Thirty-six gilts were used in an experiment of 2³ factorial
design. The experiment consisted of two breeds (Yorkshire-
Berkshire and Yorkshire), two feeding regimens (pre-breeding and
post-breeding) and two levels of dichlorvos (2, 2-dichlorovinyl
dimethyl phosphate, 0 and 800 mg. per gilt per day). Pre-breeding
treatment consisted of feeding dichlorvos...
Purebred Yorkshire gilts from a confinement managed herd were reared to test weights away from the sow and boar herd. Thirty-eight gilts weighing between 73 and 80 kilograms constituted group A gilts; 38 gilts weighing between 91 and 100 kilograms constituted group B gilts; and 47 gilts weighing 114 kilograms...
An experiment was conducted with 51 control and 51 experimental confinement-
managed purebred Yorkshire sows of various parities to (1) determine
whether confinement-managed sows during lactation would exhibit estrus,
mate, and conceive as a consequence of a daily regimen of a short period of
separation from their litters, mixing sows...
Two experiments were conducted utilizing crossbred gilts to evaluate follicle characteristics at puberty and to determine the effect of exogenous estradio1-17β on embryonic mortality in the mature cycling gilt. Experiment 1 was conducted to compare preovulatory follicle numbers and sizes and follicular fluid concentrations of progesterone, estradio1-17β, plasminogen activator and...
Purebred Yorkshire gilts with weights ranging from 70 to 105
kilograms were moved from a total-confinement rearing unit to a
total-confinement brood stock unit where approximately ten gilts
per pen were mixed to provide new penmates. Each gilt was thus
exposed to an unfamiliar environment and to foreign penmates along...
In a swine production and breeding experiment, Yorkshire
gilts were evaluated for the influences of heredity-and some environmental components on occurrence of puberty in gilts in confinement. In the first experiment, 186 Yorkshire gilts reared and
maintained in total confinement were used in a study to assess
effects of several...
The role of the pituitary gland and uterus in regulating ovarian
function in the estradiol-treated gilt and ewe was investigated in two
experiments.
Pituitary gonadotropin content, ovarian follicular development and
corpus luteum function were studied following daily intramuscular
injection of seven gilts with 7 mg of 17β-estradiol from day 11...
A study was made of blood glucose levels and their relationship
to reproduction in gilts.
Twelve blood samples, two in each of three successive weeks,
before and after breeding were taken. Half of the samples were
obtained from gilts in a fasting state and half after feeding. All
samples were...
An experiment was conducted to compare the reproductive
performance and serum concentrations of progesterone and estrogen of
mated first (n=18) and third (n=18) estrous gilts slaughtered in equal
numbers on days 3, 15 and 30 postmating. Fertilization rate did not
differ between mated first and third estrous gilts. Embryonic survival...