نتایج جستجو برای: cross breeding
تعداد نتایج: 546122 فیلتر نتایج به سال:
A scientific substantiation of the main directions program for creating a domestic breed red dairy cattle has been developed, which provides pure breeding and various cross-breeding options to obtain high-producing animals with good reproductive performance productive longevity.
Crossbreeding programmes in pigs exploit between breed complementarity of additive genetic effects and heterosis generated by non-additive genetic effects. Within breed, improvement programmes may focus on additive effects and hence the enhancement of complementarity, but non-additive variation is not generally used in within line selection or for mate selection at the multiplier or commercial ...
Calving traits for frequently used dairy breeds and crossbreeds were investigated using calving records collected in Australia over a period of 18 years. Dystocia (calving difficulty) was highest for heifers calving to Holstein-Friesian bulls, and Jersey calves caused the least dystocia. Incidence of dystocia in Holsteins was influenced by the season (gestation lengths were longer in winter, re...
Future progress in genetic improvement and the monitoring of genetic resources in beef cattle requires a detailed understanding of the population under selection. This study examines the gene flow in the UK beef population with an uncommon breeding structure involving interaction between the beef and dairy populations. British Cattle Movement Service records were used as the primary source of i...
Genetic reference populations in model organisms are critical resources for systems genetic analysis of disease related phenotypes. The breeding history of these inbred panels may influence detectable allelic and phenotypic diversity. The existing panel of common inbred strains reflects historical selection biases, and existing recombinant inbred panels have low allelic diversity. All such popu...
Although differences in breeding lifespan are an important source of variation in male fitness, the factors affecting the breeding tenure of males have seldom been explored. Here, we use cross-species comparisons to investigate the correlates of breeding lifespan in male mammals. Our results show that male breeding lifespan depends on the extent of polygyny, which reflects the relative intensit...
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