not excessive. It was assumed that the procedures used yielded
a satisfactory comparison of the pasture programs.
 Bulls were placed with the cows for a period of 70 days (-
5 days) beginning March 10. Calves were weighed and graded
all at one time during the last 10 days of August. During the last
five years of the trial, calves were left with the cows for another
four to six weeks. Since the practice was not followed throughout
the project, all the programs were evaluated on the basis of the
late August weights. On good pastures, however, the practice of
later weaning of calves is an economical one for many operations.
 Steer calves were placed on feed at weaning and fed to aver-
age slaughter weights of approximately 950 pounds. Heifer
calves were wintered on roughage (pasture, hay, or silage) with
4 to 6 pounds of a protein-energy supplement until clover was
available for grazing. Heifers were bred to calve during the
normal calving season at two years of age. Upon calving they
were put on a full feed of corn silage plus 5 to 8 pounds of a
grain-protein supplement until the beginning of the breeding
season, March 10. After this, they were managed in the same
manner as mature brood cows. Young cows were not added to
experimental pastures until the mating season at 3 years of age.

 Results
 Results by pasture program.-The least squares means and
standard errors for the production traits are shown in Table 11.
Analyses of variance are shown in Table 12. These data show
that the only individual trait significantly influenced by pasture
Table 11.-Least Squares Means for Cattle Performance Traits by
 Pasture Program, 1965-1972.
 Program
 Trait 1 2 3
 Carrying capacity, cows per acre .74 .70 .80
 Pregnancy rate, % 92.31.4 91.2--1.4 94.1+1.8
 Calf survival, % 94.9+1.1 93.6E1.2 95.61.5
 Weaning rate, % 87.61.6 85.4+1.8 90.0+2.0
 Birth weight, lb. 66.1 +0.5 66.10.5 65.4_-0.6
 205-day weight, lb. 458.1-2.2 460.7-2.3 462.6-2.9
 Weaning weight, lb. 508.5+2.4 511.42.5 514.4-3.2
 Condition, score 10.9+0.1 11.10.1 11.1+0.1
 Production per cow, Ib. 445.4 436.7 463.0
 Calf production per acre, Ib. 329.8 306.3 370.4
 August weight of cows, lb. 1090 1093 1096