Smallholder Farming Areas Of Zimbabwe Research Articles

Effects of dietary supplementation and work stress on ovarian activity in non-lactating Mashona cows in a small-holder farming area of Zimbabwe

AbstractThe effects of work stress and dietary supplementation on ovarian activity were determined in 16 multiparous Mashona cows in Sanyati Communal Area, which lies in a semi-arid environment of Zimbabwe. The cows were assigned to one of four treatments: supplemented working (SW), supplemented non-working (SNW), non-supplemented working (NSW) and non-supplemented non-working (NSNW) cows in a 2 × 2 factorial treatment arrangement with two dietary and two work levels. Cows in the SW and NSW groups pulled a cart with a 200-1 water drum for 18 km (9 km with drum empty, 9 km with drum full) every day for 5 days/week for a total of 12 weeks.Rectal temperatures were recorded at specific points along the route to and from the river where the water was obtained. Blood samples were collected by jugular venipuncture once a week, before working, for the determination of plasma glucose and non-esterified fatty acids (NEFA). In addition, blood samples were collected once every 3 days for the determination of progesterone concentration. There were no differences (P> 0⋅05) in the rectal temperatures between SW and NSW cows. Cows in the NSW group had the highest decrease in glucose levels and also showed marked increases in NEFA concentrations. The incidence of ovarian activity was similar between SNW and SW cows (P> 0⋅05). The incidence of ovarian activity was least in NSW cows. We conclude that nutritional stress was more important in suppressing ovarian activity than work stress and that dietary supplementation can reduce the negative effects of draught on ovarian activity.

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.