This is simply untrue. Lactation is a physiological response that follows giving birth. The cow cannot avoid giving milk any more than she can avoid producing urine. The same is true of chickens and egg-laying; the egg output is manipulated to a high level by selective breeding, carefully regulated conditions that simulate a continuous summer season, and a carefully controlled diet. To drive this point home further, consider that over the last five decades, the conditions for egg-laying chickens have become increasingly unnatural and confining (see question #49), yet the egg output has increased many times over. Chickens will even continue to lay when severely injured; they simply cannot help it. DG p>
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