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Dairy cattle undergo dramatic metabolic, endocrine, physiologic and immune changes during the peripartal period largely due to combined increases in energy requirements for fetal growth and development, milk production, and decreased dry matter intake. The negative nutrient balance that develops results in body fat mobilization, subsequently leading to triacylglycerol (TAG) accumulation in the liver along with reductions in liver function, immune dysfunction and a state of inflammation and oxidative stress. Mobilization of muscle and gluconeogenesis are also enhanced, while intake of vitamins and minerals is decreased, contributing to metabolic and immune dysfunction and oxidative stress. Enhancing post-ruminal supply of methyl donors is one approach that may improve immunometabolism and production synergistically in peripartal cows. At the cellular level, methyl donors (e.g. methionine, choline, betaine and folic acid) interact through one-carbon metabolism to modulate metabolism, immune responses and epigenetic events. By modulating those pathways, methyl donors may help increase the export of very low-density lipoproteins to reduce liver TAG and contribute to antioxidant synthesis to alleviate oxidative stress. Thus, altering one-carbon metabolism through methyl donor supplementation is a viable option to modulate immunometabolism during the peripartal period. This review explores available data on the regulation of one-carbon metabolism pathways in dairy cows in the context of enzyme regulation, cellular sensors and signaling mechanisms that might respond to increased dietary supply of specific methyl donors. Effects of methyl donors beyond the one-carbon metabolism pathways, including production performance, immune cell function, mechanistic target or rapamycin signaling, and fatty acid oxidation will also be highlighted. Furthermore, the effects of body condition and feeding system (total mixed ration vs. pasture) on one-carbon metabolism p

[EN] Mechanisms controlling immune function of dairy cows are dysregulated during heat stress (HS). Methyl donor supply-methionine (Met) and choline (Chop-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 degrees C; TN) or heat stress (42 degrees C; HS) temperatures with 3 levels of Chol (0, 400, or 800 mu g/mL) or 3 ratios of Lys:Met (Met; 3.6:1, 2.9:1, or 2.4:1). Supernatant concentrations of IL-1 beta, IL-6, and tumor necrosis factor-alpha 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 degrees C (HS) relative to 37 degrees 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 mu g of Chol/mL, heat-stressed PMN supplemented with Chol at 400 or 800 mu g/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 mu g of Chol/mL compared with PMN receiving 0 mu g 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 abu

The present experiment aimed to investigate (1) the effect of weaning age on rumen fermentation, dietary intake, growth, and rumination behavior at 20 d after weaning in Simmental calves, and (2) the relationship between rumination time measured by the Hr-Tag rumination-monitoring system (Hr-Tag; SCR Engineers Ltd, Netanya, Israel) and rumen fermentation variables. Ten Simmental calves were randomly assigned at birth to be weaned at 45 (early weaning, EW) or 60 d of age (normal weaning, NW). EW calves were offered 6 L of bulk whole milk/d from d 2 to 38 and 3 L/d from d 39 to 45, while NW were offered 6 L of bulk whole milk/d from d 2 to 53 and 3 L/d from d 54 to 60. Individual calf starter intake was recorded daily and average daily gain (ADG) was calculated taken into account the BW at 6 d after weaning and final BW at 20 d after weaning. On d 20 after weaning, samples of rumen fluid were obtained via an esophageal tube. These samples were used to determine pH and volatile fatty acids (VFAs) concentration. Throughout the entire experiment, the Hr-Tag system continuously recorded the rumination time (RT) by Hr-Tag loggers positioned on the left side of the neck. No treatment differences were detected for total VFAs concentration and molar proportion of acetate, propionate, and butyrate (P > 0.05). Overall in the period -25 to 20 d relative to weaning time, daily RT did not differ between NW and EW calves and it increased around weaning in both groups. Hr-Tags revealed no differences in daily RT pattern (2h-RT) during the 3 d before rumen collection, while during the day (24 h) 2h-RT significantly varied overall in both EW and NW groups. Daily RT measured by Hr-Tags positively correlated to pH (r = 0.98; P < 0.001), and negatively correlated to concentration of total VFAs (r = −0.90; P < 0.001), acetate (r = −0.85; P < 0.001), and propionate (r = −0.90; P < 0.001). On the contrary, a positive linear relationship was found between daily RT and the mola

Background To reduce costs of rearing replacement heifers, researchers have focused on decreasing age at breeding and first calving. To increase returns upon initiation of lactation the focus has been on increasing mammary development prior to onset of first lactation. Enhanced plane of nutrition pre-weaning may benefit the entire replacement heifer operation by promoting mammary gland development and greater future production. Methods Twelve Holstein heifer calves (< 1 week old) were reared on 1 of 2 dietary treatments (n = 6/group) for 8 weeks: a control group fed a restricted milk replacer at 0.45 kg/d (R, 20% crude protein, 20% fat), or an accelerated group fed an enhanced milk replacer at 1.13 kg/d (EH, 28% crude protein, 25% fat). At weaning (8 weeks), calves were euthanized and sub-samples of mammary parenchyma (PAR) and mammary fat pad (MFP) were harvested upon removal from the body. Total RNA from both tissues was extracted and sequenced using the Illumina HiSeq2500 platform. The Dynamic Impact Approach (DIA) and Ingenuity Pathway Analysis (IPA) were used for pathway analysis and functions, gene networks, and cross-talk analyses of the two tissues. Results When comparing EH vs R 1561 genes (895 upregulated, 666 downregulated) and 970 genes (506 upregulated, 464 downregulated) were differentially expressed in PAR and MFP, respectively. DIA and IPA results highlight a greater proliferation and differentiation activity in both PAR and MFP, supported by an increased metabolic activity. When calves were fed EH, the PAR displayed transcriptional signs of greater overall organ development, with higher ductal growth and branching, together with a supportive blood vessel and nerve network. These activities were mediated by intracellular cascades, such as AKT, SHH, MAPK, and Wnt, probably activated by hormones, growth factors, and endogenous molecules. The analysis also revealed strong communication between MFP and PAR. Conclusions The transcriptomics and bioinformat

The present experiment aimed to evaluate the potential of the Hr-Tag rumination-monitoring system (Hr-Tag; SCR Engineers Ltd., Netanya, Israel) to describe the variation in rumination activity behavior in pre-weaned calves from 2 until 35 days of age. The study was carried out in a commercial farm and involved 9 Italian Simmental calves (3 females and 6 males). All calves were provided ad libitum access to water and starter throughout the study and were offered 6 L of bulk whole milk/d from an open-bucket starting at day 2 from birth and through 5 weeks. The Hr-Tag system continuously recorded the rumination time (RT) by Hr-Tag loggers positioned on the left side of the neck, and data were summarized in 2-h intervals. RT recorded by Hr-Tag loggers increased (P < 0.0001) through the first 4 weeks, reaching a plateau at wk 5 and the pattern of daily RT was similar along the weeks. Around milk feeding the observed 2-h intervals of RT drastically decreased (P < 0.0001) compared to the 2-h intervals before. These data shed light on the daily pattern of rumination activity in pre-weaned calves, showing a distinct daily behavior, as observable in adult cattle. Data of this study support the use of the Hr-Tag system for studying rumination activity behavior in the pre-weaning phase of calves.

Background: A transcriptomic approach was used to evaluate potential interactions between prepartum body condition score (BCS) and feeding management in the weeks before calving on hepatic metabolism during the periparturient period. Methods: Thirty-two mid-lactation grazing dairy cows of mixed age and breed were randomly allocated to one of four treatment groups in a 2×2 factorial arrangement: two prepartum BCS categories [4.0 (thin, BCS4) and 5.0 (optimal, BCS5); based on a 10-point scale], and two levels of energy intake during the 3weeks preceding calving (75 and 125% of estimated requirements). Liver samples were obtained at 7, 7, and 28 d relative to parturition and subsequent RNA was hybridized to the Agilent 44K Bovine (V2) Microarray chip. The Dynamic Impact Approach was used for pathway analysis, and Ingenuity Pathway Analysis was used for gene network analysis. Results: The greater number of differentially expressed genes in BCS4 cows in response to prepartum feed allowance (1071 vs 310, over the entire transition period) indicates that these animals were more responsive to prepartum nutrition management than optimally-conditioned cows. However, independent of prepartum BCS, pathway analysis revealed that prepartal feeding level had a marked effect on carbohydrate, amino acid, lipid, and glycan metabolism. Altered carbohydrate and amino acid metabolism suggest a greater and more prolonged negative energy balance postpartum in BCS5 cows overfed prepartum. This is supported by opposite effects of prepartum feeding in BCS4 compared with BCS5 cows in pathways encompassing amino acid, vitamin, and co-factor metabolism. The prepartum feed restriction ameliorates the metabolic adaptation to the onset of lactation in BCS5 cows, while detrimentally affecting BCS4 cows, which seem to better adapt when overfed. Alterations in the glycosaminoglycans synthesis pathway support this idea, indicating better hepatic health status in feed-restricted BCS5 and overfed BCS

The immunometabolic status of peripartal cows is altered due to changes in liver function, inflammation, and oxidative stress. Nutritional management during this physiological state can affect the biological components of immunometabolism. The objectives of this study were to measure concentrations of biomarkers in plasma, liver tissue, and milk, and also polymorphonuclear leukocyte function to assess the immunometabolic status of cows supplemented with rumen-protected methionine (Met) or choline (CHOL). Forty-eight multiparous Holstein cows were used in a randomized complete block design with 2×2 factorial arrangement of Met (Smartamine M, Adisseo NA, Alpharetta, GA) and CHOL (ReaShure, Balchem Inc., New Hampton, NY) level (with or without). Treatments (12 cows each) were control (CON), no Met or CHOL; CON and Met (SMA); CON and CHOL (REA); and CON and Met and CHOL (MIX). From -50 to -21d before expected calving, all cows received the same diet [1.40Mcal of net energy for lactation (NEL)/kg of DM] with no Met or CHOL. From -21d to calving, cows received the same close-up diet (1.52Mcal of NEL/kg of DM) and were assigned randomly to each treatment. From calving to 30d, cows were on the same postpartal diet (1.71Mcal of NEL/kg of DM) and continued to receive the same treatments until 30d. The Met supplementation was adjusted daily at 0.08% DM of diet, and CHOL was supplemented at 60g/cow per day. Liver (-10, 7, 21, and 30d) and blood (-10, 4, 8, 20, and 30d) samples were harvested for biomarker analyses. Neutrophil and monocyte phagocytosis and oxidative burst were assessed at d 1, 4, 14, and 28d. The Met-supplemented cows tended to have greater plasma paraoxonase. Greater plasma albumin and IL-6 as well as a tendency for lower haptoglobin were detected in Met- but not CHOL-supplemented cows. Similarly, cows fed Met compared with CHOL had greater concentrations of total and reduced glutathione (a potent intracellular antioxidant) in liver tissue. Upon a pathogen chal

The onset of lactation in dairy cows is characterized by high output of methylated compounds in milk when sources of methyl group are in short supply. Methionine and choline (CHOL) are key methyl donors and their availability during this time may be limiting for milk production, hepatic lipid metabolism, and immune function. Supplementing rumen-protected Met and CHOL may improve overall performance and health of transition cows. The objective of this study was to evaluate the effect of supplemental rumen-protected Met and CHOL on performance and health of transition cows. Eighty-one multiparous Holstein cows were used in a randomized, complete, unbalanced block design with 2×2 factorial arrangement of Met (Smartamine M, Adisseo NA, Alpharetta, GA) and CHOL (ReaShure, Balchem Inc., New Hampton, NY) inclusion (with or without). Treatments (20 to 21 cows each) were control (CON), CON+Met (SMA), CON+CHOL (REA), and CON+Met+CHOL (MIX). From -50 to -21d before expected calving, all cows received the same diet (1.40Mcal of NEL/kg of DM) with no Met or CHOL. From -21d to calving, cows received the same close-up diet (1.52Mcal of NEL/kg of DM) and were assigned randomly to treatments (CON, SMA, REA, or MIX) supplied as top dresses. From calving to 30 DIM, cows were fed the same postpartal diet (1.71Mcal of NEL/kg of DM) and continued to receive the same treatments through 30 DIM. The Met supplementation was adjusted daily at 0.08% DM of diet and REA was supplemented at 60g/d. Incidence of clinical ketosis and retained placenta tended to be lower in Met-supplemented cows. Supplementation of Met (SMA, MIX) led to greater DMI compared with other treatments (CON, REA) in both close-up (14.3 vs. 13.2kg/d, SEM 0.3) and first 30d postpartum (19.2 vs. 17.2kg/d, SEM 0.6). Cows supplemented with Met (SMA, MIX) had greater yields of milk (44.2 vs. 40.4kg/d, SEM 1.2), ECM (44.6 vs. 40.5kg/d, SEM 1.0), and FCM (44.6 vs. 40.8kg/d, SEM 1.0) compared with other (CON, REA) treatments. Milk f