Comparison of metabolic and immune biomarkers between primiparous and multiparous dairy cows during the peripartum period

International audienceThe peripartum period can decrease immune capacity leading to a higher risk of infectious diseases. The objective of this study was to investigate the influence of parity on metabolic biomarkers (NEFA, glucose, β-hydroxybutyrate, urea) and immunity (cytokines) before calving and at the beginning of lactation. Fifteen Holstein cows were classified into 4 groups according to calving date with 7 primiparous heifers and 8 multiparous cows. Blood samples were collected 3 weeks before calving, and 4, 8, 12 weeks postpartum and milk was samples at the same times only after calving. Cows were fed ad libitum a total mixed diet based on maize silage and milked twice a day. Milk minerals were measured by ICP-OES. In the plasma, metabolic markers were analyzed by spectrophotometry. Plasma pro- and anti-inflammatory cytokines were analyzed after an ex vivo challenge of whole-blood cells with or without heat-killed Escherichia coli using a bead-based multiplex assay. Data were analyzed with a mixed model including parity, week, and their interaction as fixed effects, and cow as a random effect. Milk production was higher in multiparous than in primiparous cows (x vs y kg/d on average over 12 weeks). During the first weeks of lactation, NEFA and BOH (parity x week interaction effect), and urea (parity effect) were higher in multiparous cows, whereas glucose was lower. Milk cell count was lower in multiparous than in primiparous cows in the 2nd week after calving but was always lower than 100,000 cells/mL. Parity did not affect the integrity of the mammary epithelium (milk Na+/K+ ratio). The key inflammatory cytokines CXCL10, CCL2, IL1Rα and IFNγ were lower in the plasma of multiparous cows. At the 3rd week before and the 8th week after calving, the immunity of multiparous cows could be less effective with lower levels of IL1α and TNFα, compared with primiparous cows. The parity effects on immunity contrasted with what is observed for the metabolic markers and milk production. The effect of parity must be considered for the research studies of immunity in dairy cows during the peripartum period

Caractérisation du processus d’exfoliation des cellules épithéliales mammaires au cours de la traite chez la vache laitière

Caractérisation du processus d’exfoliation des cellules épithéliales mammaires au cours de la traite chez la vache laitière. 23. Rencontres autour des Recherches sur les Ruminant

Effects of parity on metabolism, redox status and cytokines in early lactating dairy cows

International audienceIn dairy cows during early lactation, inflammation and oxidative stress can occur and lead to a risk of cell damages and may be related to the metabolic status. Our objective was to investigate the influence of parity on the metabolic, redox status and immunity of dairy cows. Fifteen Holstein cows were classified into four groups according to calving date with 7 primiparous and 8 multiparous cows. Blood samples were collected 3 weeks before calving and 4, 8 and 12 weeks postpartum and after calving milk was sampled at the same times. Plasma metabolic and redox status markers were analysed by spectrophotometry. In leucocytes collected from milk, the expression of genes coding for antioxidant enzymes were analysed by RTqPCR. Plasma cytokines were analysed after an ex vivo challenge of whole-blood cells with or without heat-killed Escherichia coli. Data were analysed with a mixed model including parity, week, and their interaction as fixed effects, and cow as a random effect. As expected, milk production was higher in multiparous than in primiparous cows. Plasma non-esterified fatty acids and β-hydroxybutyrate were higher in multiparous than in primiparous respectively at the 2nd and the 4th weeks of lactation, whereas glucose was lower. Multiparous cows have higher d-ROM at 8 weeks in plasma, higher GPX activity in erythrocytes at 4 weeks, and higher Sod1 expression levels at 4 weeks in milk leucocytes. Associated with these results, multiparous cows had a higher level of vitamin E but lower plasma concentrations of cytokines CXCL10, CCL2, IL1Rα and IFNγ. After E. coli challenge, at the 3rd week before and the 8th week after calving, the immunity of multiparous cows would be less effective with lower IL1α and TNFα. The increased energy metabolism is accompanied by an increase in the antioxidant response to resolve redox balance, and by a probably less effective immunity in multiparous compared with primiparous cows

Maternal age, parity and nursing status at fertilization affects post-partum lactation up to weaning in horses

International audienceNulliparity is associated with intra-uterine growth retardation and foal delayed catch-up growth. Older mares produce larger/taller foals than the precedents. Nursing at conception on foal growth had not been investigated yet. In any case, milk production conditions the foal's growth. This study aimed to determine effects of mare parity, age and nursing on subsequent lactation quantity and quality. Saddlebred mares and their foals (N=43) run as a single herd over the same year were: young (6-7-year-old) primiparous, young multiparous, old (10-16-year-old) multiparous nursing at insemination time or old multiparous barren the previous year. No young nursing nor old multiparous mares were available. Colostrum was collected. Milk production and foal weight were monitored at 3-, 30-, 60-, 90- and 180-days post-foaling. The foal average daily weight gain (ADG) was calculated for each period between 2 measurements. Milk fatty acid (FA), sodium, potassium, total protein and lactose contents were determined. The primiparous vs multiparous colostrum was richer in immunoglobulin G, with lower production but greater FA contents in milk. The primiparous foals had a lower ADG for 3-30 days post-partum period. Old mares' colostrum contained more SFA and less polyunsaturated FA (PUFA) whereas their milk was richer in proteins and sodium and poorer in short-chain-SFA with a reduced PUFA/SFA ratio at 90 days. Nursing mares' colostrum was richer in MUFA and PUFA and late-lactation milk production was reduced. In conclusion, parity, age and nursing at conception affect mare's colostrum and milk production and foal growth and should be considered for broodmares' management