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Biomedical subjects

Peter J Chenoweth

Publications and source records attributed to Peter J Chenoweth.

5 recordsLinked to original sources

Efficacy of training in theriogenology as determined by a survey of veterinarians.

OBJECTIVE: To determine whether veterinarians perceive that theriogenology training at veterinary medical schools in North America and the Caribbean is adequate for achievement of theriogenology skills commonly used in private practice. PROCEDURES: A survey was mailed to members of the veterinary medical associations of Alabama, Kansas, Pennsylvania, and Washington. With regard to reproductive procedures in bovine, equine, porcine, small ruminant, camelid, and small animal species, veterinarians (predominantly practitioners) were asked to rate the importance of that procedure in their job and to assess their own degree of competency in that procedure at the time of their graduation from veterinary school. RESULTS: Procedures considered most valuable in practice were those that represent basic theriogenology education and training, such as transrectal palpation of cows and mares and interpretation of vaginal cytologic specimens in bitches. Dystocia management was a high priority in all species. Correlations between rankings for value in practice and competency at graduation were good, varying from 0.75 in cattle and 0.78 in horses to 0.98 in dogs and 1.0 in cats, small ruminants, and pigs. CONCLUSIONS: Analysis of these data suggests that appropriate theriogenology procedures are being taught in veterinary medical schools but perhaps not to the extent required to achieve adequate competency immediately at graduation. Issues requiring further investigation include the effect of tracking in the veterinary curriculum on theriogenology training, methods by which more students could receive greater practical exposure during theriogenology training, and the apparent relative lack of theriogenology training (including contraception) in small animals and exotic animals.

Animals↗

Availability of theriogenology training at North American and Caribbean veterinary colleges.

A survey of the veterinary colleges in North America and the Caribbean was undertaken to determine the extent of availability of theriogenology training. Didactic training in at least one species was required at all schools that responded to the survey. Laboratory experience in at least one species was required by 75.0% and clinical theriogenology experience in at least one species by 72.7%. The mean number of board-certified or board-eligible theriogenology faculty did not vary between 1995 and 2005, but there was a decrease in the number of such faculty at 57.2% of the schools that responded to the survey.

Animals↗

Genetic sperm defects.

Genetic sperm defects are specific sperm defects, which have been shown to have a genetic mode of transmission. Such genetic linkage, either direct or indirect, has been associated with a number of sperm defects in different species, with this number increasing with improved diagnostic capabilities. A number of sperm defects, which have proven or suspected genetic modes of transmission are discussed herein, with particular emphasis on cattle. These include: 1. Acrosome defects (knobbed, ruffled and incomplete); 2. Head defects (abnormal condensation, decapitated, round head, rolled head, nuclear crest); 3. Midpiece abnormalities ("Dag" defect, "corkscrew" defect, "pseudo-droplet" defect); 4. Tail defects ("tail stump" defect, primary ciliary dyskinesia).

Acrosome↗

Environmental, genetic and social factors affecting the expression of estrus in beef cows.

Genetic, social and environmental factors affecting behavioral estrus were evaluated in Angus (n = 10), Brahman (n = 10) and Senepol (n = 10) cows during a PGF2alpha synchronized estrus and subsequent spontaneous estrus. Cows were equally stratified by breed to two groups of 15. Both groups were pre-synchronized with a modified two-injection PGF2alpha protocol. At the start of the experiment, cows were treated with 25 mg PGF2alpha followed by a second and third administration of 12.5 mg PGF2alpha, 11 and 12 days later to induce synchronized estrus. The subsequent estrus was designated as spontaneous estrus. Behavioral estrus data including the onset and end of estrus, estrous duration and the total number of mounts received for the synchronized and spontaneous estruses were collected using HeatWatch". Interval from the third PGF2alpha, treatment to the onset of a HeatWatch" estrus occurred earlier (P < 0.05) in Angus (31 +/- 5 h) than Brahman (53 +/- 7 h) or Senepol (53 +/- 4 h) cows, with dominant Senepol and Brahman cows taking longer to exhibit estrus after PGF2alpha than subordinate cows. The duration of the synchronized estrus tended to be shorter (P < 0.06) in Senepol (12 +/- 3 h) than in Angus (19 +/- 2 h) or Brahman (17 +/- 2 h) cows. Behavioral estrus data between the two periods were confounded by greater temperature-humidity index (THI) values during spontaneous estrus. The THI during spontaneous estrus appeared (P = 0.09) to affect the duration of estrus (9 +/- 1 h versus 16 +/- 1 h) and did affect (P < 0.0001) the total number of mounts received (8 +/- 4 mounts versus 34 +/- 4 mounts) during spontaneous estrus compared to synchronized estrus. Breed had no effect (P > 0.10) on the duration and total number of mounts received during synchronized and spontaneous estruses. In conclusion, type of estrus (synchronized or spontaneous), THI, social dominance and breed exerted significant effects on characteristics associated with behavioral estrus in beef cattle in subtropical environments.

Animals↗