1367
INFLUENCE OF PRE-PELLETING INCLUSION OF WHOLE CORN ON PERFORMANCE, NUTRIENT UTILIZATION AND DIGESTIVE TRACT MEASUREMENTS OF YOUNG BROILERS
The objective of the present study was to examine the effects of pre-pelleting inclusion of whole corn on performance, digestive tract measurements and nutrient utilization in broiler starters. Five diets, containing 60% ground corn or 15, 30, 45 and 60% whole corn replacing (w/w) ground corn, were formulated and cold-pelleted at 65 oC. Each diet was offered ad libitum to six replicates (8 birds per replicate cage) from d 1 to 21 post-hatch. Weight gain (1005, 990, 919, 933 and 857 g/bird, respectively) and feed intake (1303, 1312, 1214, 1226 and 1136 g/bird, respectively) decreased linearly (P<0.001) with increasing pre-pelleting inclusion of whole corn. Feed per gain (quadratic effect, P<0.05) increased as the inclusion level of whole corn increased to 30% and then plateaued with further inclusions. Relative gizzard weight (12, 14, 15, 16 and 16 g/kg body weight, respectively; quadratic effect, P<0.05) and apparent metabolisable energy (3400, 3450, 3466, 3424 and 3435 kcal/kg, respectively; quadratic effect, P<0.05) increased with increasing inclusion of whole corn up to 30% and then levelled off. Ileal digestibility of starch (linear effect, P<0.001) and nitrogen (linear effect, P=0.07) increased with increasing inclusion levels of whole corn. Pellet quality, measured as pellet durability index (64, 78, 78, 82 and 84, respectively; quadratic effect, P<0.001), increased sharply with the inclusion of whole corn to 15% , then plateaued and a further increase was observed at the inclusion level of 45%. The present data showed that, despite improvements in gizzard development, nutrient utilization and pellet quality, weight gain of broilers were poorer with pre-pelleting inclusion of whole corn due largely to the reduced feed intake.
Keywords:
Broilers, pre-pelleting, whole corn