The feeding value of different classes of wheat for grower finisher pigs

Abstract

A factorial experiment involving two levels of feeding (restricted and ad libitum) and four classes of wheat, these being Australian standard white wheat (ASW), feed wheat damaged by rust (FR), general purpose wheat damaged by weather (GPW) and general purpose wheat damaged by rust (GPR), was carried out to study the effects of different classes of wheats on the growth performance and carcase quality of pigs between 23 and 70 kg liveweight. The digestible energy (DE) contents (+SD) of the wheats, on an air basis were 14.8 (+0.20), 14.8 (+0.20), 14.9 (+0.22) and 14.3 (+0.12) MJ kg-1 for ASW, FR, GPW and GPR, respectively. Wheat class did not affect feed intake of pigs or cause variation in carcase quality. However, pigs fed diets containing GPR or FR wheats did not perform as well as pigs fed diets based on GPW or ASW wheat. This lower growth performance was due to the lower DE content of GPR wheat and the reduced digestibility of protein in both GBR and FR wheats. Pigs fed ad libitum grew faster, had fatter carcases and over the weight range 45 to 70 kg required more feed per unit liveweight gain than pigs fed in restricted amounts.