-2-


appeared indicated. Hence, the emphasis was placed on selection from the whole
crossbred herd, without breeding especially for percentage of crossbreeding in
the individual.

 Progeny TestinSg Birth weights and growth records are maintained on
all animals. In addition to this, some of the best growing bulls are consigned
annually to the Bull Feeding Trials at Brooksville, Florida. The ability to grow
rapidly has been established as a highly inherited characteristic* The two
crossbred bulls, No. 1115 and No. 1147, presently in service, gained at the rate
of 3 pounds per day for 140 days in the 1956 feeding trials. Such sires may im-
prove the growing ability of the calves in the "Bravon" herds.


 Analyses of Herd Records. Examination of the records of the Evorglados
Station herd for the last 25 yearL' indicates that the weight of calves at 180
days of age is a good measure of relative perfornance(l). The average 180 day
weights of animals of various breeding are listed in the following table. These
records are obtained from 877 calves in the Brahnan-Devon groups and 163 calves
in the Brahman-AnCus groups.


Table 1. Weight of purebred and crossbred calves at 180 days.(2)


 Breeding of Sire Breeding of Dam Average Weight


1 Angus Angus 305 pounds
2 Brahman Brahman 320 pounds
3 Devon Devon 342 pounds
4 Brahman Devon 391 pounds
5 Devon Brahman 374 pounds
6 Brahman Angus 350 pounds
7 Angus Brahman 345 pounds
8 Devon Brahman x Devon 388 pounds
9 Brahman Brahman x Devon 374 pounds
10 Brahman Brahman x Angas t10 pounds
11 Brahman x Devon Devon 398 pounds
12 Brahman x Devon Brahnan x Devon 361 pounds


 Breeding groups 1, 2 and 3 in the table represent the foundation pure-
breds in the three breeds, Angus, Brahman and Devon. All of the crossbred cattle
were heavier at 180 days than any of the purebred parent breeds. The reciprocal
crosses, groups 4 and 5 and groups 6 and 7, show a slightly higher weight when
the sire is Brahman and the dam European. These differences are too small, how-
ever, to be considered of practical significance.

 These records indicate that crossbred cows have better calves frma
purebred sires than from crossbred sires. The data may require further investi-
gation or the increased numbers of successive generations for verification.


(1) Two graduate students have done this as their theses for Master's degrees at
 the University of Florida. These men are Harold V. Clum and John Liddon,

 (2) The weights are corrected for sex, age of dam, month and year of birth.