Rumen-protected methionine compared with rumen-protected choline improves immunometabolic status in dairy cows during the peripartal period.

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 challenge in vitro, blood polymorphonuclear leukocyte phagocytosis capacity and oxidative burst activity were greater in Met-supplemented cows. Overall, liver and blood biomarker analyses revealed favorable changes in liver function, inflammation status, and immune response in Met-supplemented cows.

Body condition score and plane of nutrition prepartum affect adipose tissue transcriptome regulators of metabolism and inflammation in grazing dairy cows during the transition period.

Recent studies demonstrating a higher incidence of metabolic disorders after calving have challenged the management practice of increasing dietary energy density during the last ~3 wk prepartum. Despite our knowledge at the whole-animal level, the tissue-level mechanisms that are altered in response to feeding management prepartum remain unclear. Our hypothesis was that prepartum body condition score (BCS), in combination with feeding management, plays a central role in the peripartum changes associated with energy balance and inflammatory state. Twenty-eight mid-lactation grazing dairy cows of mixed age and breed were randomly allocated to 1 of 4 treatment groups in a 2 × 2 factorial arrangement: 2 prepartum BCS categories (4.0 and 5.0, based on a 10-point scale; BCS4, BCS5) obtained via differential feeding management during late-lactation, and 2 levels of energy intake during the 3 wk preceding calving (75 and 125% of estimated requirements). Subcutaneous adipose tissue was harvested via biopsy at -1, 1, and 4 wk relative to parturition. Quantitative polymerase chain reaction was used to measure mRNA and microRNA (miRNA) expression of targets related to fatty acid metabolism (lipogenesis, lipolysis), adipokine synthesis, and inflammation. Both prepartum BCS and feeding management had a significant effect on mRNA and miRNA expression throughout the peripartum period. Overfed BCS5 cows had the greatest prepartum expression of fatty acid synthase (FASN) and an overall greater expression of leptin (LEP); BCS5 was also associated with greater overall adiponectin (ADIPOQ) and peroxisome proliferator-activated receptor gamma (PPARG), whereas overfeeding upregulated expression of proadipogenic miRNA. Higher postpartum expression of chemokine ligand 5 (CCL5) and the cytokines interleukin 6 (IL6) and tumor necrosis factor (TNF) was detected in overfed BCS5 cows. Feed-restricted BCS4 cows had the highest overall interleukin 1 (IL1B) expression. Prepartum feed restriction resulted in greater chemokine ligand 2 (CCL2) expression. Overall, changes in mRNA expression were consistent with the expression pattern of inflammation-related miRNA. These data shed light on molecular mechanisms underlying the effect of prepartum BCS and feeding management on metabolic and inflammatory status of adipose tissue during the peripartum period. Data support the use of a controlled feed restriction prepartum in optimally conditioned cows, as well as the use of a higher level of dietary energy in under-conditioned cows.

Selection for milk coagulation properties predicted by Fourier transform infrared spectroscopy in the Italian Holstein-Friesian breed.

Milk coagulation is based on a series of physicochemical changes at the casein micelle level, resulting in formation of a gel. Milk coagulation properties (MCP) are relevant for cheese quality and yield, important factors for the dairy industry. They are also evaluated in herd bulk milk to reward or penalize producers of Protected Designation of Origin cheeses. The economic importance of improving MCP justifies the need to account for this trait in the selection process. A pilot study was carried out to determine the feasibility of including MCP in the selection schemes of the Italian Holstein. The MCP were predicted in 1,055 individual milk samples collected in 16 herds (66 ± 24 cows per herd) located in Brescia province (northeastern Italy) by means of Fourier transform infrared (FTIR) spectroscopy. The coefficient of determination of prediction models indicated moderate predictions for milk rennet coagulation time (RCT=0.65) and curd firmness (a30=0.68), and poor predictions for curd-firming time (k20=0.49), whereas the range error ratio (8.9, 6.9, and 9.5 for RCT, k20, and a30, respectively) indicated good practical utility of the predictive models for all parameters. Milk proteins were genotyped and casein haplotypes (αS1-, ß-, αS2-, and κ-casein) were reconstructed. Data from 51 half-sib families (19.9 ± 16.4 daughters per sire) were analyzed by an animal model to estimate (1) the genetic parameters of predicted RCT, k20, and a30; (2) the breeding values for these predicted clotting variables; and (3) the effect of milk protein genotypes and casein haplotypes on predicted MCP (pMCP). This is the first study to estimate both genetic parameters and breeding values of pMCP, together with the effects of milk protein genotypes and casein haplotypes, that also considered k20, probably the most important parameter for the dairy industry (because it indicates the time for the beginning of curd-cutting). Heritability of predicted RCT (0.26) and k20 (0.31) were close to the average heritability described in literature, whereas the heritability of a30 was higher (0.52 vs. 0.27). The effects of milk proteins were statistically significant and similar to those obtained on measured MCP. In particular, haplotypes including uncommon variants showed positive (B-I-A-B) or negative (B-A(1)-A-E) effects. Based on these findings, FTIR spectroscopy-pMCP is proposed as a potential selection criterion for the Italian Holstein.