Effect of chronic treatment with bromocryptine on the corpus luteum function of the cow

Abstract

Six heifers received an intramuscular injection of 15 mg bromocryptine twice daily from day 1 (the day of standing oestrus was defined as day 0) until 50 h after the start of luteal regression. The overall mean level of prolactin was 0.22 __ 0.01 #g/1 (SEM; n = 6) in the bromocryptine-treated group and 10.7 + 2.7 ttg/1 (SEM; n=6) in the control group. No significant differences in the overall mean level of progesterone and LH, the mean length of the early-luteal phase, the luteal phase and the period of luteal regression were measured between the two groups. The results provide strong evidence that prolactin has no luteotrophic properties in the cow during the oestrous cycle.

Synthetic Alkaloid Treatment Influences the Intestinal Epithelium and Mesenteric Adipose Transcriptome in Holstein Steers

“…Lactating cows fed endophyte-infected fescue or treated with bromocriptine had over 90% of differentially expressed genes (>850 genes) influenced in a similar manner when compared with control cows (15). Doses of bromocriptine have ranged from 15 to 80 mg/animal, and treatment frequencies have ranged from two times a day to three times per week (16)(17)(18)(19)(20) but provide a model to decrease prolactin and initiate fescue toxicosis symptoms in cattle with much greater control by not relying on animal intake. Thus, the hypothesis of this study was that ergot alkaloid exposure via bromocriptine treatment would impact the transcriptome of the intestinal epithelium and mesenteric adipose tissue relevant to beef production of growing Holstein steers without impacting feed intake.…”