Effect of pad-fan cooling and dietary organic acid supplementation during late gestation and lactation on reproductive performance and antioxidant status of multiparous sows in hot weather

Evaluation of the effect of the indoor environment on the physiological responses of early-gestation sows in a commercial house in China

Objective

The environment influences the sow's health and physiology during gestation. This study was conducted to evaluate indoor environmental parameters and physiological responses of early-gestation sows and investigate the possible methods for assessing the thermal environment in commercial houses.

Methods

A total of 20 early-gestation sows (commercial purebred Yorkshire) with an average body weight of 193.20 ± 3.62 kg were used for this study in winter, spring, summer, and autumn. The indoor environment parameters comprising dry-bulb temperature (T_db), relative humidity (RH), and carbon dioxide (CO₂) were recorded in 30-min intervals. Physiological parameters including heart rate (HR) and respiration rate (RR) of sows were also measured every 30 min. Wet-bulb temperature (T_wb) was calculated using T_db, RH and atmospheric pressure was recorded at a nearby weather station.

Results

The average indoor T_db and RH were 12.98 ± 2.03°C and 80.4 ± 6.4% in winter, 18.98 ± 2.68°C and 74.4 ± 9.0% in spring, 27.49 ± 2.05°C and 90.6 ± 6.4% in summer, and 17.10 ± 2.72°C and 64.5 ± 10.9% in autumn. A higher average concentration of CO₂ was observed in winter (1,493 ± 578 mg/m³) than in spring (1,299 ± 489 mg/m³), autumn (1,269 ± 229 mg/m³), and summer (702 ± 128 mg/m³). Compared with the HR and RR in the optimum environment, high RH in the house led to a significant decrease in both HR and RR (P < 0.05). In addition, a significant decline in HR was also obtained at high temperatures (P < 0.05). A temperature humidity index (THI), THI = 0.82 × T_db + 0.18 × T_wb, was determined for early-gestation sows, and the THI thresholds were 25.6 for HR. The variation in THI in summer showed that heat stress still occurred under the pad-fan cooling system.

Conclusion

This study demonstrated the critical significance of considering physiological responses of early-gestation sows in commercial houses and THI thresholds. We recommend that much more cooling measures should be taken for early-gestation sows in summer.

Maternal supplementation with glycerol monolaurate improves the intestinal health of suckling piglets by inhibiting the NF-κB/MAPK pathways and improving oxidative stability

Glycerol monolaurate (GML) is a food safe emulsifier and a kind of MCFA monoglyceride that has been proven to confer positive benefits in improving animal health, production and feed digestibility as a feed additive. This study aims to evaluate whether supplementation of a sow diet with GML could affect the intestinal barrier function and antioxidant status of newborn piglets and to explore its regulatory mechanism. A total of 80 multiparous sows were divided into two groups, which were fed a basal diet or a basal diet supplemented with 0.1% GML. The results indicated that maternal supplementation with GML significantly increased fat, lactose and protein in sow colostrum, as well as fat and protein in sow 14-day milk (P < 0.05). The results showed that GML significantly reduced the concentrations of IL-12 in the duodenum, TNF-α, IL-1β and IL-12 in the jejunum, and IL-1β in the ileum of piglets (P < 0.05). Higher concentrations of T-AOC, T-SOD, GSH and GSH-Px and lower MDA in the intestine were observed in the GML group than in the control group. Correspondingly, the villi height, crypt depth and the ratio of villi height to crypt depth (V/C) in the jejunum and the V/C in the ileum in the GML group were significantly higher than those in the control group (P < 0.05). Moreover, the GML group displayed significantly increased protein abundance of zonula occludens (ZO)-1, occludin, and claudin-1 in the small intestine (P < 0.05), mRNA expression of mucins (MUCs) in the small intestine (MUC-1, MUC-3 and MUC-4), and mRNA expression of porcine beta defensins (pBDs) in the duodenum (pBD1 and pBD2), jejunum (pBD1, pBD2 and pBD129) (P < 0.05), and ileum (pBD2, pBD3 and pBD114) (P < 0.05). Further research showed that GML significantly reduced the phosphorylation of the NF-κB/MAPK pathways in the small intestine (P < 0.05). In addition, the results of 16S rDNA sequencing showed that maternal supplementation with GML altered the colonic microbiotic structure of piglets, and reduced the relative abundance of Escherichia shigella. In summary, a sow diet supplemented with GML enhanced the offspring's intestinal oxidative stability and barrier function and attenuated the offspring's intestinal inflammatory response, possibly by suppressing the activation of the NF-κB/MAPK pathways.

Acidifiers Attenuate Diquat-Induced Oxidative Stress and Inflammatory Responses by Regulating NF-κB/MAPK/COX-2 Pathways in IPEC-J2 Cells

In this study, we evaluated the protective effects and potential mechanisms of acidifiers on intestinal epithelial cells exposure to oxidative stress (OS). IPEC-J2 cells were first pretreated with 5 × 10⁻⁵ acidifiers for 4 h before being exposed to the optimal dose of diquat to induce oxidative stress. The results showed that acidifiers attenuated diquat-induced oxidative stress, which manifests as the improvement of antioxidant capacity and the reduction in reactive oxygen species (ROS) accumulation. The acidifier treatment decreased cell permeability and enhanced intestinal epithelial barrier function through enhancing the expression of claudin-1 and occludin in diquat-induced cells. Moreover, acidifier treatment attenuated diquat-induced inflammatory responses, which was confirmed by the decreased secretion and gene expression of pro-inflammatory (TNF-α, IL-8) and upregulated anti-inflammatory factors (IL-10). In addition, acidifiers significantly reduced the diquat-induced gene and protein expression levels of COX-2, NF-κB, I-κB-β, ERK1/2, and JNK2, while they increased I-κB-α expression in IPEC-J2 cells. Furthermore, we discovered that acidifiers promoted epithelial cell proliferation (increased expression of PCNA and CCND1) and inhibited apoptosis (decreased expression of BAX, increased expression of BCL-2). Taken together, these results suggest that acidifiers are potent antioxidants that attenuate diquat-induced inflammation, apoptosis, and maintain cellular barrier integrity by regulating the NF-κB/MAPK/COX-2 signaling pathways.

Evaluation of an automated temperature control equipment for lactating sows

The present study aimed to develop and evaluate an automated cooling control system (ATCE) for sows in the farrowing phase. The experiment was conducted at the Swine Production Unit, Federal Institute of Education, Science and Technology, Campus Machado, Machado, state of Minas Gerais. Sixteen sows and their offspring were evaluated, eight treated and eight controls, in a randomized block design, with eight replications. Surface temperature, body temperature and respiratory rate of the animals were evaluated, in addition to floor temperature and performance parameters. The use of ATCE decreased the floor temperature (12h) and neck temperature (12 and 16h) (p < 0.10). In addition, there was a reduction in rectal temperature (12h) and respiratory rate (12 and 16h) in ATCE animals (p < 0.10). No significant differences were detected in the coefficient of variation (CV) of birth weight, but at weaning the CV of piglet weight was 26.3% lower in animals subjected to the ATCE (p = 0.079). Furthermore, the difference in CV between birth and weaning was also lower with the use of ATCE (p = 0.015). It can be concluded that the use of ATCE has a positive influence on the thermal comfort of females, in addition to improving litter uniformity.

Organic Acids Improve Growth Performance with Potential Regulation of Redox Homeostasis, Immunity, and Microflora in Intestines of Weaned Piglets

The objective of this study is to evaluate the effects of organic acids on piglet growth performance and health status. A total of 360 weanling pigs (5.3 ± 0.6 kg) were randomly allotted to 3 treatment groups with 12 replicates of 10 pigs/pen. Piglets were fed the same basal diet and given either water (control) or water plus 2.0 L/Ton organic acid (OA) blends, such as OA1 or OA2, respectively, for 7 weeks. Compared to the control, OA1 and OA2 improved growth performance and/or reduced the piglets' diarrhea rate during the various periods and improved small intestinal morphology at days 14 and/or 49. OA1 and OA2 also increased serum CAT and SOD activities and/or T-AOC and, as expected, decreased MDA concentration. Moreover, at day 14 and/or day 49, OA1 and OA2 increased the jejunal mRNA levels of host defense peptides (PBD1, PBD2, NPG1, and NPG3) and tight junction genes (claudin-1) and decreased that of cytokines (IL-1β and IL-2). Additionally, the two acidifiers regulated the abundance of several cecum bacterial genera, including Blautia, Bulleidia, Coprococcus, Dorea, Eubacterium, Subdoligranulum, and YRC2. In conclusion, both of the organic acid blends improved piglet growth performance and health status, potentially by regulating intestinal redox homeostasis, immunity, and microflora.

Maternal supplementation with a combination of wheat bran and sugar beet pulp during late gestation and lactation improves growth and intestinal functions in piglets

Maternal diet has a profound impact on growth and immune development of offspring. This study aimed to evaluate the effects of maternal supplementation with a combination of wheat bran (WB, a source of insoluble dietary fiber) and sugar beet pulp (SBP, a source of soluble dietary fiber) on growth and intestinal morphology, immunity, barrier function and microbiota in piglets. Thirty sows (Landrace × Yorkshire; 3-6 parity) were randomly allocated to 2 dietary treatments from d 85 of gestation to weaning (d 21 of lactation). The 2 dietary treatments were: a control diet (CON, a corn-soybean meal diet) and a dietary fiber diet (DF, 15% WB and 10% SBP during gestation and 7.5% WB and 5% SBP during lactation). Maternal DF supplementation improved growth, serum growth hormones and ileal morphology in piglets. Piglets fed DF showed enhanced intestinal barrier function as indicated by reduced serum concentrations of diamine oxidase and endotoxin, and increased ileal mRNA level of occludin. Maternal DF supplementation reduced pro-inflammatory cytokines in the colostrum, milk and serum of piglets. Furthermore, maternal DF supplementation decreased the colonic abundance of Subdoligranulum and Mogibacterium, and increased the colonic abundance of Lactobacillus and norank_f__Bacteroidales_S24-7_group and the colonic concentration of acetate and butyrate in piglets. In summary, maternal supplementation with a combination of SBP and WB during late gestation and lactation improved cytokines in colostrum and milk, growth, immune responses, intestinal morphology, barrier function and microbiota in piglets, which may be a potential strategy to improve offspring growth and intestinal functions.

Effect of replacing inorganic trace minerals at lower organic levels on growth performance, blood parameters, antioxidant status, immune indexes, and fecal mineral excretion in weaned piglets

Organic trace minerals (OTMs) have the potential to replace inorganic trace minerals (ITMs), but the degree to which the dietary levels can be reduced is not well defined. This study aimed to investigate the effect of replacing of ITMs with lower levels of OTMs on growth performance, blood parameters, antioxidant status, and immune indexes in weaned piglets. The experiment was conducted in a subtropical city in Guangdong Province in South China (subtropical climate) from July to September 2018. A total of 600 pigs with an average initial BW of 8.90 kg were allotted by gender and weight to 5 treatments with 6 replicate pens per treatment. Experimental treatments: (A) Control group (a basal diet with iron, copper, manganese, and zinc from sulfates and sodium selenite providing commercially utilized levels in China of 150, 25, 40, 150, and 0.5 mg/kg, respectively). (B) 1/2 ITM group (inorganic trace minerals providing 1/2 control group levels). (C) 1/2 OTM group (1/2 control group trace mineral levels with manganese, iron, zinc, and selenium from Sel-Plex® and Cu from Bioplex®). (D) 1/3 ITM group (1/3 control group trace mineral levels from inorganic forms). (E) 1/3 OTM group (1/3 control group trace mineral levels from organic forms). The results suggest no significant effects of trace mineral sources or levels, on average daily gain (ADG) and average daily feed intake (ADFI) among different treatments during the entire experiment. The level of zinc in serum was significantly decreased in the 1/3 ITM group. The 1/3 OTM group had a significantly higher (P < 0.05) immunoglobulin G (IgG) level in serum. Fecal mineral excretion decreased significantly (P < 0.05) when decreased dietary levels of trace minerals were included at 1/2 and 1/3 levels regardless of sources. Fecal concentrations of zinc excretion were lower (P < 0.05) with 1/2 OTM supplementation than 1/2 ITMs. The present study shows that replacing high doses of ITMs with low concentrations (1/3) of OTMs does not adversely affect the growth performance of piglets. At low levels, total replacement of ITMs with OTMs improved IgG and reduced fecal excretion of copper, zinc, iron, and manganese, thereby mitigating environmental pollution.

Increasing selenium supplementation to a moderately-reduced energy and protein diet improves antioxidant status and meat quality without affecting growth performance in finishing pigs

BACKGROUND

Along with economic development and living standards' improvement, more and more attention has been converted from satisfying meat quantity to pursuing meat quality.

RESEARCH PURPOSE

This study was conducted to evaluate the effects of increasing selenium (Se) supplementation to a moderately-reduced energy and protein diet (MREP) on growth performance, antioxidant status, meat quality in finishing pigs.

BASIC PROCEDURES

A total of 144 "Duroc × Landrace × Yorkshire" pigs with the average body weight of 75 ± 1 kg were randomly allotted to 3 dietary treatments with six replicates per treatment and eight pigs per replicate. The 3 experimental diets were as follows: (1) Normal energy and protein (NEP) +0.2 mg/kg Se diet (14.02 MJ/kg DE, 14% CP and 0.2 mg/kg Se as selenite sodium), (2) MREP +0.2 mg/kg Se diet (13.60 MJ/kg DE, 13% CP and 0.2 mg/kg Se as selenite sodium), and (3) MREP +0.5 mg/kg Se diet (13.60 MJ/kg DE, 13% CP, 0.2 mg/kg Se as selenite sodium, and 0.3 mg/kg Se as Se-enriched yeast). The study lasted for 45 days.

MAIN FINDINGS

The results show that there were no differences for growth performance, antioxidant status and meat quality of finishing pigs between NEP +0.2 mg/kg Se group and MREP +0.2 mg/kg Se group (P＞0.05). However, compared to pigs from MREP +0.2 mg/kg Se group, pigs from MREP +0.5 mg/kg Se group had greater Se concentration, GSH-Px activity and GSH concentration, but lower MDA concentration in serum (P＜0.05). Also, pigs from MREP +0.5 mg/kg Se group had greater Se concentration, T-AOC, and SOD activity, but lower MDA concentration in loin compared with pigs from MREP +0.2 mg/kg Se group (P＜0.05). As for meat quality, pigs from MREP +0.5 mg/kg Se group had greater a* value (relative redness) at 45 min and 24 h in loin compared with pigs from MREP +0.2 mg/kg Se group (P＜0.05). Compared to pigs from MREP +0.2 mg/kg Se group, pigs from MREP +0.5 mg/kg Se group had lower MDA concentration of fresh pork during a simulated retail display at 0, 1, 2, 4, 6 and 7 day (P＜0.05).

PRINCIPAL CONCLUSIONS

In conclusion, increasing selenium supplementation to a moderately-reduced energy and protein diet improved antioxidant status and meat quality without affecting growth performance in finishing pigs. (New Aspects) The present study provided a nutritional strategy for reducing feed costs and improving pork quality without influencing growth performance in finishing pigs.

Effects of Maternal Supplementation with Rare Earth Elements during Late Gestation and Lactation on Performances, Health, and Fecal Microbiota of the Sows and Their Offspring

Simple Summary

The immunological and metabolic status of breeding sows directly affect the overall productivity of porcine operations. Especially, maternal health status during the transition from gestation to lactation are important in maintaining health and growth of the suckling piglets. Rare earth elements (REEs) have been considered as a promising natural feed additive and been reported to exert their activity locally within the gastrointestinal tract, including effects on the bacterial microflora and on nutrient utilization. The present study was conducted to explore the effects of dietary maternal REE supplementation during late gestation and lactation on sows and their offspring. After the experiment, we found that maternal REE addition enhanced antioxidant activity and immunity of sows and their suckling piglets. At the same time, REE supplementation during perinatal period improved the reproductivity of the sows as well as the growth of their offspring. Besides, maternal REEs supply altered the intestinal microbiota community and composition of sows as well as their offspring, and Spearman correlation analysis shows that fecal bacteria are associated with the antioxidase, inflammatory factors of the sows and offspring as well as average daily gain of the suckling piglets. In addition, our results suggested that REE supplementation during both gestation and lactation are more beneficial to sows and their offspring than supplementation during only late gestation. This paper holds promise in providing efficient feeding strategies in swine production.

Abstract

The study was conducted to investigate the effects of maternal supplementation with rare earth elements (REEs) on sows and their offspring. During late gestation, 120 multiparous sows were divided randomly into the control group (Basal diet) and REE-G group (Basal diet supplemented with 200 mg REE/kg). After delivery, REE-G group was further divided into two groups: REE-L- (Change to basal diet during lactation) and REE-L+ group (REE diet all the time). Our results showed that maternal REE supplementation improved the antioxidant and immunity of sows and piglets. Additionally, REE supply during late gestation significantly decreased the coefficient of within-litter variation (CV) in birth weight and increased the weaning weights and the average daily gain (ADG) of piglets. During lactation, the insulin-like growth factor-1 (IGF-1) levels in piglets of REE-L+ group were higher, while no difference between REE-L- and the control group. More beneficial bacteria (Christensenellaceae and Ruminococcaceae) were found in the REE-L+ group while some opportunistic pathogens (Proteobacteria and Campylobacter) were relatively suppressed. Fecal microbiota showed correlation with antioxidase, inflammatory factors, and average daily gain (ADG). Collectively, our findings indicated that REEs added in both gestation and lactation was more conducive to establish a healthier status for sows and their offspring.

Increasing selenium supply for heat-stressed or actively cooled sows improves piglet preweaning survival, colostrum and milk composition, as well as maternal selenium, antioxidant status and immunoglobulin transfer

This study aimed to evaluate the effects of increasing selenium (Se) supply for heat-stressed or actively cooled sows on sow productivity, colostrum and milk composition, as well as the selenium and antioxidant status and immunoglobulin levels of sows and nursing piglets. The study was a 2 × 2 factorial design, where the first factor was farrowing environment [heat stress vs. actively cooling, temperature: 29.61 ± 0.19 ℃ (27.70-31.60 ℃) vs. 27.90 ± 0.15 ℃ (26.90-30.20 ℃); temperature-humidity index: 72.91 ± 0.26 (70.30-75.70) vs. 70.81 ± 0.22 (69.30-73.80)], and the second factor was dietary Se level during late gestation and lactation [(0.3 vs. 1.2 mg/kg Se as Se-yeast, the basal diet was corn-soybean meal diet formulated according to NRC (2012) except for Se level]. Forty multiparous sows (Landrace × Yorkshire) were randomly allotted to 1 of 4 treatments (10 sows and following 90 piglets per treatment, respectively). The results show that: (1) There were no interactions of farrowing environment with Se treatments with the exceptions of nutrient content of 7-d milk; (2) As for zootechnical measures, piglets of sows receiving increasing Se tended to have greater preweaning survival compared with those of sows receiving control diet without interactions of environment and Se treatments; (3) As to colostrum and milk composition, greater concentrations of protein, lactose, solids-not-fat in colostrum, and greater fat concentration in 7-d and 14-d milk were found for sows fed increasing Se; (4) Regarding Se and antioxidant status, increasing Se supply for sows increased Se content in colostrum and 21-d milk, as well as in plasma of 1-day-old and 21-day-old piglets. Meanwhile, increasing Se supply for sows improved antioxidant status in colostrum (MDA content) and 21-d milk (T-AOC and MDA content), as well as in plasma of 1-day-old and 21-day-old piglets (GSH-Px activity and MDA content); (5) With regard to immunoglobulins, sows fed increasing Se had higher IgM levels in colostrum, and higher IgA in 21-d milk. Also, piglets from sows fed increasing Se had higher plasma IgA at 1 d of age, and higher IgA and IgG levels at 21 d of age. Collectively, increasing selenium supply for heat-stressed or actively cooled sows improved piglet preweaning survival, colostrum and milk composition, as well as maternal selenium, antioxidant status and immunoglobulin transfer irrespective of the climatic conditions, which indicates that Se requirements for sows should be urgently reassessed.