Prepartum and postpartum levels of progesterone and estradiol in beef heifers fed two levels of energy.

Influence of prepartum nutrition on the reproductive performance of beef females and the performance of their progeny.

Two experiments were designed to assess the importance of maternal nutrition in the later stages of gestation on reproductive performance of beef females and on the growth and survival of their calves. In experiment 1, 59 Hereford first-calf heifers were assigned to one of two levels of dietary energy (high [HI which was 100% of the recommended level of prepartum energy or low [L] which was 65%...

Production from first-calf beef heifers fed a maintenance or low level of prepartum nutrition and ruminally undegradable or degradable protein postpartum.

Two experiments were conducted in consecutive years to determine the effects of prepartum nutrient level and postpartum ruminally undegraded protein intake on nutrient status, milk production, subsequent calf production, and reproductive performance of 126 crossbred, primiparous beef heifers. Prepartum treatments were low nutrient intake (LN) (approximately 2.5 kg of TDN, .5 kg of CP animal-1.d...

Influence of pre- and post-partum nutrition on LH secretion in suckled postpartum beef heifers.

The influence of nutrition during the last trimester of pregnancy and the early postpartum period on postpartum LH secretion was evaluated in two-year-old Hereford and Simmental heifers maintained on a high or low plane of nutrition (experiment 1) or in Hereford heifers fed a high or low energy (150% vs 100% NRC) ration (experiment 2). Amount of LH released with 10 mg estradiol benzoate (IM) at...

response of lactating karakul ewes to two levels of exogenous estradiol 17.B along with progesterone and pregnant mare serum for induction of fertile estrus at early postpartum

Characterization of hormonal patterns in the beef cow during postpartum anestrus.

Levels of luteinizing hormone (LH), prolactin, progesterone, cortisol, estrone and estradiol-17~ were determined during the postpartum anestrous period in samples collected from six second-calf, crossbred, suckled beef cows. Blood samples were collected at 6-h intervals beginning 2 wk before expected parturition and continuing until 10 d after first postpartum estrus. Samples were also collecte...