Administration of pig relaxin to beef heifers 4 or 7 days pre partum

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...

Reproductive Management of Beef Heifers

Effects of bovine somatotropin administration on growth, physiological, and reproductive responses of replacement beef heifers.

This experiment compared growth, body composition, plasma IGF-I and leptin, and reproductive development of beef heifers receiving or not recombinant bovine ST (BST) beginning after weaning until the first breeding season. Fifty Angus × Hereford heifers (initial BW = 219 ± 2 kg; initial age = 208 ± 2 d), weaned at approximately 6 mo of age, were assigned to the experiment (d 0 to 210). On d 0, ...

Levels of Supplementation for Grazing Beef Heifers

The objective of this experiment was to evaluate the effect of providing different levels of a supplement on the nutritional characteristics and productive performance of heifers on pasture during the rainy-dry transition and dry season in Brazil or tropical area. Thirty crossbred heifers with predominance of Zebu breed were used in a completely randomized experimental design. Treatments consis...

Effects of Label-Dose Permethrin Administration on Reproductive Function and Embryo Quality on Superovulated Beef Heifers

and Implications Commercial pyrethroid pour-ons are commonly applied in cow-calf operations to eliminate the potential for insect borne diseases and to improve productivity. However, recent literature has focused on potential negative reproductive effects in the bull after exposure to pyrethroids. While the female bovine has been primarily neglected from the debated pyrethroid concern on reprod...