Some factors Influencing intercalving periods of imported and home-reared Holstein cattle in western Nigeria

Abstract

The average of 160 intercalving periods of 47 imported and 33 home-reared purebred Holsteins in western Nigeria during 1967-75 was 628( + 45) days. The probable effects of seven variables including origin of cow, sex of calf, season of calving, age of cow at calving, parity, year of calving and calf birth weight were investigated through an intra-class linear regression model in which the first three factors were treated as qualitative and the last four as quantitative factors. Origin of cow, sex of calf and season of calving did not significantly affect calving interval. Effects of age at calving, parity, year of calving and calf birth weight were highly significant (P < 0-01) but individual effects adjusted for others were not quite significant. These four quantitative factors were, however, highly interrelated; simple correlations which varied between 0-33 and 0-86 were highly significant. Interactions between the two sets of factors were negligible.

Embryonic mortality, calf production, calving interval and life span of imported Friesian cattle in western Nigeria

“…The observed small and inactive uteri of some animals during the breeding season also suggest that only heifers which possess desirable proven dairy traits and adaptation potentialities should be imported. Adeneye & Bamiduro (1980) have suggested ways of shortening calving intervals in the herd. Infertility, diseases and senescence were the apparently major causes of animal disposal (Table 4).…”