dams (AC) appeared to have a slight advantage for 205-day calf weight
(450 vs 438 lb [204 vs 199 kg]). These variations suggest the possibility
that reciprocal differences are related to dam size, as the Charolais cows
weighed 1076 lb (488 kg) vs 855 lb (388 kg) for the Angus (Table 4).
Montana research (Pahnish et al., 4) on the same breed combination did
not find differences in 205-day weight of calves from F, reciprocal Char-
olais-Angus crossbred dams, even though the Charolais were 10
heavier than Angus dams.
 Research on maternal effects for weaning weight of reciprocal F, calves
 was conducted in Florida by Peacock et al. (6). With the Angus-Brahman
 combinations, Fi calves produced by Brahman dams were 5.8% heavier
 (P < 0.05) at weaning than those from Angus dams, but when adjusted
 for age, the difference (3.5%) was not significant (Table 3). The variation
 (P < 0.10) in weight of these reciprocals existed at 2 years of age (Peacock
 and Koger, 5), and also at maturity (Table 4). The positive effect of the
 Brahman dam on preweaning response of calves was greater in the
 Charolais-Brahman crosses. Calves from Brahman dams weighed 8.5%
 more (P < 0.01) at weaning, and 4.4% more (P < 0.05) when calf weights
 were adjusted for age, than the reciprocals from Charolais dams. How-
 ever, this advantage diminished to 3.5% (non-significant) at 2 years of
 age and was completely gone at maturity. These results do not support
 the theory that maternal effect is caused by difference in dam breed size,
 since Charolais dams weighed 13.7% more than Brahman dams (Table
 4). However, heterosis for growth of offspring was obtained when the
 Brahman and European cattle were crossed, and the hybrid vigor effects
 masked the maternal effects for growth.
 Research has shown no heterosis for calf weaning weight in combined
F1 reciprocals from crossing the Charolais and Angus breeds (Peacock
et al., 6). The Charolais and Angus are both European breeds, even
though large differences existed in mature size. The Charolais cow was
25.8% heavier than the Angus 1076 vs 855 lb (488 vs 388 kg). Reciprocal
crossing resulted in Charolais cows producing 13% more calf than the
Angus cow, 6.2% more when the calves reached 2 years of age. At
maturity this F, Angus x Charolais cow weighed 5.0% more (P < 0.01)
than its reciprocal from Angus cows. Even though real differences did not
occur among offspring of these reciprocal Charolais-Angus cows, addi-
tivity for dam breed size was present in F1 cows, diminishing in the
succeeding generation until equilibrium was reached.
 Weights of reciprocal F, females out of Brahman cows at 2 years of age
slightly favored the Brahman dam over Angus and Charolais dams (non-
significant), with the influence of the Charolais dam over the Angus
diminished in the F, but still at a 6.1% advantage (P < 0.05) over the
Angus (Peacock and Koger, 5).