Effect of under- and overfeeding on sheep and goat milk and plasma enzymes activities related to oxidation

Oral exposure to bisphenol S is associated with alterations in the oviduct proteome of an ovine model, with aggravated effects in overfed females

BACKGROUND

Bisphenol S (BPS) is a substitute for bisphenol A in plastic manufacturing and, as a potential endocrine disruptor, may alter the physiology of the oviduct, in which fertilization and early embryo development take place in mammals. The objective of this study was to assess the effect of a daily dietary exposure to BPS combined with a contrasted diet on the oviduct fluid proteome using an ovine model.

RESULTS

Eighty adult cyclic ewes were allotted to four groups (20/group): overfed (OF) consuming 50 µg/kg/day of BPS in their diet, underfed (UF) consuming 50 µg/kg/day of BPS, and non-exposed controls in each diet group. After three months, the mean body condition score, plasma levels of glucose and non-esterified fatty acids were significantly higher in OF than in UF females. The proteins in collected OF samples (50 µg) were analyzed by nanoliquid chromatography coupled with tandem mass spectrometry (nanoLC-MS/MS). Overall, 1563 proteins were identified, among which 848 were quantified. Principal component analysis of the data revealed a clear discrimination of samples according to the diet and a segregation between BPS-exposed and non-exposed females in overfed ewes. Hierarchical clustering of differentially abundant proteins (DAPs) identified two clusters of 101 and 78 DAPs according to the diet. Pairwise comparisons between groups revealed a stronger effect of BPS in OF than in UF females (70 vs. 24 DAPs) and a stronger effect of the diet in BPS-exposed than non-exposed females (56 vs. 36 DAPs). Functional analysis of DAPs showed an enrichment in metabolic processes, immune system, cell response to stress, and reproductive processes.

CONCLUSIONS

This work highlights for the first time the important impact of BPS on the oviduct proteome, with larger effects seen in OF than UF females. These results, together with previous ones, raise health concerns for everyone and call for a greater regulation of BPS in the food industry.

Dietary supplement of fermented grass forage regulates growth performance, antioxidant capacity, and immune response of broiler chickens

The current study aimed to determine the effects of different levels of fermented Juncao grass (FG) on growth parameters, blood constituents, immunity, and antioxidative properties of broilers. A total of 240 (21-d-old) broiler chicks were randomly distributed to four dietary treatments of sixty birds, with six replicate pens and ten birds in each. Fermented grass was added to the basal diet at four levels with 0, 5, 10, and 15% FG. The results revealed that broilers fed 5% FG had significantly higher (P < 0.05) final body weight (FBW), average daily gain (WG) and average daily feed intake (ADFI). The best conversion ratio (FCR) was recorded for broilers supplemented with 5% FG compared to the group supplemented with 15% FG (P < 0.05). Increasing FG % decreased (P < 0.05) anti-inflammatory cytokines IL-4, IL-6, and IL-10. However, FG increased (P < 0.05) proinflammatory cytokines IFN-γ, IL-1, IL-2, IL-12, and TNF-α (P < 0.05). Moreover, IgA, IgG, and IgM levels increased (P < 0.05) with increasing FG %. In addition, increasing FG % in broiler rations significantly increased (P < 0.05) serum antioxidant levels of T-AOC, GSH-PX, SOD, CAT, NO and GSH, but decreased (P < 0.05) MDA levels compared to the control group. Conclusively, fermented Juncao grass would be considered a novel herbal feed additive for improving broiler performance, immunity, antioxidant, and health status. Nevertheless, further research at the molecular level is needed to quantify the effects of these herbal components on cellular and humoral immune functions in broiler chickens.

The Effect of Dietary Supplementation with Probiotic and Postbiotic Yeast Products on Ewes Milk Performance and Immune Oxidative Status

The administration of yeast products as feed additives has been proven to beneficially affect animal productivity through energy, oxidative, and immune status improvement. This study evaluated a combination of Saccharomyces cerevisiae live yeast (LY) with yeast postbiotics (rich in mannan-oligosaccharides (MOS) and beta-glucans) and selenium (Se)-enriched yeast on ewes' milk performance and milk quality, energy and oxidative status, and gene expression related to their immune system during the peripartum period. Ewes were fed a basal diet (BD; F:C = 58:42 prepartum and 41:59 postpartum) including inorganic Se (CON; n = 27), the BD supplemented with a LY product, and inorganic Se (AC; n = 29), as well as the combination of the LY, a product of yeast fraction rich in MOS and beta-glucans, and organic-Se-enriched yeast (ACMAN; n = 26) from 6 weeks prepartum to 6 weeks postpartum. The β-hydroxybutyric acid concentration in the blood of AC and ACMAN ewes was lower (compared to the CON) in both pre- and postpartum periods (p < 0.010). Postpartum, milk yield was increased in the AC and ACMAN Lacaune ewes (p = 0.001). In addition, the activity of superoxide dismutase (p = 0.037) and total antioxidant capacity (p = 0.034) measured via the 2,2-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) method was increased in the blood plasma of the ACMAN postpartum. Higher ABTS values were also found (p = 0.021), while protein carbonyls were reduced (p = 0.023) in the milk of the treated groups. The relative transcript levels of CCL5 and IL6 were downregulated in the monocytes (p = 0.007 and p = 0.026 respectively), and those of NFKB were downregulated in the neutrophils of the ACMAN-fed ewes postpartum (p = 0.020). The dietary supplementation of ewes with yeast postbiotics rich in MOS and beta-glucans, and organic Se, improved energy status, milk yield and some milk constituents, and oxidative status, with simultaneous suppression of mRNA levels of proinflammatory genes during the peripartum period.

Postnatal Overfeeding in Rodents Induces a Neurodevelopment Delay and Anxious-like Behaviour Accompanied by Sex- and Brain-Region-Specific Synaptic and Metabolic Changes

Nutritional disturbances during the early postnatal period can have long-lasting effects on neurodevelopment and may be related to behavioural changes at adulthood. While such neuronal connection disruption can contribute to social and behaviour alterations, the dysregulation of the neuroendocrine pathways involved in nutrient-sensing balance may also cause such impairments, although the underlying mechanisms are still unclear. We aimed to evaluate sex-specific neurodevelopmental and behavioural changes upon postnatal overfeeding and determine the potential underpinning mechanisms at the central nervous system level, with a focus on the interconnection between synaptic and neuroendocrine molecular alterations. At postnatal day 3 (PND3) litters were culled to three animals (small litter procedure). Neurodevelopmental tests were conducted at infancy, whereas behavioural tests to assess locomotion, anxiety, and memory were performed at adolescence, together with molecular analysis of the hippocampus, hypothalamus, and prefrontal cortex. At infancy, females presented impaired acquisition of an auditory response, eye opening, olfactory discrimination, and vestibular system development, suggesting that female offspring neurodevelopment/maturation was deeply affected. Male offspring presented a transitory delay in locomotor performance., while both offspring had lower upper limb strength. At adolescence, both sexes presented anxious-like behaviour without alterations in short-term memory retention. Both males and females presented lower NPY1R levels in a region-specific manner. Furthermore, both sexes presented synaptic changes in the hippocampus (lower GABAA in females and higher GABAA levels in males), while, in the prefrontal cortex, similar higher GABAA receptor levels were observed. At the hypothalamus, females presented synaptic changes, namely higher vGLUT1 and PSD95 levels. Thus, we demonstrate that postnatal overfeeding modulates offspring behaviour and dysregulates nutrient-sensing mechanisms such as NPY and GABA in a sex- and brain-region-specific manner.

Essential and Toxic Mineral Content and Fatty Acid Profile of Colostrum in Dairy Sheep

Simple Summary

Colostrum is of interest to the scientific community because of its nutritional and therapeutic capabilities. The aims of this study were to characterize the macro and micro composition of colostrum from Sarda dairy sheep and to compare it with the composition of the mature milk of the same breed. The results of this survey showed a large variation in the immunoglobulin concentration in colostrum, which could affect the acquisition of passive immunity by lambs. The strong correlation between immunoglobulin G and the total protein content suggests that this can be used to estimate the immunoglobulin content in sheep colostrum. The concentration of essential minerals is higher in colostrum than in milk as a result of mineral salt block supplementation at the end of gestation. Colostrum has a significantly different fatty acid profile than milk, and this is due to the specific needs of newborn lambs.

Abstract

Colostrum is a major source of immunity in ruminants. It allows the transfer of antibodies from the mother to the fetus, and it is the exclusive source of nutrients for the newborn. The objectives of this study were (i) to characterize the macro and the micro composition of colostrum; (ii) to analyze the antioxidant capacity, fatty acid profile, and essential and toxic mineral content of colostrum; and (iii) to compare FA profiles and the amount of trace elements between colostrum and mature milk. For these purposes, samples of colostrum and milk were collected from a representative sample of animals from eight sheep dairy farms in the north of Sardinia (Italy). Fat, proteins, and seven essential and toxic minerals were measured in all samples of colostrum and milk. Furthermore, the FA profile was also measured in both matrices, while total antioxidant capacity was measured only in colostrum samples. The average amounts of fat and protein (TP) concentration in colostrum were 7.8% and 16%, respectively. Additionally, an average amount of 40 ± 20 g dm⁻³ was found for immunoglobulin G (IgG). As regards the antioxidant capacity of colostrum, a large variation was observed between samples from different farms for test 2, 2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), which was 30 ± 10% (mean ± standard deviation). High levels of selenium (Se), zinc (Zn), and copper (Cu) were found in colostrum (200 µg kg⁻¹, 25,000 µg kg⁻¹, and 1200 µg kg⁻¹, respectively). A strong positive correlation between TP and IgG was observed (r = 91%). In colostrum, the amount of IgG is positively correlated with Se and Zn, as they are essential minerals to the immune system. The FA profile demonstrated higher levels of medium and long chain fatty acids in colostrum than in mature milk, and this is mainly true for arachidonic acid (ARA), ecosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA). This study provided new information on the quality of colostrum in Sarda dairy sheep and showed the different composition of fatty acids between colostrum and mature milk.

The Effect of Dietary Inclusion of Microalgae Schizochytrium spp. on Ewes’ Milk Quality and Oxidative Status

An unprecedented challenge for nutritionists arises during the 21st century in order to produce highly nutritious and functional food which promotes human health. Polyunsaturated fatty acids (PUFA) that are highly contained in microalgae have broadly been confirmed for preventing cardiovascular diseases and regulating immune-oxidative status. However, their optimum dietary inclusion level needs to be defined since PUFA are prone to oxidation. For this purpose, 24 cross-bred dairy ewes, were separated into four groups (n = 6) and were fed with different levels of microalgae Schizochytrium spp. [0 (CON, no microalgae), 20 (SC20), 30 (SC30) and 40 (SC40) g/ewe/day] for 60 days. The results showed that although the production parameters were not impaired, milk fat content was decreased in medium and high-level supplemented groups while protein content was suppressed only for the medium one. Concerning the fatty acids (FA) profile, the proportions of C_14:0, trans C_18:1, trans-11 C_18:1, cis-9, trans-11 C_18:2, trans-10, cis-12 C_18:2, C_20:5 (EPA), C_22:5n-6 (DPA), C_22:6n-3 (DHA), the total ω3 FA and PUFA were significantly increased, while those of C_18:0, cis-9 C_18:1 and C_18:2n-6c were decreased in the milk of treated ewes. Additionally, in the S40 group an oxidative response was induced, observed by the increased malondialdehyde (MDA) levels in milk and blood plasma. In conclusion, the dietary inclusion of 20 g Schizochytrium spp./ewe/day, improves milks’ fatty acid profile and seems to be a promising way for producing ω3 fatty acid-enriched dairy products.

A diverse diet as an alternative to ryegrass can improve the total antioxidant status of dams at lambing

The objective of this experiment was to determine if providing ewes in the final trimester of pregnancy with choice from diverse diet components would reduce markers of oxidative and metabolic stress in ewes and improve lamb birth weights relative to ewes offered only one forage species, repetitively. Fifty-four, twin bearing Coopworth ewes [initial live weight (LW) = 69.82 ± 1.16 kg] were blocked by weight onto iso-energetic diets with either choice from taxonomically diverse plants [DIV; spatially separated strips of ryegrass (Lolium perenne L.), chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.), red clover (Trifolium pratense L.), and alfalfa (Medicago sativa L.)] or a ryegrass only diet (RYE) for the final third of gestation. The ewes offered the DIV diet birthed 8.9% heavier lambs (5.64 ± 0.20 kg) than RYE ewes (5.18 ± 0.20 kg; P = 0.03). In addition, the DIV ewes had greater (P &lt; 0.01) glutathione peroxidase and total antioxidant status, and lower (P = 0.01) plasma non-esterified fatty acid concentrations than the RYE fed ewes 24 h after lambing. The results indicate that the DIV diet can improve antioxidant status and reduce some markers of oxidative and metabolic stress at lambing compared to a conventional RYE diet.

Long-term administration of a commercial supplement enriched with bioactive compounds does not affect feed intake, health status, and growth performances in beef cattle

Abstract. Feed additives including natural bioactive compounds (BCs) in combination with vitamin E (VitE) and organic Se could mitigate animal stress associated with intensive livestock farming due to their anti-inflammatory and antioxidant properties. Yeast and yeast derivate are included in feed additives as probiotic products and digestion promoters. Scutellaria baicalensis is a source of bioactive compounds and has been tested in monogastrics, exhibiting many immunostimulating and hepato-protective activities. However, the literature lacks information regarding S. baicalensis effects on beef cattle performance and health status. The aim of the present study was to evaluate the impact on beef cattle's feed intake, health and oxidative status, and growth performances of the inclusion of a commercial supplement (CS) containing VitE, organic Se, yeast derivate, and S. baicalensis extract during the fattening and finishing period. A total of 143 Charolaise male cattle were allotted into 12 pens of 11–12 animals each and assigned to a control (463.9±21.48 body weight – BW) or a treated (469.8±17.91 BW) group. Each group included two replicates of three pens. The treated groups were supplemented with 20 gCSanimal-1d-1. Feed intake was measured monthly on a pen base during two consecutive days. Total mixed ration and fecal samples were collected at three time points (monthly, from November to February) and pooled by replicate for the analyses to monitor digestibility. Blood samples were individually collected at the beginning and at the end of the trial for oxidative status and metabolic profile determination. Final BW and carcass weight were individually recorded to calculate average daily gain, feed conversion ratio, and carcass yield. Similar feed digestibility between groups were observed during the whole experiment. Feed intake, growth performances, final body weight, average daily gain, feed conversion rate, oxidative status, and metabolic profile were not affected by the dietary inclusion of the tested CS indicating no detrimental effect of the treatment. Different doses of this product should be tested in the future in order to provide a more complete report on the product efficacy.

Monthly Dynamics of Plasma Elements, Hematology, Oxidative Stress Markers, and Hormonal Concentrations in Growing Male Shiba Goats (Capra hircus) Reared in Tokyo-Japan

Simple Summary

During the first stage of an animal’s life, various physiological alterations with the concomitant development of different body organs occur. This period is also accompanied by different kinds of stressors, including, but not limited to, the stress of weaning, metabolic change, and peri-puberty changes in reproductive functions. Shiba goats, the main goat breed in Japan, are not commonly used as food animals. However, male Shiba goats largely contribute to reproductive and cardiology research activities, as well as being used for educational purposes for elementary school children. The physiological data regarding laboratory measurements in Shiba goats are lacking, especially at a young age. In this study, we investigated the age-related changes in hematology, plasma mineral concentrations, hormones, and oxidative stress markers during the first five months (neonatal and peri-puberty age) in male Shiba goats.

Abstract

From a clinical point of view, the establishment of laboratory variables during the first few months of an animal’s life helps clinicians to make sure they base their medical decisions on laboratory values for the specific breed and age group. The present study aimed to investigate the monthly dynamics in some plasma elements, hematology, reproductive hormones, and oxidative stress marker profiles during the first five months of age (neonatal and peri-puberty stage) in male Shiba goat’s kids. Sixteen kids were investigated from the first to the fifth month (M1 to M5), and the data were presented as the statistical difference between them. Whole blood and plasma samples were collected monthly for analysis of basal hematology, plasma elements concentration (trace elements: Cu, Zn, Se, Fe, and Cr; macroelements: Ca and Mg), circulating hormones (cortisol, FSH, LH, IGF1, immunoreactive inhibin, testosterone, T3, and T4), and oxidative stress markers (MDA, CAT, SOD, and GPX). The results showed age-related changes in the observed parameters. The fifth month recorded the lowest level of almost all investigated minerals, except for Cr. Plasma hormone levels revealed age-dependent increases in IGF-1 and testosterone, age-related decreases in T3 and T4, and non-significant changes in cortisol and FSH. Besides, the concentrations of inhibin and LH were significantly higher at M1–M3 compared with M4–M5. Plasma SOD, GPX, and CAT were increased with age. In conclusion, age-related changes and a distinction of age in months was found necessary to interpret the laboratory results, specifically in terms of age in months and the peri-puberty stage in young goats, which are important to follow up the age-specific diseases, reproductive status, and treatment follow-ups in this stage.

The Impact of Dietary Berberine Supplementation during the Transition Period on Blood Parameters, Antioxidant Indicators and Fatty Acids Profile in Colostrum and Milk of Dairy Goats

The objective of this study was to investigate the effect of berberine (BBR) supplementation on productivity, antioxidant markers, and the fatty acid (FA) profile in the colostrum and milk of goats. Twenty-four primiparous Saanen goats were supplemented with 0, 1, 2, and 4 g/d (per goat) of BBR in control (CON), BBR1, BBR2, and BBR4 groups (n = 6 per group), respectively, from 21 days before expected kidding to 21 days after parturition. Blood sampling was carried out at −21, −14, −7, 0, 7, 14, and 21 d relative to delivery. Colostrum was collected within the first and second milking (d 1 of lactation), and milk was harvested weekly after kidding. Both BBR2 and BBR4 increased dry matter intake (DMI) (p ≤ 0.05) and energy balance (EB) as well as colostrum and milk production. Both BBR2 and BBR4 decreased (p ≤ 0.05) plasma levels of cholesterol, haptoglobin, and ceruloplasmin, while elevating the plasma albumin and paraoxonase (p ≤ 0.05), which may indicate that BBR mitigates inflammation during the transition period. BBR reduced (p ≤ 0.05) malondialdehyde (MDA) and increased (p ≤ 0.05) total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in blood, colostrum, and milk. Concentrations of de novo fatty acid in colostrum and milk were increased (p ≤ 0.05) with both BBR2 and BBR4. Free fatty acid (FFA) concentration in colostrum and milk fat were lower (p ≤ 0.05) in BBR2 and BBR4 compared to CON. The concentration of saturated fatty acids (SFAs) in colostrum and milk fat increased (p ≤ 0.05) with BBR2 and BBR4, while unsaturated fatty acids (USFAs) decreased (p ≤ 0.05) in milk. In summary, supplementation with at least 2 g/d BBR may enhance the EB and antioxidant status of dairy goats.

Effect of a Carotenoid Extract from Citrus reticulata By-Products on the Immune-Oxidative Status of Broilers

Although carotenoids generally possess antimicrobial and antioxidant properties, the in vivo synergistic action of carotenoid blends derived from plant-based by-products has not been thoroughly studied. Therefore, the carotenoid characterization and antimicrobial potential of Citrus reticulata extract as well as the impact of this carotenoid-rich extract (CCE) dietary supplementation on the performance, meat quality, and immune-oxidative status of broiler chickens were determined. One hundred and twenty one-day-old hatched chicks (Ross 308) were allocated to two dietary groups, with four replicate pens of 15 birds each. Birds were fed either a basal diet (CON) or the basal diet supplemented with 0.1% CCE (25 mg carotenoid extract included in 1 g of soluble starch) for 42 d. β-Cryptoxanthin, β-Carotene, Zeaxanthin, and Lutein were the prevailing carotenoid compounds in the Citrus reticulata extract. The CCE feed additive exerted inhibitory properties against both Gram-positive (Staphylococcus aureus) and negative (Klebsiella oxytoca, Escherichia coli, and Salmonella typhimurium) bacteria. Both the broiler performance and meat quality did not substantially differ, while the breast muscle malondialdehyde (MDA) concentration tended to decrease (p = 0.070) in the CCE-fed broilers. The inclusion of CCE decreased the alanine aminotransferase and MDA concentration, and the activity of glutathione peroxidase, while the activity of superoxide dismutase was increased in the blood. Catalase and NADPH oxidase 2 relative transcript levels were significantly downregulated in the livers of the CCE-fed broilers. Additionally, Interleukin 1β and tumor necrosis factor (TNF) relative transcript levels were downregulated in the livers of the CCE- fed broilers, while TNF and interferon γ (IFNG) tended to decrease in the spleens and bursa of Fabricius, respectively. The present study provided new insights regarding the beneficial properties of carotenoids contained in Citrus reticulata in broilers’ immune-oxidative status. These promising outcomes could be the basis for further research under field conditions.

Assessing the Optimum Level of Supplementation with Camelina Seeds in Ewes' Diets to Improve Milk Quality

Camelina sativa seeds are rich in bioactive compounds such as polyunsaturated fatty acids (PUFA) and antioxidants, thus, their supplementation in ewes’ diets, may be an effective way to develop high nutritional dairy products. Therefore, the present study investigates the effect of the dietary inclusion of Camelina sativa seeds in ewes’ oxidative status and milk quality. Forty-eight dairy Chios ewes were divided into four homogenous groups and were fed individually. The concentrate of the control group (CON) had no inclusion of Camelina seeds, while the treatment groups (CSS6, CSS11, CSS16) were supplemented with 6%, 11%, and 16%, respectively. Including Camelina seeds in 6% and 11%, had no impact on milk performance, while in the CSS16, milk fat was significantly decreased compared to the CON. Supplementing Camelina seeds improved milk quality from a human health perspective by modifying the content of saturated fatty acid, the proportions of α-linolenic (C_{18:3 n-3}), and C_{18:2 cis-9, trans-11} (CLA), and the ω6/ω3 ratio. Furthermore, the activity of catalase (CAT) was significantly increased in the CSS11 and CSS16, and superoxide dismutase (SOD) activity also significantly upsurged in the CSS16. Still, the levels of malondialdehyde (MDA) were significantly increased in the CSS11 compared to the CON and CSS6, and in the CSS16 compared to the CSS6. In CSS16, protein carbonyls were significantly increased. Finally, in the CSS-fed ewes, milk oxidative stability was fortified, as suggested by the modifications in the activities of SOD, CAT, and glutathione peroxidase (GSH-Px), in the antioxidant capacity, and the oxidative stress biomarkers. Consequently, the incorporation of 6% Camelina seeds in the concentrates of ewes improves milk’s fatty acid profile and oxidative status. However, more research is required regarding the possible negative effects of the constant consumption of Camelina seeds by ewes.

Antioxidant Status of Broiler Chickens Fed Diets Supplemented with Vinification By-Products: A Valorization Approach

Vinification by-products display great potential for utilization as feed additives rich in antioxidant compounds. Thus, the effect of dietary ground grape pomace (GGP), wine lees extract rich in yeast cell walls (WYC), and grape stem extracts (PE) on the relative expression of several genes involved in liver oxidative mechanisms and the oxidative status of the blood and breast muscle of broiler chickens was investigated. In total, 240 one-day-old as hatched chicks (Ross 308) were assigned to four treatments, with four replicate pens and 15 birds in each pen. Birds were fed either a basal diet (CON) or a basal diet supplemented with 25 g/kg GGP, or 2 g/kg WYC, or 1 g starch including 100 mg pure stem extract/kg (PE) for 42 days. The polyphenolic content of vinification by-products was determined using an LC-MS/MS library indicating as prevailing compounds procyanidin B1 and B2, gallic acid, caftaric acid, (+)-catechin, quercetin, and trans-resveratrol. Body weight and feed consumption were not significantly affected. The relative transcript level of GPX1 and SOD1 tended to increase in the liver of WYC-fed broilers, while NOX2 tended to decrease in the PE group. SOD activity in blood plasma was significantly increased in WYC and PE compared to the CON group. The total antioxidant capacity measured with FRAP assay showed significantly higher values in the breast muscle of PE-fed broilers, while the malondialdehyde concentration was significantly decreased in both WYC- and PE-fed broilers compared to the CON group. The exploitation of vinification by-products as feed additives appears to be a promising strategy to improve waste valorization and supply animals with bioactive molecules capable of improving animals' oxidative status and products' oxidative stability.

Effects of Inclusion of Schizochytrium spp. and Forage-to-Concentrate Ratios on Goats' Milk Quality and Oxidative Status

Although the dietary inclusion level of polyunsaturated fatty acids (PUFA) and the forage: concentrate (F:C) ratio affect milk quality, their interaction has not been broadly studied. To address such gaps and limitations a two-phase trial using twenty-two dairy goats was carried out. During the first phase, both groups (20 HF n = 11; high forage and 20 HG n = 11; high grain) were supplemented with 20 g Schizochytrium spp./goat/day. The 20 HF group consumed a diet with F:C ratio 60:40 and the 20 HG-diet consisted of F:C = 40:60. In the second phase, the supplementation level of Schizochytrium spp. was increased to 40 g/day/goat while the F:C ratio between the two groups were remained identical (40 HF n = 11; high forage and 40 HG n = 11; high grain). Neither the Schizochytrium spp. supplementation levels (20 vs. 40) nor the F:C ratio (60:40 vs. 40:60) affected milk performance. The high microalgae level (40 g) in combination with high grain diet (40 HG) modified the proportions of docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), and conjugated linoleic acid (CLA) and the ω3/ω6 ratio in milk, to a beneficial manner according to human health recommendation guidelines. However, the highest inclusion level of Schizochytrium spp. (40 g) and foremost in combination with the high grain diets (40 HG) induced an oxidative response as observed by the increased protein carbonyls (CP) and malondialdehyde (MDA) levels in milk and blood plasma indicating severe limitations for a long-term, on-farm application. In conclusion, the supplementation with 20 g Schizochytrium spp. and high forage diet (60:40) appears to be an ideal formula to enrich dairy products with essential biomolecules for human health without adversely affect milk oxidative stability.

Effects of Supplementing Rumen-Protected Methionine and Lysine on Milk Performance and Oxidative Status of Dairy Ewes

There is limited information on the impact of dietary supplementation with separate rumen-protected (RP) amino acids (AA), or with their combination, on ewes' oxidative status. Sixty ewes were divided into five groups; C: basal diet (control); M: basal diet + 6 g/ewe RP methionine; L: basal diet + 5 g/ewe RP lysine; LML: basal diet + 6 g methionine and 5 g lysine/ewe; and HML: basal diet + 12 g methionine + 5 g lysine/ewe. Milk's fat content increased in RP-AA fed ewes, while that of protein in M and L only. In blood plasma, the malondialdehyde (MDA) content was reduced in the M, LML, and HML compared to C-fed ewes. An increase in glutathione transferase activity in the blood plasma of the M and LML compared to the C and HML-fed ewes were found. In milk, lower values of the ferric reducing ability of plasma (FRAP) in the LML and HML-fed ewes and of 2,2'-Azino-bis 3-ethylbenzthiazoline-6-sulfonic acid (ABTS) in LML only, were found. Lysine increased milk's FRAP values and MDA content. Both L and HML diets increased milk's protein carbonyls content. Methionine improves the organism's oxidative status, without adversely affecting milk's oxidative stability. Lysine dietary inclusion affects negatively the oxidative stability of milk.

Sesame Meal, Vitamin E and Selenium Influence Goats' Antioxidant Status

This study aimed to determine the impact of sesame meal, selenium (Se), and vitamin E (VitE) on goats’ oxidative status. Thirty mid-lactation crossbred goats were divided into five homogeneous groups, and were fed 1 kg of alfalfa hay and 1.2 kg of concentrates daily. The control group (C) received a basal diet. In the concentrates of the treated groups, 10% of the soybean meal was replaced by sesame meal and no extra VitE or Se (SM), or an extra 60 mg of VitE (SME), or 0.1 mg organic Se (SMSe), or their combination (60 mg VitE and 0,1 mg organic Se/kg of concentrate (SMESe). In the plasma of the goats, the dietary treatments did not affect glutathione reductase, glutathione peroxidase, glutathione transferase, catalase, superoxide dismutase activities, malondialdehyde (MDA) content, or the total antioxidant capacity. A reduction and a trend for lower protein carbonyls content was found in goats fed SM (p = 0.03) and SME (p = 0.06) compared to SMESe. In the milk, the lactoperoxidase activity decreased with SMSe and SMESe. A numerical decrease in the total antioxidant capacity and an increase in the MDA content in the milk of the SMESe group compared with the other treated groups was found. In mid-lactation goats, SM improves the oxidative status of both the organism and the milk.

Dietary Supplementation of a Live Yeast Product on Dairy Sheep Milk Performance, Oxidative and Immune Status in Peripartum Period

This study evaluated the dietary administration of Saccharomyces cerevisiae live yeast on milk performance and composition, oxidative status of both blood plasma and milk, and gene expression related to the immune system of lactating ewes during the peripartum period. Chios ewes were fed either a basal diet (BD) (Control, n = 51) or the BD supplemented with 2 g of a live yeast product/animal (ActiSaf, n = 53) from 6 weeks prepartum to 6 weeks postpartum. Fatty acid profile, oxidative, and immune status were assessed in eight ewes per treatment at 3 and 6 weeks postpartum. The β-hydroxybutyric acid concentration in blood of ActiSaf fed ewes was significantly lower in both pre- and postpartum periods. A numerical increase was found for the milk yield, fat 6% corrected milk (Fat corrected milk (FCM_6%)), and energy corrected milk yield (ECM) in ActiSaf fed ewes, while daily milk fat production tended to increase. The proportions of C_15:0, C_16:1, C_18:2n6t, and C_18:3n3 fatty acids were increased in milk of ActiSaf fed ewes, while C_18:0 was decreased. Glutathione reductase in blood plasma was increased (p = 0.004) in ActiSaf fed ewes, while total antioxidant capacity measured by 2,2'-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) method was decreased (p < 0.001). Higher ABTS values were found in the milk of the treated group. The relative transcript levels of CCL5, CXCL16, and IL8 were suppressed, while that of IL1B tended to decrease (p = 0.087) in monocytes of ActiSaf fed ewes. In conclusion, the dietary supplementation of ewes with S. cerevisiae, improved the energy utilization and tended to enhance milk performance with simultaneous suppression on mRNA levels of pro-inflammatory genes during the peripartum period.

Oxidative Status of Goats with Different CSN1S1 Genotypes Fed ad Libitum with Fresh and Dry Forages

Forty late-lactation Girgentana goats were used to study the effect of diets fed ad libitum and αS1-casein (CSN1S1) genotype on redox balance. The goats genotyped at CSN1S1 locus (A/A, A/F) were subjected to four feeding treatments different for percentage inclusion of dry and fresh forage: DAF100 (98% of Dry Alfalfa Forage), DAF65 (65% of Dry Alfalfa Forage), FSF100 (100% of Fresh Sulla Forage) and FSF65 (65% of Fresh Sulla Forage). Blood samples were analyzed for superoxide dismutase (SOD) and glutathione peroxidase (GPX) activity, reactive oxygen metabolites (ROMs), biological antioxidant potential (BAP) and non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), albumin, glucose and cholesterol contents. The oxidative stress index (OSI) was calculated as percentage ratio of ROMs to BAP. Redox balance was improved by Sulla inclusion, as reflected in the lower OSI values found in FSF100 and FSF65 groups. DAF100 group displayed the highest GPX activity, while other groups exhibited the highest SOD activity. Fresh forage diets increased albumin concentration while no effect of tested factors was noted on glucose, NEFA, BHBA and cholesterol contents. The interaction diet × genotype was significant only for GPX activity. GPX and albumin were negatively correlated and were correlated positively and negatively with ROMs, respectively. Diet rather than genotype affects redox balance in dairy goats and a possible role of forage polyphenol compounds on oxidative status needs to be tested in future studies.

Effect of milking frequency and α-tocopherol plus selenium supplementation on sheep milk lipid composition and oxidative stability

The aim of this research was to study the effect of milking frequency [once-daily milking (ODM) vs. twice-daily milking (TDM)] and antioxidant (AOX) supplementation on fatty acid (FA) profile and oxidative stability in sheep milk. Sixteen Assaf ewes were used; 8 did not receive any vitamin-mineral supplement (control), and the other 8 received an oral dose of 1,000 IU of α-tocopherol and 0.4 mg of Se daily. The experiment consisted of 2 consecutive periods; the first was 3 wk with TDM of both mammary glands. The second period was 8 wk and consisted of ODM of one mammary gland and TDM of the other gland. All ewes were fed ad libitum the same total mixed ration from lambing and throughout the experiment. There were no differences in plasma or milk Se concentrations between control and AOX ewes. However, plasma and milk α-tocopherol concentrations and AOX capacity were increased in ewes receiving the AOX supplement. Milk FA profile was practically unaffected after 21 d of AOX supplementation. However, after 77 d, AOX supplementation increased the relative percentage of C16:0 and cis-9 C18:1 and reduced the proportions of some saturated FA with less than 16 carbons and cis-9 C12:1. Antioxidant supplementation had no effect on the proportions of conjugated linoleic acid or total polyunsaturated FA (PUFA) but decreased the proportion of trans-7,cis-9 C18:2 and increased that of n-6 C20:3. Once-daily milking did not affect α-tocopherol, Se, or fat resistance to oxidation in milk. Total monounsaturated FA, cis-9 C16:1, and several cis and trans isomers of C18:1 were increased and total saturated FA were decreased in milk from ODM glands. Compared with TDM, ODM increased the proportions of cis-9,cis-12 C18:2 and several isomers of C18:2 and reduced those of cis-9,cis-12,cis-15 C18:3 and some PUFA of 20 and 22 carbons, but total proportion of PUFA was unaffected. Once-daily milking and AOX supplementation modified milk FA profile, but the effects of ODM could be considered of little biological relevance for consumer health. Supplementing ewes with α-tocopherol plus Se could be considered an effective strategy to improve plasma AOX status and reduce milk fat oxidation without substantial changes in the milk FA profile.