The sum of progressive changes over time at the level of the individual, species, higher taxa, or production categories/breeds/lines.
Paired bare skin structures below the ear of chickens, slanting down toward the ...
Ability for faster growth and earlier completion of body development compared to...
Ability to start egg laying as early as possible while meeting requirements for ...
An animal’s propensity to consume feed—intensity and amount—affected by appetite...
The ratio of the amount of a nutrient retained in the organism or in a product f...
Products of the reproductive organs of female birds; differ by species in weight...