Work

PSXIII-28 Effects of replacing dry-rolled flint corn with reconstituted corn grain silage in supplements for beef cattle finished on pasture provided on different days after mixing

Year: 2024

Type: article

Abstract: The study was carried out to assess how replacing dry-rolled flint corn (DRC) with reconstituted corn grain silage (RCGS) in a supplement, exposed in aerobic conditions for different periods before delivery to cattle (fresh, 3 d, or 6 d), affects the performance of Nelore bulls intensively finished on pasture with high supplementation. Nellore bulls [n = 864; body weight (BW) = 408 ± 35 kg; 22 mo old) were used in a randomized block design and distributed into 12 paddocks (10 ha, n = 6; 8 ha, n = 6; 8 bulls/ha). The treatments consisted of control (CON; DRC supplement); T0 (70% of DRC replaced with RCGS and provided after mixing); T3 (70% DRC replaced with RCGS and provided 3 d after mixing); and T6 (70% of DRC replaced with RCGS and provided 6 d after mixing). The control supplement was composed of 67.3% DRC, 11.0% cottonseed whole, 17.4% cottonseed cake, and 4.30% mineral premix. The RCGS was inoculated using Lactobacillus hilgardii (CNCM I-4785) + Lactobacillus buchneri (NCIMB 40788), both at 1.5x105 cfu/g, and opened after 60 d of storage in silos bag (61% DM). Bulls were fed ad libitum for 102 d. Intake was measured daily. Performance data was calculated considering supplement intake (DMIsup) and initial carcass dressing was considered 50%. All data were analyzed as orthogonal contrasts using SAS: C1: CON vs T0; L: linear effect of exposure time; Q: quadratic effect of exposure time. Orthogonal contrasts were analyzed considering P < 0.05 as significant effect and P ≤ 0.10 as tendency. Bulls consuming RCGS supplements tended to exhibit a linear response in DMIsup (% BW) over the day of supplement air exposure. No effect was detected in the other assessments for L and Q contrasts (P ≥ 0.11). Bulls consuming fresh RCGS supplement tended to have heavier final BW (P = 0.06) and to consume 5% less supplement (P = 0.09; Table 1). The average daily gain (ADG) was 3.9% greater for T0 animals in comparison with CON (P = 0.03). Supplement intake as % BW was 5.4% less (P < 0.01), and feed efficiency was 10.5% better for cattle consuming fresh supplement in comparison with CON (P < 0.01). Hot carcass weight tended to be greater for T0 bulls compared with CON bulls (P = 0.09) and carcass ADG presented the same behavior (P = 0.09). Carcass feed to gain (F:G) was 7.17% better for T0 bulls compared with CON bulls (P < 0.01). Fecal starch and feces pH presented better results for T0 in comparison with CON (P < 0.01). Nellore cattle consuming fresh RCGS supplement had better ADG, carcass characteristics, and feed efficiency than cattle consuming DRC supplement. Cattle consuming air-exposed RCGS supplements performed similarly to cattle consuming fresh RCGS supplement.

Source: Journal of Animal Science

DOI: 10.1093/jas/skae234.895