Reproductive capacities of control mallard ducks (Anas platyrhynchos) during a one-generation reproduction study
Piccirillo, V.J.; Quesenberry, R.P.
Journal of Environmental Pathology and Toxicology 4(5-6): 133-139
1980
ISSN/ISBN: 0146-4779 PMID: 7217841 Document Number: 154583
Reproduction data were studied over 1 generation for 75 female mallards (1 male and 5 females per pen). The pre-egg laying cycle lasted 10 wk. For the first 8 wk, the photoperiod was 7 h light per day, and was then increased to 17 h to induce laying. Eggs were collected daily for 8 wk, and were incubated. Shell thickness was measured on 1 egg from each pen every 2 wk. The mean reproductive index was 2.18% for number of eggs cracked as a percentage of number of eggs laid, 85.2% for number of viable 11-day-old embryos as a percentage of number of eggs set, 97.6% for number of live 21-day-old embryos as a percentage of number of viable 11-day-old ducklings, 80.6% for number of ducklings hatched as a percentage of number of live 21-day-old embryos, 89.3% for the number of viable 14-day-old ducklings as a percentage of the number of ducklings hatched.The mean egg shell thickness for 60 eggs was 0.378 mm.