A.
The concerns in animal welfare can include how animals are slaughtered for food, how they are used in scientific research, how they are kept (as pets, in zoos, farms, circuses, etc.), and how human activities affect the welfare and survival of wild species.
B.
Respect for animal welfare is often based on the belief that non-human animals are sentient and that consideration should be given to their well-being or suffering, especially when they are under the care of humans.
C.
Animal welfare science uses various measures, such as longevity, disease, immunosuppression, behavior, physiology, & reproduction, although there is debate about which of these indicators provide the best information.
D.
Animal welfare is the well-being of animals. The standards of "good" animal welfare vary considerably between different contexts.