title: Peripartum changes of plasma and milk vitamin A and beta-carotene among dairy cows with or without mastitis.
abstract: Over 12 mo we studied the relationship between peripartum concentrations of vitamin A and beta-carotene in blood plasma and milk of 93 Holsteins with or without subsequent mastitis. Blood was sampled daily from 7 days prepartum through 7 days postpartum and on alternate weeks through wk 10 of lactation. Milk samples were collected daily for 7 days postpartum and then biweekly for 10 wk. Somatic cell counts were on biweekly milk samples. Vitamin A and beta-carotene of blood plasma decreased rapidly prepartum to reach minimum concentrations at calving (vitamin A) or on day 4 to 6 postpartum (beta-carotene). Thereafter, both vitamin A and beta-carotene increased rapidly through 10 wk postpartum. Concentrations of vitamin A and beta-carotene in colostrum were higher than concentrations in milk. Cows with mastitis (somatic cells greater than 500,000 cells/ml milk) had lower vitamin A in blood plasma during days 0 to 7 and wk 2 and 4 postpartum than cows without mastitis. When data were analyzed with loge of somatic cell count as an independent regression variable, results were similar. In contrast to vitamin A, peripartum beta-carotene in blood plasma was higher among mastitic cows and was related to higher loge of somatic cell count. No significant difference was observed between mastitic and non-mastitic cows for vitamin A and beta-carotene in milk. Lower concentrations of plasma vitamin A and higher concentrations of beta-carotene during the immediate postpartum period were associated with higher milk somatic cell counts among dairy cows during lactation.
mesh_terms: D000818:Animals; D002338:Carotenoids / Q000097:blood / Q000378:metabolism*; D002417:Cattle; D005260:Female; D008414:Mastitis, Bovine / Q000378:metabolism*; D008892:Milk / Q000378:metabolism; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000378:metabolism / Q000662:veterinary*; D011645:Puerperal Infection / Q000378:metabolism / Q000662:veterinary*; D014801:Vitamin A / Q000097:blood / Q000378:metabolism*; D019207:beta Carotene
chemical_list: D019207:beta Carotene; D014801:Vitamin A; D002338:Carotenoids