Abstract

Data obtained from Holeta Agricultural Research Center in Ethiopia were analyzed to compare the Boran cattle and the crossbreds and estimate genetic and crossbreeding parameters for first lactation traits. First lactation traits studied were first lactation total milk yield (FLMY), first lactation length (FLL), milk yield per day to first lactation (FLDMY), first 305 days milk yield (MY305) and adjusted first lactation 305 days milk yield (AFL305DMY). The effect of genetic group was significant (p<0.05). Boran cattle were inferior to any of the crosses. There was no significant (p>0.05) difference between HF x Bo and HF x HFBo or J x Bo and J x JBo and thus exotic inheritance beyond 50% showed no improvement in first lactation traits. The heritability estimates were medium (0.21+03) for FLL to high (0.39+0.40) for FLDMY. The breed additive difference for HF or Jersey was positive and significant (p<0.05) for all traits. The breed additive for HF were estimated as 2713.89 ± 406.60 kg, 110.27 ± 61.23 days, 6.09 ± 0.88 kg, 1169.43 ± 336.87 kg and 1432.86 ± 263.10 kg, whereas breed additive for Jersey were 2269.96 ± 486.05 kg, 59.37 ± 73.20 days, 5.25 ± 1.05 kg, 1207.56 ± 431.46 kg and 1413.28 ± 314.51 kg for FLMY, FLL, FLDMY, M305 and AFL305DMY, respectively. The individual heterosis was significant (p<0.05) for HF x Boran crosses, but not (p>0.05) for Jersey x Boran crosses except FLDMY and AFL305DMY. Crossbreeding improved first lactation traits three to four folds. Thus, crossbreeding with management interventions could be recommended to improve milk production.

 Key words: Crossbreeding, genetic parameters, milk yield, non-genetic factors.