title: Seasonal variation in serum levels of steroid hormones and their relation with seminal quality and libido in buffalo bulls.
abstract: Blood samples from 15 breeding male Murrah buffaloes were collected during the winter, summer and monsoon seasons. Seminal characteristics and sexual behaviour were also studied. Serum samples were analysed for testosterone, progesterone and estradiol-17beta levels by radioimmunoassay. The studies showed significantly lower values for testosterone during winter (0.53 +/- 0.06 ng/ml) than during summer (1.22 +/- 0.19 ng/ml) and monsoon (1.06 +/- 0.12 ng/ml). The progesterone level was lowest during monsoon (84 +/- 9 pg/ml), intermediate during winter (115 +/- 14 pg/ml) and highest during summer (224 +/- 24 pg/ml). The mean level of estradiol-17beta was almost double (9 +/- 0.7 pg/ml) during monsoon as compared to winter (5 +/- 0.1 pg/ml). The correlations between hormone levels, seminal characteristics and sexual behaviour were of low magnitude.
authors.affiliation: Department of Veterinary Physiology Haryana Agricultural University Hisar-125 004, India.
authors.forename: N K
authors.initials: NK
authors.lastname: Dixit
authors.forename: S P
authors.initials: SP
authors.lastname: Agarwal
authors.forename: V K
authors.initials: VK
authors.lastname: Agarwal
authors.forename: P K
authors.initials: PK
authors.lastname: Dwaraknath