Eisen E J, Hörstgen-Schwark G, Bandy T R, Saxton A M
J Anim Sci. 1984 Apr;58(4):863-77. doi: 10.2527/jas1984.584863x.
Postpartum dam performance was studied in a complete diallel design involving five lines of mice. The selection criterion in each line was: large litter size at birth (L+); large 6-wk body weight (W+); an index for large litter size and small 6-wk body weight (L+W-); the complementary index (L-W+) and random (K). Females from the five lines and 20 reciprocal F1 crosses were mated to sires of a randomly selected control line (CC). Correlated responses in average direct genetic and average maternal genetic effects for dam body weight and litter size at parturition persisted throughout lactation, indicating important pleiotropic effects. Major correlated responses occurred for litter weight, feed intake and litter feed efficiency, primarily due to average direct genetic effects. Using general combining ability and net line effects as criteria for choosing among lines, L+ had a distinct advantage if the objective was to increase litter size in a crossing program. If the objective was to maximize litter weaning weight, then W+ would be favored for net line effects, while L+ and W+ would be about equivalent for general combining ability. None of the lines had an advantage for litter feed efficiency. Direct heterosis for dam weight at 12 and 21 d of lactation averaged 2.7 and 1.9%, while for litter size the respective averages were 7.4 and 7.3%. The W+ X L+W- cross exhibited overdominance for litter size. Direct heterosis was moderate for feed intake and litter weight, but was negligible for litter feed efficiency because of the mathematical relationship among the three traits. Maternal heterosis for preweaning progeny growth was suppressed because of heterosis for litter size in the dam. Grand-maternal effects on growth of the young were small and would not be an important consideration in choosing among these lines in a crossbreeding program.
在一个涉及五条品系小鼠的完全双列杂交设计中，对产后母鼠的性能进行了研究。每条品系的选择标准为：出生时窝仔数多（L+）；6周龄体重高（W+）；窝仔数多且6周龄体重小的指数（L+W-）；互补指数（L-W+）和随机（K）。来自这五条品系的雌性小鼠以及20个正反交F1杂交组合与随机选择的对照品系（CC）的雄性小鼠交配。母鼠体重和分娩时窝仔数的平均直接遗传效应和平均母体遗传效应的相关反应在整个哺乳期持续存在，表明存在重要的多效性效应。主要的相关反应出现在窝仔体重、采食量和窝仔饲料效率方面，主要是由于平均直接遗传效应。以一般配合力和净系效应作为品系选择标准，如果目标是在杂交计划中增加窝仔数，L+具有明显优势。如果目标是使窝仔断奶体重最大化，那么就净系效应而言W+更受青睐，而就一般配合力而言L+和W+大致相当。没有一个品系在窝仔饲料效率方面具有优势。哺乳期第12天和第21天母鼠体重的直接杂种优势平均分别为2.7%和1.9%，而窝仔数的相应平均值分别为7.4%和7.3%。W+×L+W-杂交组合在窝仔数方面表现出超显性。采食量和窝仔体重的直接杂种优势适中，但由于这三个性状之间的数学关系，窝仔饲料效率的直接杂种优势可忽略不计。由于母鼠窝仔数的杂种优势，断奶前后代生长的母体杂种优势受到抑制。祖母对幼仔生长的影响很小，在杂交育种计划中选择这些品系时不是一个重要考虑因素。
