Some non-genetic factors affecting commercial pig production in Zimbabwe

Author: F. Mungate, K. Dzama, K. Mandisodza and A. Shoniwa
Year: 1999
Issue: 3
Volume: 29
Page: 164 - 173

The effect of environmental factors on pre-weaning performance traits was studied using 3556 records collected between 1980 and 1995. Sow performance in terms of number born alive was higher if sows farrowed in summer months of October to April than at any other time of the year (P < 0.05). The heaviest piglets were also born during the same period (P < 0.05) even though they did not maintain the weight advantage through to 21 days and to weaning age at 35 days (P < 0.05). Sows in parity seven and beyond had smaller litters, with lower birth weights and growth rates to weaning (P < 0.05) thus justifying the practise of culling sows after the sixth parity. Crossbred sows generally outperformed pure-bred sows for litter size because they exhibit maternal heterosis. Hampshire sired litters were significantly larger than those sired by other sire breeds (P < 0.05). Furthermore Hampshire and Duroc sired piglets generally performed better than both the Landrace and Large White sired litters. Discrimination of coloured breeds carcasses means that producers in Zimbabwe cannot take advantage of their superiority.

Keywords: Non-genetic factors, pigs., Zimbabwe
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