The effects of lighting program, ingredient particle size and feed form on the performance of broiler turkeys

Abstract

Two experiments were done to examine the effects of lighting program, ingredient particle size and feed form on the performance of female and male medium White turkey broilers. The poults (1200 initially of each sex) were randomly assigned, within sexes, among 48 floor pens (4.83 × 2.95 m; initially 50 birds each) located in a light-tight house. The treatments were distributed among the pens according to a 3 × 2 × 4 factorial arrangement that contained three lighting programs (four cycles daily of 4L:2D [INT]; 6L:18D at 3 d gradually increasing to 22L:2D at 77 d [INC]; and INC with a 1-h light at the mid-point of the dark period [INC + 1]) and four feed forms (fine mash [FM], FM pelleted [FMP]; course mash [CM]; and CM pelleted [CMP]). The FM was produced by grinding the dietary corn and wheat through hammer mills that contained 3.2- and 4.0-mm screens, respectively, and the CM by grinding the corn in a hammer mill (5.6-mm screen) and passing the wheat through a roller mill in which the spacing between the rollers was about 1.6 mm. All poults received 24L:0D for the first 72 h after housing. Feed and water were provided ad libitum over the 84-d experimental period. During the starter period, the pelleted feeds (FMP and CMP) were crumbled.Turkeys subjected to the INT lighting program had higher body weight gains (P < 0.001), feed intakes (P < 0.001 − 0.05) and mortality (P > 0.05) than the birds under the INC and INC + 1 schedules, but the feed conversions were similar (P > 0.05) for the birds under the three lighting programs. Economic returns from the turkeys subjected to the INC program were higher (P < 0.05) than from those under the other two programs. Body weight gains and feed intakes were higher (P < 0.001 − 0.05) for the birds given the mash feed (FM and CM) than for those fed pellets (FMP and CMP), even though feed conversions were better (P < 0.001) for the turkeys receiving the pelleted feeds. Economic returns were highest for the turkeys fed the CM feeds and lowest for those given the FM feeds; the difference was 3.3%. In conclusion, both lighting program and feed form influenced the economics obtained for broiler turkeys, but fineness of grind had little effect. Key words: Particle size, feed form, lighting program, turkeys, performance