Litter Size Trait as a Selection Criterion in Merino Crossbred Rams
نویسندگان
چکیده
منابع مشابه
Ovulation Rate as the Selection Criterion for Litter Size in Sheep
Egg transfer experiments have consistently failed to find differences among sheep breeds in their ability to support a given number of fertilised eggs. The literature on egg survival rate in pregnant, multiple ovulating ewes is also remarkably consistent across a wide range of breeds and environments in terms of the ratio of foetuses (or lambs) to corpora lutea. Two reports on egg survival in e...
متن کاملOestradiol Implant Reduces Litter Size in the Booroola Merino
The litter size of homozygous Booroola Merino ewes results in high perinatal mortality. One subcutaneous implant of crystaline oestradiol in silastic tubing in heterozygous Booroola Merino ewes decreased ovulation rate from 3.18 -r0.15 (n = 39) to 2.03 & 0.14 (n = 35), and decreased litter size (5 8 weeks pregnant) from 2.49 + 0.13 (n = 39) to 1.47 + 0.12 (n = 32), providing a useful management...
متن کاملComparison of Introgression and Synthetic Breed Strategies for Litter Size Trait in Sheep using Computer Simulation
The objective of this study was to compare introgression and synthetic breed strategies for litter size trait improvement in sheep using computer simulation. For this purpose, a trait with heritability of 0.1, consisting of two chromosomes was simulated. On chromosome 1, a single QTL as the major gene was created that accounted for 40% of the total genetic variance. The effect of favorable and ...
متن کاملSingle-trait and antagonistic index selection for litter size and body weight in mice.
INDIVIDUAL SELECTION BASED ON FEMALE PERFORMANCE ONLY WAS CONDUCTED IN FOUR LINES OF MICE: L(+) for increased litter size, W(+) for increased 6-week body weight, L(-)W(+) for a selection index aimed at decreasing litter size and increasing 6-week body weight and L(+)W(-) for a selection index aimed at increasing litter size and decreasing 6-week body weight. A fifth line (K) served as an unsele...
متن کاملWeaning Weights in a Range Purebred Merino and Crossbred Merino x Rambouillet Flock
The Rafter 7 Merino flock was initiated in Nevada in 1990 with the purchase of 500 purebred Rambouillet ewes. A gradeup program was initiated using Australian Merino genetics with the aim of developing a purebred Merino flock. Early in the project the Rafter 7 Merino line was created, which is approximately 5/8 Merino and 3/8 Rambouillet and has been a closed line since 1999. In a genetic selec...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Pakistan Journal of Zoology
سال: 2023
ISSN: ['0030-9923']
DOI: https://doi.org/10.17582/journal.pjz/20210205030242