SUPPLEMENTATION OF SKIM MILK FED TO VEAL CALVES. PERFORMANCE, BLOOD PARAMETERS AND HEALTH

Abstract

Twenty-four Holstein male calves, initially averaging 55 kg, were individually housed and randomly assigned to four dietary treatments. Skim milk alone or supplemented with emulsified powdered tallow was offered to provide diets with digestible energy (DE) of 54, 100, 123, and 147 kJ g−1 of digestible protein (DP) for treatments 1, 2, 3, and 4, respectively. Dietary fat content in the skim milk was 0.1%. The higher levels of fat in treatments 3 and 4 were introduced at days 28 and 56, respectively. Dietary dry matter intake level (g/calf/day) was similar in treatments 2, 3, 4 and lower in treatment 1. Increasing DE to 100 kJ g−1 of DP brought about significantly improved (P < 0.05) daily gains, efficiency of dry matter and protein conversion, lower blood urea levels and improved fecal fluidity, consistency and color. Higher inclusion of dietary fat (treatments 3 and 4) significantly increased the content of blood hemoglobin with a possible negative effect on the lightness of meat color. The overall efficiency of DM conversion into gain equalled (treatment 1) or was better (treatments 2, 3, 4) than that considered acceptable for commercial veal operations (1.65 kg kg−1 of gain). With the exception of the blood urea levels, widening of DE:DP ratio beyond 100:1 (kJ:g DP) was not justified on the basis of the evaluation criteria used above. Key words: DE:DP ratios, veal calves, emulsified tallow, blood urea