-3-


were not penned separately.

 Final live weights, taken after trucking 3 miles to Ouincy in the early morning,
were shrunk 3 percent. Final shrunk weights were used ih calculating gains, carcass yields,
and on-foot sale prices. As previously stated, starting weights were not shrunk This
procedure was used to minimize the fill factor in computing gains.

 Carcass weights were hot weights less 2 1/2 percent. After a 48 hour chill,
carcasses were ribbed and graded to the nearest third of a grade by a U. S. grader and
Experiment Station personnel. Sale prices were actual prices paid by the packer for the
carcasses (Table 2).

 Feed costs were based on local prices at the time cattle were in the feedlot
(Table 1). Prices are shown for various ingredients and an average for the entire ration.
Other costs (labor, pen rent, interest, and other expenses) were included in the charge
of $0.10 per head daily.

 Carcass maturity, conformation, degree of marbling, and USDA quality grade data
were recorded for each carcass. Fat thickness over rib eye, amount of kidney and pelvic
fat, area of rib eye, and carcass weight data were used in estimating percentage of
closely trimmed boneless cuts from the round, rump, loin, rib, and chuck.

 RESULTS AND DISCUSSION

 Gains generally were smaller and less efficient than in preceding trials
(Table 3)3, probably because only half of each group was implanted with stilbestrol. As
shown in Table 4, implanted calves gained considerably faster than those not implanted,
with the exception of steers in Lot 33 where implantation gave no benefit. Unfortunately
differences in feed intake between implanted and non-implanted calves are not available.
Implanted calves had heavier carcasses with no appreciable difference in other carcass
characteristics resulting from implantation. Differences due to implants were particularly
large in the two Charolais cross groups (Lots 34 and 35). Stilbestrol implants stimulated
gains for the first 152 days of the trial; response was negligible during the sixth month.

 As shown in Table 3, Hereford calves (Lot 32) made the largest, most efficient
gain but did not have carcass yields as high as the five crossbred groups. If live
weights are adjusted to the same carcass yield, average daily gains of the crossbred lots
will be increased from 0.10 to 0.21 pound, and gains of the 3/4 Brahman-1/4 Shorthorn
calves (Lot 36) will be approximately the same as that of Lot 32. Net return based on
actual sale of carcasses was more favorable for the Hereford calves because of slightly
smaller feed intake and lighter initial weight, which was valued at a relatively high $24
per hundredweight. Because of the negative margin between cost of feeder calves and sale
of fat cattle, all groups showed an economic loss. The maximum initial value per 100 pounds
of the feeder calves going into the feedlot was calculated using the formula:

 Gross sale price minus feed costs minus other feedlot costs X 100
 Weight of feeder calves going into the feedlot

Using these calculations, values per 100 pounds ranged from $16.92 to $17.60 for the
various groups with the exception of Lot 35 which had an initial value of only $14.58
per hundredweight because of unusually slow, costly gains. Excluding Lot 35, there was a
difference of only $0.68 per hundredweight between the "break even" price that could
have been paid for the top and bottom performing group of calves. The margin needed to


3See footnote 2, page 1.