Evaluation of nutritional regime of small-scale dairy farms in Khartoum State

Abstract

A program based on Nutrient Requirements of Dairy Cattle (NRC, 1989; 2001) was used for the prediction of the protein and net energy of lactation (NEL) requirement of dairy cows in fifty small-scale dairy farms located in Khartoum, Omdorman and Khartoum North based upon measurable, or observable, characteristics. The experimental design was completely randomized with 3×3 factorial arrangement of treatments. The cows of each locality (Khartoum, Omdorman and Khartoum North) were divided into three groups according to milk yield (low: 0-6 kg/day; medium: 6-12 kg/day; high: 12 kg/day and above). The calculated protein and NEL requirements were compared with the actual protein and NEL intake. The average crude protein content in the DM of the rations was 29.5, 24.66 and 24.05% for Omdorman, Khartoum North, and Khartoum, respectively. Both the locality and milk yield had a significant effect (p<0.05) on protein over supply which was higher for Omdorman (180.9%) compared to 141.9 and 108.4% for Khartoum North and Khartoum, respectively. However, the protein over supply was 101.8, 150.6 and 176.8% for high, medium and low milk yield cows, respectively. The energy used for urea synthesis and excretion, as percent of NEM, was 25.2, 16.6 and 14.7% for Omdorman, Khartoum North and Khartoum, respectively, iv however, low milk yield cows spent more energy for the synthesis and excretion of urea (20.4 %) followed by medium (18.8 % ) and high milk yield cows (17.3 % ). Moreover, producers in Omdorman, Khartoum North and Khartoum exceeded the total energy required for lactation by 81.4, 69.7 and 45.1%, respectively. The excess energy reached 100% of the total energy requirement for low milk yield cows, 53.3% for medium milk yield and 42.3% for high milk yield cows. In conclusion, producers in small-scale dairy farm in Khartoum state feed their herds’ excess amounts of CP and energy following "one size fits all" approach, resulting in more energy used for urea synthesis and excretion. Therefore, guidelines need to be developed for optimal production efficiency