An experiment was conducted to determine if selection from
standardized litters would be effective in separating lines of mice
selected for increased and decreased litter weight at 14 days of age,
and if response to selection on this maternally influenced trait could
be accurately predicted.
Data were collected on litter...
An experiment was conducted to examine the responses to
selection for high and low rate of gain in the mouse under a system
whereby inbreeding was maximized. Rate of gain was measured by an
index designed to include gains in both the pre- and postweaning
periods with the gains in...
Crossmatings were accomplished among three semi-closed lines within a population of pigs, for the purpose of investigating effects of crossbreeding on reproductive traits. Two of the lines were purebred (Berkshire and Yorkshire); the third line ("Composite") consisted of descendants from inter se matings among offspring of crosses of the Berkshire...
The present study was designed to investigate the relationship
of milk production and milk quality to growth rate and certain organ-oleptic
measurements of lambs of mutton breeds, Nine mature ewes
in their fourth lactation of the Border Cheviot, Dorset Horn,
Columbia, Suffolk, and Willamette breeds were acquired making a
total...
Data were taken, following irradiation exposure to
100r and 300r cumulative dose, on 89 rabbits of three
breeds that vary greatly in body size. Hematological,
intestinal motility, and ear vascularity examinations
were performed. Least square estimates have been obtained and an analysis of variance has been conducted in
order estimate...
This investigation for the first time reports information on the
correlation of various forms and ratios of nicotinamide nucleotide
coenzymes in the liver tissue and endocrine glands weight with
various production traits. Fifty-five inbred and line cross beef bulls
raised under standard management conditions and slaughtered at 1000
lbs. body...
In the present study, five breeds of ewes and their lambs were
utilized. The breeds used were: Border Cheviot, Dorset Horn, Columbia,
Suffolk and Willamette. In all, 31 ewes and 42 lambs were involved.
The blood constituents which were determined for the ewes and
lambs were: acid and alkaline phosphatase,...
Mice were used to compare the index and elite selection
methods for simultaneous selection of four traits. Selection was
for litter size, birth weight, weaning weight and post-weaning
gain. Progress was evaluated by examining total phenotypic merit.
The standard deviations from the cycle mean for the four traits
were summed...
The effects of x-irradiation on quantitative genetic traits was
investigated by comparing the response of irradiated mice to selection
for litter size and 28-day weight with the response to selection
for the same two traits in non-irradiated lines. Irradiated lines
were maintained at three levels of x-irradiation, 25 r, 50...
The effects of x-irradiation on quantitative genetic traits was
investigated by comparing the response of irradiated mice to selection
for litter size and 28-day weight with the response to selection
for the same two traits in non-irradiated lines. Irradiated lines
were maintained at three levels of x-irradiation, 25 r, 50...
The investigations were based on a complete diallel cross
among three inbred lines of Hereford cattle. Records of Angus calves
born during the same period were used to obtain more accurate
estimates of environmental effects and to determine breed differences
among the various traits included in the study. Estimates of...
The investigations were based on a complete diallel cross
among three inbred lines of Suffolk sheep. Line of sire effects were
assumed to be an estimate of general combining ability effects while
sire x dam interaction was assumed to be an estimate of specific
combining ability. The line of dam...