Medycyna Wet. 66 (4), 228-231, 2010
| Bigoszewski M. , Janowski T. |
| Mechanisms of the influence of Fatty Liver Syndrome on hypothalamo-pituitary-ovarian axis functioning and fertility in cows |
| This review article describes mechanisms and consequences of fatty liver for the hypothalamo-pituitary-ovarian axis and fertility in cows. Massive lipolysis in dairy cattle which occurs post partum as a result of an inappropriate feeding strategy ante partum is connected with the progressive deprivation of lipid metabolism, increasing plasma level of non-esterified fatty acid, negative energy balance, a decreasing body condition score followed by fatty liver development. All these changes trigger hormonal and metabolic status mediator imbalance that affects reproduction. Low glucose, insulin, leptin, and Insulin-like Growth Factor – I post partum have an influence on pulsatile secretion of GnRH/LH, influence ovarian responsiveness to FSH and LH, and impair steroidogenesis. Metabolic status mediators not only influence the hypothalamo-pituitary-ovarian axis, but also each other. Consequently, delayed first ovulation, a prolonged calving to conception period, and an increased insemination rate are noticed. |
| Keywords: reproduction, fatty liver, hypothalamo-pituitary-ovarian axis, GnRH, LH |