Study design

The initial brooding temperature in the house was set to 32^oC, then reduced to 29^oC in week 1, to 26^oC in week 2 and then kept at 25^oC from week 3 until the end of the experiment in week 8. After brooding, which lasted four weeks, chicks were spread out in four 2.24 m² compartments in the poultry house so that there were 10 birds per m².

Chicks were fed starter crumbles for the first three weeks, then changed to mixed fowl feed in weeks 4 and 5. From week 6 to week 8 chickens were let out to forage on Kikuyu grass (Penisetum clandestinum) while supplemented with mixed fowl feed. All chickens were fed ad libitum using feeding troughs throughout the eight weeks of the experiment. Feeders were topped up to three quarters full at 0600 hours daily.