Effect of Aureomycin on Young Dairy Calves Raised in a New Environment

Abstract

The effect of oral-fed (50 mg daily) and intramuscular-injected (400 mg weekly) Aureomycin on young male Holstein and Jersey calves raised in a new uncontaminated and in an old environment was investigated. Regardless of the environment, Aureomycin administration statistically (P< 0.01) increased body weight gains and efficiency of feed utilization at 12 weeks of age. An earlier stimulation in growth was observed in calves raised in a new barn than in those raised in an old barn. The growth response from antibiotic administration was detected earlier in the oral-fed groups than in the injected-treated animals. In the new barn, the growth-promoting effect of Aureomycin administration was detected as early as 2 weeks, whereas in the old barn the effect was not seen for 4 weeks. This finding indicates that the cleanliness and sanitary conditions of the environment favor a greater and more effective growth-stimulation response of Aureomycin feeding. There was no significant difference in white blood cell counts among the antibiotic and control groups in the old and new quarters, indicating that all calves apparently were in a similar state of health.