3 resultados para Pigs

em Dalarna University College Electronic Archive


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Marxist themes of Roddy Doyle’s The Commitments have not often been looked at. Yet, they are decidedly prominent. The band make use of a Marxist image and of collectivist easy-played, easily-understood music in order to gain working class listeners. In fact, the band itself is based on an egalitarian structure, until it, due to an increasing individualist wish for success, falls apart. The aim of this essay is thus to argue, through pointing to the Marxist rhetoric of the band and the hypocrisy around it, and through a comparative reading between The Commitments and Orwell’s Animal Farm, that The Commitments has an allegorical value, much like Animal Farm does, when it comes to depicting the way Marxism has worked and failed as it has been practised in reality.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The genetic improvement in litter size in pigs has been substantial during the last 10-15 years. The number of teats on the sow must increase as well to meet the needs of the piglets, because each piglet needs access to its own teat. We applied a genetic heterogeneity model on teat numberin sows, and estimated medium-high heritability for teat number (0.5), but low heritability for residual variance (0.05), indicating that selection for reduced variance might have very limited effect. A numerically positive correlation (0.8) between additive genetic breeding values for mean and for variance was found, but because of the low heritability for residual variance, the variance will increase very slowly with the mean.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Animal traits differ not only in mean, but also in variation around the mean. For instance, one sire’s daughter group may be very homogeneous, while another sire’s daughters are much more heterogeneous in performance. The difference in residual variance can partially be explained by genetic differences. Models for such genetic heterogeneity of environmental variance include genetic effects for the mean and residual variance, and a correlation between the genetic effects for the mean and residual variance to measure how the residual variance might vary with the mean. The aim of this thesis was to develop a method based on double hierarchical generalized linear models for estimating genetic heteroscedasticity, and to apply it on four traits in two domestic animal species; teat count and litter size in pigs, and milk production and somatic cell count in dairy cows. The method developed is fast and has been implemented in software that is widely used in animal breeding, which makes it convenient to use. It is based on an approximation of double hierarchical generalized linear models by normal distributions. When having repeated observations on individuals or genetic groups, the estimates were found to be unbiased. For the traits studied, the estimated heritability values for the mean and the residual variance, and the genetic coefficients of variation, were found in the usual ranges reported. The genetic correlation between mean and residual variance was estimated for the pig traits only, and was found to be favorable for litter size, but unfavorable for teat count.