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INTRODUCTION
An objective assessment of the reproductive qualities of male farm animals is based on a direct method based on insemination and the number of pregnancies that have occurred. However, it takes a long time. In some cases, a convenient and quick indirect method is used, based on laboratory assessment of quantitative and qualitative parameters of sperm, such as motility, concentration, morphology and viability of semen and other parameters (Morrell et al., 2017).
Long-term studies show that changes in the characteristics of these indicators are influenced by external factors, such as ambient temperature, humidity, pressure, feeding level and housing conditions (Bhakat, 2014; Brown, 1994; Ibrahim, 1997; Mislei et al., 2020), as well as internal, such as breed, age, collection frequency and ejaculate number (Folch, 1984; Leahy and Gadella, 2011; Turner, 2019).
The photoperiod affects the production of hormones and, as a result, the quality parameters of semen and the sexual behavior of males, which differ in the breeding season and the period of non-breeding (Leahy et al., 2010). The manifestation of these fluctuations is influenced by the genetic factor, i.e. the geographical location of the breed. For example, sheep raised in mid-latitudes > 40° are more seasonal (Ibrahim, 1997) than sheep from tropical and subtropical regions 10-30° (Chemineau et al., 1986). In the process of gametogenesis in sheep and rams, there are significant differences, both at the behavioral and endocrine levels. In rams, the seasonal reactions of extinction (inhibition) of reproductive function are less pronounced, while the process of spermatogenesis in rams occurs throughout the year. This can make it possible to obtain semen from rams, accumulate it throughout the year and use it for insemination of sheep with good results (Magomedov, 2007).
Sheep breeding in Russia is a traditional type of farming activity that allows you to receive significant profits and natural products for marketing. However, the key problem remains the clearly pronounced seasonality of domestic breeds, in which the reproductive use of sheep occurs only during the breeding season (August-November).
Recently, great interest has been shown in the promising breed of the Dzhalginsky merino, developed in 2013 on the maternal basis of the Stavropol breed and Australian rams from the Uardry plant. Australian merino species are of agricultural importance in many countries and...