EFFECTS OF PRIOR EXPERIENCE AND TRAINING ON DIET SELECTION OF BROILER-CHICKENS USING WHEAT

Female broiler chickens were given various types of training to famili arise them with whole wheat and their subsequent selection between who le wheat and a standard grower food was studied. In the first experime nt birds were either given starter food and wheat on alternate days or a choice between the two foods for 4 days, in the first, second or th ird weeks after hatching; other groups were fed either the two foods o n alternate days or free choice throughout. Prior exposure to wheat of fered on alternate days led to subsequent lower intakes of wheat compa red with similar but choice-fed birds and those trained in Week 1 had particularly low intakes of wheat in the test period. Experiment 2 exa mined the effects on subsequent selection of giving wheat in the train ing period (Weeks 1-3) either for 2 or 6 h per day, either following a 2 h fast or not, and with whole wheat or an equal mixture of wheat an d starter food. Length of exposure did not affect food intake in the s ubsequent choice feeding period but sole access to wheat in the traini ng period resulted in higher subsequent wheat intake compared with exp osure to a mixture of crumbs and grain Carcass and abdominal fat pad w eights were not affected by any of the treatments, showing that compen sation for training differences had occurred during the test period. T he last experiment studied the effect of prior training over 6 days in the fourth week after hatching with wheat only, starter food only, al ternate feeding in half-day, whole-day or 3-day periods, or choice thr oughout. The proportion of wheat eaten in the subsequent test period w as significantly higher for those choice-fed throughout and there were no significant differences in carcass weight at 7 weeks of age, excep t for the lower weight of those offered only wheat during the training period. It was concluded that choice-fed chickens do not need special prior training when whole wheat is used as long as both foods are off ered from an early age.