Breed and Heterosis Utilization in Rotational and Composite Crosses
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چکیده
منابع مشابه
Periodic rotational crosses. II. Optimizing breed and heterosis use.
Choice of the optimal number and sequence of breeds in a periodic cross was determined by comparing the trade-off between increased utilization of breed differences and decreased utilization of heterosis. It was shown that the change in mean efficiency resulting from adding the next best breed to the best conventional n-breed rotation is always less than the change in efficiency predicted from ...
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Purebred Angus (A), Polled Hereford (PH) and Santa Gertrudis (SG) bulls were mated to grades, two-breed and three-breed rotational crosses of these breeds (seven herds) to produce three generations (G1, G2 and G3) of calves. The grade A and PH cows were higher in A and PH breeding, respectively, than grade SG cows were in SG breeding. Reproductive performance among grade and rotational-cross he...
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Crossbred steer and heifer progeny from 5-, 6- and 7-yr-old dams produced in a four-breed diallel crossing experiment involving the Brown Swiss, Red Poll, Hereford and Angus maternal grandsires and maternal granddams were evaluated for postweaning growth and carcass traits to estimate breed mean maternal heterosis, maternal heterosis for specific breed cross females, average maternal heterosis ...
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The study was performed on 4 609 ejaculates obtained from 32 boars, including 14 purebred and 18 two-breed crosses. The ejaculates were collected manually every 4-5 days. The study involved ejaculates collected from each boar from the first day of its insemination use until the day of semen depletion. Each ejaculate was assessed for the following physical parameters: ejaculate volume, sperm con...
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