Utilitarianism and Animal Husbandry - Killing Happy Animals: Explorations in Utilitarian Ethics - page 33

Utilitarianism does not categorically condemn the killing of animals.
The average view as a method of aggregation would require killing all
sentient beings, except for the happiest one, as this raises the average
level of happiness. From the perspective of the total view, killing an
animal that would have had a pleasant life is a loss of welfare. This is
because the welfare that the animal would have experienced is lost. In
the case of animal husbandry, the enjoyment that is gained from using
the animals cannot compensate for the welfare loss that is inflicted on
the animals. Alternatives are available that score better in terms of both
animal and human welfare. Neither is the killing necessary in order to
avoid greater welfare loss to the animal or others.
There is an argument that specifies conditions under which the
welfare loss due to the killing can be compensated and the killing can be
justified. We have seen that the welfare loss caused by the killing can in
principle be compensated by the utility that is gained by other individ-
uals. In animal husbandry, a new animal that would not otherwise have
existed replaces every killed animal. According to the Replaceability
Argument, the welfare of this newly created animal can compensate for
the welfare loss due to the killing.
Utilitarianism's support of animal-friendly animal husbandry rests on
the plausibility of the Replaceability Argument. It is therefore worthwhile
to explore the Replaceability Argument in some detail. In Chapter 4, I
will present the Replaceability Argument and I will show that it depends
on a view that is controversial within utilitarianism.