Aureomycin Supplementation of Rations for Dairy Calves

Aureomycin has been fed with milk replacement formulas (3,5,7,9, 14) and calf starters (4,11,12), as well as with whole milk (4,5,6,8,9,10) and directly by capsule (1, 2).These reports indicated an increase in growth rate and a decrease in the incidence of scours in young dairy calves fed this antibiotic.The objective of the experiment presented in this report was to determine the effects upon the growth of young dairy calves of feeding aureomycin supplements in several combinations of a milk replacement and starter.Supplementation was made so as to approach various feeding conditions which might occur on farms. F_,XPEmMENT.XL PROCEDUREThe male Holstein calves used in this trial were obtained from Pennsylvania state institutional herds during the fall of 1951.The calves ranged in weight from 90 to 115 lb.Housing was in a steam heated, ventilated, and artificially lighted stable.The temperature was maintained at 65 ° F. by thermostatie eontrol.All calves were housed in individual pens equipped with a water bowl, concentrate box, hay rack, and iodized salt block.In determining growth rate, measurements of body weight and withers height were taken once each week by the same person, starting at the same time of day, and in the same order.The general appearance, vigor, and feces condition of each calf were noted daily.When scours persisted longer than 24 hours, 8 g. of sulfathaladine in bolus form were given, followed by a 4-g.dose at each of the next two successive feedings.The 36 calves in this trial were divided into six comparable groups of six calves each and were placed on trial no later than 4 days after birth.The calves in groups II, III, IV, and V were on trial for 12 weeks, and those in groups I and VI were maintained on the experiment for 16 weeks.The basic milk replacement formula used for all calves had the following percentage composition : 50 lb.dried skimmilk, 15 lb.distillers' dried corn solubles, 5 lb.oat flour, 10 lb.blood flour, 7 lb.dextrose, 10 lb.dried whey, 0.5 lb.vitamin A and D meal (4,000 U.S.P. units vitamin A and 500 U.S.P. units vitamin D2 per gram) and 2.5 lb.mineral mix.The antibiotic supplements added to the basic milk replacement formula were crystalline aureomycin-hydrochloride and an aureomycin supplement containing 2.0 g. of aureomycin per pound, as shown in Table 1.Each basic milk replacement was dissolved in water and fed twice daily at 100 ° F. according to the following schedule : First through 4th day, dam's milk ;