THE EFFECT OF THE SUPPLEMENT OF COBALT MINERAL WITH CASSAVA LEAF IN THE DIET OF CORN BRAN FED TO SHEEP

Abstract

A 56-day feeding trial was carried out to study the influence of cassava leaf meal and cobalt mineral supplement on the feeding value of cassava peeling waste-based diet in the sheep. Sixteen (16) weanling West African Dwarf sheep of average initial live weight; 9.27 + 2.94kg were divided into four similar groups. Each group was randomly assigned to one of four treatment diets in a 2 × 2 factorial experiment. The animals were fed at 3% of their body weights. They had unrestricted access to clean drinking water and mineralized salt lick throughout the 56-day feeding trial. Dietary treatments consisted of two inclusion levels (7.74 and 37.53%) of cassava leaf meal; and two levels (0, and 1.0 ppm) of cobalt supplement. The diets were in four treatments; A (Low inclusion level of cassava leaf meal (7.74%) without cobalt supplement), B (Low inclusion level of cassava leaf meal (7.74%) with 1ppm cobalt supplement), C (High inclusion level of cassava leaf meal (37.53%) without cobalt supplement), and D (High inclusion level of cassava leaf meal (37.53%) with cobalt supplement) respectively. Response criteria were; average dry matter and nutrient intake, nutrients digestibility, body weight gain, nitrogen retention, urinary and serum thiocyanate levels, serum total protein and urea-nitrogen concentrations. All measurements were taken at the 4th and 8th weeks of the feeding trial. Body weight gains in the sheep were; 19.21, 8.28, 23.75, and 34.46 g/day at the 28th day measurement and 8.93, 5.36, 24.82, and 26.34 g/day at the 56th day measurement for dietary treatments A, B, C, and D respectively. The body weight gain values obtained in sheep on diet D were higher (P<0.05) than for those on diets A and B at the 28th and 56th days measurements. Similar trends were obtained for nitrogen retention in the sheep. Sheep receiving dietary treatment D had higher (P<0.5) serum thiocyanate level at the 56th day measurement when compared to those on dietary treatment A or B. Similar trends were obtained for urea- nitrogen. Effect of the treatments on serum total protein and urinary thiocyanate levels were not significant (P>0.05) among the four treatment groups. It was concluded that sheep consuming high level of cassava leaf meal in cassava peeling waste-based diet, benefited from dietary cobalt supplement in terms of body weight gain and nitrogen retention.