-2-


 PROCEDURE

 On October 26, groups of 1/2 Charolais-1/4 Brahman-1/4 Hereford, 1/2 Hereford-
1/4 Brahman-l/4 Angus, and 1/2 Charolais-1/4 Brahman-1/4 Angus calves were trucked to
Quincy from Clewiston, Florida. On November 3, 7/8 Angus-1/8 Brahman and Angus groups
were trucked to Quincy from Raiford, Florida. As in the 1966-1967 trial, there was an
interval of about 6 to 8 weeks between weaning and shipment to Quincy. In years prior to
1966, the interval was much shorter from weaning to shipment. After arrival at the North
Florida Station, limited grain (5 pounds per head daily) and self-fed grass hay were given
to all calves until November 15, at which time they weighed about 3 percent more than when
they left the ranch.

 As in previous trials, initial feedlot weights were only slightly heavier than ranch
delivery weights, and these initial weights were not shrunk. Final weights, taken in
early morning after trucking 3 miles to Quincy, were shrunk 3 percent to put them on a
market weight basis. Thus experimental live weights were on a ranch delivery to shrunk
sale weight basis. The same final live weight was used in calculating both feedlot gain
and dressing percentage. Carcass weights were hot weights less 2 1/2 percent shrink.

 When the trial began, feed was increased gradually for approximately three weeks after
which each group received all the concentrates it would clean-up between once-a-day
feedings. Hay was self-fed at the beginning of the feeding period but restricted
thereafter. Salt and steamed bonemeal were supplied free-choice throughout the trial.
Each calf was ear implanted with 24 mg stilbestrol at the beginning of the trial. Vitamin
A was mixed with the protein concentrate to furnish 25,000 I. U. vitamin A per head daily.
The following ration was fed:

 Ground snapped corn -- full-fed according to appetite
 Citrus molasses -- 2.5 pounds per head daily
 Oil meal -- 2.4 pounds per head daily
 Argentine Bahia hay -- fed as previously noted
 Salt and steamed bonemeal -- free-choice
 Vitamin A -- 25,000 I. U. per head daily

The ground snapped corn and oil meal were mixed each morning, and citrus molasses was
poured on top of the mixture in the trough. In the first half of the feeding period, 41%
cottonseed meal was fed, while in the last half 44% soybean oil meal was the protein
concentrate. As shown in Table 1, ratios of concentrates to roughage ranged from 73:27
to 75:25, depending on hay consumption by the various groups during the first part of the
feeding period. Cob and shuck in the snapped corn were included in the roughage. Average
daily feed consumption for each lot is also shown in Table 1. Prices of feed are given
for individual ingredients as well as complete rations for each group. Feed costs were
based on local prices (Quincy, Florida) at the time cattle were in the feedlot, with no
mixing or handling charges included. Other costs (labor, pen rent, interest, and other
expenses) are included in the assumed charge of $0.10 per head daily.

 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 trough space per head.

 After a 48-hour chill, carcasses were ribbed and graded to the nearest third of a grade
by a USDA grader and IFAS personnel. Sale prices were actual prices paid by the packer
for the carcasses (Table 2), with prices shown on both a hot and chilled (hot weight less
2 1/2 percent) basis.

 Carcass maturity, conformation, degree of marbling, and other USDA grade data were
recorded for each carcass. Fat thickness over ribeye at the twelfth rib, percent kidney