Evaluation of the Production and Genetic Potential of Indigenous Mukota and their Crosses with Large White Pigs in Zimbabwe.

Abstract

Mukota pig populations in smallholder areas of Zimbabwe are decreasing. The objective of this study was to evaluate the production and genetic potential of the Zimbabwean indigenous pig and Large White × Mukota in commercial pig production. The trial was conducted at the University of Zimbabwe Farm, Harare, Zimbabwe. All dry sows were fed on a high fibre diet. All the fixed effects were analysed using generalised linear models procedure of SAS (2000) and genetic parameters were estimated using average information restricted maximum likelihood. Piglets were weaned at 35 days.

Sows mated to Large White boars had larger litter sizes and total litter weight than Mukota. The growth rate of the two genotypes before weaning was not different (P>0.05). Post-weaning growth showed that boars had higher body weight gains than gilts (P<0.05). Body weights were consistently higher in the crossbred than in the Mukota pigs (P<0.05). Mukota pigs showed a peak growth between 12 and 16 weeks post-weaning. Crossbred pigs had longer (P<0.05) carcasses than Mukota (507.2 ± 0.92 versus 655.5 ± 1.68 mm). The genetic correlation between the direct and maternal genetic effects on birth weight was –0.354 and –0.295.

The heritabilities for litter weight at three weeks (LTHRWT), litter weight at weaning (LWWT) and mothering ability (MA) were 0.18, 0.15 and 0.05, respectively. There were no genetic relationships between MA and LTHRWT and LWWT. The heritabilities for growth rates, before and after 12 weeks, were 0.27, 0.21, respectively. There was a positive genetic correlation between weight at weaning and average daily gain from weaning to 12 weeks ( = 0.68). The backfat thickness at 50 and 75 mm were highly correlated ( = 0.88). Weight at birth was positively correlated with average daily gain from birth to weaning, whereas the relationship of BWT versus weight gain from 12 weeks to slaughter was unfavourable. Selection and crossbreeding can be used to improve smallholder pig production. The presence of the genetic correlations demonstrates the need to use multitrait analyses in evaluating genetic worthiness of pigs.