Use of prostaglandin F<SUB><SUB>2α</SUB></SUB> and pregnant mare serum gonadotropin for estrous synchronization in beef cows

Pregnant Mare Serum Gonadotropin

Procedures have been developed for the purification of pregnant mare serum gonadotropin (PMSG) and its a and jl subunits. The procedure for the hormone purification involves three steps of column chromatography on Sephadex G-100, DEAE-Sephadex A-50, and hydroxyapatite. The preparation of subunits involves the dissociation of PMSG with 10 M urea followed by their separation by chromatography on ...

Estrous Synchronization in Lactating Cows

Product Development for Estrous Synchronization : Beef Cattle

Physiological principals underlying synchronization of estrus identified 1) hormones naturally controlling the estrous cycle of cattle, 2) hormones commercially available, 3) mode of action of the hormones commercially available, and 4) when/how they might be used to manage estrus and breeding of beef cattle. The products available are progestogens (melengestrol acetate (MGA) and progesterone d...

Evaluation of luteolysis and estrous synchronization by a prostaglandin analog (Luprostiol) in Brahman cows and heifers.

A trial was conducted to evaluate the ability of a prostaglandin analog, Luprostiol (LP), to synchronize estrus in Brahman cows and heifers. Animals were injected with either 0, 3.75, 7.5, 15 or 30 mg LP or 500 micrograms cloprostenol (CLP) on d 8 or 9 after estrus (d 0). All concentrations of LP (greater than 0 mg) and CLP caused luteolysis in cows and heifers, as indicated by a decline (P les...

Estrous Synchronization Programs for Dairy Cows and Heifers

Introduction: Although milk production as measured by rolling herd averages has increased markedly for dairy herds in the Western United States over the last decade, reproductive performance of these herds has declined significantly. Average days open have increased by 25 days and fertility has declined as measured by an increase of 0.37 services per conception and first service conception rate...