A floor pen experiment was conducted in Israel to evaluate the effect of corn particle size in the presence of either time-limited or ad libitum feeding and used wood shavings litter, on broiler live performance from 1 to 48 days of age.
A group of Ross 344 x 708 male chicks were assigned to a factorial arrangement of treatments consisting of two dietary inclusions of coarse corn (CC) in the presence of two feeding programmes (ad libitum or time-limited). Each of the four treatment combinations was replicated with 24 pens of 15 birds each.
Fine corn (FC) was ground to 262 microns (2.4 mm screen) while CC was ground to 1082 microns. The FC and CC were blended to create the CC inclusion levels of 20, 35, 50% in starter, grower, and finisher diets, respectively. Feed intake and bodyweight were determined at 14, 28, 35, and 48 days of age and adjusted feed conversion ratio (Adj FCR) was calculated by including bodyweight of mortality.
The CC broilers consumed less feed but there was no effect on bodyweight, mortality, or cloacal temperature at 49 days. Thus, CC significantly improved Adj FCR. Broilers consuming the 20-35-50% CC diet series exhibited decreased relative proventriculus weight but increased relative gizzard weight. Feed intake and bodyweight were increased by ad libitum feeding. However, time-limited feeding improved Adj FCR while it decreased mortality to 49 days, probably due to decreased cloacal temperature.
The study demonstrated that CC and time-limited feeding significantly improved AdjFCR. The mechanism responsible for decreased mortality of broilers grown in hot weather may be a lower body temperature.
Source: Satid Auttawong and John Brake, North Carolina State University, Raleigh, NC USA and Shlomo Yahav, Institute of Animal Science, Bet Dagan, Israel
Proceedings of the 2014 International Poultry Scientific Forum, Atlanta, GA, USA