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Biomedical subjects

R L Snyder

Publications and source records attributed to R L Snyder.

At least 73 records · Page 4Linked to original sources

Sexual maturity and persistency of lay in the Chukar partridge given stimulatory light at different ages.

In two separate trials, age at sexual maturity (lay of 1st egg) and total eggs laid in a 13-week production period were determined for the Chukar partridge given stimulatory light at 16, 18, 20, 22, 24, 26, 28 or 30 weeks. The best responses occurred with hens given stimulatory light when 26 weeks of age or older. More than 85 percent of these hens laid, and production ranged from 15 to 25 eggs per hen. The youngest age at 1st egg was 161 days, required by one hen given stimulatory light at 16 weeks. Many hens given stimulatory light at 24 weeks or younger failed to lay, and egg production was extremely poor in those that did lay. Based on our results, best egg production can be attained when birds are given stimulatory light at 28 weeks, allowed to lay for 13 weeks, then cycled to lay again when 50 weeks of age. Hens of superior laying ability can be detected in the first cycle of lay, thus reducing the time that would be required to identify these same birds if allowed to lay under natural daylight conditions.

Age Factors↗

Effect of forced molting on quantity and quality of semen in turkey breeder males as influenced by diet.

Broad Breasted White turkey males were induced to molt by imposing periods of nonstimulatory light and short periods of water and feed deprival starting at 54 weeks of age. Birds kept under 8 or 10 hours of light per day began to molt within 3 weeks, and most had terminated semen production within 4 weeks. When returned to stimulatory light, the birds began to produce semen within 4 weeks and reached peak production within 10 weeks. However, this level of production was lower than the original level attained as young birds. The recycled males produced approximately 20 percent more semen than the males kept under constant stimulatory light, and the semen from the recycled males contained 1 to 2 billion additional sperm per ml. The percentage of normal sperm decreased with increase in age of birds irrespective of light treatment. A skip-a-day-per-week feeding schedule imposed on all males from 54 to 78 weeks of age had no appreciable effect on body weight or efficiency of feed utilization. Also, imposition of feed and water restrictions had no apparent effect on early termination or recovery of semen production.

Animal Feed↗