title: Influence of feeding coarse corn on performance, nutrient utilization, digestive tract measurements, carcass characteristics, and cecal microflora counts of broilers.
abstract: The objective of the present study was to examine the effects of feeding coarsely ground corn on performance, digestive tract measurements, nutrient utilization, and cecal microflora counts in broilers. Five diets containing 600 g/kg of finely ground corn (hammer milled) or 150, 300, 450, and 600 g/kg of coarse corn (cracked in roller mill) replacing (wt/wt) finely ground corn were formulated. Each diet in mash form was offered ad libitum to 6 replicate cages of broilers (8 birds per cage) from d 11 to 35 posthatch. Weight gain increased (linear effect, P < 0.01) with increasing inclusion levels of coarse corn. Feed intake (quadratic effect, P < 0.05) increased at 150 g/kg of coarse corn inclusion, plateaued until 450 g/kg, and then increased again to 600 g/kg. Feed per gain increased (quadratic effect, P < 0.05) as inclusion of coarse corn increased to 300 g/kg and then decreased with further inclusion. Apparent metabolizable energy and total tract DM retention (quadratic effect, P < 0.01) was unaffected up to 300g/kg inclusion, and then decreased with further inclusion of coarse corn. Relative gizzard weight increased (linear effect, P < 0.05) with increasing inclusion of coarse corn. Inclusion of coarse corn had no effect (P > 0.05) on ileal digestibility of DM, N, and starch. Breast meat yield decreased (linear effect, P < 0.05 and abdominal fat increased (linear effect, P < 0.001) with increasing inclusion levels of coarse corn, but there was no effect (P > 0.05) on the carcass yield. A linear (P < 0.05) effect was observed for cecal microflora counts. Lactobacillus spp. and Bifidobacteria spp. counts increased and counts of Clostridium spp., Campylobacterium spp., and Bacteroides spp. decreased with increasing inclusion levels of coarse corn. The present data showed that feeding of coarse corn increased weight gain and gizzard size, and modified gut microflora profile toward beneficial species and that it can totally replace ground corn in broilers fed mash diets.
authors.affiliation: Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North 4442, New Zealand.
authors.forename: Y
authors.initials: Y
authors.lastname: Singh
authors.forename: V
authors.initials: V
authors.lastname: Ravindran
authors.forename: T J
authors.initials: TJ
authors.lastname: Wester
authors.forename: A L
authors.initials: AL
authors.lastname: Molan
authors.forename: G
authors.initials: G
authors.lastname: Ravindran
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena / Q000187:drug effects; D000818:Animals; D002432:Cecum / Q000187:drug effects / Q000382:microbiology*; D002645:Chickens / Q000254:growth & development / Q000382:microbiology* / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D004063:Digestion / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism / Q000187:drug effects*; D041981:Gastrointestinal Tract / Q000187:drug effects / Q000254:growth & development*; D005895:Gizzard, Avian / Q000254:growth & development; D008297:Male; D009929:Organ Size / Q000187:drug effects; D015430:Weight Gain / Q000187:drug effects; D003313:Zea mays / Q000737:chemistry*
keywords: broiler; coarse corn; digestive tract; nutrient utilization; particle size