Influence of some non-genetic factors on fertility traits of cows in the black pied cattle population

Abstract

The results of investigation of some non-genetic factors on fertility traits of cows in the Black Pied cattle population are presented. The cows are of European Black and White cattle which are genetically improved with Holsteins. In total, there were 319 cows with 845 calvings. The influence of calving order, year and season of calving on insemination index service period, duration of pregnancy, calving interval and weight of calves at birth were investigated. The influence of independent factors was done by Least square method (Harvey, 1987). It was estemeted by investigation that calving order had very significant effect on duration of pregnancy and the weight of calves at calving (P lt 0,01), significant on insemination index (P lt 0,05) while non-significant effects were on service period and between calvings interval (P>0,05). The expected values were estimated for duration of pregnancy and calve weight at birth at heifers (277.96 days and 36.53 kg). The year of calving had very significant effect on insemination index and weight of calves at birth (P lt 0,01), while on service period, duration of pregnancy and calvings interval influence was not significant (P>0,05). Rather different influence was of season of calving, Table 3, which was very significant on insenination index (P lt 0,01), significant on duration of pregnancy (P lt 0,05) and non-significant (P>0.05) on other investigated traits.

S obzirom da je uspeh u poboljšanju plodnosti genetskim putem dosta ograničen, to na njeno poboljšanje se uglavnom može uticati preko paragenetskih činioca. U tom cilju vršena su ispitivanja uticaja teljenja po redu, godine i sezone teljenja na indeks osemenjavanja, servis period trajanje bremenitosti, međuteldidbeni interval i masu teladi pri rođenju. Istraživanja su obuhvatila 319 krava crno-bele rase oplemenjene genima holštajna, koje su ukupno imale 845 teljenja. Za analizu delovanja pojedinih uticaja na plodnost krava korišćen je metod najmanjih kvadrata -LSMLMW (Harvej, 1987),fiksni model. Teljenje po redu je visoko značajno uticalo na trajanje bremenitosti i masu teladi pri rođenju (P lt 0,01), a značajno na indeks osemenjavanja (P lt 0,05), za razliku od dužine trajanja servis perioda i međutelidbenog intervala, gde nije ispoljena statistička značajnost (P>0,05). Godina teljenja je visoko značajno uticala na indeks osemenjavanja i masu teladi pri rođenju (P lt 0,01), dok za ostale osobine plodnosti nije utvrđena stataistička značajnost (P>0,05). Sezona teljenja je statistički visoko značajno uticala na indeks osemenjavanja (P lt 0,OJ), značajno na trajanje bremenitosti (P lt 0,05), dok njen uticaj na dužinu servis perioda i međutelidbenog intervala, kao i mase teladi pri rođenju nije bio statistički značajan (P>0,05).