Ảnh hưởng của tuổi và mùa vụ đến testosterone của cừu Phan Rang nuôi tại Trung tâm Nghiên cứu và Phát triển Chăn nuôi gia súc lớn

Abstract

The purpose of this study was to monitor serum testosterone concentrations in male Phan Rang sheep according to season and age. The study was conducted on 20 male Phan Rang sheep weaned at two months of age and 30 adult male sheep (10 two-year-old sheep, 10 three-year-old sheep and 10 four-year-old sheep at the beginning of the monitoring period). Blood samples were taken from the jugular vein once a month, serum was collected, and testosterone concentrations were determined by electrochemiluminescence using the Cobas E601 immunoassay system. The results showed that the average serum testosterone concentration in sheep under 12 months ranged from 0.53 to 11.50 ng/ml and gradually increased with each month of age, with stability from the ninth month of age. Serum testosterone concentrations in male Phan Rang sheep varied significantly with season, with higher levels observed during the rainy season than during the dry season. The lowest plasma testosterone concentration was 4.12±0.73 ng/ml (in four-year-old sheep, in February), while the highest was 12.25±2.27 ng/ml (in two-year-old sheep, in November). The findings of this study contribute to the rational utilisation and reproductive support of Phan
Rang sheep.