Growth, carcase composition and profitability of meat chickens given pellets, mash or free‐choice diet

Abstract

1. Equal numbers of 21‐d‐old male and female meat chickens were given their dietary ingredients either mixed and presented as pellets or mash, or as separate ingredients presented on a free‐choice basis, to determine whether presentation method caused any differences in growth, carcase composition or profitability to 42 d of age. 2. The proportions of ingredients eaten by the chickens given a free choice varied widely during the first 56 h of the trial. Thereafter, the proportions did not vary widely and birds given the free choice ate approximately ½ of their intake as whole wheat, ? of their intake as concentrate (high protein meals plus vitamin and mineral premixes), and 1/7 of their intake as whole sorghum each week for the three‐week trial period. 3. The nutrient composition of the free‐choice diet selected by the birds over the trial period averaged 12.09 MJ ME/kg feed, 210 g/kg crude protein, 14 g/kg calcium and 7 g/kg phosphorus. 4. At the end of the trial the average live body weights of the birds differed significantly according to method of feeding, in the descending order of pellets > mash > free choice. 5. The empty gizzard weight of birds differed significantly according to the method of feeding, in the descending order of free choice > mash > pellets. 6. The plucked empty bodies of birds given the free choice had a significantly lower concentration of crude protein than the plucked empty bodies of birds fed on mash or pellets. There were no significant differences between the treatments in the plucked empty body concentrations of fat, calcium or phosphorus. 7. Financial analysis indicated that free‐choice feeding was more profitable than feeding mash or pelleted diets to broiler chickens by 3.6% and 33.4% respectively.