Study of Some Testicular Dimensions and Their Relationship to Body Weight in Karadi Ram Lambs

Abstract

This study was carried out to measure the development of some testicular traits and to investigate the relevance between testicular parameters with body growth in growing Karadi ram lambs. Twenty-seven single born Karadi ram lambs apparently clinical healthy, aged six months, were used. The Testicular measurements including: length, diameter, and circumference of their testes and body weight were recorded once monthly. The testicular measurement (cm) and body weight (kg) were subjected to linear (Y= a+bX) where, Y means the testicular measurement and X is the body weight, a and b are constants due to the intercept and the regression coefficient, respectively. The results revealed that there was a gradual and linear increase in testicular dimensions from six to eight months of age. The average scrotal circumference (SC) showed significant (P≤0.05) increase from 10.66±0.74 to 17.88±1.19 cm at 6 and eight months of age, respectively. Corresponding changes in the average testicular volume were found to be 14.31±3.66, 77.66±23.54 and 104.23±23.92 cm 3 at 6, 7 and eight months of age, respectively. All measurements of testis, live weight, were positively and significantly correlated with each other. While a significant positive correlation were found at seven and eight months of age between all testicular measurements. These results showed that testicular measurements, such us scrotal circumference, can be used as criteria for early selection of ram lambs to be utilize in breeding especially for young ages. Due to the strong correlation between body weight and testicular measurements, body measurements can be used to select Karadi ram lambs for breeding programs. However, further studies are needed to determine the relationship between these subjective morphological criteria and the actual fertility and semen quality in Karadi rams.