Influence of Sex and Sire on Weaning Weights of Southwestern Range Calves2

Sire by environment interactions for growth traits in beef cattle

“…Several studies, using beef cattle growth traits, have examined the interaction of genotype of sire with several types of environmental effects. Pahnish et al (1961), Tanner et al (1970) and Thrift et al (1970) found little evidence of sex by sire interactions for weaning weight or postweaning gain. Bradley et al (1966) reported no significant sex by sire interactions for birth weight; however, Buchanan and Nielson (1979) found evidence of significant sex by sire interactions for birth weight and weaning weight.…”

The effect of certain factors on weaning weight and weaning grade of beef cattle

“…indicating an age of calf by year interaction. In their Arizona study Pahnish e^ al. (1961) reported the ranch by year interaction had a significant effect (P < .05) on weaning weight.…”

“…Often in mathematical models describing environ mental factors contributing to the variation in pre-weaning and weaning traits these interactions have been assumed to be' zero (Brown, 1961;Lehmann et al, 1961;Marlowe and Gaines, 1958). In many cases the problem of interactions has been at least partially avoided by conduct ing the analysis on a within subclass basis (Koch andClark, 1955b, 1955c; Marlowe and Gaines, 1958;Marlowe et al, 1965;Marlowe, 1962;Minyard and Dinkel, 1960;Pahnish et al, 1958;Pahnish et al, 1961;Swiger £t , 1962;Brinks et al, 1967). However, there are indica tions that some attention should in fact be given to these interactions.…”

“…In this study the sex by age of dam interaction was non significant. Pahnish et al (1961) studied Hereford bull and heifer calves from two Arizona ranches. When sex, year, ranch and all two-way interactions were included in the model for weaning weight, after correction to 270 days at weaning and for age of dam, only the sex by ranch interaction was significant (P < .05).…”

Beef calf weights at 100 days and 205 days as indicators of dams' producing ability

“…In Koch's study a linear dependency between year and age of dam was encountered when cow differences were con sidered simultaneously with the other variables. Swiger (1961) and Pahnish ^ (1961) Tables 5 and 6 show that the calves in the creep and non-creep regimes did grow somewhat differently during the second half of the preweaning suckling period. In the creep records this regression was 0.147 pounds per day and in the non-creep records the regression was -0.215.…”