Twenty-eight Columbia ewes were made available for study
during their breeding and anestrous seasons. After the regularity
of the estrous cycles had been established, eight of the ewes were
sacrificed in pairs at four different stages of the estrous cycle.
Eight additional ewes were sacrificed during anestrus. Pituitary
glands, ovaries,...
Five experiments were conducted to study the activity of the
pituitary gland in sheep as influenced by estrogen administered alone
or in combination with progesterone. Particular emphasis was given
to the study of gonadotropic activity.
Mature wethers (experiments I, III, IV and V) or ewes (experiment
II) were utilized as...
This study examined the effects of sire breed and
weight on the performance of 117 crossbred wether lambs
born at the Oregon State University Agricultural
Experiment Station, Corvallis. Lambs were produced by
mating Clun Forest,Polypay, Dorset, Border Leicester, and
Suffolk sires to Columbia-type ewes. After weaning at
approximately 90 days...
During years 2005, 2006, and 2007 ewes of predominantly Polypay breeding were bred to either Dorper or Polypay rams for spring lambing. Ewes were assigned to single-sire mating groups based on age and genotype. Internally generated replacements were added to the flock for the 2007 lambing season and bred to...