Table 13.-Production Performance of Cow Herd at Progressive Stages
 of Breeding Project.


Group


Preg. Wean Wean Prod.
Rate Rate Weight per Cow Ratio


 % % lb. lb. %
 Brahman-Native Foundation 60 58 388 225 100
 Selected Brahman-Native Cows 73 68 418 284 126
 First Generation Crossbred Cows 85 82 436 358 159
 Experimental Groups, 1965-72 92 88 511 448 199


 Table 14.-Average Production Performance for Five Experimental
 Breeding Programs at Beef Research Unit, 1961-1972.
 Breeding Systema
 Gr. Gr. A-H A-B H-SG
 Trait A H Rot. Rot. Rot.
 Pregnancy rate, % 90.2 91.0 93.6 89.9 90.3
 Calf survival, % 95.6 93.2 94.7 92.6 92.1
 Weaning rate, % 86.2 84.5 88.6 83.3 83.2
 Weaning weight, Ib 463 534 501 515 541
 Production per cow, Ib 400 458 444 428 450
 Condition score of calf 11.1 11.3 11.2 11.0 11.0
 Avg. Wt. of cows, lb 1008 1173 1091 1082 1140
 Prod. per cow/cow wt., % 40 39 41 40 39
 20-month heifer wt., Ib 743 828 792 817 856
 Fourteen-month steers
 Carcass wt., Ib 510 578 558 576 576
 Carcass grade ch- g+ ch- g+ g
 Feed/gain, Ib 10.8 10.3 10.2 10.2 10.1
 aBreed designation:
 Gr. A=graded to Angus
 Gr. H=graded to Hereford
 A-R Rot= Angus-Hereford sire rotation
 A-B Rot=Angus-Brahman sire rotation
 H-SG Rot= Hereford-Santa Gertrudis sire rotation

 These data, used in a separate study (4), came from both Phases
 2 and 3, and thus are not directly comparable with those of
 Tables 11, 12 and 13. Here it is seen that the principal differences
 were in size and growth rate. This would be anticipated in view
 of the sire-breeds represented. Difference in weaning rate were
 statistically non-significant due to large standard errors for
bimodal data. Considering that all non-pregnant females were
eliminated from all groups, large differences in fertility would
not be anticipated. Some of the differences observed, however,