title: Effects of various roughage levels with whole flint corn grain on performance of finishing cattle.
abstract: Performance responses to steam flaking flint corn as well as to the addition of roughage to finishing diets composed of whole flint corn were evaluated. Ninety-six Nellore bulls were stratified by initial BW (373 ± 11 kg) and randomly allotted to 16 feedlot pens (6 bulls/pen) in a randomized complete block design with 4 replicates/treatment. Dietary treatments for the 86-d feeding trial consisted of (DM basis) 1) 78.8% steam-flaked flint corn with 6% sugarcane bagasse and 0.20% urea, 2) 85% whole flint corn without sugarcane bagasse, 3) 81.9% whole flint corn with 3% sugarcane bagasse and 0.10% urea, and 4) 78.8% whole flint corn with 6% sugarcane bagasse and 0.20% urea. All diets contained 15% (DM basis) of a pelleted protein, mineral, and vitamin supplement. Compared with whole flint corn grain, flaking of flint grain decreased ( < 0.01) DMI but did not alter ADG ( = 0.86), so G:F was increased ( = 0.02). Although steam flaking did not alter final BW and carcass characteristics ( > 0.47), it increased energy content of the diet ( < 0.03) and total tract starch digestibility ( < 0.01). In addition, flaking increased ( < 0.01) NEg of flint corn when compared with whole corn. Increasing the roughage content of WC-based diets resulted in quadratic ( < 0.02) responses in DMI, NEm and NEg intakes, ADG, and final BW but had no effect ( > 0.47) on G:F or on observed energy content of the diet. In summary, steam flaking of flint corn when fed in diets containing 6% sugarcane bagasse decreased DMI by 17% but increased G:F by 20% and NEg of corn calculated from feedlot performance by 23%; these responses markedly exceed those typically observed with dent corn grain. Moreover, adding 3% sugarcane bagasse to a flint whole corn grain diet optimized feedlot performance of Nellore bulls.
authors.forename: R S
authors.initials: RS
authors.lastname: Marques
authors.forename: L J
authors.initials: LJ
authors.lastname: Chagas
authors.forename: F N
authors.initials: FN
authors.lastname: Owens
authors.forename: F A P
authors.initials: FA
authors.lastname: Santos
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle; D002482:Cellulose; D004032:Diet / Q000662:veterinary*; D004043:Dietary Fiber; D019587:Dietary Supplements; D005511:Food Handling; D008297:Male; D008903:Minerals; D013213:Starch; D014508:Urea / Q000008:administration & dosage; D003313:Zea mays
chemical_list: D004043:Dietary Fiber; D008903:Minerals; D014508:Urea; D002482:Cellulose; D013213:Starch; C027433:bagasse