The Protective Role of Vitamin E against Oxidative Stress and Immunosuppression Induced by Non-Esterified Fatty Acids in Bovine Peripheral Blood Leukocytes

High levels of non-esterified fatty acids (NEFAs) during the transition period lead to increased oxidative stress and immunosuppression in cows. Feeding them a vitamin-E-supplemented diet reduces reactive oxygen species (ROS) levels in the blood and diminishes immunosuppression in the transition period. However, whether the restoration of immune cell function occurs through the direct action of vitamin E in cells is still a topic that requires further discussion. Therefore, in this experiment, we aimed to investigate the effect of NEFAs on peripheral blood leukocytes (PBLs) and whether vitamin E mitigates the impact of NEFAs. We employed three groups: (1) blank, (2) NEFA only, and (3) pre-culturing with vitamin E before NEFA treatment (VENEFA). In peripheral blood mononuclear cells (PBMCs), there were no differences in vitamin E content among the three groups. However, in the vitamin E pre-treatment group, the vitamin E levels of polymorphonuclear neutrophils (PMNs) were significantly higher than those in the other two groups. NEFA levels increased malondialdehyde (MDA) levels in PBMCs, but pre-treatment with vitamin E reduced accumulation of MDA levels. Regarding the expression of proinflammatory genes, NEFAs increased the expression of interleukin-1β in PBMCs and colony-stimulating factor 2 in PMNs. Vitamin E pre-treatment restored the increase in interleukin-1β levels caused by NEFAs in PBMCs. None of the groups affected the phagocytosis of PMNs. Few studies have confirmed that NEFAs cause oxidative stress in bovine PBLs. In summary, this study found that NEFAs induce oxidative stress in PBLs and alter the expression of inflammation-related genes; meanwhile, vitamin E can reduce some of the effects caused by NEFAs. This result may suggest that vitamin E can assist bovine PBLs in resisting the immune suppression caused by an NEB during the transition period.

Blood thyroid hormones, insulin and leptin, metabolites and enzymes in transition dairy ewes, as affected by dietary linseed and physiological stage

This study investigated the effects of dietary linseed and physiological state on blood concentrations of some metabolic hormones and indicators, in transition dairy ewes. From 21 d before lambing to 60 d post-partum, ewes were provided with one of three isoenergetic and iso‑nitrogenous pelleted concentrates, without (CTR, n = 21), or with 100 (EL-10, n = 22) or 200 g/kg (EL-20, n = 22) of extruded linseed. Animals were fed alfalfa hay ad libitum and had access to mixed pasture. Plasma thyroid hormones and insulin concentrations were not affected by diet and significantly changed by time. The last week of pregnancy T3 (2.27 ± 0.15 ng/mL) and T4 (102.63 ± 2.85 ng/mL) were lower than at 4 weeks before lambing (T3: 3.27 ± 0.27 ng/mL; T4: 125.89 ± 2.63 ng/mL). After lambing, T3 rose to be highest at 4 and 8 weeks of lactation (3.41 ± 0.22). Mean insulin peaked 2 weeks after lambing (0.31 ± 0.02 ng/mL) vs. late pregnancy (0.22 ± 0.01 ng/mL) and progressing lactation (0.18 ± 0.01 ng/mL). Plasma Leptin concentration (2.43 ± 0.03 ng/mL) was not affected by diet nor time. All the blood metabolites and enzymes investigated showed significant time x treatment interaction. Differences of several haematological parameters were found in EL vs. CTR (cholesterol, triglycerides, total protein, bilirubin, ALP, ALT), however, in most cases the values were fairly within the reference physiological ranges. Metabolic hormones are confirmed to be mainly linked to the different physiological states, energy intake and variations of energy balance, without clear effects by different sources of energy and quality of dietary lipids.

Glucose metabolism and the somatotropic axis in dairy cows after abomasal infusion of essential fatty acids together with conjugated linoleic acid during late gestation and early lactation

Sufficient glucose availability is crucial for exploiting the genetic potential of milk production during early lactation, and endocrine changes are mainly related to repartitioning of nutrient supplies toward the mammary gland. Long-chain fatty acids, such as essential fatty acids (EFA) and conjugated linoleic acid (CLA), have the potential to improve negative energy balance and modify endocrine changes. In the present study, the hypothesis that combined CLA and EFA treatment supports glucose metabolism around the time of calving and stimulates insulin action and the somatotropic axis in cows in an additive manner was tested. Rumen-cannulated German Holstein cows (n = 40) were investigated from wk 9 antepartum (AP) until wk 9 postpartum (PP). The cows were abomasally supplemented with coconut oil (CTRL, 76 g/d); 78 g/d of linseed and 4 g/d of safflower oil (EFA); Lutalin (CLA, isomers cis-9,trans-11 and trans-10,cis-12 CLA, each 10 g/d); or the combination of EFA+CLA. Blood samples were collected several times AP and PP to determine the concentrations of plasma metabolites and hormones related to glucose metabolism and the somatotropic axis. Liver tissue samples were collected several days AP and PP to measure glycogen concentration and the mRNA abundance of genes related to gluconeogenesis and the somatotropic axis. On d 28 AP and 21 PP, endogenous glucose production (eGP) and glucose oxidation (GOx) were measured via tracer technique. The concentration of plasma glucose was higher in CLA than in non-CLA-treated cows, and the plasma β-hydroxybutyrate concentration was higher in EFA than in non-EFA cows on d 21 PP. The eGP increased from AP to PP with elevated eGP in EFA and decreased eGP in CLA-treated cows; GOx was lower in CLA than in CTRL on d 21 PP. The plasma insulin concentration decreased after calving in all groups and was higher in CLA than in non-CLA cows at several time points. Plasma glucagon and cortisol concentrations on d 21 PP were lower in CLA than non-CLA groups. The glucagon/insulin and glucose/insulin ratios were higher in CTRL than in CLA group during the transition period. Plasma IGF-I concentration was lower in EFA than non-EFA cows on d 42 AP and was higher during the dry period and early lactation in CLA than in non-CLA cows. The IGF binding protein (IGFBP)-3/-2 ratio in blood plasma was higher in CLA than in non-CLA cows. Hepatic glycogen concentration on d 28 PP was higher, but the mRNA abundance of PC and IGFBP2 was lower in CLA than non-CLA cows on d 1 PP. The EFA treatment decreased the mRNA abundance of IGFBP3 AP and PCK1, PCK2, G6PC, PCCA, HMGCS2, IGFBP2, and INSR at several time points PP. Results indicated elevated concentrations of plasma glucose and insulin along with the stimulation of the somatotropic axis in cows treated with CLA, whereas EFA treatment stimulated eGP but not mRNA abundance related to eGP PP. The systemic effects of the combined EFA+CLA treatment were very similar to those of CLA treatment, but the effects on hepatic gene expression partially corresponded to those of EFA treatment.

Effects of dietary conjugated linoleic acid on metabolic status, BW and expression of genes related to lipid metabolism in adipose tissue of dairy cows during peripartum

Conjugated linoleic acid (CLA) dietary supplementation reduces milk fat content and yield, but its effects on lipid metabolism and energy status remain controversial. The objective of this study was to investigate the effects of dietary CLA on adipose tissue (AT) mRNA abundance of genes related to lipid metabolism, plasma indicators of metabolic status, body condition score (BCS) and BW changes in dairy cows. Sixteen multiparous Holstein cows (3.2 ± 1.4 lactations, 615 ± 15 kg BW) were randomly assigned to treatments: 1) CLA; rumen-protected CLA (75 g/d) or 2) Control; equivalent amount of rumen inert fatty acid (FA) as the previous diet (78 g/d), from -20.2 ± 3.2 (mean ± SEM) to 21d relative to calving (d 0). Subcutaneous AT was biopsied from the tail-head region at d 21 to determine the mRNA abundance of genes related to lipid metabolism. Blood samples were collected at -20.2 ± 3.2, 0, 7, 14 and 21d relative to calving to determine plasma non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), insulin and glucose. Conjugated linoleic acid decreased milk fat yield and milk fat content by 15 and 16%, respectively. Cows fed CLA had lower plasma NEFA and BHBA and greater glucose and insulin concentrations (P < 0.05). Mean BCS at 21d postpartum was greater (P < 0.01; 2.89 vs 2.25), and BCS loss from the day of enrollment to 21d postpartum was reduced (P < 0.01; -0.13 vs -0.64) in the CLA group. The expression of acylcoenzyme A oxidase, carnitine palmitoyltransferase 1A, hormone-sensitive lipase, β2 adrenergic receptor and acetyl-CoA carboxylase was downregulated by CLA supplementation, whereas the expression of sterol regulatory element binding protein, lipoprotein lipase and peroxisome proliferator-activated receptor gamma was upregulated (P < 0.01). In summary, CLA-supplemented cows showed signs of better metabolic status and less severe fat mobilization. Moreover, CLA increased mRNA abundance of genes related to lipogenesis and decreased mRNA abundance of genes related to FA oxidation and lipolysis in the AT of dairy cows during early lactation.

Relationship between body condition score loss and mRNA of genes related to fatty acid metabolism and the endocannabinoid system in adipose tissue of periparturient cows

The endocannabinoid system (ECS) controls feed intake and energy balance in nonruminants. Recent studies suggested that dietary management alters the expression of members of the ECS in the liver and endometrium of dairy cows. The aim of this study was to determine the relationship between body condition score (BCS) loss and the mRNA abundance of genes related to fatty acid metabolism and the ECS in the subcutaneous adipose tissue (AT) of dairy cows. The BCS was determined in multiparous (3.2 ± 0.5 lactations) Holstein cows at -21 and 42 days relative to calving (designated as d = 0). Cows were grouped into three categories according to BCS loss between both assessments as follows: (1) lost ≤0.25 unit (n = 8, low BCS loss (LBL)), (2) lost between 0.5 and 0.75 units (n = 8, moderate BCS loss (MBL)) and (3) lost ≥1 unit (n = 8, high BCS loss (HBL)). Concentrations of haptoglobin and non-esterified fatty acids (NEFAs) were determined in plasma. Real-time PCR was used to determine mRNA abundance of key genes related to fatty acid metabolism, inflammation and ECS in AT. Milk yield (kg/day) between week 2 and 6 post-calving was greater in the LBL group (49.4 ± 0.75) compared to MBL (47.9 ± 0.56) and HBL (47.4 ± 0.62) groups (P < 0.05). The overall mean plasma haptoglobin and NEFA concentrations were greater in MBL and HBL groups compared with the LBL group (P < 0.05). The mRNA abundance of TNF-α, Interleukin-6 (IL-6) and IL-1β was greatest at 21 and 42 days post-calving in HBL, intermediate in MBL and lowest in LBL groups, respectively. Cows in the HBL group had the greatest AT gene expression for carnitine palmitoyltransferase 1A, hormone sensitive lipase and adipose triglyceride lipase at 21 and 42 days post-calving (P < 0.05). Overall, mRNA abundance for very long chain acyl-CoA dehydrogenase and peroxisome proliferator-activated receptor gamma, which are related to NEFA oxidation, were greater in MBL and HBL groups compared to the LBL group at 42 days post-calving. However, mRNA abundance of fatty acid amide hydrolase was lower at 21 and 42 days post-calving in HBL cows than in LBL cows (P < 0.05). In summary, results showed a positive association between increased degree of BCS loss, inflammation and activation of the ECS network in AT of dairy cows. Findings suggest that the ECS might play an important role in fatty acid metabolism, development of inflammation and cow's adaptation to onset of lactation.

Nutrigenomics in livestock-recent advances

The study of the effects of nutrients on genome functioning, in terms of gene transcription, protein levels, and epigenetic mechanisms, is referred to as nutrigenomics. Nutrigenomic studies in farm animals, as distinct from rodents, are limited by the high cost of keeping livestock, their long generational distance, and ethical aspects. Yet farm animals, and particularly pigs, can serve as valuable animal models for human gastrological diseases, since they possess similar size, physiology, and nutritional habits and can develop similar pathological states. In livestock, the effects of dietary modifications have mostly been studied with reference to effective breeding and their influence on production traits and animal health. The majority of such studies have looked at the impact of various sources and quantities of fat and protein, supplementation with microelements, and plant-derived additives. The period of life of the animal—whether prenatal, neonatal, or mature—is typically considered when a modified diet is used. This review presents a summary of recent nutrigenomic studies in livestock.

Antioxidant levels, copper and zinc concentrations were associated with postpartum luteal activity, pregnancy loss and pregnancy status in Holstein dairy cows

The role of oxidative stress in the control of female reproduction has not been fully elucidated in ruminants; however, it seems that antioxidants can make influence to the reproductive axis at different levels. Therefore, the aim of this study was to determine the relationship between antioxidant status and concentrations of trace minerals (chromium (Cr), copper (Cu), iron (Fe), and zinc (Zn)) with postpartum luteal activity and fertility in Holstein dairy cows. The cows (n = 100, a parity range of 2-5, and a body condition score (BCS) of 3.0 ± 0.25, mean ± SEM) were assigned to the experiment at second week post calving. Ovarian follicular dynamics were monitored twice a week (from 3rd to 6th weeks post calving) by transrectal ultrasonography (US). Blood samples were collected twice weekly from the 3rd to the 6th weeks post calving at timed artificial insemination (TAI), and days 32 and 50 post AI to determine superoxide dismutase (SOD), glutathione peroxidase (GPX), total antioxidant capacity (TAC), and trace mineral concentrations. There were associations between plasma concentrations of SOD, GPX, and TAC with postpartum luteal activity (PLA, P = 0.01) and ovulation (P = 0.03). Mean plasma SOD and GPX activities and TAC levels (U/mL) were greater in cows with normal luteal activity (NLA) than prolonged luteal phase (PLP) and anovulation (AO) cows, as well as in ovulated compared to AO cows (P = 0.03). Pregnant cows had greater levels of SOD, GPX, and TAC (U/mL) at TAI than non-pregnant cows (P = 0.01). Plasma Cu and Zn concentrations increased in pregnant compared to non-pregnant cows at TAI. In conclusion, antioxidant levels and Cu and Zn concentrations were associated with PLA and fertility.

Increasing metabolisable energy and protein supplementation to stimulate the subsequent milk production during late gestation by increasing proliferation and reducing apoptosis in goat mammary gland prepartum

In total, 32 pregnant goats were assigned randomly to four diets fed from Day 100 of pregnancy to Day 30 after parturition, to determine the effects of metabolisable energy (ME) and metabolisable protein (MP) supplementation levels on feed intake, subsequent colostrum and milk production and expression of genes regulating mammary-cell proliferation and apoptosis. Diets were as follows: (1) diet with ME and MP provided according to NRC recommendations (control), (2) diet with extra 10% ME, (3) diet with extra 10% MP, and (4) diet 1 with 10% extra of both ME and MP. Mammary biopsies were obtained from each udder half 24 h after parturition. Feed intake (g/day), and colostrum (kg/day) and milk (kg/month) production increased when the extra ME and MP were provided together prepartum and in early lactation (P &lt; 0.05). Relative mRNA expressions significantly increased in the mammary gland of insulin-like growth factor 1 (IGF-1, 4.3-fold), IGF-1 receptor (IGF-1R, 3.6-fold) and B-cell lymphoma 2 (Bcl-2, 4.6-fold), whereas insulin-like growth factor binding protein 3 (IGFBP-3, 3.2-fold), Bcl-2-associated X protein (Bax, 16.7-fold) and the ratio of Bax:Bcl-2 expressions significantly decreased (69.8-fold) with increased ME and MP levels fed in late gestation. In conclusion, colostrum production and milk yield in the early lactation period are sensitive to nutrient supply during gestation, where increased dietary ME as well as MP supplementation levels during late gestation will favour mammary development, by increasing expression of genes stimulating cellular proliferation (IGF-1, IGF-1R, Bcl-2) and reduced those stimulating apoptosis (IGFBP-3, Bax).

Effect of Dietary Fish Oil on Mammary Gland Development and Milk Production of Holstein Cow

The aim of this study was to evaluate the effect of feeding oil supplement on mammary gland development and milk production responses in Holstein cows. Ten multiparous Holstein cows (42.2±9.2 d before calving, 3.25±0.25 body condition score, and 620±35 kg body weight) were randomly assigned to treatments. Treatments were a diet with oil added as palm oil (PO; n=5), or fish oil (FO; n=5) given to cows until 63 d in milk. Milk yield was recorded daily, milk composition (fat, protein, lactose, total solid and somatic cell count) was measured weekly and fatty acid profiles of milk fat were determined at first and last week of the experiment. Samples of mammary tissue were obtained at 7 and 63 d in milk by biopsy gun. Tissue slides were analyzed by Image J software. Results showed that fish oil supplemented diet compared to the palm oil supplemented diet increased milk production after 6 weeks of lactation (P<0.05), content of polyunsaturated fatty acids milk fat (P<0.05) and docosahexaenoic acid (P<0.01). Moreover, n-6:n-3 ratio was decreased by fish oil supplement (P<0.05). Histological studies showed that FO increased the relative percentage of tissue area occupied by epithelial cells as well as a number of total alveoli in each microscopic field (P<0.05). Data suggested that feeding fish oil during the dry period and early lactation could improve development and function of the mammary gland in the dairy cow.

Effects of feeding a source of omega-3 fatty acid during the early postpartum period on the endocannabinoid system in the bovine endometrium

A total of sixteen Holstein dairy cows (35 ± 1.1 kg/d of milk yield) were randomly assigned to consider the effects of feeding omega-3 sources on endometrial endocannabinoids system (ECS) genes expression to understand the effect mechanism of omega-3 on reproductive performances during the early postpartum period to evaluate to what extent can be intervened in reproduction, e.g. via nutrition to improve fertility. Experimental diets were 1) either protected palm oil (control) or 2) extruded linseed (linseed). Cows (n = 16) were fed from calving date to 70 days in milk (DIM). There was no difference between groups (mean ± S.E.M.) in parity (3.0 ± 1.00) or body condition score (BCS) at calving day (3.1 ± 0.25). At 30 DIM, the ovulatory cycles of cows were synchronized using two injections of prostaglandin F2α (PGF2α) with a 14-day interval. On day 15 of synchronized estrous cycle (d0 = ovulation) uterine endometrial biopsies were collected to evaluate the expression of genes related to ECS (endocannabinoid receptor (CNR2), N-acyl phosphatidylethanolamine phospholipase D (NAPEPLD), fatty acid amide hydrolase (FAAH), N-acylethanolamine acid amidase (NAAA), monoglyceride lipase (MGLL)) and PGF2α. Results showed that dry matter intake and milk yield were not affected by diets. Uterine endometrial NAAA (7.69 fold), and MGLL (1.96 fold) genes expression were greater (P < 0.05) in cows fed linseed compared with control ones. The messenger RNA (mRNA) levels of CNR-2 (4.26 fold), and NAPEPLD (20.0 fold) were decreased (P < 0.05) in animals fed linseed compared to control cows. The expression of mRNA for the FAAH was not influenced by the diets. First service conception rate was greater in cows fed linseed compared to control cows (75 vs. 25%). Pregnancy loss within 32-60 day after artificial insemination (AI) was lower in cows fed linseed compared to control cows (0 vs. 100%). In conclusion these data demonstrated that positive effect of omega-3 on reproduction may act through a mechanism involving the ECS. However, more studies to be undertaken to confirm these results.

Dietary supplement of conjugated linoleic acids or polyunsaturated fatty acids suppressed the mobilization of body fat reserves in dairy cows at early lactation through different pathways

To investigate the metabolic changes in the adipose tissue (AT) of dairy cows under milk fat depression (MFD), 30 cows were randomly allocated to a control diet, a conjugated linoleic acid (CLA)-supplemented diet, or a high-starch diet supplemented with a mixture of sunflower and fish oil (2:1; as HSO diet) from 1 to 112 d in milk. Performance of animals, milk yield, milk composition, energy balance, and blood metabolites were measured during lactation. Quantitative PCR analyses were conducted on the AT samples collected at wk 3 and 15 of lactation. The CLA and HSO diets considerably depressed milk fat yield and milk fat content at both wk 3 and 15 in the absence of significant changes in milk protein and lactose contents. In addition, the HSO diet lowered milk yield at wk 15 and decreased dry matter intake of cows from wk 3 to 15. Compared with the control, both CLA and HSO groups showed reduced body weight loss, improved energy balance, and decreased plasma concentrations of nonesterified fatty acids and β-hydroxybutyrate at early lactation. The gene expression analyses reflected suppressed lipolysis in AT of the CLA and HSO groups compared with the control at wk 3, as suggested by the downregulation of hormone-sensitive lipase and fatty acid binding protein 4 and the upregulation of perilipin 2. In addition, the HSO diet promoted lipogenesis in AT at wk 15 through the upregulation of 1-acylglycerol-3-phosphate O-acyltransferase 2, mitochondrial glycerol-3-phosphate acyltransferase, perilipin 2, and peroxisome proliferator-activated receptor γ. The CLA diet likely regulated insulin sensitivity in AT as it upregulated the transcription of various genes involved in insulin signaling, inflammatory responses, and ceramide metabolism, including protein kinase B2, nuclear factor κ B1, toll-like receptor 4, caveolin 1, serine palmitoyltransferase long chain base subunit 1, and N-acylsphingosine amidohydrolase 1. In contrast, the HSO diet resulted in little or no change in the pathways relevant to insulin sensitivity. In conclusion, the CLA and HSO diets induced a shift in energy partitioning toward AT instead of mammary gland during lactation through the regulation of different pathways.

Supplemental flaxseed modulates ovarian functions of weanling gilts via the action of selected fatty acids

The aim of this study was to examine the influence of dietary flaxseed on the endocrine and ovarian functions of weanling gilts challenged with E. coli and Coronavirus infections treated with dietary probiotic cheeses and to understand the possible mechanisms of its effects on ovarian function. Probiotics were used as a natural substitution for antibiotics and 10% dietary flaxseed is an effective prebiotic which supports the action of probiotics and has other beneficial effects on the organism. Probiotics with or without flaxseed were fed to weanling gilts starting 10 days before and lasting up until 14 days after weaning. The ovaries were measured and histologically analysed. The blood samples for the levels of steroid hormones and insulin-like growth factor I (IGF-I) were assessed using immunoassays and the levels of fatty acids were assessed using gas chromatography. All samples were collected on the day of weaning and 14 days after weaning. On the day of weaning, increased levels of linoleic acid and IGF-I was associated with higher body weight. The steroid hormones were not affected by the diet. The conversion of alpha-linolenic acid (ALA) to timodonic (EPA) and cervonic (DHA) acids were lower compared to controls, and together with high levels of myristic, palmitic and palmitoleic acids was associated with the higher proliferation and lower apoptosis in the primordial, primary and secondary follicles; although the inhibition of the cell cycle was observed in relation to the low level of eicosadienoic acid. The high levels of ALA, EPA and DHA and the low levels of myristic, palmitic and palmitoleic acids may have been the effect of flaxseed feeding 14 days post-weaning and may have had a reverse effect on the proliferation and apoptosis of ovarian follicles. These data suggest that flaxseed may suppress the follicle development in weanlings via the stimulation of apoptosis and the inhibition of proliferation via the modulation of the metabolism of selected fatty acids.

Effect of omega-3 and omega-6 polyunsaturated fatty acid enriched diet on plasma IGF-1 and testosterone concentration, puberty and semen quality in male buffalo

The objective of the present study was to evaluate the effect of omega-3 and omega-6 PUFA enriched diet on plasma IGF-1 and testosterone concentrations, puberty, sperm fatty acid profile and semen quality in male buffalo. Eighteen male buffalo calves were distributed randomly in three different groups and fed concentrate mixture along with green fodder and wheat straw in 50:40:10 ratios as per requirements. Basis ration of animals in group I was supplemented with 4% of prilled fat (PFA), while in group II and group III were added 4.67% of Calcium salt from Soybean (CaSFA) and Linseed oil (CaLFA), respectively. Male buffalo fed omega-3 PUFA high diet significantly increased concentrations of IGF-1 and testosterone in plasma as compared to two other diets (p<0.05). The age of puberty and scrotal circumference significantly increased by dietary fat effect (p<0.05) of which n-3 PUFA enriched diet (CaLFA) had the largest influence as compared to other diets (PFA and CaSFA). Feeding of n-3 PUFA rich diet significantly increased the DHA (C22:6n-3) content in sperm (p<0.05), which contributed to increased fluidity of plasma membrane, elevated quality of sperm (motility, viability) and in vitro fertility (plasma membrane integrity, acrosome integrity) in both fresh and post-thawing semen. These findings indicate that feeding of n-3 PUFA enriched diet increased IGF-1 and testosterone secretion, reduced pubertal age and improved both fresh and post-thawing semen quality in male buffalo.