Ultimobranchial gland in relation to age and egg laying cycle in chickens

The present study was planned to elucidate the developmental activities of the ultimobranchial gland in Fayoumy chicken at different ages with special emphasis on its activity during theegg laying cycle. The study has been conducted on 50 one-day old Fayoumy chicks kept unu e r tine usual sJstem of manageaerrt , Chicks were slaU0htered at the ages of 12, 17 and 22 weeks, respectively. At the age of maturity (32 weeks), laying henswere slaughtered 8 ho ur s , 16 hours, 24 hours and 32 hours after egg laying, respectively. The site and form of the egg insidethe reproductive tract were recorded. Serum was separatea from blood collected from each bird and was utilized for the deter- mination of calcitonin, total calcium, magnesium, inorganic phosphorus, phosphatase activities as well as sodium and pota-Ssium levels. At the sametime, the body weight was recorded and the ovaries and u~tiwbbrunchiul gland w~re weighed. Ultimobran- chial glands were kept separa~ely in Buain’s solution and were,sectioned for histolo6ica1 and hi~tochemical investigations usinb haematoxylin & eosin, tle~dennine’s iroll lla~matoxy~La anu per~odic acia schiff techniques of staining. Data were subjected to statistical analysis and the results were tabulated.The results revealed the following:1.Under the conditions of tIle present study, the weiglit of ultimobranchial gland was significantly higher at the age of 17 and 22 weeks wuen compared to its weight at the younger age; 12 weeks.