-2 -
 in
 generally been as high as those of British cattle, although/the first experiment, 3/8
 Brahman-3/8 Charolais-1/4 Hereford carcasses and in both the second and third tests,
 1/2 Brahman-1/2 Hereford carcasses graded slightly lower. Lowest grading carcasses had
 the highest estimated cutout each year. In two of the three years, carcass grades were
 not as high as expected, largely because of lack of marbling in both Brahman hybrid and
 British calves. Most of the carcasses graded U. S. Good with a few U. S. Choice and U. S.
 Standard. In all trials a margin of approximately $3 per 100 pounds animal weight between
 the cost going on feed and the selling price of the fat cattle would have allowed a modest
 profit. A majority of livers from cattle originating in South Florida had live flukes at
 slaughter. When cattle with fluke-infested and clean livers were compared, it was
 apparent that fluke infestation did not adversely affect feedlot performance, although
 loss of the liver itself was significant economically.

 The trial reported herein is a continuation of the study with finishing heavy
 calves in the feedlot.

 PROCEDURE

 Shortly after weaning, Brahman-European hybrid calves were trucked to Quincy from
 Clewiston and Cocoa, Florida. Ten head each of 1/4 Brahman-1/4 Angus-1/2 Hereford, 3/8
 Brahman-3/8 Charolais-1/4 Hereford, and 3/8 Brahman-3/8 Charolais-1/4 Angus were delivered
 to the North Florida Experiment Station on September 13. Groups of 3/4 Brahman-1/4
 Shorthorn and 1/2 Brahman-1/2 Shorthorn arrived on September 17. Hereford calves of
 approximately the same age were delivered from Tallahassee on August 30. All steer
 calves were placed in dry lot on a light feed of grain and self-fed grass hay until
 October 1, when they were individually tagged, weighed, and started on trial. Initial
 weights were early morning weights at the feedlot with no shrink. The calves were
 maintained on the short preliminary feed to overcome shipping shrink before weighing on
 experiment. The Herefords weighed exactly the same going on test as previously at the
 Tallahassee farm. Brahman-Shorthorn crossbreds weighed an average of 13 pounds more when
 placed on trial than before shipping from Cocoa. Clewiston calves were not weighed by
 experimental groups before shipping; from the foregoing weights of the remainder of the
 calves and experience in preceding trials, it can be assumed that their initial weights
 on trial were about the same as their sale weights were when shipped from Clewiston.

 As the trial began, feed was gradually increased for approximately three weeks
when each group was consuming all the concentrates cleaned up between once-a-day feedings.
Minerals were self-fed throughout the feeding period, while hay was self-fed for the
first 70 days but restricted thereafter. Ratios of concentrates to roughages consumed
(including cob and shuck in snapped corn) ranged from 68:32 during the first month to
79:21 during the last month, with a gradually increasing proportion of concentrates
throughout the feeding period. Table 1 shows the average percentages of concentrates
and roughage consumed by each group for the entire trial. The following ration was fed:

 Ground snapped corn -- full-fed according to appetite
 Citrus molasses -- 2.0 pounds per head daily first 60 days and 4.0
 pounds thereafter
 41% cottonseed meal -- 2.5 pounds per head daily
 Argentine Bahia grass hay -- self-fed the first 70 days but restricted
 thereafter
 Salt and steamed bonemeal -- free-choice
 Vitamin A 25,000 I.U. per head daily
 The corn and cottonseed meal were mixed each morning, and citrus molasses was
poued on top of the mixture in the trough. Half of the calves in each group were given
a 2 mg stilbestrol implant at the beginning of the trial. The calves were confined to
dry lot in a well-bedded steer feeding barn with 60 square feet of pen space and 2 feet
of tough space per head. Stilbestrol implanted and non-implanted calves in each group