Life Sciences Commons^™

Physiology Of Male Reproduction, R. P. Amann, B. D. Schanbacher

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The major advances over the past 25 yr in male reproductive physiology of cattle, sheep, swine and horses are reviewed. Those findings which have allowed efficient culling of subfertile males and exploitation of the reproductive capacity of genetically superior sires are emphasized.

Hormones secreted by the male gonad early in gestation induce regression of potentially female structures and development of the male reproductive tract. Compartmentalization of the testis and formation of the bloodtestis barrier during prepubertal development permit the steroidogenic and gametogenic activities of the adult testes to proceed normally. The role of the central nervous system, hypothalamus and anterior …

G83-666 Breeding Soundness Examination Of Beef Bulls, James A. Gosey

University of Nebraska-Lincoln Extension: Historical Materials

This NebGuide describes factors to consider when evaluating a beef bull's reproductive ability. These include the reproductive tract, semen and mating desire. A herd bull that will settle a higher percentage of cows during a limited breeding season is essential to a successful cow-calf operation. In many cow-calf operations, however, the bull's role in the herd's reproductive performance is taken for granted. The bull's fertility is several times more important than that of a cow. Each bull can be expected to settle as many as 30 cows. The bull also contributes half of the genetic potential of the entire calf …