Serum Profile of Thyroid Hormones from Birth to Puberty in Buffalo Calves and Heifers

In tropical countries, unlike other dairy animals the buffalo presents the farmers with problems of growth and late maturity, which reduces their total life time productivity. The exotic buffalo heifers have been reported to reach puberty at the age of 15 - 16 months and 15 - 17 months in Italy and Egypt, respectively. In contrast, our indigenous buffalo breeds, namely, Nili-Ravi, Surti and Mehsana reach puberty at an age of 26, 28.2 and 30.1 months, respectively. Murrah buffaloes exhibit delayed maturity even more, which limits their productive life. The study investigated the serum thyroid patterns in female Murrah buffalo calves and heifers from birth to puberty. TSH concentration did not differ and remained almost the same from birth to 4 - 6 mths. The TSH then gradually increased and reached a highest value at 24 - 30 mths. The TSH concentration recorded at 21 - 24 mths and 24 - 30 mths i.e. at the age of attaining the puberty, was about 3 - 4 times higher than recorded at birth. The T3 concentration recorded at 0 - 7 days of age was significantly higher than recorded for other age groups, except at 18 - 21 mths, 21 - 24 mths and 24 - 30 mths. The T3 concentration did not exhibit specific trend during the ages 16 days - 1 mth to 15 - 18 mths. The highest T4 concentration was recorded in 0 - 7 days old buffalo calves. The concentration decreased to lower value at 1 - 2 mths. The T4 concentration from 2 - 4 mths of age increased significantly and the values remained almost similar with minor fluctuations upto 24 -30 mths. The T4 : T3 ratio recorded at different ages did not exhibit specific trend