Rates of eating by domestic fowls in relation to changing food deficits

Rates of eating by immature female fowls declined in a curvilinear way in the 30 min after return of food after 0-4 h deprivation. Amounts eaten in the first 5-10 min were related positively to the length of deprivation and were greater with pelleted food than with mash. Times taken by birds to reach a presumed equilibrium between probabilities of feeding starting and stopping, at two consecutive minutes with less than 0.2 g eaten, were related positively to the deprivation period and were greater with mash than with pellets. At these times, however, more had been eaten with pellets than with mash, and none of the deprived birds had eliminated their estimated food deficits. Furthermore, in only one out of ten treatments did birds compensate imbalances completely by the end of the 90 min test. It is proposed that the observed changes in eating rate may reflect interactions between pecking success, increasing fatigue and decreasing hunger. It is also concluded that, while short-term adjustments in feeding may be limited by preabsorptive factors, eventual compensation of imbalances depends on postabsorptive control.