Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.
Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.
INFLUENCE OF BETA-CAROTENE SUPPLEMENTATION ON BOVINE REPRODUCTION (DAIRY CATTLE, PROGESTERONE)
Abstract
Five experiments were conducted to determine the endocrine response and reproductive performance of dairy cattle provided 300-600 mg supplemental beta-carotene daily. Supplementation increased concentrations of beta-carotene in the blood after 1 to 2 wk compared to control animals in each experiment. Experiment 1 consisted of three trials and a total of 56 Holstein heifers. Treatment periods were from 11 to 13 wk. Concentration of progesterone and LH in blood serum, intervals from prostaglandin F(,2) (PGF(,2(alpha))) to estrus and preovulatory LH peak or estrual activity following PGF(,2(alpha)) injection were not altered by supplemental beta-carotene. Experiment 2 utilized 23 prepubertal Holstein heifers during a 45 wk treatment period. Supplemental beta-carotene had no effect on hormone profiles during the estrous cycle and during luteolysis or on releasable progesterone at d 11 to 13 of the estrous cycle. However, the total progesterone release in response to administration of human chorionic gonadotropin was greater at 2 to 3 mo gestation in the beta-carotene supplemented heifers. In experiment 3, 13 Holstein cows were fed either 0 or 600 mg supplemental beta-carotene daily for 27 wk. Supplemental beta-carotene had no effect on basal concentrations of LH in blood, frequency and amplitude of LH pulses or release of LH in response to GnRH in ovariectomized cows. The fourth experiment consisted of two trials with a total of 57 Holstein cows. The treatment period was from 30 d before parturition to 98 d postpartum. Supplemental beta-carotene reduced the incidence of calving difficulty in trial 1 only. No effects were noted on incidences of placental retention, ovarian cysts or mastitis, rate of uterine involution or fertility. Experiment 5, involving 54 Holstein cows was conducted from d 3 to d 98 postpartum. Clinical mastitis was reduced by beta-carotene supplementation but rate of uterine involution, ovarian cyclicity and activity were not altered. From these results it was concluded that although feeding supplemental beta-carotene increased the concentration of beta-carotene in the blood it had no major influence on reproduction in Holstein heifers or cows.
Subject Area
Livestock
Recommended Citation
WANG, JIA-YU, "INFLUENCE OF BETA-CAROTENE SUPPLEMENTATION ON BOVINE REPRODUCTION (DAIRY CATTLE, PROGESTERONE)" (1986). ETD collection for University of Nebraska-Lincoln. AAI8624620.
https://digitalcommons.unl.edu/dissertations/AAI8624620