27个小鼠杂交组合的终生亲代繁殖力。II. 反映繁殖和泌乳的断奶性状。

Lifetime parental productivity in twenty-seven crosses of mice. II. Weaning traits reflecting reproduction and lactation.

作者信息

Newman S, Harris D L, Doolittle D P

出版信息

J Anim Sci. 1985 Aug;61(2):367-75. doi: 10.2527/jas1985.612367x.

DOI:10.2527/jas1985.612367x

Abstract

Twenty-seven crosses of mice derived from three random-mating, unselected strains (SWO, J. PGH) with 16 matings/pureline or cross were cohabited continuously and monogamously for a 365-d reproduction period to evaluate lifetime reproductive performance of the parents. Data from 3,249 litters born (2,792 surviving to weaning) were analyzed to study the effects of parity (number of litters) and type of cross (pureline, two-way, backcross, three-way) on certain traits measured at weaning (21 d). The traits evaluated were 1) weaning to weaning interval (WWI), 2) litter size at weaning (LSW), 3) fraction alive at weaning (FAW)-the ratio of LSW to number born alive, 4) total litter weight at weaning (LWT), 5) pup weight at weaning (PWT), 6) weaning weight per pup observed alive at birth (WPP), 7) parental feed consumption per day (FPD) and 8) parental costs (PCT). Cost per live weanling animal was estimated as the ratio of cumulative parental costs to cumulative number weaned. Cost per unit of weaning weight was defined as the regression of cumulative parental costs on cumulative litter weight. Parity effects were important (P less than .01) for all traits measured. Type of cross effects were noted for LSW, LWT, PWT, WPP, FPD (P less than .01) and PCT (P less than .05). A parity X cross-type interaction was expressed for WWI, LSW, PWT, WPP, FPD (P less than .01) and FAW (P less than .05). Three-way crosses were more productive than backcrosses, two-way crosses and pureline matings for all traits studied. Three-way crosses displayed the smallest cost per animal weaned and smallest cost per unit of weaning weight. The influence of parity on traits measured at weaning was less than for traits measured at birth. Weight per pup born alive (WPP) was found to be a better indicator of reproduction and lactation ability than LWT because WPP accounts for preweaning mortality.

摘要

从三个随机交配、未经过选择的品系（SWO、J、PGH）中获得了27个小鼠杂交组合，每个纯系或杂交组合有16次交配，这些小鼠在365天的繁殖期内持续、一夫一妻制地共同生活，以评估亲本的终生繁殖性能。对出生的3249窝（2792窝存活至断奶）的数据进行分析，以研究胎次（产仔窝数）和杂交类型（纯系、双向杂交、回交、三向杂交）对断奶时（21日龄）测量的某些性状的影响。评估的性状包括：1）断奶到断奶间隔（WWI）；2）断奶时窝仔数（LSW）；3）断奶时存活比例（FAW）——LSW与出生时存活仔数的比值；4）断奶时窝仔总重（LWT）；5）断奶时仔鼠体重（PWT）；6）出生时存活且断奶时每只仔鼠的断奶体重（WPP）；7）亲本每日采食量（FPD）；8）亲本成本（PCT）。每只存活断奶动物的成本估计为累积亲本成本与累积断奶数的比值。每单位断奶体重的成本定义为累积亲本成本对累积窝仔重量的回归。胎次效应对于所有测量的性状都很重要（P<0.01）。杂交类型效应在LSW、LWT、PWT、WPP、FPD（P<0.01）和PCT（P<0.05）方面被观察到。在WWI、LSW、PWT、WPP、FPD（P<0.01）和FAW（P<0.05）方面表现出胎次×杂交类型的相互作用。对于所有研究的性状，三向杂交比回交、双向杂交和纯系交配更具生产力。三向杂交显示出每只断奶动物的成本最低，每单位断奶体重的成本也最低。胎次对断奶时测量的性状的影响小于对出生时测量的性状的影响。发现出生时存活的每只仔鼠体重（WPP）比LWT更能反映繁殖和泌乳能力，因为WPP考虑了断奶前的死亡率。