Comparative Effects of Crystalline Antibiotics and Crude Antibiotic Supplements (Aureomycin and Terramycin) on the Growth and Metabolism of Young Dairy Calves

Abstract

New born dairy calves (40) were used in studying the comparative effects of crystalline antibiotics and crude antibiotic supplements (Aureomycin and Terramycin) on growth and metabolism. Both antibiotics in the crude and crystalline form improved the growth rate of the calves, although not statistically significant. Calves fed Aurofac increased in growth rate slightly faster than other antibiotic fed calves. All calves fed antibiotics tended to consume more starter than the control calves, but the antibiotics had very little effect upon the consumption of hay. Calves fed antibiotics tended to be slightly more efficient in feed conversion than the control calves as measured by the pounds of feed required per pound of gain. Neither of the antibiotics in either form had any significant effect upon the digestion of feed nutrients or the retention of N. Likewise neither antibiotic had any effect on the blood levels of urea N or total nonprotein N. The results of this study indicate that antibiotics when fed to young dairy calves does not alter significantly the N metabolism of the calf.