01898naa a2200217 a 450000100080000000500110000800800410001902200140006010000200007424500570009426000090015130000150016049000310017552012770020665000120148365000120149565000300150765000120153765000100154977301210155910095572018-02-03       2013    bl uuuu     u00u1 u    #d  a1688-92661 aWETTEMANN, R.P.  aNutritional influences on reproduction of beef cows.  c2013  ap. 247-264  a(INIA Serie Técnica; 208)  aABSTRACT.  Production of weaned calves is relatively inefficient. Many cows and heifers exposed to bulls do not become pregnant because they are not in estrus during the breeding season. Losses from less than optimal reproductive performance also results in reduced weaning weights of younger calves the next year. Body energy reserves and nutrient intake are major regulators of reproduction of beef cows. Inadequate body energy reserves at parturition increase the interval to first estrus and ovulation, and postpartum nutrient intake can influence length of the anestrous interval in cows with thin to moderate body condition score (BCS). Nutritional restriction causes decreased secretion of gonadotropin releasing hormone and luteinizing hormone, reduces follicular growth, and decreases concentrations of estradiol in plasma. In addition to direct and indirect effects of decreased energy intake on the hypothalamus and pituitary, nutrition may influence ovarian function. Adequate body energy stores and sufficient plasma concentrations of metabolic regulators, are necessary for ovulation in postpartum cows. Complex interactions between hormones, metabolic compounds and other signals control follicular maturation, estrus, and ovulation in postpartum beef cows.  aANESTRO  aBOVINOS  aNUTRICION DE LOS ANIMALES  aURUGUAY  aVACAS  tIn: QUINTANS, G.; SCARSI, A. (Eds.). Seminario de actualización técnica: cría vacuna Montevideo (UY): INIA, 2013.