title: Effect of beta-carotene supplementation on reproductive performance of lactating Holstein cows.
abstract: Fifty-four lactating Holstein cows were assigned by parity and calving date to a 2 X 3 factorial arrangement of a randomized block design to determine effects of beta-carotene supplementation and ration fiber content on reproduction. Because ration fiber treatments did not differ in their effects on reproductive performance, data for beta-carotene analyses were pooled over the three rations. From 3 to 98 d postpartum, cows were individually fed either 0 or 300 mg supplemental beta-carotene daily by adding it on top of their complete mixed ration. By wk 3 postpartum, concentrations of beta-carotene in blood serum were higher in cows fed supplemental beta-carotene and remained higher throughout the experimental period. Feeding supplemental beta-carotene had no effect on the interval from the time of parturition to uterine involution, ovulation, first observed estrus, or conception. Feeding beta-carotene did not influence incidence of cystic follicles based on palpation, ovarian cyclicity based on blood progesterone patterns, peak progesterone concentrations, or first service conception rate. Cows fed supplemental beta-carotene required fewer treatments for clinical mastitis. Reproductive performance in lactating Holstein cows was not improved by feeding supplemental beta-carotene.
authors: Department of Animal Science, University of Nebraska, Lincoln 68583-0908.
authors: J Y
authors: JY
authors: Wang
authors: F G
authors: FG
authors: Owen
authors: L L
authors: LL
authors: Larson
mesh_terms: D000818:Animals; D002338:Carotenoids / Q000494:pharmacology*; D002417:Cattle / Q000502:physiology*; D005260:Female; D007774:Lactation / Q000187:drug effects*; D049590:Postpartum Period / Q000187:drug effects*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000187:drug effects*; D019207:beta Carotene
chemical_list: D019207:beta Carotene; D002338:Carotenoids