Feeding value of whole raw soya beans as a protein supplement for beef cattle consuming low-quality forages

MARTÍNEZ MARCELA FERNANDA; ARELOVICH HUGO MARIO; TORRE ROMÁN; TORRE ROMÁN; LABORDE HUGO EDUARDO; LAGRANGE, SEBASTIÁN; LABORDE HUGO EDUARDO; LAGRANGE, SEBASTIÁN; MARTÍNEZ MARCELA FERNANDA; ARELOVICH HUGO MARIO

JOURNAL OF ANIMAL PHYSIOLOGY AND ANIMAL NUTRITION

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2017

0931-2439

Experiments (Exp) I and II were conducted to compare raw whole soya beans (WSB), roasted (rWSB) or other protein sources as supplements of low-quality forages fed ad libitum to beef cattle, upon DM intake (DMI), ruminal and blood parameters, and animal performance. Exp I: treatments for wheat straw fed to 4 ruminally cannulated steers were: (1) Control-WS: nosupplement; (2) WSB-WS: whole soya beans; (3) rWSB-WS: roasted WSB; (4) SBM-WS: soybean meal-wheat midds mixture; all fed at 1.4 kg DM/d. Exp II: 12 steers grazed deferred grain-sorghum (DS) receiving these treatments: (1) Control-DS: no supplement; (2) WSB-DS: 1.26 kg DM/d whole soya beans and (3) SFM-DS: 1.35 kg DM/d of sunflower meal. In Exp I, WS DMI resulted 47, 52, and 41 % greater for WSB-WS, rWSB-WS, and SBM-WS respectively than Control-WS (p < 0.05). In Exp II, the DMI of DS was unaffected by supplementation; a substitution of DS by supplement was found for WSB-DS (p < 0.05); however, total diet and digestible DMI increased with supplementation (p < 0. 05). Rumen pH in Exp I remained unaffected by supplementation, but N-NH3 as well as blood urea-N in Exp II increased (p < 0.05). In Exp II, average daily weight gains improved similarly with both supplements compared with Control-DS. Additionally, feed to gain ratio decreased (p < 0.05), being lower for WSB-DS (8.3) vs. SFM-DS (9.9). Roasting effects of WSB as a supplement for low-quality forages were not detected, all protein sources increased total diet DMI and forage utilization. Only moderate cattle weight gains could be expected for unsupplemented DS.