Interaction of Dietary Coarse Corn With Other Dietary and Environmental Factors on Broiler Live Performance.

AUTTAWONG, SATID. Interaction of Dietary Coarse Corn With Other Dietary and Environmental Factors on Broiler Live Performance. (Under the direction of Dr. John T. Brake.) An experiment was conducted to examine the effect of percentage coarse corn (CC) of total dietary corn and distiller’s dried grains with solubles (DDGS) on the performance of broilers to 47 d of age. A total of 2,160 day-old Ross 344 x 708 broiler chicks were used in a factorial arrangement of treatments consisting of 3 dietary inclusion levels of CC (0, 10, 20% of total dietary corn in starter and 0, 25, 50% in grower and finisher diets) and 3 inclusion levels of DDGS (0, 6, 12% in starter and 0, 15, 30% in grower and finisher diets). Feed consumption and BW were determined at 14, 35, and 47 d of age and adjusted feed conversion ratio (AdjFCR) was calculated by including BW of mortalities. Percentage CC of total dietary corn significantly improved AdjFCR and reduced feed consumption without negative effects on BW at 47 d of age. Chickens fed CC exhibited larger gross and relative gizzard weights at 48 d of age than broilers fed fine corn. Broilers fed DDGS exhibited significantly poorer feed AdjFCR as well as reduced BW. Feed consumption was not affected by DDGS treatments. Mortality rate was significantly reduced by increasing DDGS, probably due to slower growth. The results of this study demonstrated that increasing percentage CC of total dietary corn in an age-related increasing manner had a beneficial effect on feed efficiency and gizzard function without negative effect on BW. There were no interactions of DDGS and CC inclusion levels, which suggested that CC could not be used to improve DDGS utilization. A second experiment was conducted to evaluate the effect of feeding program, percentage CC of total dietary corn, dietary metabolizable energy (ME), and main site of liquid fat application on broiler live performance to 48 d of age. Ross 344 x 708 male chicks (n = 1,440) were assigned to a factorial arrangement of treatments consisting of two levels of coarse corn; two levels of ME; two types of fat application and two feeding programs. The coarse corn treatments consisted of no coarse corn (0%) or 20, 35, and 50% coarse corn of total dietary corn in the starter, grower, and finisher diets. Dietary ME treatments consisted of two low level of 2.95 kcal ME/g and 3.05 kcal ME/g in grower and finisher diets and two high level of 3.05 kcal ME/g and 3.15 kcal ME/g in grower and finisher diets. The two types of fat application consisted of all fat in mixer or 0.75% in mixer plus the remainder added post-pellet. The two feeding programs consisted of ad libitum or time-limited. Feed intake (FI) and BW were determined at 14, 28, 35, and 48 d of age and adjusted feed conversion ratio (AdjFCR) was calculated. The results showed that broilers fed time-limited feeding significantly reduced BW prior to heat stress but broilers experienced acute heat stress at 5 wk of age exhibited improved AdjFCR and mortality during heat stress. The CC had no effect on BW at 48 d of age, but significantly reduced FI and improved AdjFCR relative to 100% FC. The low and high dietary ME treatments produced the same BW at 48 d of age but the higher ME level significantly improved AdjFCR. Mixer fat application increased FI but AdjFCR was improved by the post pellet fat application. Broilers fed CC based diets on an ad libitum basis exhibited better results than broilers fed time-limited while pellet quality played an important role in the presence of an ad libitum feeding program. © Copyright 2013 by Satid Auttawong All Rights Reserved Interaction of Dietary Coarse Corn With Other Dietary and Environmental Factors on Broiler Live Performance