Two-stage Selection for Ovulation Rate and Litter Size in Swine â•fl An Effective Procedure to Increase Reproductive Rate
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چکیده
منابع مشابه
Direct and correlated responses to two-stage selection for ovulation rate and number of fully formed pigs at birth in swine.
Our objectives were to estimate responses and genetic parameters for ovulation rate, number of fully formed pigs at birth, and other production traits following two-stage selection for increased ovulation rate and number of fully formed pigs. Eight generations of selection were practiced in each of two lines. One selection line was derived from a line that previously selected eight generations ...
متن کاملGenetic implications of a simulation model of litter size in swine based on ovulation rate, potential embryonic viability and uterine capacity: II. Simulated selection.
Direct selection for ovulation rate, uterine capacity, litter size and embryo survival and selection for indexes of ovulation rate with each of the remaining traits were simulated for a swine population. The relationships among these traits were determined from a simulation model that assumed that litter size was always less than or equal to both ovulation rate and uterine capacity. Heritabilit...
متن کاملChanges in ovulation rate, uterine capacity, uterine dimensions, and parity effects with selection for litter size in swine.
This study was conducted with random samples of pigs of a line (LS) selected for eight generations for litter size and a randomly selected control line (RS) in the Nebraska Gene Pool population and of crosses of these lines with a Large White-Landrace composite line (I) that was selected for an index of ovulation rate and embryonic survival to 50 d of gestation. Two experiments were done to obt...
متن کاملRole of the Gonadotropin-Releasing Hormone (GnRH) Receptor in Determination of Ovulation Rate Between Lines of Swine
gonad anterior pituitary estrogen progesterone (Litter er size plays a major role in the economics of swine production. Even modest increases in average litter size can have considerable effects on overall profitability. Two major components of litter size, 1) ovulation rate, and 2) embryonic survival, have been used in a selection index project ongoing for several generations at the University...
متن کاملDirect responses to selection for increased litter size, decreased age at puberty, or random selection following selection for ovulation rate in swine.
Nine generations of selection for high ovulation rate were followed by two generations of random selection and then eight generations of selection for increased litter size at birth, decreased age at puberty, or continued random selection in the high ovulation rate line. A control line was maintained with random selection. Line means were regressed on generation number and on cumulative selecti...
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