Variation in Testicular Morphometric Traits in Djallonke Sheep of North and South Ecotypes of Benin and their Relationships with Body Weight and Characteristics

Abstract

The study aims to determine the variability of testicular morphometric traits in Djallonke sheep reared under traditional system in Benin according to the ecotype and their relationships with their body traits. Data were collected from November 2014 to December 2015 on 21 rams of North ecotype and 24 rams of South ecotype of 12 months old. It appears that chest circumference, back width, pelvis length, paired testes weight, testes length, testes diameter, testes volume, testes density, paired epididymal weight, epididymal length, epididymal volume, and the epididymal density depend on ecotype (P˂0.05). The highest chest circumference (69.24 vs 73.29 cm), back width (15.78 vs 14 cm) and pelvis length (23.03 vs 16.8 cm) were recorded in the animals of North ecotype (P˂0.05). similarly, the highest values (P˂0.05) of paired testes weight, testes length, testes diameter, testes volume, testes density, paired epididymal weight, epididymal length, epididymal volume, and the epididymal density were found in rams of North ecotype (respectively of 300.86g, 6.91 cm, 4.82cm, 146.14 ml, 1.02 g/cm 3 , 27.8 g and 20.1 cm). However, the head length, whither's height, scapulo-ischium length, scrotal length, scrotal circumference, epididymal volume and the epididymal density were similar among ecotypes and was respectively on average 18.21 cm; 54.64 cm; 60.61 cm; 14.09 cm; 22.17cm; 15.35ml and 0.87g/cm 3. In sheep of South ecotype, the live weight was strongly and positively associated with scrotal length, scrotal circumference, paired testes weight, testes length, testes diameter, testes volume, paired epididymal weight, epididymal length and epididymal volume (0.80≤ r ≤0.90; P<0.001); while in sheep of North ecotype, the live weight was proportional to scrotal circumference, paired testes weight, testes length, testes diameter, testes volume, paired epididymal weight, epididymal length and epididymal volume (0.87≤ r ≤0.99; P<0.001). Therefore, improve live weigth will improve the gonads traits as a correlated response.