نتایج جستجو برای: breeding programs

تعداد نتایج: 251526  

2011
Bettina Wachter Susanne Thalwitzer Heribert Hofer Johann Lonzer Thomas B. Hildebrandt Robert Hermes

Re-introduction programs rely on reproductively sound individuals and high offspring survival once captively bred species are released into their natural habitat. Some species involved in captive breeding programs reproduce poorly: one prominent example is the cheetah (Acinonyx jubatus). Here we use the cheetah as a case study to test predictions from all current hypotheses explaining this phen...

اسلمی نژاد, علی اصغر, رکوعی, محمد, شریعتی, محمدمهدی, طهمورث پور, مجتبی, فرجی آروق, هادی,

The effects of herd size, semen type, generation overlapping and breeding goal on genetic gain in Holstein cows were studied through stochastic simulation. Three levels of herd size (100, 200, and 400), two levels of semen type (unsexed and sexed), three levels of generation overlapping (low, average and high) and two levels of breeding goal (narrow and broad) were combined together to make 36 ...

Journal: :پژوهش های علوم دامی ایران 0
مسعود علی پناه حمید تقوی آدم ترکمن زهی مصطفی یوسف الهی

the important of ostrich breeding have been increased in the iran as other country around the world. lack of sexual dimorphism in many species of birds including ostrich (struthio camelus), making it difficult to differentiate between males and females, especially in young birds. this can be problematic for breeding programs. blood samples from randomly chicks in the first days were collected a...

2007
PHILLIP JACKSON SCOTT CHAPMAN ALLAN RATTEY XIANMING WEI

AUSTRALIAN sugarcane breeding programs in the past have maintained fairly separate breeding and selection programs targeting different regions. This structuring implied an assumption that genotype x region interactions are important relative to genotype x environment interactions within regions, but this had not been tested. A research project was initiated in 1997 to help address this issue an...

ژورنال: علوم زراعی ایران 2022

Exploitation of heterosis in hybrid breeding and development of synthetic cultivars is an essential procedure in plant breeding programs. The main goal of hybrid breeding programs is to select desirable parental genotypes to maximize the expression of heterosis. However, since development of high yielding hybrids and synthetic cultivars are costly and time-consuming, the accurate prediction of ...

Journal: :Agricultural history 2009
Jonathan Harwood

Despite their success in boosting cereals production overall, the Green Revolution programs of the 1950s and 1960s were often criticized for failing to achieve their declared aim of alleviating world hunger. Most critics argued that the programs had produced a technology unsuited to the needs of small peasant farmers. This paper explores why such inappropriate technology might have been develop...

Journal: :Poultry science 2010
H-W Cheng

Chickens, as well as other animals, have the ability to change their behavior (behavioral plasticity) and physiology (physiological plasticity) based on the costs and benefits to fit their environment (adaptation). Through natural selection, the population preserves and accumulates traits that are beneficial and rejects those that are detrimental in their prevailing environments. The surviving ...

Journal: :Genetics 1957
W D Hanson H W Johnson

ELECTION indexes have been proposed in animal and plant breeding programs S as a criterion for selection when certain quantitative characters are considered. Such characters present particular difficulty in selection programs since heritable variations are often masked by nonheritable variations. Investigations have demonstrated that a selection index based on a number of measurements could be ...

2011
Matias Kirst Márcio Resende Patricio Munoz Leandro Neves

Background Growing demand for food and fiber, and a rapidly changing climate will require that plant breeders accelerate the improvement of germplasm adapted to new sources of biotic and abiotic stress. In trees, the threat from climate change is more evident and the solutions more challenging than in any other plant species, due to the complexity and cost of breeding programs, and the long bre...

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