Abstract
A successful mating involves the coordination of many physiological events including insemination, gamete transport and ovulation. As more basic information about these processes becomes available, it is apparent that there are opportunities for manipulating these physiological events and enhancing the reproductive success of natural and artificial matings. The primary intent of this review is to examine the effectiveness of several of these strategies, as determined by their influence on farrowing rate and litter size. It is evident that the timing, duration and pattern of ovulation in pigs are extremely variable. Thus, increasing the frequency and changing the timing of matings during oestrus has received renewed interest. In general, if a female exhibits oestrus for more than 1 day, then increasing the frequency of matings has a greater influence on reproductive performance than does altering the timing of matings. In addition, litter size is more responsive to increased mating frequencies than is farrowing rate. Increasing the number of matings per oestrus via the use of combinations of natural service and artificial insemination, compared with the use of either alone, appears to enhance reproductive performance. It has been well documented that several aspects of the mating process itself can advance the onset of ovulation and enhance sperm transport and storage in the female reproductive tract. As a result, the use of these stimuli in conjunction with natural and artificial matings provide opportunities for enhancing fecundity. Pre- and post-breeding treatments with vasectomized boars, nonviable semen, oestrogens and seminal plasma have all been reported to increase farrowing rate and litter size. With artificial insemination, additions of prostaglandins, oxytocin, oestrogens and leucocytes to semen have been reported to enhance reproductive performance, albeit with varying degrees of success. Personnel and boar needs are important components in optimizing breeding management. Estimates of these needs for artificial and natural matings are discussed.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
