Biomedical subjects

R Borgwardt

Publications and source records attributed to R Borgwardt.

4 recordsLinked to original sources

PubMed1998

Early sexual experience fails to enhance sexual performance in male goats.

We studied the effects of early sexual experience on the adult sexual performance of male dairy goats. Seven postpubertal males were exposed to an estrous female on four occasions during their 1st yr of life. These males were housed with six additional males (controls) that received no early sexual experience. As yearlings, the 13 males were individually exposed to two estrous does for 30 min on three occasions at weekly intervals. Mounts with and without ejaculation were recorded. Sexually experienced and inexperienced males did not differ for either of these variables or a measure of mating efficiency (mounts per ejaculation). Mating efficiency improved for the experimental males during their four initial exposures to estrous females (P < .05). We conclude that male goats, in contrast to male sheep, are not likely to exhibit substandard sexual performance if denied heterosexual experience in their 1st yr.

Animals↗

PubMed1996

Repeated matings with individual ewes by rams differing in sexual performance.

Twenty-four sexually mature rams were individually exposed to 10 estrous ewes on three occasions to determine the relationship between levels of sexual performance (ejaculation rate or serving capacity) and the incidence of repeated matings (ejaculations) with individual ewes. Rams that attained six ejaculations in a relatively short period of time (HP rams) mated fewer times with individual ewes than low-performing (LP) rams (P < .01). As a consequence, HP rams tended to mate with a greater number of different ewes than did LP rams (P < .06). In addition, time required to attain six ejaculations was inversely correlated with the number of different ewes mated (P < .03). The HP rams did not differ from LP rams in the number of different ewes investigated and courted. These findings highlight the value of using rams with relatively rapid ejaculation rates when breeding large groups of naturally cycling or synchronized ewes.

Animal Husbandry↗

PubMed1994

Fostering in swine as affected by age of offspring.

Forty-eight pigs were fostered at 2 to 9 h or at 2, 4, or 7 d of age to determine age-related differences in the behavioral interactions between fostered pigs, resident pigs, and the sow during the first 6 h after fostering. Pigs were fostered in pairs to sows with litters of comparable age. In each test, the two fostered pigs and two resident pigs of similar body weight were observed for 6 h, and rate of ambulation, successful and unsuccessful suckling attempts, vocalizations, and approaches to within a body length of the sow's snout were recorded. Sniffs and aggression directed at the fostered and resident pigs by the sow were also recorded. Eleven of 12 pigs fostered at 2 to 9 h of age met the criterion for successful suckling within 6 h of fostering. Suckling success at the three older ages (2, 4, and 7 d) was much lower (25 to 50%; P < .005) after 6 h had passed. The behavior of pigs fostered at 2 to 9 h was similar to that of the resident pigs at all ages, whereas the pigs fostered at 2, 4, or 7 d showed a greater reluctance to engage in suckling, higher rates of ambulation, and more frequent vocalizations. Sows tended to be more aggressive toward older fostered pigs. It was concluded that fostering pigs older than 1 to 2 d of age will slow the rate at which they integrate into the new sow-litter environment and engage in suckling behaviors.

Adaptation, Physiological↗

PubMed1992

Measures of libido and their relation to serving capacity in the ram.

The purpose of this study was to determine whether the ejaculation rate (serving capacity) of sexually experienced rams could be estimated by selected measures of sexual libido when rams were exposed to estrous ewes under conditions that prevented copulations. Twenty-four crossbred rams selected for either high or low rates of copulation were exposed to two restrained estrous ewes under three treatment conditions that 1) permitted the full range of precopulatory and copulatory behaviors, 2) permitted precopulatory behaviors and mounting but precluded copulation, or 3) permitted precopulatory behaviors but not mounting or copulation. Frequencies of precopulatory behaviors (bouts of leg-kicking and anogenital sniffing) in each of the three treatment conditions and mounting frequency in Treatment 2 occurred in proportion to the ram's characteristic ejaculation rate (P < .001), suggesting that the mating potential of rams can be estimated under conditions that preclude copulation. Frequencies of precopulatory behaviors and mounting were lower when the rams were allowed to copulate, due largely to periods of sexual inactivity after ejaculations.

Animals↗