Flint corn grain processing and citrus pulp level in finishing diets for feedlot cattle

Author(s)

Gouvea, V. N. ^[1] ; Batistel, F. ^[1] ; Souza, J. ^[1] ; Chagas, L. J. ^[1] ; Sitta, C. ^[1] ; Campanili, P. R. B. ^[1] ; Galvani, D. B. ^[2] ; Pires, A. V. ^[1] ; Owens, F. N. ^[3] ; Santos, F. A. P. ^[1]

Affiliation

^[1] Univ Sao Paulo, Escola Super Agr Luiz de Queiroz, Dept Zootecnia, BR-13418900 Piracicaba, SP - Brazil

^[2] Empresa Brasileira Pesquisa Agr, Embrapa Caprinos & Ovinos, BR-62010970 Sobral, CE - Brazil

^[3] DuPont Pioneer, 7300 NW 62nd Ave, Johnston, IA 50131 - USA

• Document type: Journal article
• Source: JOURNAL OF ANIMAL SCIENCE; v. 94, n. 2, p. 665-677, FEB 2016.
• Web of Science Citations: 6

Abstract

Four trials were conducted to evaluate the effects of flint corn processing and the replacement of corn with citrus pulp (CiP) in diets for Nellore feedlot cattle. In a 103-d finishing trial, 216 Nellore bulls (350 +/- 24 kg initial BW) were used in a randomized complete block design with a 2 x 4 factorial arrangement of treatments. Factors included 2 processing methods, either ground corn (GC) or steam-flaked corn (FC), with CiP replacing each corn type at 4 levels (0, 25, 50, and 75% of DM). All diets contained 12% sugarcane bagasse and 88% concentrate (DM basis). Treatments were also evaluated in metabolism trials, in which 10 ruminally cannulated Nellore steers (389 +/- 37 kg) were assigned to 2 independent but simultaneous 5 x 5 Latin squares, each using 1 method of corn processing (GC and FC). Interactions (P < 0.05) between corn processing and CiP inclusion level were observed for final BW, DMI, ADG, G:F, and HCW. With FC-based diets, added CiP linearly decreased final BW (P = 0.04), whereas with GC-based diets, added CiP quadratically increased final BW (P = 0.002). With FC-based diets, the inclusion of CiP linearly increased DMI (P = 0.03) and linearly decreased ADG (P = 0.03) and G: F (P = 0.001). Increasing CiP in GC-based diets quadratically increased DMI (P = 0.001), ADG (P = 0.005), and HCW (P = 0.003). In FC-based diets, CiP inclusion had no effect on HCW (P = 0.21). Dressing percent, LM area, and 12th-rib fat were not affected by diet (P = 0.05). For steers fed GC diets, CiP inclusion in the diet quadratically decreased the molar proportion of isovalerate (P = 0.001) but linearly increased ruminal butyrate (P = 0.006). No differences (P >= 0.16) were observed for total VFA concentrations, acetate: propionate ratio, and ruminal NH3-N as CiP replaced GC. For steers fed FC diets, the molar proportion of acetate linearly increased (P = 0.002) whereas the proportion of propionate was linearly decreased (P < 0.001), resulting in a linear increase (P = 0.001) in the acetate: propionate ratio. Replacing corn with CiP linearly reduced NEm (P = 0.001) and NEg (P < 0.001) of FC-based diets but did not affect (P = 0.15) NE values of CG-based diets. Steam flaking flint corn improved cattle performance in this trial more than has been reported for dent corn in the published literature. (AU)

• FAPESP's process: 09/13608-1 - Grain processing and inclusion of by-products in the diet of cattle Finishing in feedlot.
• Grantee: Vinícius Nunes de Gouvêa
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 10/12396-8 - Substituition of citrus pulp for flaked or finely ground corn in feedlot finished Nelore cattle diets.
• Grantee: Flávio Augusto Portela Santos
• Support Opportunities: Regular Research Grants