نتایج جستجو برای: for breeding purposes

تعداد نتایج: 10373288  

2013
Marine Desprez Clive R McMahon Mark A Hindell Robert Harcourt Olivier Gimenez

Studying the demography of wild animals remains challenging as several of the critical parts of their life history may be difficult to observe in the field. In particular, determining with certainty when an individual breeds for the first time is not always obvious. This can be problematic because uncertainty about the transition from a prebreeder to a breeder state - recruitment - leads to unc...

Journal: :Proceedings. Biological sciences 2014
Stefan Fischer Markus Zöttl Frank Groenewoud Barbara Taborsky

In cooperative breeding systems, dominant breeders sometimes tolerate unrelated individuals even if they inflict costs on the dominants. According to the 'pay-to-stay' hypothesis, (i) subordinates can outweigh these costs by providing help and (ii) dominants should be able to enforce help by punishing subordinates that provide insufficient help. This requires that dominants can monitor helping ...

Journal: :Poultry science 1998
X Jiang A F Groen E W Brascamp

The objectives of this study were to derive economic values in broiler breeding and to determine their relationship with production circumstances. Economic values were derived using a deterministic economic model based on profit equations with a fixed amount of broiler meat output of the production system. Nonintegrated and the integrated broiler production systems were studied. The difference ...

Journal: :Journal of animal science 1946
L N HAZEL C E TERRILL

D IFFERENCES in type (mutton conformation) and condition (degree of fatness) are generally considered to be responsible for differences in the price per pound when range lambs are sold on the market. Since these traits are most evident when the first culling of lambs occurs soon after weaning, it seems probable that they receive considerable emphasis in most sheep breeding enterprises. Despite ...

Journal: :Proceedings. Biological sciences 2003
Denis Réale Andrew G McAdam Stan Boutin Dominique Berteaux

Climate change is predicted to be most severe in northern regions and there has been much interest in to what extent organisms can cope with these changes through phenotypic plasticity or microevolutionary processes. A red squirrel population in the southwest Yukon, Canada, faced with increasing spring temperatures and food supply has advanced the timing of breeding by 18 days over the last 10 ...

2012
Barbara Taborsky Cornelia Arnold Julian Junker Andreas Tschopp

Social competence is defined as the ability of an animal to optimize the expression of social behaviour as a function of the available social information. The social environment encountered early in life can affect the expression of various social behaviours later in life. We investigated whether early social experience can affect social competence. In the cooperatively breeding cichlid Neolamp...

Journal: :Journal of animal science 2011
N T Pegolo L G Albuquerque R B Lôbo H N de Oliveira

The interest in the effect of genotype × environment interaction is increasing because animal breeding programs have become geographically broader. Climate changes in the next decades are also expected to challenge the present breeding goals, increasing the importance of environmental sensitivity. The aim of this work was to analyze genotype × environment interaction effect on cattle BW using t...

Journal: :The American naturalist 2011
Walter D Koenig Eric L Walters Joseph Haydock

The ecological conditions leading to delayed dispersal and helping behavior are generally thought to follow one of two contrasting scenarios: that conditions are stable and predictable, resulting in young being ecologically forced to remain as helpers (extrinsic constraints and the habitat saturation hypothesis), or that conditions are highly variable and unpredictable, leading to the need for ...

Journal: :Biology letters 2008
Nichola J Raihani Amanda R Ridley

In cooperatively breeding species, helpers can alleviate reproductive constraints by assuming the role of primary carers to first-born young, liberating breeders to invest in subsequent broods. However, evidence on how first-born young are transferred to helpers is currently lacking. We propose that breeder-offspring aggression might facilitate inter-brood division and test this idea using data...

2008
ALI RISVANLI

Sera samples from 89 dairy cows with repeat breeder and 94 healthy pregnant dairy cows (controls) from Elazig province of eastern Turkey were tested for presence of Neospora caninum antibodies by use of a competitive enzyme linked immunosorbent assay (cELISA). Fifteen out of 183 cows tested (8.19%) were found to be seropositive to N. caninum antibody. Overall, seroprevalence of N. caninum was s...

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