Traditional wisdom holds that an animal’s genetics and the environment it lives in can both affect feed efficiency (and other traits). In contrast, an animal’s genes do not directly influence the environment, and the environment does not directly influence an individual’s genes. Genetic influences are passed on from parents to offspring, while environmental influences are not.
There is growing evidence that the situation is not that straightforward; in some cases the environment may have a direct impact on the expression of an individual’s genes. This environmental impact might also be inherited, and is called epigenetics. Continue reading