Seasonal effect on the scrotal circumference, concentration of testosterone and some biochemical parameters in Nuaimie breed rams in Salah-din province

Abstract

The current study aimed to determine the effect of the seasons on the scrotal circumference, serum concentration of testosterone and some of the chemical parameters in Nuaimie breed rams in Salah-din province. Thirteen Nuaimie rams were used in this study. They were 3-4 years old and weighed 45-55 kg reared in a herd of sheep in Tikrit for the period from 15-8-2016 to 15-7-2017. Results showed that the scrotal circumference increased significantly (P≤0.05) during autumn (30.58±0.54 cm) and reaches lowest value during summer (29±0.32 cm). Highest concentration (P≤0.05) of testosterone was recorded in winter and autumn and lowest concentration in the spring and summer. The chemical analysis of ram blood serum revealed that the season has an effect on the value of triglyceride, glucose and cholesterol and the significant increase were recorded in autumn and winter. In conclusion, the reproduction in Nuaimi breed rams is characterized by distinct seasonal variations in scrotal circumference and blood testosterone concentration and that the highest measurements of these parameters are in autumn season. The season has a clear effect on the levels of triglycerides, glucose and cholesterol in ram's blood serum, which may give a good indication of reproductive performance in rams.