Different Protein Levels with and without Antibiotics for Growing-Finishing Swine: Effect on Growth Rate and Feed Efficiency

Effect of Chlortetracycline on Nutrient Utilization by Dairy Calves

“…The beneficial effects of chlortetracycline in swine rations have been confirmed recently by a number of workers (3,4,11,15,17,39,51,60,92,150) According to Jukes (68), greater responses to antibiotic feeding are obtained with beef cattle when the animals are on rations high in roughage; however, there appears to be no readily available explanation as to why this should be the case.…”

Least-Cost Livestock Production Rations

“…Data from four swine feeding studies and/or analyses of feeding studies provided data to estimate the relationships of feed conversion and gain with crude protein and energy (metabolizable calories per pound) levels for two growth stages [1,4,6,12]. The growth stages chosen were: 40-125 lbs.…”

“…Swine nutritional data and current recommended feeding practices demonstrate the problem. Considerable research shows the effect of varying energy and protein levels on feed conversion and gain for swine, [1,5,6,7,8,12,13]. However, little nutritional research has been directed at the influence of simultaneous protein and energy level variations on feed conversion and average daily gain.…”

The effect of chlortetracycline on nutrient utilization by dairy calves

“…The beneficial effects of chlortetracycline in swine rations have been confirmed recently by a number of workers (3,4,11,15,17,39,51,60,92,150) although some reports (60, 144b, 161) Taylor and Rowell (150) recently reported a study involv ing 279 pigs in which they sought to determine the influence of level of antibiotic feeding on growth response-Their results suggest that the improvement in growth rate and feed conversion increases with the dose level of penicillin or chlortetracycline, at least within the range of 2 to 256 gm.…”

“…Mameesh et al(98) have reported, however, that penicillin was ineffective in altering the thiamine require ment of the rat.Protein sparing actionCombs(26) noted that while reports have varied as to whether antibiotic feeding enhances the efficiency of protein utilization by chickens and turkeys, it would appear that under certain conditions lower protein levels are satisfac tory when antibiotics are fed. More recently, West and Hill(163, 164) have reported on studies with broilers involving a total of more than 1,400 chicks and have concluded that in the presence of certain antibiotics (chlortetracycline, oxytetracycline, bacitracin and penicillin) ; optimal growth and feed efficiency were obtained with two percentage units less protein in the ration than was needed without an anti biotic .A number of reports(20,60,68,100) have appeared which indicate, in general, that from 2 to 4# less protein is needed in swine rations fortified adequately with one of the effec tive antibiotics-Other workers (68, 104, 105, 162) have failed to substantiate this finding, and Meade (104) sug gested that an antibiotic might spare protein indirectly by virtue of increasing the feed intake of pigs fed diets con taining lower levels of protein. Meade and Forbes.…”