Purdue University Agricultural Experiment Station Lafayette, Indiana
Mimeo A.S. 236 August 22, 1958 (Progress Report)
THE EFFECTS OF FEED ADDITIVES ON GROWING-FINISHING .SWINE*
C. E. Jordan, J. H. Conrad, and W. M. Beeson Department of Animal Science
With the widespread usage of feed additives in swine rations the question arises as to which combination of antibiotics, arsenicals or other feed additives are most efficient* It is thought that the continuous feeding of antibiotics has probably changed the kinds of microorganisms which normally inhabit the intestinal tract and thus may cause a decrease in responseo If a certain antibiotic affects a particular bacteria or group of bacteria, it might be assumed that a combination of antibiotics would result in a greater response than a single antibiotic which had been previously fed. Results reported in A. H. Mimeo 214 (October, 1957) pointed out that a combination of bacitracin and penicillin produced a 10. increase in gains over the control pigs fed no antibiotics, whereas pigs given a single antibiotic gained only 4«5$ faster than the controls.
Various arsenicals have been shown by numerous investigators to have a growth stimulating effect in swine as well as increasing feed efficiency. More recent results have indicated that an arsenical (3~nitro-4“hydraxyphenylarsonic acid) decreased backfat in finishing swine.
Continuous low level feeding of piperazine phosphate has recently been reported to increase growth rate. This seemed to be a direct result of increased feed consumption and not a result of an anthelmintic action (expelling intestinal worms) at the low level used.
The purpose of this experiment is to determine the effects of certain combinations of antibiotics, arsenicals or a low level feeding of piperazine phosphate on growth and feed efficiency of growing-finishing swine fed in concrete-paved lots. Another phase of this trial will be to determine the effect, if any, of these products on carcass quality of swine. As each individual hog reaches a 210 pound market weight (+ 5 pounds) it will be slaughtered and complete carcass measurements collected (carcass length, backfat thickness, primal and lean cut yields and loin eye area).
Ninety-six Duroc weanling pigs averaging approximately 35 pounds were allotted into eight lots of twelve pigs each on the basis of sex, weight, litter and general appearance. All lots were fed a complete mixed ration in concrete-paved lots. All pigs were wormed with piperazine phosphate before being placed on experiment.
-''-The authors wish to acknowledge D. M Nelson, Swine Herdsman, and his associates for feeding and caring for the experimental animals. Arsanilic acid was furnished by Abbotts Laboratories, North Chicago, Illinois5 Aureomycin and Arsenobenzene by American Cyanamid Co., Pearl River, New York; Zinc-Bacitracin-Penicillin by Commercial Solvents Corp., Terre Haute, Indiana; 3~nitro-4-hydroxyphenylarsonic acid by Dr. Salsbury?s Laboratories, Charles City, Iowa; Penicillin-Streptomycin-Sulfaquinoxaline combination by Merck and Company, Rahway, New Jersey; piperazine phosphate by Chemo Puro Manufacturing Corp., Newark, New Jersey; and Terramycin by Chas. Pfizer and Co., Terre Haute, Indiana.
Experimental Plan