منابع مشابه
Selection for superior growth advances the onset of puberty and increases reproductive performance in ewe lambs.
The reproductive efficiency of the entire sheep flock could be improved if ewe lambs go through puberty early and produce their first lamb at 1 year of age. The onset of puberty is linked to the attainment of critical body mass, and therefore we tested whether it would be influenced by genetic selection for growth rate or for rate of accumulation of muscle or fat. We studied 136 Merino ewe lamb...
متن کاملBreed, heterosis and environmental influences on growth and puberty in ewe lambs.
A study involving 825 spring ewe lambs was conducted to evaluate effects of breed, heterosis, type of birth and rearing, age of dam and preweaning and postweaning growth rate on occurrence of puberty before November 10. Within a breed or breed-cross, preweaning competition among twin and triplet lambs reduced lamb weights by 4 or 5 kg at 70 (weaning), 160 and 230 days of age and by about 3 kg a...
متن کاملNutritional effects on puberty and production performance of ewe lambs and goat kids
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متن کاملEffect of feed treatment and exogenous estrogen and progestogen on puberty and lambing rates in ewe lambs.
Four hundred seventy-four ewe lambs (5 to 6 mo of age) were assigned within breed to two postweaning feed treatments; 1 = alfalfa pellets ad libitum and 2 = alfalfa pellets plus 20% barley or wheat ad libitum. Ten days prior to the start of breeding, approximately one-half of the ewe lambs within each feed treatment were treated with a single injection of 2.5 mg of estradiol valerate and 1.5 mg...
متن کاملReproductive characteristics of Ethiopian highland sheep. I. Genetic parameters of testicular measurements in ram lambs and relationship with age at puberty in ewe lambs.
A study was conducted to estimate heritabilities of, and genetic correlations among, body weight (WT) and testicular measurements - scrotal circumference (SC), testicular diameter (TD), testicular length (TL) and epididymal diameter (ED) - in ram lambs between 6, 9 and 12 months old, and relationship of the testicular traits with age at puberty in ewe lambs (AP). Two fat-tailed sheep breeds, th...
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ژورنال
عنوان ژورنال: Reproduction
سال: 1985
ISSN: 1470-1626,1741-7899
DOI: 10.1530/jrf.0.0740119