Early growth of oviducts, changes in plasma oestradiol-17beta concentration and response to oestrogen in weight increase of oviducts in guinea fowls and White Leghorn chickens.

摘要

Body weight, oviduct weight and plasma oestradiol-17beta (E2) concentration were measured every week from hatching to 10 weeks of age in guineafowls and White Leghorn (WL) fowls. Body weight was greater in guineafowls than in WLs from 3 weeks of age, and oviduct weight was also greater in guineafowls from 4 weeks of age. Oviduct weight per 100 g body weight did not show any appreciable change from 2 weeks of age in guineafowls and WLs, and no difference was observed between them. Plasma E2 concentration did not change up to 8 weeks of age in guineafowls, but increased after 4 weeks of age in WLs. When diethylstilboestrol was injected once daily for 5 consecutive days into guineafowls and WLs at 5 weeks of age, oviduct weight on the 6th day was found to be increased; the increase was proportional to the daily dose (62.5-1000μg/bird). The response in guineafowls was less than that of WLs. Similar injections were also made into guineafowls at 4 weeks of age, and the response was also less than thatof WL at 5 weeks of age. The results suggested that the greater oviduct weight in guineafowls compared with WLs during the early growth period may not be related to differences in oestrogen secretion or responsiveness to oestrogen.