Effects of semen quality, the season, cows and a bull age, breed of bull on the fertility results obtained through Non Return method | Uticaj kvaliteta semena, godišnjeg doba, starosti plotkinje i bika i rase bika na rezultate plodnosti dobijene Non Return metodom
2011
Prka, I., Stočarsko veterinarski centar, Beograd - Krnjača (Serbia) | Vuković, D., Fakultet veterinarske medicine, Beograd (Serbia) | Perković, S., Stočarsko veterinarski centar, Beograd - Krnjača (Serbia)
For evaluation of cows and heifers reproductive results, different fertility parameters are used: service period, insemination index and inter-calving period. Fertility of breeding bulls is often estimated by non-return method. Bulls ejaculates must fulfill precise quality parameters to be submitted to further processing. Semen evaluation includes macroscopic (volume, color, consistency, smell and pH) and microscopic examination (mobility, density, percentage of live and damaged or abnormal sperm). Non-return method is defined as a ratio between number and percentage of inseminated cows over certain period of time. If cows are not showing signs of estrus 60 to 90 days (3 to 4 expected cycles) following insemination they are considered as pregnant. In addition to sperm quality and fertility of female individuals, the results AI are influenced by number of exogenous factors (season, age, race, insemination technique). All of them might have serious impact on the cows fertility. In this paper, we present results obtained by non return method following first artificial insemination of more than 10,000 heifers collected over 6 years period. We also analyzed the influence of semen quality, season, age of cow and a bull, bulls breed on the fertility results.
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