Annual Change of the Testosterone Hormone in Male White Goats

In this research,changes of testosterone hormone in the blood serum of 9 male(3 of age 2 and 6 of age 4) White goats have been studied for a duration of one year.Analyses performed show that the general monthly averages of the testosterone hormone of the male White goats in the period of 12 months starting in January were(2.11±.73),(2.22±.52),(2.44±.59),(2.10±.41),(2.35±.00),(3.42±.48),(4.77±.32),(5.61±.40),(7.91±.24),(10.84±.59),(7.82±.60),and(2.63±.61) ng mL-1,respectively(P<0.05).The effect of the age factor on the testosterone production in White goats(age 2 and 4) was generally significant(P <0.05) for differences among months in each age group,but not significant for differences between age groups in each month.The testosterone hormone levels of male White goats encountered significant changes(P<0.05) with respect to the season.