Comparative development of the small intestine in the turkey poult and Pekin duckling.

Turkey poults and Pekin ducklings hatch from eggs of similar weights and have the same incubation periods and body weights at hatch. The male Pekin duckling, however, can attain a market weight of 3.2 kg in approximately 6 wk, whereas at the same age, male turkeys only weigh approximately 2.1 kg. For this study, fertile turkey eggs (n = 400, mean weight: 87.2 g, range: 85 to 89.9 g) and Pekin duck eggs (n = 565, mean weight: 88.6 g, range: 85 to 92.0 g) were weighed and incubated. Embryos and hatchlings were sampled during the last week of incubation, at hatch, and through 7 d of age. Yolk-free BW of poults were 2.7 g heavier than ducklings at hatch. Yolk-free BW of ducklings, however, were greater than poults at 1 d of age (P > or = 0.06), and by 7 d of age ducklings were 140 g heavier (P < or = 0.01). Yolk sac weight was similar at 21 and 25 d of incubation, yet was significantly lower in ducks at hatch, 1, and 2 d of age (P < or = 0.05). In the duckling, jejunum and ileum weights (3.7x heavier), length (1.6x longer), and density (g/cm; 2.3x more dense) were consistently heavier than in the turkey from hatch through 7 d (P < or = 0.01). Histological sections of the distal jejunum revealed more rapid villus growth in the duck from 0 to 3 d of age. The combination of increased intestinal growth (weight and length) and maturation (villus length) allowed ducks to achieve an additional 143 g of BW gain during the critical hatch through 7 d of growth.