Knapp B W, Pahnish O F, Urick J J, Brinks J S, Richardson G V
J Anim Sci. 1980 May;50(5):801-7.
Effects of maternal heterosis were estimated from preweaning and weaning data on 178 three-breed cross progeny of straight Hereford, Angus and Charolais heifers (beef) and contemporary reciprocal cross heifers. In addition, 27 three-breed cross calves produced by beef x Brown swiss females were used for a comparison of beef x beef with beff x Brown Swiss crossbred dams. Statistical analyses were performed with and without the data from the 27 beef x Brown Swiss calves. Only first-calf records, obtained from 1965 through 1967, were used to evaluate maternal qualities of straightbred and crossbred dams. Breed of sire of sow was a source of variation (P less than .01) in all progeny traits, and breed of dam of cow was a source of variation (P less than .05 to P less than .01) in all of these traits except birth weight. Interaction effects of breed of sire of cow x breed of dam of cow were consistenetly nonsignificant. Estimated maternal heterosis percentages were 1.4, 1.0, 1.1 and .4 (.02 of one grade) for birth weight, average daily gain from birth to weaning, 205-day weaning weight and weaning conformation score of progeny, respectively. Comparison of beef x Brown Swiss dams with beef cross dams showed that beef x Brown Swiss dams had calves with higher average birth weight, higher preweaning average daily gain, higher average 205-day weaning weight and higher average weaning score (P less than .05 to P less than .01).
根据178头纯种赫里福德、安格斯和夏洛来小母牛（肉牛）及其同期正反交杂种小母牛的断奶前和断奶数据，估算了母体杂种优势的效应。此外，还使用了由肉牛×瑞士褐牛母牛所产的27头三元杂交犊牛，来比较肉牛×肉牛与肉牛×瑞士褐牛杂交母牛的情况。统计分析分别在包含和不包含这27头肉牛×瑞士褐牛犊牛数据的情况下进行。仅使用1965年至1967年获得的头胎记录，来评估纯种和杂种母牛的母体品质。公猪的品种是所有后代性状变异的一个来源（P小于0.01），而母牛的品种是除出生体重外所有这些性状变异的一个来源（P小于0.05至P小于0.01）。母牛的父本品种×母牛的母本品种的互作效应一直不显著。后代出生体重、出生至断奶的平均日增重、205日龄断奶体重和断奶体型评分的母体杂种优势估计百分比分别为1.4、1.0、1.1和0.4（相差0.02个等级）。肉牛×瑞士褐牛母牛与肉牛杂交母牛的比较表明，肉牛×瑞士褐牛母牛所产犊牛的平均出生体重更高、断奶前平均日增重更高、平均205日龄断奶体重更高且平均断奶评分更高（P小于0.05至P小于0.01）。
