Morphological Studies on the Adrenal Gland of Kuttanad Ducks (Anas platyrhynchos domesticus) During Post Hatch Period

Abstract

Post hatch development of adrenal gland in Kuttanad ducks was studied using 78 female birds ranging from day-old to 24 weeks of age. Adrenal glands were collected from six birds in each age group at fortnightly intervals. The glands were too small in the day-old ducklings and were located in the body cavity ventral to the anterior pole of cephalic lobe of kidney just posterior to the lungs. The left adrenal was closely related to the ovary in all the age groups and was deeply embedded in the ovary occasionally. In day-old ducklings, both the glands were globular in shape but later the right adrenal became roughly pyramidal with the apex pointing caudally, while the left one was elongated and flattened dorsoventrally. The glands were cream or yellow in colour in younger birds, but later the colour changed to brown. The left adrenal gland was slightly heavier than the right in all the age groups. The mean weight of the gland increased progressively from day-old to 12 weeks of age and thereafter it showed an irregular pattern up to sexual maturity. The absolute mean adrenal weight in Kuttanad duck was 6.27 mg per 100 g body weight at 12th week of age and reached a level of 5.31 mg at 16th week (at the beginning of egg laying) and again increased to 9.60 mg per 100 g body weight at 24 weeks of age. The combined adrenal weight was more correlated with the age than with the body weight. The proportionate mean weight of the adrenal glands to the body weight showed a decreasing trend