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...