Immune Function Of Dairy Cows Research Articles

Effect of different dietary regimens at dry-off on performance, metabolism, and immune system in dairy cows

Concentrate withdrawal and feed restriction are commonly used to reduce milk production and to facilitate dry-off, but may impair immune function in dairy cows. We investigated the effect of feed rations providing different amounts of nutrients in combination with feed restriction on performance, endocrine, and metabolic responses, as well as on leukocyte function before and after abrupt dry-off. Forty-three cows were studied from d 12 before until d 6 after dry-off (56 d before scheduled calving). Cows were fed experimental concentrates rich in crude protein (nitrogenic, n = 14), glucogenic precursors (glucogenic, n = 14), or lipids (lipogenic, n = 15). On d 3 before dry-off, total feed allowance was restricted to 50% in half of the animals of each dietary group, whereas feed allowance remained unchanged in the other animals. Performance parameters (milk yield, milk composition, and dry matter intake) were recorded, and daily blood and milk samples were taken and analyzed for various metabolic and endocrine parameters. Additionally, activity and mRNA abundance of several genes in leukocytes were measured at selected time points before and after feed restriction and dry-off, respectively. Feed restriction immediately resulted in a negative energy balance and decreased milk production. Concomitantly, concentrations of nonesterified fatty acids increased, whereas insulin, insulin-like growth factor-1, and glucagon decreased. After dry-off, energy balance turned positive and plasma nonesterified fatty acids decreased. Plasma glucose, insulin, and insulin-like growth factor-1 concentrations increased in all groups after dry-off. Glucose, insulin, and glucagon concentrations in plasma were higher in nonrestricted compared with restricted animals after dry-off. The experimental concentrate types marginally affected the investigated metabolic and endocrine factors, with the exception of elevated milk and plasma urea concentrations in cows fed the nitrogenic concentrate. Chemotactic and phagocytic activity of leukocytes were not affected by diets, feed restriction, or dry-off. Likewise, blood leukocyte mRNA abundance encoding for tumor necrosis factor α (TNF), heat shock protein family A (HSP70), and the glucose transporters (GLUT) 1 and 3 remained unchanged throughout the study period. Overall, the short-term negative energy balance induced by feed restriction was temporarily accompanied by metabolic adaptations, but did not alter the studied factors related to the immune system. Metabolic and endocrine adaptations supporting milk synthesis were continued during the first days after dry-off despite cessation of milking. Thus, the abrupt dry-off resulted in a short-term increase of glucose and triglyceride concentrations, with a delayed endocrine response to re-establish nutrient homeostasis in blood.

Vitamin D in dairy cows: metabolism, status and functions in the immune system

ABSTRACT The function of vitamin D in calcium homoeostasis in dairy cows, such as in other vertebrates, is known for many years. In recent years, new and interesting, non-classical functions of vitamin D have been elucidated, including effects on the immune system. The major aim of this review is to provide an overview of effects of vitamin D or its metabolites on the immune system in dairy cows. The first part of the review provides an overview of vitamin D metabolism, with particular reference to the role of various proteins (25- and 1-hydroxylases, vitamin D binding protein, vitamin D receptor) in vitamin D signalling. The second part deals with the role of the concentration of 25-hydroxyvitamin D [25(OH)D] in plasma as an indicator of the vitamin D status in dairy cows, and its dependence on sunlight exposure and dietary vitamin D supplementation. In this part also the “free hormone hypothesis” is discussed, indicating that the concentration of free 25(OH)D might be a more valid indicator of the vitamin D status than the concentration of total 25(OH)D. The third part deals with classical and the non-classical functions of vitamin D. Among the non-classical functions which are based on an autocrine vitamin D signalling, particular reference is given to the effects of vitamin D and vitamin D metabolites on the immune system in bovine immune cells and in dairy cows. Recent findings provide some indication that vitamin D or its metabolite 25(OH)D could enhance the immune function in dairy cows and be useful for the prevention and therapy of mastitis. However, the number of studies reported so far in this respect is very limited. Thus, much more research is required to yield clear concepts for an optimised usage of vitamin D to improve the immune system and prevent infectious diseases in dairy cows.

Effect of Copper, Zinc, and Selenium on the Migration of Bovine Neutrophils.

Neutrophils represent the first line of mammary gland defense against invading pathogens by transmigration across the mammary epithelial cell barrier. The effect of trace elements on the migration of bovine neutrophils is not clear. In this study, we investigated the effect of copper (Cu; 0.5, 1.0 and 1.5 mg/L), zinc (Zn; 1.0, 5.0 and 10 mg/L) and selenium (Se; 0.1, 1.0 and 2.0 mg/L) on the migration of bovine neutrophils by using a Transwell assay. The results showed that Cu, Zn and Se promoted the number of neutrophils in the trans-mammary epithelium. With the increased concentration of Cu at 1.5 mg/L, the number of neutrophils in the trans-mammary epithelium was increased significantly (p < 0.05). Zn (5.0 mg/L) and Se (0.1 mg/L) increased the migrated number of neutrophils (p < 0.01) to an extremely significant degree. These findings provided a theoretical and experimental basis for mammary gland immunity in dairy cows. Thus, we suggest that adding moderate amounts of different trace elements can improve the immune function of dairy cows.

Effect of Different Combinations of Dietary Vitamin A, Protein Levels, and Monensin on Inflammatory Markers and Metabolites, Retinol-Binding Protein, and Retinoid Status in Periparturient Dairy Cows.

Simple SummaryThe transition period is a challenging time, which combines a massive increase in nutrient requirements and leads to a negative energy balance. Therefore, disorders related to negative energy balance, such as ketosis, are more frequent. In addition, in this period, oxidative stress increases, favoring immune suppression functions and inflammation, which may lead to increased susceptibility to other diseases such as metritis and mastitis. Therefore, the combination of ionophores, such as monensin, that mitigate the accentuated negative energy balance; vitamin A, which plays an important role in supporting the immune system; and a high level of crude protein might improve immune parameters in dairy cows in the transition period. This study demonstrated that monensin and vitamin A supplementation and high crude protein levels enhanced some vitamin status and inflammatory markers when used during the late prepartum period.The objective of this study was to determine the effect of feeding different combinations of dietary vitamin A supplementation (0 or 110 IU/kg body weight), protein (10.3% or 12.2%), and an ionophore (monensin at 0 or 400 mg/day) on retinoid metabolism and immune function of dairy cows. Eighty multiparous Holstein dairy cows were studied from d −35 to +21 relative to expected parturition in a complete randomized block design with a 2 × 2 × 2 factorial arrangement of treatments. The significance of treatments was declared at p ≤ 0.05. Dairy cows receiving high crude protein (CP) diets with monensin had a greater retinol-binding protein serum concentration than cows receiving high CP diets without monensin (p = 0.04). Animals supplemented with vitamin A showed lower SCC (p = 0.04) and a higher thiobarbituric acid reactive substances concentration (p = 0.06) than cows non-supplemented. Moreover, cows receiving low crude protein diets had a greater haptoglobin concentration (p = 0.01). In addition, cows fed a high crude protein diet had a greater TNF-α expression in peripheral blood mononuclear cells (p = 0.04). Animals fed diets without monensin had a greater serum haptoglobin on day 3 postpartum than those fed monensin (p = 0.01). Moreover, dietary vitamin A increased serum 13-cis retinoic acid postpartum. We conclude that vitamin A, crude protein levels, and monensin fed during the close-up period affect milk somatic cell count, some vitamin statuses, and inflammatory markers during early lactation.

Effects of dietary 25-hydroxyvitamin D3 on the lactation performance, blood metabolites, antioxidant and immune function in dairy cows

The objective of this study was to evaluate the effects of 25-hydroxyvitamin D3 on the lactation performance, blood metabolites, and antioxidant and immune function in dairy cows. Thirty-six mid-lactation Holstein dairy cows were blocked according to day in milk, milk yield and somatic cell counts (SCC) and were randomly assigned to 3 treatments. Treatments were a basal diet plus 0 mg, 1 mg or 3 mg 25-hydroxyvitamin D3 per cow per day throughout a 9-week trial period. Cows were milked three times daily, and dry matter intake and milk yield were measured daily. Milk components were sampled at days 0, 21, 42 and 63 for milk fat, protein, lactose and SCC analysis. Blood was sampled for blood metabolites, parameters of antioxidant and immune function at days 0, 21, 42 and 63. Dairy cows fed 25-hydroxyvitamin D3 showed linear increases (P < 0.05) in milk yield, energy-corrected milk, milk protein and lactose yield and a decrease in somatic cell counts in milk (P < 0.01). Feeding dietary 25-hydroxyvitamin D3 linearly increased serum total Ca, P, 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 and had no negative effect on blood biochemical parameters and markers of fat mobilization. Additionally, dietary 25-hydroxyvitamin D3 linearly increased (P < 0.05) total antioxidant capacity, total superoxide dismutase, glutathione peroxidase, immunoglobulin A and immunoglobulin G and linearly decreased (P < 0.05) malondialdehyde and tumor necrosis factor-α. In summary, dietary supplementation with 25-hydroxyvitamin D3 increased milk yield and decreased SCC, improved serum minerals, 25-hydroxyvitamin D3 levels, and antioxidant and immune function of dairy cows.

Comparison of the effectiveness of selenium and vitamin E supplementation on the health of the mammary gland of sheep

Article Details: Received: 2020-10-14 | Accepted: 2020-11-27 | Available online: 2021-01-31 https://doi.org/10.15414/afz.2021.24.mi-prap.75-79 In this study we observed the effect of peroral and parenteral supplementation of Selenium (Se) and vitamin E (VTE) on the selected antioxidant parameters in blood and on the incidence of mastitis in ewes after the first lambing. Of the 350 sheep of Improved Walachian and Lacaune breeds, situated in eastern Slovakia under standard zootechnical and animal hygiene conditions, we selected thirty one-year-old ewes before their first lambing. The ewes were divided into three groups according to the method of supplementation of Se and VTE. The blood samples from vena jugularis were collected on day 30 before lambing (control sampling) and on days 3 and 30 after lambing. Ewes were checked for mastitis on days 10 and 30 after lambing. On the day of the control sampling the ewes from the B1 group were perorally supplemented with 0.3 mg Se/kg/DM in the form of Na2SeO3 and 50 IU/vitamin E/kg/DM, while ewes from the B2 group were injected subcutaneously Se with VTE at a dose of 6.6 mg/Se and 1,000 IU/VTE. Changes in the concentration of Se and VTE in the blood plasma of ewes were determined only in the perorally supplemented group (B1) on day 3 after lambing. At 30 days after lambing the the incidence of mastitis in this group was half as lower (10%) as in the control group (20%). Keywords: sheep, mastitis, supplementation, glutathione peroxidase, selenium, bacteria References Cohen, RD a kol. (1991). Účinky parenterálnej suplementácie tehotných hovädzích kráv selénom / vitamínom E na selén kravy a teľaťa a produktivitu. Konzerva. Vet. Jour . 32,113-115. https://www.ncbi.nlm.nih.gov/pubmed/17423734 Grešáková, L. a kol. (2013). Retencia selénu u jahniat kŕmených krmivom doplneným selénom z anorganických zdrojov. Výskum malých prežúvavcov , 111, 76–82. https://doi.org/10.1016/j.smallrumres.2012.10.009 Fthenakis, GC (1995). Kalifornský test na mastitídu a Whitesideov test na diagnostiku subklinickej mastitídy mliečnych bahníc. Výskum malých prežúvavcov, 16, 271–276. https://www.sciencedirect.com/science/article/pii/0921448895006382 Hess, D. et al. (1991). Simultaneous determination of retinol, tocopherols, carotenes and lycopene in plasma by means of high-performance liquid chromatography on reversed phase. International Journal of Vitamin and Nutrition Research , 61, 232–238. https://pubmed.ncbi.nlm.nih.gov/1794952/ Kafilzadeh, F. et al. (2014). Comparing the effect of oral supplementation of vitamin E, injective vitamin E and selenium or both during late pregnancy on production and reproductive performance and immune function of dairy cows and calves. The Scientific World Journal , 5. http://dx.doi.org/10.1155/2014/165841 Misurova, L. et al. (2009). Selenium metabolism in goats – maternal transfer of selenium to newborn kids. Veterinarni Medicina 54, 125–130. https://www.agriculturejournals.cz/publicFiles/05520.pdf Paglia, D. E, Valentine, W. N. (1967). Studies on the quantitative and qualitative characterization of erytrocyte glutathione peroxidase. The Journal of Laboratory and Clinical Medicine , 70, 158–169. http://garfield.library.upenn.edu/classics1989/A1989T143200001.pdf Persson, W. K. et al. (2007). Supplementation of RRR-alpha-tocopheryl acetate to periparturient dairy cows in commercial herds with high mastitis incidence. Journal of Dairy Science , 90, 3640–3646. http://dx.doi.org/10.3168/jds.2006-421 Pavlata, L. et al. (2002). Selenium status of cattle in the Czech Republic. Acta Veterinaria Brno , 71, 3–8. https://actavet.vfu.cz/71/1/0003/ Pavlata, l. et al. (2012). Direct and indirect assessment of selenium status in sheep – a comparison. Veterinarni Medicina , 57, 219–223. http://vri.cz/docs/vetmed/57-5-219.pdf Smith, K. L. et al. (1997). Dietary vitamin E and selenium affect mastitis and milk quality. Journal of Animal Science , 75, 1659–1665. https://pubmed.ncbi.nlm.nih.gov/9250530/ Spears, J. W., Weiss, W. P. (2008). Role of antioxidants and trace elements in health and immunity of transition dairy cows. The Veterinary Journal , 176, 70–76. https://pubmed.ncbi.nlm.nih.gov/18325801/ Vasiľ, M. a kol. (2018). Patogény stožiar izolované izolované od vzoriek mlieka v chove oviec nachádzajúcich sa v okrajových častiach Slovenska. V infekčné a parazitárne choroby zvierat, 6. ročník medzinárodnej vedeckej konferencie , 13.-14. Septembra, Košice. s. 244–248. ISBN 978-80-8077-583-4

Methyl donor supply to heat stress-challenged polymorphonuclear leukocytes from lactating Holstein cows enhances 1-carbon metabolism, immune response, and cytoprotective gene network abundance

Mechanisms controlling immune function of dairy cows are dysregulated during heat stress (HS). Methyl donor supply-methionine (Met) and choline (Chol)-positively modulates innate immune function, particularly antioxidant systems of polymorphonuclear leukocytes (PMN). The objective of this study was to investigate the effect of Met and Chol supply in vitro on mRNA abundance of genes related to 1-carbon metabolism, inflammation, and immune function in short-term cultures of PMN isolated from mid-lactating Holstein cows in response to heat challenge. Blood PMN were isolated from 5 Holstein cows (153 ± 5 d postpartum, 34.63 ± 2.73 kg/d of milk production; mean ± SD). The PMN were incubated for 2 h at thermal-neutral (37°C; TN) or heat stress (42°C; HS) temperatures with 3 levels of Chol (0, 400, or 800 μg/mL) or 3 ratios of Lys:Met (Met; 3.6:1, 2.9:1, or 2.4:1). Supernatant concentrations of IL-1β, IL-6, and tumor necrosis factor-α were measured via bovine-specific ELISA. Fold-changes in mRNA abundance were calculated separately for Chol and Met treatments to obtain the fold-change response at 42°C (HS) relative to 37°C (TN). Data were subjected to ANOVA using PROC MIXED in SAS (SAS Institute Inc., Cary, NC). Orthogonal contrasts were used to determine the linear or quadratic effect of Met and Chol for mRNA fold-change and supernatant cytokine concentrations. Compared with PMN receiving 0 μg of Chol/mL, heat-stressed PMN supplemented with Chol at 400 or 800 μg/mL had greater fold-change in abundance of CBS, CSAD, GSS, GSR, and GPX1. Among genes associated with inflammation and immune function, fold-change in abundance of TLR2, TLR4, IRAK1, IL1B, and IL10 increased with 400 and 800 μg of Chol/mL compared with PMN receiving 0 μg of Chol/mL. Fold-change in abundance of SAHH decreased linearly at increasing levels of Met supply. A linear effect was detected for MPO, NFKB1, and SOD1 due to greater fold-change in abundance when Met was increased to reach Lys:Met ratios of 2.9:1 and 2.4:1. Although increasing Chol supply upregulated BAX, BCL2, and HSP70, increased Met supply only upregulated BAX. Under HS conditions, enhancing PMN supply of Chol to 400 μg/mL effectively increased fold-change in abundance of genes involved in antioxidant production (conferring cellular processes protection from free radicals and reactive oxygen species), inflammatory signaling, and innate immunity. Although similar outcomes were obtained with Met supply at Lys:Met ratios of 2.9:1 and 2.4:1, the response was less pronounced. Both Chol and Met supply enhanced the cytoprotective characteristics of PMN through upregulation of heat shock proteins. Overall, the modulatory effects detected in the present experiment highlight an opportunity to use Met and particularly Chol supplementation during thermal stress.

Transcriptome Functional Analysis of Mammary Gland of Cows in Heat Stress and Thermoneutral Condition.

Simple SummaryThe current study employed RNA-seq technology to analyze the impact of heat stress on the whole transcript sequencing profile in the mammary glands of lactating Holstein dairy cows. In the findings of the current study, heat stress downregulated the expression of casein genes, which resulted in a decrease in milk production. Moreover, heat stress upregulated the gene expression of HSPA1A and HSP90B1, while it downregulated the expression of immune response-related genes that resulted in a reduction in milk yield. Furthermore, there was an increased synthesis of heat shock proteins and unfolded proteins that could reduce the availability of circulating amino acids for milk protein synthesis. The findings of the current experiment may help to explore the impact of heat stress on immune function, milk production, and milk protein synthesis in cows.Heat stress (HS) exerts significant effects on the production of dairy animals through impairing health and biological functions. However, the molecular mechanisms related to the effect of HS on dairy cow milk production are still largely unknown. The present study employed an RNA-sequencing approach to explore the molecular mechanisms associated with a decline in milk production by the functional analysis of differentially expressed genes (DEGs) in mammary glands of cows exposed to HS and non-heat-stressed cows. The results of the current study reveal that HS increases the rectal temperature and respiratory rate. Cows under HS result in decreased bodyweight, dry matter intake (DMI), and milk yield. In the current study, a total of 213 genes in experimental cow mammary glands was identified as being differentially expressed by DEGs analysis. Among identified genes, 89 were upregulated, and 124 were downregulated. Gene Ontology functional analysis found that biological processes, such as immune response, chaperone-dependent refolding of protein, and heat shock protein binding activity, were notably affected by HS. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis found that almost all of the top-affected pathways were related to immune response. Under HS, the expression of heat shock protein 90 kDa beta I (HSP90B1) and heat shock 70 kDa protein 1A was upregulated, while the expression of bovine lymphocyte antigen (BoLA) and histocompatibility complex, class II, DRB3 (BoLA-DRB3) was downregulated. We further explored the effects of HS on lactation-related genes and pathways and found that HS significantly downregulated the casein genes. Furthermore, HS increased the expression of phosphorylation of mammalian target of rapamycin, cytosolic arginine sensor for mTORC1 subunit 2 (CASTOR2), and cytosolic arginine sensor for mTORC1 subunit 1 (CASTOR1), but decreased the phosphorylation of Janus kinase-2, a signal transducer and activator of transcription factor-5. Based on the findings of DMI, milk yield, casein gene expression, and the genes and pathways identified by functional annotation analysis, it is concluded that HS adversely affects the immune function of dairy cows. These results will be beneficial to understand the underlying mechanism of reduced milk yield in HS cows.

Rubber seed oil and flaxseed oil supplementation on serum fatty acid profile, oxidation stability of serum and milk, and immune function of dairy cows

ObjectiveThis study was designed to investigate the effect of diet supplementation with rubber seed oil and flaxseed oil on serum fatty acids profile, oxidation stability of serum and milk, and immune function of dairy cows.MethodsForty-eight mid-lactation Holstein dairy cows were randomly assigned to one of four treatments for 8 wk, including basal diet (CON) or the basal diet supplemented with 4% rubber seed oil (RO), 4% flaxseed oil (FO) or 2% rubber seed oil plus 2% flaxseed oil (RFO) on a dry matter basis.ResultsCompared with CON, all the oil groups increased the levels of trans-11 C18:1 (vaccenic acid), cis-9, trans-11 C18:2 (conjugated linoleic acid, CLA) and C18:3 (α-linolenic acid, ALA) in serum. Both the activity of glutathione peroxidase and catalase in serum and milk in oil groups were decreased, which were negatively correlated with the levels of cis-9, trans-11 CLA and ALA. The concentrations of proinflammatory factors (tumor necrosis factor α and interferon γ) in serum of oil groups were lower than that from the CON cows.ConclusionThese results indicate that diet supplementation with RO or FO could alter serum fatty acid profile and enhance the immune function of dairy cows. However, the negative effect on milk oxidation stability should be considered when feeding these n-3 polyunsaturated fatty acid-enriched oils in dairy production.

Far-off and close-up feeding levels affect immunological performance in grazing dairy cows during the transition period.

During the peripartum period, dairy cows often have signs of inflammation. Various stresses, including infectious and metabolic diseases, have been discussed as causative for this inflammation. In this study, expression profiles for 17 immune markers were measured in whole blood preparations from 78 dairy cows over a time frame starting 1 wk before calving to 4 wk after calving. Additionally, the effects of far-off and close-up feeding on immune function of dairy cows during the peripartum period were investigated. Cows were assigned to 1 of 2 feeding levels in late lactation to achieve a low and high BCS at the time of dry-off (approximately 4.25 and 5.0 on a 10-point scale). Following dry-off, both herds were managed to achieve a BCS of 5.0 one month before calving; this involved controlled feeding (i.e., maintenance) and over-feeding of ME during the far-off dry period. Within each far-off feeding-level treatment, cows were offered 65, 90, or 120% of their precalving ME requirements for 3 wk precalving in a 2 × 3 factorial arrangement. Analysis of gene expression profiles from blood cells revealed effects of time indicating that the transition cow's immune system counteracts the peripartum inflammation, whereas later postcalving it becomes activated to provide protection against postpartum infections. Far-off feeding affected (P < 0.05) the expression of 2 of the investigated genes at calving. Interleukin-6 (IL-6) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) expression in unstimulated, peripheral leukocytes were lower (P < 0.05) in animals from the Far-Off_Over-fed group compared with the Far-Off_Control-fed group. Close-up feeding had several effects on gene expression, indicating that immune function in Feed120 animals was distinct from the Feed90 and Feed65. In conclusion, feeding management precalving becomes an important intervention to ensure immunocompetence at and after calving.

Effects of fermented Chinese herbal medicines on milk performance and immune function in late-lactation cows under heat stress conditions

Heat stress (HS) causes significant economic losses and has become a continual challenge in the dairy industry worldwide. The objective of this study was to evaluate the effects of a dietary supplement on milk performance and immune function in late-lactation cows under HS conditions. The supplement was a fermented Chinese herbal medicines (CHMs) mixture consisting of 18 herbs. Forty lactating Holstein cows (560 ± 51.0 kg of initial BW, 230 ± 10.0 DIM, 16 ± 3.0 kg of milk per day) were randomly assigned into 4 treatment groups (10 cows per group). Each group was fed a dietary supplemented with 0, 25, 50, or 100 g CHMs per cow per day. Cows were housed at high ambient temperature-humidity index (average 74.5) for an experimental period of 42 d during the summer months. Milk yield, composition, immune responses involving blood lymphocyte apoptosis rate, serum biochemical parameters, and genes expression in lymphocytes were evaluated on days 14, 28, and 42, respectively. Results showed that milk yield, milk fat, and protein content were greater (all P < 0.05) for 50 or 100 g/d CHMs compared with the group without CHMs supplements throughout the experimental period. On the other hand, increasing CHMs dose demonstrated a greater lymphocyte or leukocyte count (P < 0.01). By flow cytometry analysis, early or late apoptosis rate of the lymphocytes was decreased (P < 0.05) by CHMs supplements. The immunity-related biochemistry and genes transcript responses involving cytokines (IL-1, IL-2, IL-6, and IL-12), apoptosis (Bak, Mcl-1, Bax, Bcl-2, Bcl-xl, and P53), and immunoglobulins (IgA, IgG, and IgM) were investigated. Compared with the unsupplemented group, the serum IL-2 and IL-6 levels, as well as IL-2 mRNA expression, increased (P < 0.05) for 100 g/d. However, the serum IL-1 level tended to decrease (P = 0.08) with increasing CHMs dose, and IL-1 mRNA expression was down-regulated (P = 0.02) by up to 24% for 100 g/d. Additionally, the serum Bax level decreased (P < 0.01) and Bcl-2 level increased (P = 0.01) for 100 g/d. Bax and Bak mRNA expressions were down-regulated (P < 0.05), and Bcl-2 and Bcl-xl expression were up-regulated (P < 0.05) for 50 or 100 g/d. The mRNA expressions of P53 and Mcl-1 were not affected by CHMs (P > 0.10). Besides, serum IgG levels were greater (P < 0.01) for 50 or 100 g/d, compared with unsupplemented group. In conclusion, CHMs supplements may improve milk performance and immune function in dairy cows under HS conditions.

Effects of Bupleurum extract on blood metabolism, antioxidant status and immune function in heat-stressed dairy cows

This experiment was conducted to evaluate the effects of Bupleurum extract (BE) on blood metabolites, antioxidant status, and immune function in dairy cows under heat stress. Forty lactating Holstein cows were randomly assigned to 1 of 4 treatments. The treatments consisted of 0, 0.25, 0.5, and 1.0 g of BE kg−1 dry matter. Supplementation with BE decreased (P<0.05) blood urea nitrogen (BUN) contents and increased blood total protein (TP) and albumin (ALB) levels compared with control cows, but it had no effects (P>0.05) on blood glucose (GLU), nonesterified fatty acid (NEFA), total triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high density lipoprotein cholesterol (HDL-C). Compared with control cows, cows fed BE had higher (P<0.05) superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity. However, supplementation with BE had no effect (P>0.05) on total antioxidant capacity (T-AOC) or malondialdehyde (MDA) levels. The immunoglobulin (Ig) A and G contents increased (P<0.05) in cows fed 0.25 or 0.5 g of BE kg−1. Interleukin (IL)-2 and IL-4 levels were higher (P<0.05) in cows fed 0.5 and 1.0 g of BE kg−1, and IL-6 was significantly elevated (P<0.05) in cows fed 0.5 g of BE kg−1. There were no treatment effects (P>0.05) on the CD4+ and CD8+ T lymphocyte ratios, CD4+/CD8+ ratio, or tumor necrosis factor-α (TNF-α) level among the groups. These findings suggest that BE supplementation may improve protein metabolism, in addition to enhancing antioxidant activity and immune function in heat-stressed dairy cows.

Different durations of whole raw soybean supplementation during the prepartum period: Measures of cellular immune function in transition cows

The objective of this study was to evaluate different durations of whole raw soybean (WS) supplementation (diet rich in n-6 fatty acid) during the prepartum period on cellular immune function of dairy cows in the transition period and early lactation. Thirty-one Holstein cows were used in a completely randomized design and assigned to 4 experimental groups (G) [G90, G60, G30, and G0 (control)] supplemented with a diet containing 12% of WS from 90, 60, 30 and 0 d relative to the calving date, respectively. Cows were dried off 60 d before the expected calving date. After parturition, all cows were fed a diet containing 12% of WS until 84 DIM. Blood samples were collected before the morning feeding (d -56 ± 2, -28 ± 2, -14 ± 2, -7 ± 2, at the day of partum, 7 ± 2, 14 ± 2, 28 ± 2, and 56 ± 2 relative to parturition). Cell phenotyping and phagocytosis assays were carried out using monoclonal antibodies and flow cytometry technique. Duration of WS supplementation linearly increased the percentage of blood CD3+ cells, as well as increased the percentage of blood CD8+ cells in the postpartum period, notably in G30, whereas the lowest values were observed in G0. Further, the duration of WS supplementation linearly increased the reactive oxygen species median fluorescence intensity of CH138+ cells after phagocytizing Staphylococcus aureus in the postpartum period. Longer periods of WS supplementation linearly increased phagocytosis median fluorescence intensity of CH138+ cells in the prepartum period of cows. Duration of WS supplementation linearly increased the percentage of blood CD14+ cells producing reactive oxygen species when stimulated either by Staph. aureus or Escherichia coli in the postpartum period. In conclusion, longer periods of WS supplementation during late lactation and the dry period (beginning on d 90 of the expected calving date) alter the leukocyte population and improve neutrophil immune response in the postpartum period with no detrimental effects on cow performance.

113 Supplementation of blackberry pomace during the transition phase may improve health and immune function of dairy cows in the week before calving

113 Supplementation of blackberry pomace during the transition phase may improve health and immune function of dairy cows in the week before calving

Effect of tea saponins on milk performance, milk fatty acids, and immune function in dairy cow

This study investigated the effects of tea saponins (TSP) on milk performance, milk fatty acids, and blood immune function in dairy cows. A total of 20 early-lactation Holstein cows (days in milk = 66.4 ± 16.8 d; parity = 1.75 ± 0.91; and milk yield = 36.3 ± 7.32 kg/d; mean ± standard deviation) were randomly divided into 4 homogeneous treatment groups, with TSP added at 0, 20, 30, and 40 g/d per head, respectively. All cows had 2 wk of adaptation and 6 wk of treatments. Feed, milk, and blood were sampled and analyzed weekly. At the end of the experimental period (wk 6), the dry matter intake and yields of energy-corrected milk, milk, and milk protein, fat, and lactose in the cows fed TSP showed a quadratic response, with the lowest values in cows fed TSP at 40 g/d. The milk fat content of cows fed TSP increased linearly. Significant interactions for treatment by week were found in milk C16:1 cis-9 and C18:1 cis-9, with the highest values at wk 2, 3, and 4 in the cows fed TSP at 40 g/d. The levels declined quickly after 4 wk of feeding to values similar to those for other TSP treatments and the control at wk 5 and 6. Plasma malondialdehyde concentration decreased as the supplement level of TSP increased. The concentration of superoxide dismutase increased as the supplement level of TSP increased. The plasma concentration of tumor necrosis factor-α increased as the supplement level of TSP increased. In summary, this study showed that an intermediate dose of TSP (20 and 30 g/d) had no significant effect on feed intake, but the supplementation of 40 g/d TSP decreased feed intake, resulting in a lower milk yield. The energy-corrected milk of cows fed 40 g/d TSP declined at first but increased after 3 wk of feeding, indicating the potential adaptation to high doses of TSP supplements in dairy cows. The supplementation of TSP could reduce oxidative stress in cows and improve the immunity of dairy cows during 6 wk of feeding.

Effect of Single Nucleotide Polymorphisms of Toll-Like Receptor 4 (TLR 4) on Reproductive Performance and Immune Function in Dairy Cows.

In dairy cows, inflammatory diseases caused by infection with pathogenic bacteria post calving affect ovarian functions. This study examined the relationship between single-nucleotide polymorphisms (SNPs) of Toll-like receptor 4 (TLR4), reproductive performances [the number of artificial insemination (AI) application and days open], and immune cell functions (apoptosis and migration). Two hundred Holstein cows from the Obihiro University farm were included. The SNPs of TLR4 were genotyped by PCR-restriction fragment length polymorphism (PCR-RFLP) method. Polymorphonuclear leukocytes (PMNs) and peripheral blood mononuclear cells (PBMCs) were isolated from whole blood. The number of AI application in the animals with T/C genotype in the TLR4 exon3 was lower than that in animals with C/C genotype (1.6±0.2 and 2.2±0.2, respectively). Among the animals with TLR4 exon3 polymorphisms, the days open was shorter for the T/C cows than that for C/C cows (100.7±6.9days and 136.6±9.0days, respectively). The SNPs in the TLR4 intron did not affect the number of AI and days open. The apoptosis percentage of PMNs treated with lipopolysaccharide (LPS; 0.001 and 1μg/ml) tended to be lower in the T/C genotype compared to that in the C/C genotype. The transmigration rates of PMNs, and IL-1β production in PBMCs were tended to be higher for the animals with the T/C genotype compared to those for animals with the C/C genotype. Taken together, these results suggest that TLR4 polymorphisms offer a meaningful tool to judge the reproductive potential and immune activity in individual cows.

Does Heat Stress Affect Immune Function in Dairy Cows?

Clinical bottom line&#x0D; Heat stress appears to generally suppress innate immune function in both dry and lactating dairy cows. Immune effects that are decreased include cytokine production, proliferation of immune cells, migration of lymphocytes to the udder and cell viability. This may lead to an increase in the risk of clinical diseases such as mastitis and metritis. &#x0D;

Effects of monensin and starch level in early lactation diets on indices of immune function in dairy cows

The objective of this study was to evaluate the effect of dietary starch level and monensin on immune function. Prior to parturition, primiparous (n=21) and multiparous (n=49) Holstein cows were fed a common controlled energy close-up diet with a daily topdress of either 0 or 400mg/d monensin. From 1 to 21d in milk (DIM), cows were fed a high-starch (HS; 26.2% starch) or low-starch (LS; 21.5% starch) total mixed ration with a daily topdress of either 0 or 450mg of monensin/d continuing with prepartum topdress assignment. From 22 through 63 DIM, all cows were fed HS and continued with assigned topdress treatment until 63 DIM. Endometrial cytology and whole-blood immune function were assessed at 8 DIM and on 1d between 40 and 60 DIM. At 8 DIM, cows fed HS had an increased percentage (%) of phagocytic monocytes and tended to have a greater phagocytosis index (% of positive cells × mean fluorescence intensity) in monocytes compared with cows fed LS. At 8 DIM, cows fed HS also tended to have a higher percentage of monocytes involved in oxidative burst and a higher monocyte oxidative burst index compared with LS cows. At 8 DIM, blood polymorphonuclear neutrophils (PMN) isolated from cows fed monensin during the periparturient period tended to have higher PMN glycogen content compared with control cows. At 40 to 60 DIM, the incidence of cytological endometritis as diagnosed by uterine cytology was not affected by dietary treatment. However, at 40 to 60 DIM, cows fed monensin had an increased percentage of Escherichia coli-stimulated PMN, tended to have a greater percentage of monocytes involved in oxidative burst, and tended to have an increased E. coli-stimulated monocyte oxidative burst index. At 40 to 60 DIM, blood PMN isolated from cows fed HS during early lactation had higher PMN glycogen content compared with cows fed LS during early lactation. Overall, results suggest that feeding higher starch diets postpartum and peripartal supplementation with monensin may have some beneficial effects on immune function, although uterine cytology was not affected by treatment.

Associations between the degree of early lactation inflammation and performance, metabolism, and immune function in dairy cows

The objective of the current study was to determine associations between the severity of systemic inflammation during the early postpartum period and performance, energy metabolism, and immune function in dairy cows. Cows were assigned to categorical quartiles (Q; Q1=0.18–0.59, Q2=0.60–1.14, Q3=1.15–2.05, and Q4=2.06–2.50g of haptoglobin/L) based on the highest plasma haptoglobin (Hp) concentration measured during wk 1 postpartum. Although cows were assigned to different categories of inflammation during the postpartum period, we detected a quadratic relationship of inflammation on prepartum dry matter intake (DMI) and body weight (BW) such that cows in Q2 had lower prepartum DMI and cows in Q2 and Q3 had lower prepartum BW compared with cows in the other quartiles. We also detected a quadratic association of inflammation with postpartum DMI and BW such that cows in Q2 and Q3 also had generally lower postpartum DMI and BW compared with cows in Q1. There was a tendency for a Q × time interaction for milk yield and Q × time interactions for 3.5% fat-corrected milk and energy-corrected milk yields; quadratic relationships suggested decreased milk yield for Q2 and Q3 cows. We also found Q × parity and Q × time interactions for plasma glucose and insulin concentrations, suggesting alterations with differing degrees of inflammation. There was also a Q × time interaction for plasma nonesterified fatty acids concentration. In addition, alterations in liver triglyceride and glycogen contents for cows with inflammation as well as alterations in [1-14C]propionate oxidation in vitro were observed. Although we observed limited effects of inflammation on neutrophil and monocyte phagocytosis at d 7 postpartum, inflammation appeared to alter neutrophil and monocyte oxidative burst. Overall, cows with any degree of elevated haptoglobin in the first week after calving had alterations in both pre- and postpartum intake and postpartum metabolism.

Effects of vitamin A on the milk performance, antioxidant functions and immune functions of dairy cows

Due to their high rates of metabolism, dairy cows experience considerable oxidative stress, resulting in susceptibility to disease pathogens. Vitamin A (VA) is an important factor in improving immune function and attenuating oxidative stress. The effects of dietary VA concentration on milk production, antioxidant status and immune function in dairy cows were assessed. Twenty-eight Holstein cows with similar parity, body weight (BW, 550±50kg), and milk production (20.75±0.50kg) and at similar stages of lactation (150±10 d in milk) were divided into two groups with 14 replicates in each group. The only independent factor in this experiment was the concentration of supplemental VA provided in the cows’ diet (control: 110IU/kg BW or high dose VA supplementation: 220IU/kg BW). This experiment consisted of a 15-d adaptation period and a 60-d collection period. The ratio of concentrate to forage in the diets was 42:58. The results indicated that milk yield and milk composition were not changed upon supplementation with a higher dose of VA compared with the control, but VA concentration within the milk was increased. The results also indicated that supplementation with 220IU of VA/kg of BW significantly increased the concentrations of immunoglobulin A, immunoglobulin M, immunoglobulin G, interleukin-1, tumour necrosis factor-alpha and soluble CD4; selenoprotein P content; the activities of glutathione peroxidase, superoxide dismutase and catalase; total antioxidant capacity; the hydroxyl radical inhibition capability; and soluble CD4/soluble CD8 in the serum. Feeding a high dose of VA (220IU/kg BW) resulted in a significant reduction in the somatic cell count of the milk, the concentrations of soluble CD8 and malonaldehyde, as well as reactive oxygen species in the serum of dairy cows. These results suggested that supplementation of the diet with 220IU of VA/kg of BW may enhance the antioxidant and immune functions of dairy cows and implied that the VA requirement necessary to ensure beneficial immune and antioxidant functions of dairy cows is higher than the current recommended dose that ensures optimum production performance.