Reproductive performance and body weight changes in draught cows in a smallholder semi-arid farming area of Zimbabwe.

The reproductive performance of 46 cows in a semi-arid, smallholder farming area of Zimbabwe was monitored for a year. Half the cows were used throughout the monitoring period for various draught purposes, including ploughing and procurement of farm produce for marketing using carts. All the cows lost body weight between July and October, after which the cows that were not worked gained weight until June of the following year. In contrast, the cows that were worked continued to lose body weight until January, throughout the time during which they were used to provide draught power, after which they gained weight. Body weights were significantly higher (p < 0.05) in non-working than in working cows in January and February. Ovarian activity was higher (p < 0.001) in non-working compared to working cows, particularly between November and February, while calving rates were also higher (p < 0.05) in non-working cows. It is concluded that using cows for draught purposes caused loss of body weight and reduced ovarian activity and conception rates.