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...
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...
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 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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...