''.<..- Everglades Station Mimeo Report EES66-4., September, 1965.
'5 G'- A COMPARISON OF AN ANTIBIOTIC AND AN ENZYME
 FOR WEANLING.CALVES 1/

 C. E. Haines and R. W. Kidder 2/


 When calves are weaned,'they go through a period of adjustment and a
 small-amount of a concentrate feed in this period is"usually beneficial to-
 growth- and health." Certain feed additives often improve the weight gains'of.
 young calves receiving limited amounts of concentrate while on pasture. The
 feed additives:may be antibiotics, hormones, vitamins, enzymes and other mate-
 rials. They are usually placed in the concentrate feed to furnish individual
 aminals with a specific daily intake of the particular additive. In the study
 reported herein, an antibiotic was compared to a multiple'enzyme supplement
 for weanling calves. The antibiotic was chlortetracycline' (Aureomycin) and
 the enzyme supplement' was Zymo-Pabst supplied either continuously or for
 portions of the-test period.

 Experimental Procedure

 One'hundred weanling steer-calves were divided into five equal groups on
 the basis"'f weaning weights and breeding. The-calves averaged approximately'
 435 pounds at' the beginning of the trial" and were' purebred and crosses of
 Angus, Brahman and Hereford breeds. All of the calves:'were weaned during the
 last week of June, 1964, and were assigned to the experimental treatments 10
 days after weaning. In the short period between weaning and the beginning
 of the study, the calves learned to eat a concentrate feed mixture.

 Each group of 20 calves was kept in a four-acre pasture of Roselawn St.
 Augustinegrass-,and .given.an average -of four pounds .of a...concentrate mixture..
 per head daily. The concentrate mixture was composed of ground snapped corn,
 citrus pulp, cottonseed meal.and. mineral mixture. The test materials were
 placed in the concentrate mixture to provide an'average of either 75 mg of
 chlortetracyoline -or. one-half.a .gam of enzyme-supplement per calf daily.
 One group served as controls and received the basal concentrate mixture with-
 out an additive while a second group was fed the concentrate mixture forti-
 fied with chlortetracycline. The enzyme supplement was added to the concen-
 trate feed of the remaining three groups for certain periods of the study.
 It was used either in the first half, in the second half or for the entire
 test'period. The test period was 98 days and the calves were weighed at
 frequent intervals- during this period.

 A vitamin treatment was superimposed on the study so that one-half of
 the calves in each of the feed additive treatments received supplemental
 vitamin A. The vitamin was injected at 28-day intervals at the rate of
 500,000 I.U. per calf. This phase of the study was included to obtain in-
 formation on possible corrective measures for an eye disorder that has been
 prevalent in weanling calves at this location for several years.


 1/ Test materials were provided by the American Cyanamid Company, Princeton,
 New Jersey, and the Premier Malt Products Company, Milwaukee, Wisconsin.
 The vitamin A product used in conjunction with this study was supplied by
 the Distillation Products Industries, Rochester, New York.

 2/ Assistant Animal Husbandman and Animal Husbandman, respectively, Ever-
 glades Experiment Station, Belle Glade, Florida.