NUTRITIVE EVALUATION OF FOUR SORGUM CULTIVARS GROWN IN BOTSWANA

Botswana produces more sorghum compared to maize because of the climatic conditions that are prevalent in the country. However, most poultry feeds are manufactured based on maize even though there is high competition between the poultry industry and humans for maize. The increasing poultry feed prices have led to the collapse of most poultry projects especially, small-scale projects. A study was conducted to evaluate the amount of tannins in the sorghum varieties available in Botswana with possible inclusion in poultry diets. The poultry industry in Botswana is at its infant stage and most of the inputs are imported from neighboring countries. The tannin contents of the Phofu, Sephala, Mmabaitse and Segaolane sorghum cultivars were not significantly different (P>0.05) from each other 0.14, 0.15, 0.08 and 0.06% respectively. The crude protein contents of the four sorghum cultivars were 11.5, 10.8, 11.7 and 11.9% respectively and were also not significantly different. A similar trend was found for Phosphorus content (0.47, 0.31, 032 and 0.56%) respectively. The crude fibre content of the sorghum cultivars, (4.89, 7.40 and 6.87%) respectively, was not significantly different (P>0.05) and so was the crude fat content (4.48, 5.23, 4.27 and 8.81). Digestibility of the four sorghum cultivars was also not P>0.05 significantly different (95.47, 89.70, 89.54 and 94.16%) respectively. Energy in this was study was not measured because of lack of the equipment to do energy analysis. It was concluded that sorghum varieties grown in Botswana are not significantly different (P>0.05) in terms of tannin content and are of low tannin content. Similarly, there are no significant differences (P>0.05) between the sorghum cultivars grown in Botswana for the most important nutrients, i.e., crude protein, phosphorus, crude fibre, crude fat and digestibility. This study shows that sorghum cultivars grown in Botswana might be included in poultry feeds formulations without any deleterious effects

COMPARATIVE PERFORMANCE OF COBB 500 BROILERS FED DIETS BASED ON TWO SORGHUM bicolor CULTIVARS IN BOTSWANA

A study was conducted to compare the performance of broiler birds fed diets made of two sorghum cultivars with that of birds fed commercial maize based diet in Botswana. Two hundred and ten, Cobb 500 day old broiler birds with initial body weight of 45 g were randomly allocated equally to three treatment diets (commercial, Segaolane and Phofu) according to a complete random block design. Each treatment was replicated twice. The period lasted for five weeks in which chicks, feed intake and feed refusals were weighed weekly. Feed intake of broiler chicks fed commercial diets of 5087.6±SE g was significantly (P 0.05). The two sorghum cultivars reduced feed intake, feed efficiency and weight gain of broiler birds. They also had similar nutritive value and effects on broiler birds; therefore, they could be included in poultry feeds and may have fewer adverse effects on broiler birds’ performance since no mortalities were recorded. Since the sorghum diets used in the study were all-mash, there might have been an influence of particle size and texture on the performance of broiler birds, hence there is need to pellet these diets so that the influence of particle size and texture could be removed