Pre and Post-Weaning Growth and Survivability of Three Genotypes of Cattle at TALIRI Tanga, Tanzania

This study examined the growth performance of the three genotypes of cattle raised at TALIRI Tanga: Pure Boran (BB), Boran + Friesian (BF), and Boran + Jersey (BF) crosses. The 20 years of data (from 2001 to 2020) were used to examine the effects of calves' genotype, sex, amount of rainfall, season of birth, and type of rearing on growth parameters (birth weight, weaning weight, yearling weight, pre-weaning growth, and post-weaning growth, in kg and kg/day respectively). The General Linear Model was used to calculate growth parameters and correlations while, the Chi-square test performed to assess pre- and post-weaning survivability. BF calves were substantially heavier at birth than BB and BJ calves (P<0.05). Male calves were 4.1% heavier than female calves, at birth and the calves born during the dry season were 4.0% heavier than those born during the wet season. BB calves were significantly survived % better than BF and BJ in all growth stages female calves survived better by 3.57% than male calves and the bucket-reared calves had survived significantly higher than direct-suckled calves by 6.9% in pre-weaning stage. The phenotypic correlation between birth weight and weaning weight was moderately positive (0.3), as was between weaning weight and yearling weight. However, the correlation between weaning weight and pre-weaning growth, and between yearling weight and post-weaning were both strongly positive (0.9), while the correlation between birth weight and post-weaning growth was negative (r= -0.1). Thus, crossing exotic breeds with Boran cattle enhances crosses growth performance relative to Boran while also improving cross survivability in hot/humid environments compared to pure exotic cattle.