رفتار جنسی خوک نر

Two major characteristics of males that affect the likelihood of achieving copulation are the sexual motivation and mating competency of the male. The behavior of domestic animals, including their sexual behavior, is dependent upon a complex interaction between the organism's internal and external environment. In male pigs, as in other mammalian species, it is clear that testicular steroids are required to maintain sexual behavior and testosterone plays a critical role. Consistent with studies in other species, it is apparent in male pigs that there is a threshold circulating concentration of androgens and/or estrogens required to maintain sexual behavior and that the level of sexual motivation is unrelated to levels of sex steroids providing these are adequate for normal sexual behavior. Key aspects of the external environment that affect the sexual behavior of the male pig include genetic, seasonal, social, sexual and psychological factors.

Sexual behavior has evolved to ultimately result in the deposition of sufficient viable spermatozoa in the reproductive tract of the female at the optimum time of the estrous cycle to ensure conception. While there is little documented evidence of poor sexual behavior in commercial male pigs (boars), early reports from artificial insemination centers and commercial piggeries indicate that up to 49% of culled boars were unable to copulate or copulate at sufficient frequency (Melrose, 1966), while Rasbech (1969) suggested that about 50% of culled boars were eliminated due to poor semen quality or sexual behavioral problems. This situation may not have changed much today. Low levels of sexual behavior result from either low sexual motivation or poor mating competency, two major characteristics of males that affect the likelihood of achieving copulation. Sexual motivation, sometimes referred to as libido or sexual drive, refers to the tendency to copulate. Mating competency, sometimes referred to as mating dexterity, is the ability to copulate, that is the ability to mount, gain an erection, thrust, achieve intromission and ejaculate. Poor mating competency, if not too serious, may be overcome in some situations where matings are supervised and assisted by stockpeople. Under a general model of the control of behavior (Fraser and Broom, 1997), poor mating competency that leads to reduced mating success and consequently less positive feedback on motivation may lead in turn to poor sexual motivation. Male sexual behavior is obviously necessary to achieve impregnation in natural mating systems. Furthermore, the level of male sexual behavior may affect level of reproductive performance such as the number and timing of offspring produced, which have clear economic implications. The level of sexual behavior of rams and bulls in competitive and uncompetitive natural mating systems will affect numbers of females mated and pregnancy rate (Blockey, 1978 and Price et al., 1996). Furthermore, some studies have shown that a high level of sexual behavior in bulls can lead to greater weaning or marketing weights because the offspring are born earlier (Blockey, 1978). In artificial insemination centers, male sexual behavior is also obviously important in order to collect semen and to collect semen at the desired frequency.

Sexual behavior has evolved to ultimately result in the deposition of sufficient viable spermatozoa in the reproductive tract of the female at the optimum time of the estrous cycle to ensure conception. Two major characteristics of males that affect the likelihood of achieving copulation are the sexual motivation and mating competency of the male. The behavior of domestic animals, including their sexual behavior, is dependent upon a complex interaction between the organism's internal and external environment. An understanding of the regulation of sexual behavior is important in optimizing the reproductive performance of the boar.