One of the most important productive characteristics of hogs is reproductive efficiency. Reproductive efficiency is best measured by litter size at weaning. Litter size at birth and weight of the pigs at birth are among the most important factors affecting litter size at weaning. It has been demonstrated that less...
Research has yielded valuable information about the inheritance of body weight in many mammals. The results with one species may not be directly applicable to another species, but since the results do not contradict genetic theory, one must assume that the same general rules apply to all species.
When the...
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...
Market lamb production usually requires a short period of time. The success of production is therefore dependent upon the growth rate of the lambs which is influenced by milk yields of the ewes. Different growth potentials of animals result from a difference in their utilisation of food. Since metabolism affects...
Thirty-six female guinea pigs were placed on a scorbutogenic
diet for 14 days and then divided into groups of four. Three groups
received adrenocorticotropic hormone (ACTH) with each group given
10, 20, or 40 units. Three groups each received 50 mg of ascorbic
acid and three groups received 50 mg...
Data were taken from 47 animals consisting of five
breeds: Border Cheviot, Columbia, Dorset Horn, Suffolk,
and Willamette. Both sexes were represented in each breed,
although in unequal numbers. The pituitaries were assayed
for gonadotropic and thyrotropic hormone content by injecting
a suspension of the macerated gland in saline into...
The first study utilized ova transfer in sheep and involved
hormonal treatments for synchronization of estrus and superovulation
in an investigation of crossbred maternal influences on inbred and
linecross lambs.
Synchronization of estrus in ewes was achieved effectively
with either oral progestogen, 6 α-methyl-17α-hydroxy-progesterone
acetate (60 mg./ewe/day), or intramuscular injections...
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...
The investigations reported are based on two studies; the first
is concerned with the selection practiced for performance in one inbred
Angus and three inbred Hereford lines of cattle, the realized
responses, levels of inbreeding and associated performance, and
heritabilities of the performance traits.
Selection differentials for all performance traits...
Eight purebred rams (four Suffolk and four Panama) previously
selected as high and low on the basis of post-weaning performance
feed test of 84 days were used each of three years. Each of the
rams was mated to approximately 25 grade Panama ewes each year.
One ram and 25 ewes...
The production records used were all converted to a comparable
based, 305 day lactation period, two times a day milking, and
mature equivalent (305 days-2-x-ME) of 71 cows from four Holstein
bulls and 59 cows from four Jersey bulls were used for the study.
The Equal Parent Index, Regression Index...
Data were presented on epididymal spermatozoa from 29 inbred
and linecross bulls raised at Oregon State University in connection
with the Western Regional Beef Cattle Breeding Project, W-1. The
inbred bulls came from four inbred lines. Three of these inbred
lines were Herfords and the other line was Angus. The...
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,...
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...
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...
There were two studies involved in the thesis research. In the
first study, variation in the amount of adenohypophysis gonadotropins
among 22 individual beef bulls were investigated. These bulls
represented four inbred lines, and six linecrosses. The bulls were
raised in the Oregon State University purebred herd.
The bulls were...
Three inbred and relatively unrelated lines of Hereford cattle
(1. Lionheart, 2. Prince, and 3. David) developed at the Corvallis
branch of the Oregon Agricultural Experiment Station as part of the
W-1 project of the Western States were crossed annually from 1963
through 1965 inclusive. Data on 137 inbred and...
Eight strains of housefly, Musca domestica Linn., from two
laboratories were intercrossed to form a stock population. Virgin males and females from the stock were collected, and nine sets, each
consisting of twelve males mated to five females, were successively
done. Pupae weight, adult weight, emergence time and egg production...
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 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...
Five breeds of sheep (Columbia, Targhee, Rambouillet, Lincoln,
and Suffolk) were found to possess two hemoglobin types (Hb. A
and Hb. B) when their hemoglobins were examined by disc gel electrophoresis.
The hemoglobin alleles proved to be co-dominant.
Three of the breeds (Columbia, Targhee, and Rambouillet)
were maintained at altitudes...
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...
A total of 902 plasma samples from the Rambouillet, Targhee, Columbia, Lincoln, and Suffolk breeds of sheep were analyzed for transferrin type by disc electrophoresis. Six transferrin types, Tf[superscript A], Tf[superscript B], Tf[superscript C], Tf[superscript p], Tf[superscript E], and Tf[superscript P], were found in the Rambouillet, Targhee, and Columbia breeds...
The present investigation with the chromosomes of Zea mays
was conducted to determine: (1) the effects of chelating agents on the
process of cytological exchange, and (2) the effects of chelating agents
on genetic recombination.
To ascertain the influence of chelating agents on cytological
exchange, four known heterozygolis paracentric inversion...
Electrocardiograms from 12 compressed male (CM), 16 compressed
female (CF), ten synthetic compressed female (SCF), nine
brachycephalic female (BF), and 15 dolichocephalic female (DF)
dwarfs from Davis, California, taken in the scapular lead S-II (prescapular
position positive and right forelimb negative) were analyzed,
The data on dwarf electrocardiograms were compared...
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...
Tuberous sclerosis is a serious heritable human disorder
that involves many organ systems. It was first recognized as a
disease entity over a century ago. Its mode of transmission in
familial cases has been fairly well established to be that of a single
gene locus autosomal dominant trait. However, the...
An investigation of the effects of exogenous gonadotropic
treatments on fertility of various genetic groups of ewe lambs were
run over a six-year period. Since hormonal treatments varied and
the experimental animals were different from one breeding season to
the next, each year comprised a separate study. Hormone treatment
included...
The relationship between x-ray induced chromosome aberrations
and x-ray induced embryonic abnormalities was studied. Golden
hamsters were irradiated during four stages of gestation: the blastocyst
stage, 4.5 days post-copulation; the primitive streak stage, 6.5
days post-copulation; the organogenesis stage, 9.5 days post-copulation;
and the period of fetal growth, 11.5 days...
An F₁ population resulting from mating pygmy and normal goats (local commercial breeds) was crossed to give an F₂ population. Analysis of wither height and body weight indicated that the F₂ population was intermediate between the parental types (pygmy and normal) with little overlap of phenotypic values for body size...
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...
The relationships of serum T₄
(thyroxine) levels and liver
nicotinamide nucleotide coenzyme (NAD and NADP) levels with production
of traits of beef cattle were investigated at both weaning (182
kg) and following performance testing (363 kg). In addition, the value
of these parameters as selection criteria for improved performance
was...
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...