duodenal and jejunal mucosa. Small intestinal glutathione-S-transferase activity gradually increased until d 12 post-weaning, and this was combined with a progressive rise of mucosal GSH up till d 12 post-weaning. Oxidation of the GSH redox status (GSH/GSSG E_h) was only observed in the small intestinal mucosa of 3d3w weaned piglets at d 5 post-weaning. These piglets also demonstrated increased fluorescein isothiocyanate dextran (FD4) and horseradish peroxidase fluxes in the duodenum and distal jejunum during the experiment, and specifically demonstrated increased FD4 fluxes at d 2 to d 5 post-weaning. On the other hand, profound villus atrophy was observed during the weaning transition for all weaning treatments. Finally, LBW and NBW piglets did not demonstrate notable differences in GSH redox status, small intestinal barrier function and histo-morphology throughout the experiment.

Conclusion

Although moderate changes in the GSH redox system were observed upon weaning, the GSH redox status remained at a steady state level in 3w and 4w weaned piglets and was therefore not associated with weaning induced villus atrophy. Conversely, 3d3w weaned piglets demonstrated GSH redox imbalance in the small intestinal mucosa, and this co-occurred with a temporal malfunction of their intestinal barrier function.

Effects of phytogenic feed additives on cellular oxidative stress and inflammatory reactions in intestinal porcine epithelial cells1

Due to increasing concerns about the use of antibiotic growth promoters (AGP) in livestock production and their complete ban in the European Union in 2006, suitable alternatives are urgently needed. Among others, anti-inflammatory activities of AGP are discussed as their putative mode of action. As numerous phytochemicals are known to modulate the cellular antioxidant capacity and immune response, we studied the antioxidative and anti-inflammatory properties of a phytogenic (plant-derived) feed additive (PFA) in intestinal porcine epithelial cells (IPEC-J2). The effects of the PFA were compared with those of selected phytogenic ingredients (grape seed extract [GRS], licorice extract [LIC], menthol [MENT], methyl salicylate [MES], oak bark extract [OAK], oregano essential oil [ORE], and a plant powder mix [PLA]), and with the effects of the AGP tylosin (TYL). Oxidative or inflammatory stress was induced by stimulating IPEC-J2 with hydrogen peroxide (H2O2; 0.5 mM) or tumor necrosis factor alpha (TNF-α; 10 ng/mL), respectively. The antioxidative effects of feed additives were assessed with a reactive oxygen species (ROS)-sensitive probe and by measuring the expression of 6 antioxidative target genes via quantitative real-time PCR (RT-qPCR). Anti-inflammatory potential was analyzed using a nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) reporter gene assay. Moreover, the expression levels of 6 NF-κB target genes were measured using RT-qPCR analysis, and the release of IL-6 was analyzed via ELISA. Significant decreases in cellular ROS upon H2O2 treatment were observed for the PFA (P < 0.001), LIC (P < 0.001), ORE (P < 0.05), and GRS (P < 0.01). No significant changes in the expression of antioxidative genes were found. NF-κB activation upon TNF-α treatment was significantly inhibited by the PFA (P < 0.05) and by ORE (P < 0.001). Moreover, the PFA and ORE significantly reduced the gene expression of IL-6 (P < 0.001), IL-8 (P < 0.001), and C-C motif chemokine ligand 2 (CCL2; P < 0.05), as well as the release of IL-6 (P < 0.05). The other phytogenic compounds as well as the AGP TYL did not significantly affect any of the inflammatory parameters. In summary, we revealed the antioxidative properties of the PFA, LIC, ORE, and GRS, as well as anti-inflammatory properties of the PFA and ORE in IPEC-J2, providing a better understanding of the mode of action of this PFA under our experimental conditions.

Growth performance, oxidative stress and immune status of newly weaned pigs fed peroxidized lipids with or without supplemental vitamin E or polyphenols

Background

This study evaluated the use of dietary vitamin E and polyphenols on growth, immune and oxidative status of weaned pigs fed peroxidized lipids. A total of 192 piglets (21 days of age and body weight of 6.62 ± 1.04 kg) were assigned within sex and weight blocks to a 2 × 3 factorial arrangement using 48 pens with 4 pigs per pen. Dietary treatments consisted of lipid peroxidation (6% edible soybean oil or 6% peroxidized soybean oil), and antioxidant supplementation (control diet containing 33 IU/kg DL-α-tocopheryl-acetate; control with 200 IU/kg additional dl-α-tocopheryl-acetate; or control with 400 mg/kg polyphenols). Pigs were fed in 2 phases for 14 and 21 days, respectively.

Results

Peroxidation of oil for 12 days at 80 °C with exposure to 50 L/min of air substantially increased peroxide values, anisidine value, hexanal, and 2,4-decadienal concentrations. Feeding peroxidized lipids decreased (P < 0.001) body weight (23.16 vs. 18.74 kg), daily gain (473 vs. 346 g/d), daily feed intake (658 vs. 535 g/d) and gain:feed ratio (719 vs. 647 g/kg). Lipid peroxidation decreased serum vitamin E (P < 0.001) and this decrease was larger on day 35 (1.82 vs. 0.81 mg/kg) than day 14 (1.95 vs. 1.38 mg/kg). Supplemental vitamin E, but not polyphenols, increased (P ≤ 0.002) serum vitamin E by 84% and 22% for control and peroxidized diets, respectively (interaction, P = 0.001). Serum malondialdehyde decreased (P < 0.001) with peroxidation on day 14, but not day 35 and protein carbonyl increased (P < 0.001) with peroxidation on day 35, but not day 14. Serum 8-hydroxydeoxyguanosine was not affected (P > 0.05). Total antioxidant capacity decreased with peroxidation (P < 0.001) and increased with vitamin E (P = 0.065) and polyphenols (P = 0.046) for the control oil diet only. Serum cytokine concentrations increased with feeding peroxidized lipids on day 35, but were not affected by antioxidant supplementation (P > 0.05).

Conclusion

Feeding peroxidized lipids negatively impacted growth performance and antioxidant capacity of nursery pigs. Supplementation of vitamin E and polyphenols improved total antioxidant capacity, especially in pigs fed control diets, but did not restore growth performance.

Organic selenium supplement partially alleviated diquat-induced oxidative insults and hepatic metabolic stress in nursery pigs

The study investigated antioxidant effects of Se on resilience to diquat-induced oxidative stress in nursery pigs. Thirty-five weaned pigs were individually housed and randomly assigned to one of the five treatments. Pigs were (1) fed a basal diet and intraperitoneally injected with sterile saline (negative control), (2) fed the basal diet and injected with diquat solution (positive control, PC), or fed the basal diet supplemented with 0·3 mg Se/kg as (3) sodium selenite (SS), (4) soyabean protein-chelated Se (SC) or (5) selenised yeast (SY) and intraperitoneally injected with diquat. Pigs were fed the experimental diets for 17 d and injected with diquat at 10 mg/kg body weight or saline on the 11th day of the study (day 0 post-injection (PI)). Diquat exposure induced acute stress and innate immune activation (P < 0·05) at 6 h PI and compromised (P < 0·05) plasma glutathione peroxidase activity on day 2 PI, which was accompanied by an increase in plasma malondialdehyde at 6 h and day 2 PI (P < 0·10). Organic Se, particularly SY, enhanced (P < 0·05) endogenous antioxidant activity in various aspects compared with the PC group. The growth rate and feed intake from day 0 to day 7 PI were significantly lower in the PC, SS and SC groups than the NC group (P < 0·05). Untargeted metabolomics analysis revealed that twenty-two hepatic metabolites (false discovery rate < 0·15) associated with lipid and cellular antioxidant metabolism were altered by diquat. SY restored hepatic metabolic profiles in some but not all samples.

Sulfur-containing amino acid supplementation to gilts from late pregnancy to lactation altered offspring's intestinal microbiota and plasma metabolites

Maternal nutrition during late pregnancy and lactation is highly involved with the offspring's health status. The study was carried out to evaluate the effects of different ratios of methionine and cysteine (Met/Cys: 46% Met, 51% Met, 56% Met, and 62% Met; maintained with 0.78% of total sulfur-containing amino acids; details in "Materials and methods") supplements in the sows' diet from late pregnancy to lactation on offspring's plasma metabolomics and intestinal microbiota. The results revealed that the level of serum albumin, calcium, iron, and magnesium was increased in the 51% Met group compared with the 46% Met, 56% Met, and 62% Met groups. Plasma metabolomics results indicated that the higher ratios of methionine and cysteine (0.51% Met, 0.56% Met, and 0.62% Met)-supplemented groups enriched the level of hippuric acid, retinoic acid, riboflavin, and δ-tocopherol than in the 46% Met group. Furthermore, the 51% Met-supplemented group had a higher relative abundance of Firmicutes compared with the other three groups (P < 0.05), while the 62% Met-supplemented group increased the abundance of Proteobacteria compared with the other three groups (P < 0.05) in piglets' intestine. These results indicated that a diet consisting with 51% Met is the optimum Met/Cys ratio from late pregnancy to lactation can maintain the offspring's health by improving the serum biochemical indicators and altering the plasma metabolomics profile and intestinal gut microbiota composition, but higher proportion of Met/Cys may increase the possible risk to offspring's health.

Tissue-specific profiling reveals modulation of cellular and mitochondrial oxidative stress in normal- and low-birthweight piglets throughout the peri-weaning period

Weaning is known to induce important nutritional and energetic stress in piglets. Low-birthweight (LBW) piglets, now frequently observed in swine production, are more likely to be affected. The weaning period is also associated with dysfunctional immune responses, uncontrolled inflammation and oxidative stress conditions that are recognized risk factors for infections and diseases. Mounting evidence indicates that mitochondria, the main cellular sources of energy in the form of adenosine 5' triphosphate (ATP) and primary sites of reactive oxygen species production, are related to immunity, inflammation and bacterial pathogenesis. However, no information is currently available regarding the link between mitochondrial energy production and oxidative stress in weaned piglets. The objective of this study was to characterize markers of cellular and mitochondrial energy metabolism and oxidative status in both normal-birthweight (NBW) and LBW piglets throughout the peri-weaning period. To conduct the study, 30 multiparous sows were inseminated and litters were standardized to 12 piglets. All the piglets were weighted at day 1 and 120 piglets were selected and assigned to 1 of 2 experimental groups: NBW (n = 60, mean weight of 1.73 ± 0.01 kg) and LBW piglets weighing less than 1.2 kg (n = 60, 1.01 ± 0.01 kg). Then, 10 piglets from each group were selected at 14, 21 (weaning), 23, 25, 29 and 35 days of age to collect plasma and organ (liver, intestine and kidney) samples. Analysis revealed that ATP concentrations were lower in liver of piglets after weaning than during lactation (P < 0.05) thus suggesting a significant impact of weaning stress on mitochondrial energy production. Oxidative damage to DNA (8-hydroxy-2'-deoxyguanosine, 8-OHdG) and proteins (carbonyls) measured in plasma increased after weaning and this coincides with a rise in enzymatic antioxidant activity of glutathione peroxidase (GPx) and superoxide dismutase (SOD) (P < 0.05). Mitochondrial activities of both GPx and SOD are also significantly higher (P < 0.05) in kidney of piglets after weaning. Additionally, oxidative damage to macromolecules is more important in LBW piglets as measured concentrations of 8-OHdG and protein carbonyls are significantly higher (P < 0.05) in plasma and liver samples, respectively, than for NBW piglets. These results provide novel information about the nature, intensity and duration of weaning stress by revealing that weaning induces mitochondrial dysfunction and cellular oxidative stress conditions which last for at least 2 weeks and more severely impact smaller piglets.

Review: Link between intestinal immunity and practical approaches to swine nutrition

Gaining a deeper understanding into the underlying mechanisms associated with intestinal function and immunity during the weaning transition is critical to help shed new light into applied nutrition approaches to improve piglet performance and health during this critical life-stage transition. The transient anorexia triggered at weaning leads to compromised intestinal barrier function and a localized inflammatory response. Considering barrier function, specific nutrient fractions appear to have a significant impact on the development and function of the immune and microbial systems around weaning. Understanding the specific impact of nutrients in the small intestine and hindgut is important for helping to bring more focus and consistency to nutritional approaches to support health and immunity during the weaning transition period. The challenge continues to be how to translate these modes of action into practical and scalable approaches for swine nutrition. We will focus specifically on practical nutritional approaches to influence intestinal immunity through lipid, protein and antioxidant nutrition.