• Asian-Australasian Journal of Animal Sciences
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• v.9 no.5
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• pp.503-508
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• 1996

The data analysed consisted of records on lactation length (LL), total lactation yield (TLY), estimated 305-day yield (305 DY), days dry (DDRY), age at frist calving (AFC) and calving interval (CI) of 448 Friesian $\times$ Bunaji halfbreds that calved over a twenty-three year period (1967-1989) at the National Animal Production Research Institute, Shika, Nigeria. Least squares means of LL, TLY, 305DY, DDRY, AFC and CI were 250 days, 1,988 kg, 2,420 kg, 102 days, 35 months and 390 days, respectively. Parity, season and year of calving significantly affected LL, TLY (p < 0.01) and 350DY (p < 0.05), but not CI. DDRY was affected by season of calving only (p < 0.05). It was therefore concluded that the Shika Friesian $\times$ Bunaji crossbreeding programme was successful and beneficial in that the $F_1$ crosses calved at a younger age, produced twice as much milk, had longer lactations and slightly shorter calving intervals than the indigenous Bunaji.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.5
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• pp.509-513
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• 1996

The data analysed consisted of body weight records at birth, and at 3, 6, 9 and 12 months of age of 549 half Friesian $\times$ Bunaji crossbred heifers collected over a twenty-five year period (1965-1989). Least squares $means{\pm}s.e$. of body weights at birth, 3, 6, 9 and 12 months of age were $26.7{\pm}1.3$, $72.4{\pm}4.5$, $112.9{\pm}6.9$, $147.2{\pm}9.2$ and $182.1{\pm}11.1kg$, respectively. Year of birth was highly significant (p < 0.01) in affecting body weights at all ages, while the effect of month of birth was not. Seasonal influence on birth weight and body weights at 3 and 6 months of age was significant (p < 0.05). Phenotypic correlations between body weights at all ages were positive and highly significant (p < 0.01), ranging from 0.30 to 0.79. The results of this study showed that the beneficial effect of crossbreeding Friesian with Bunaji cattle was reflected in the growth performance of the $F_1$ crosses, since they grew faster than the indigenous Bunaji from brith to yearling age. The study also indicated that heifer selection for yearling body weight can be done early on the basis of weights at 3 and 6 months of age.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1516-1519
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• 2001

The data consisted of 369 lactation records for calvings over a sixteen-year period (1972-1987) and included only cows that had normal milk records. The data were analysed using a linear model containing the fixed effects of parity, year of calving and season of calving. The least squares means${\pm}$S.E. were $1,273{\pm}58.4kg$ for milk yield, and for post-partum body weight (kg) at 2, 3 and 4 months after calving were $343.40{\pm}3.96$, $346.10{\pm}4.10$ and $352.54{\pm}4.26$, respectively. With the exception of season of calving, the effects of parity and year of calving were significant (p<0.01) on the performance of the animals. Thus, the mean-milk yields 1162, 1351 and 1350, were similar for pre-, peak- and post rainy seasons, respectively. On the other hand, as parity increased from 1 to 3, milk yield also increased, but thereafter, there was a gradual decline in milk yield. Similarly, post-partum body weight also increased with parity. However, no consistent pattern for year effect was observed which probably was a reflection of the variation in climatic conditions, or forage quality and/or availability. The phenotypic correlations between milk yield and post-partum body weights were negative and small (ranging from -0.01 to -0.08). However, high milk production in cows was associated with longer calving interval. The implications from the phenotypic correlations are suggestive of one or two possibilities. Firstly, selection for increased body weight may actually result in decreased milk yield. Also, a substantial genetic antagonism may exist between milk yield and fertility in the crossbred cows. Therefore, it is important that selection to improve milk production should take into consideration the reproductive performance of the cows.