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Biomedical subjects

D G Levis

Publications and source records attributed to D G Levis.

2 recordsLinked to original sources

Mating management.

The mating management of pigs is conducted under a wide spectrum of management techniques because females are variously hand-mated, pen-mated, or artificially inseminated. Factors that may affect the onset of estrus when hand-mating are boar exposure, method of housing females after weaning, season, type of facilities, and parity. The expression of sexual behavior in both male and female pigs can be influenced by a variety of physiologic, psychological, and environmental factors. To optimize the efficiency of estrous detection, females should not receive boar stimuli just prior to estrous detection when either hand-mated or artificially inseminated. When females are pen-mated, management procedures need to be employed to prevent an excessive number of estrous females from accumulating, which leads to a decrease in boar fertility.

Animal Husbandry

The influence of androgenic and estrogenic hormones on sexual behavior in castrated adult male pigs.

The objectives of these studies were to evaluate the influence of testosterone propionate (TP), estradiol cypionate (EC), dihydrotestosterone propionate (DHTP), EC + TP, EC + DHTP, and TP + DHTP on traits of masculine sexual behavior in castrated adult male pigs of different breeds. Masculine sexual behavior was restored and maintained by TP, whereas EC initially activated sexual behavior, including copulation and ejaculation, but was unable to sustain copulatory behavior for the 8- to 18-week periods that were evaluated. Treatment with DHTP was ineffective for stimulation of sexual behavior; thus, it is suggested that testosterone promotes some aspects of masculine sexual behavior in male pigs via aromatization to estrogen, but both androgen and estrogen are required for maintenance of the full complement of masculine sexual behavior traits.

Androgens