Abstract
Reproductive efficiency represented by sexual desire, semen quality, testicular dimensions, and level of sex hormones are among the main components of ram fertility, which affect the fertility and productivity of the herd. Since the development of the testicles is related to reproductive activity and the ability to fertilize, so measuring the dimensions of the testicles is important in evaluating the reproductive capacity of rams. In addition, the concentration of testosterone is reflected in most of the characteristics of male sexual behavior, as it is positively and significantly correlated with ejaculate volume, mass motility, and sperm concentration. The high level of testosterone hormone in the blood plasma during reproductive season leads to an increase in male sexual desire and an improvement in the quality of semen through direct influence in the process of sperm formation and the volume ejaculate, density and vitality of semen. In addition to reproductive traits are also affected by age, body weight, season and herd management, as well as the impact of the environmental conditions, which are temperature, humidity, level of nutrition, quantity and quality, and length of the photoperiod, which is one of the most important factors affecting the reproductive performance of rams.
