Abstract
The productivities of German Brown (GB) and German Holstein (GH) cattle and crosses with N'Dama in the Ibadan area of Nigeria were assessed, along with studies of environmental factors affecting productivity, between 1969 and 1982. Average lactation yield, yield day-1 and lactation length for GB cows were 2248 kg, 6.6 kg and 331 days, respectively; for GH cows they were 2262 kg, 6.6 kg and 336 days, respectively. Corresponding lactation traits between the two breeds were not significantly different. German Brown X N'Dama (GBF1) cows, on the other hand, had average lactation yield, yield day-1 and lactation length of 388 kg, 3.0 kg and 122 days, respectively, significantly (P<0.05) less than corresponding traits for the two exotic breeds. The effects of genotype of cow, parity and year of calving on lactation yield were significant (P<0.01), but the effect of season of calving was not. The average age at first calving was 39 months for imported GB heifers and 41 months for home-bred heifers. For GH heifers it was 34 months for the imported, and 36 months for home-bred animals. In comparison, GBF1 heifers had an average age at first calving of 35 months. The average calving intervals for GB, GH and GBF1 cows were 492, 541 and 396 days, respectively, giving corresponding calving rates of 0.74, 0.67 and 0.92.
