Evaluating bull fertility based on non-return method

Abstract

Za ocenu reproduktivnih rezultata krava i junica koriste se različiti parametri plodnosti i to servis period, indeks osemenjavanja, me|utelidbeno vreme i drugo, a za bikove u priplodu vrednosti dobijene nonreturn metodom. Da bi ejakulat u Centrima za v.o. bio uzet u dalju obradu potrebno je da se zadovolje propisani parametri kvaliteta. Ocena parametara ejakulata obuhvata makroskopsku (volumen, boja, konzistencija, miris i pH vrednost) i mikroskopsku ocenu (pokretljivost, gustina, procenat živih i patološki oštećenih spermatozoida). Pored kvaliteta sperme i plodnosti ženske jedinke, na rezultate non-return metode utiče i čitav niz egzogenih uzroka (godišnje doba, starost, rasa, tehnika osemenjavanja) koji imaju ne mali uticaj na krajnji rezultat osemenjavanja – steonost. U cilju dobijanja što objektivnijeg rezultata plodnosti bikova, pristupilo se rešavanju sledećih zadataka: 1. da se non-return metodom izračuna plodnost bikova na preko 10.000 po prvi put osemenjenih krava – junica, u periodu od 6 godina i 2. da se analizira uticaj kvaliteta semena, godišnjeg doba, starosti plotkinje i bika, rase bika na dobijene rezultate plodnosti.

In order to evaluate the results of reproductive cows and heifers, different parameters of fertility are used, such as the service period, insemination index, intercalving time and others, and of the breeding bulls the values obtained through non-return. An ejaculate is taken up for further processing by veterinary centres only provided it meets the prescribed quality parameters. Rating semen parameters includes a macroscopic (volume, colour, consistency, smell and pH) and a microscopic evaluation (mobility, density, percentage of live sperm and abnormal and damaged sperm). In addition to sperm quality and the fertility of the female animal, the results of the non-return method are also influenced by a number of exogenous causes (season, age, race, insemination techniques) that have no small impact on the end result of insemination - pregnancy. In order to obtain more objective results of the fertility of bulls the following tasks were undertaken, namely: 1. to calculate with the non-return method the fertility of bulls in over 10,000 cows inseminated for the first time during a period of 6 years; and 2. to analyze the impact of semen quality, season, age of cow and bull, and the bull breed on the results of fertility.