Effects of Dietary Protein Level on Milk Yield, Composition and some Hematological Parameters in Dessert Goats of North Kordofan, Sudan

Twenty lactating Desert goats with average weight of 26.5+ 1.04 kgs were used in this study with the objectives of studying effects of feeding different levels of dietary protein levels on some hematological parameters, milk yield and composition. The goats were divided into four similar groups based on age, number of kids/ doe and initial live weight. Four rations were used for 90 days. One ration (ration I ), control, was composed exclusively of sorghum straw and was meant to represent the natural grazing available during that time of the year (December –March) and it had a CP content of 4.1%. In ration II, 50 % of sorghum straw was substituted by sorghum grains and it had a CP content of 7.6 %. Ration III and IV contained groundnut seed cake and wheat bran and had CP content of 10.0 and 11.3 % respectively. The data collected from the trial were considered as randomized completed block design and analyzed via analysis of variance. No significant differences (P > 0.05) were observed in DMI of goats on the four rations though lower feed intake was observed for goats on ration I compared with the other three groups. IVDMD was higher in rations III and IV compared with ration I and II. The highest total and daily live weight gain was recorded for goats on ration III while the greatest weight loss was in goats on ration I. Respective daily weight change of goats was -0.01, 0.02, 0.04 and 0.03 + 0.002 kgs .The highest average daily average milk yield was obtained from goats on ration III (0.21 L/d) followed by those on (P < 0.01) ration II (0.15 L/d), then from those on ration IV (0.12 L/d) and finally from goats on ration I (0.05 L/d). Nonetheless, milk protein and milk fat was significantly affected by the level of protein of the ration. Milk obtained from goats on ration I recorded the lowest (P < 0.01) protein and the highest (P < 0.05) fat content. Average weekly milk yield / goat on the four rations gradually increased to peak at the 8th week of lactation and then started to decline. It was concluded that, under rangeland conditions in North Kordofan, Sudan, lactating Desert goats should be supplemented with rations rich in protein content. This is necessary to meet the animals’ requirements for maintenance and milk production since the rangeland grasses rarely meet such needs during the dry season. More research is needed to explore other protein sources together with the economic assessment of whole process.