Effects of prior experience and training on diet selection of broiler chickens using wheat

Abstract

Female broiler chickens were given various types of training to familiarise them with whole wheat and their subsequent selection between whole wheat and a standard grower food was studied. In the first experiment 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 third weeks after hatching; other groups were fed either the two foods on alternate days or free choice throughout. Prior exposure to wheat offered on alternate days led to subsequent lower intakes of wheat compared with similar but choice-fed birds and those trained in Week 1 had particularly low intakes of wheat in the test period. Experiment 2 examined the effects on subsequent selection of giving wheat in the training 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 and starter food. Length of exposure did not affect food intake in the subsequent choice feeding period but sole access to wheat in the training period resulted in higher subsequent wheat intake compared with exposure to a mixture of crumbs and grain. Carcass and abdominal fat pad weights were not affected by any of the treatment, showing that compensation for training differences had occurred during the test period. The last experiment studied the effect of prior training over 6 days in the fourth week after hatching with wheat only, starter food only, alternate feeding in half-day, whole-day or 3-day periods, or choice throughout. The proportion of wheat eaten in the subsequent test period was significantly higher for those choice-fed throughout and there were no significant differences in carcass weight at 7 weeks of age, except 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 offered from an early age.