The Substitution of Corn with Soybean Hulls and Subsequent Impact on Digestibility of a Forage-Based Diet Offered to Beef Cattle1

Soybean hulls inclusion on silage of wet brewery waste

This study aimed to evaluate the effects of soybean hulls inclusion in the silage of wet brewery waste. The experimental design was randomized in block, where the treatments were constituted by four levels of soybean hulls on the silage (0, 15, 25, and 35%), with three (silos) replicates per treatment. All data collected were subjected to ANOVA and subsequent polynomial regression at 5%. Soybean hulls inclusion caused a linear increase (p < 0.05) in the pH, dry matter, acid detergent fiber, neutral detergent fiber and total carbohydrates content of the silage. This inclusion also caused a significant reduction (p < 0.05) in the effluent losses and percentages of crude protein, fats, hemicellulose, non-fibrous carbohydrates and total digestible nutrients. Thus, it was concluded that soybean hulls can be used as an additive in the silage of wet brewery waste. Up to 35% of inclusion, there was a significant reduction in the effluent losses, a little increase on pH and enrichment of nutritional content, especially in the dry matter.

Effect of calcium oxide and soybean hull addition to feedlot diets containing dried distillers grains and corn stover on steer performance, carcass characteristics, and digestibility

The objective of this study was to determine the effect of soybean hulls (SBH) and/or calcium oxide (CaO) on rumen pH, digestibility, and performance of steers fed diets containing dried distillers grains with solubles (DDGS). In experiment 1, Angus × Simmental steers (n = 112, body weight [BW] = 364 ± 7.8 kg) were allotted to 1 of 4 diets arranged as a 2 × 2 factorial and placed in 16 pens (7 steers/pen, 4 pens/treatment, and 28 steers/treatment). Factors were SBH (0% or 30% of diet dry matter [DM]) and CaO (0% or 1%) inclusion. Basal diets contained 20% corn stover, 30% DDGS, and 4% supplement. Diets with SBH contained 14.1% or 15.0% corn and diets without SBH contained 43.9% or 44.8% corn. In experiment two, four steers (BW = 510 ± 9.8 kg) were allotted to a 4 × 4 Latin square (21 d periods) to determine the effects of CaO and SBH on ruminal pH, volatile fatty acid (VFA), nutrient digestibility, and digestion kinetics. Statistical analyses were conducted using the MIXED procedure of SAS. In experiment 1, BW did not differ among treatments (P ≥ 0.46). Overall carcass-adjusted gain did not differ due to SBH or CaO inclusion (P ≥ 0.13); however, there was an interaction (P = 0.01) where CaO improved gain in steers fed no SBH, but not in steers fed SBH. Steers fed SBH consumed more DM than steers not fed SBH (P = 0.02) and an interaction tended to occur (P = 0.06) where CaO increased dry matter intake in steers fed no SBH, but not in steers fed SBH. Calcium oxide increased hot carcass weight and yield grade (interaction; P ≤ 0.04) and tended to increase fat thickness (interaction; P = 0.08) in steers fed no SBH, but not in steers fed SBH. Dressing percentage, longissimus muscle area, % kidney, pelvic, heart fat, and marbling score did not differ among treatments (P ≥ 0.14). Total VFA concentrations were greater with SBH inclusion and with CaO addition (P < 0.01). Digestibility of DM, neutral detergent fiber (NDF), and acid detergent fiber (ADF) was greater with CaO addition (P ≤ 0.04) and NDF and ADF digestibility were greater with SBH inclusion (P < 0.001). Inclusion of SBH did not affect (P ≥ 0.26) rate of digestion (k d) or passage (k p). Addition of CaO tended to increase mean retention time (P = 0.09). An interaction between SBH inclusion and CaO addition occurred for k d (P = 0.01), where CaO increased k d in steers fed SBH, but decreased k d when steers were fed no SBH. Total N excretion tended to be lower with SBH inclusion and CaO addition (P = 0.07). In conclusion, CaO enhances performance of cattle fed corn, DDGS, and corn stover diets, but not when corn is partially replaced by a fiber-based energy feed.

Methane emissions from Nellore bulls on pasture fed two levels of starch-based supplement with or without a source of oil

Methane emissions (CH4) from enteric fermentation represent an energy loss to the animal ranging from 2% to 12% of gross energy (GE) intake; therefore, the challenge is to develop diets and handling strategies to mitigate CH4 emissions. This study tested the hypothesis that fat supplementation as a source of energy could reduce CH4 emissions without decrease animal production, independently of the starch level utilised. Thus, the goal of this study was to assess the combined effects of high- or low-starch supplements with or without a source of oil (soybean grain) on intake, digestibility, performance, and CH4 emissions of finishing Nellore bulls [n = 44; initial bodyweight (BW) = 414 ± 12 kg; age of 20 months] grazing on Brachiaria brizantha cv. Xaraés during the dry season. No interactions between starch level and oil source (soybean grain) supplementation with respect to intake of dry matter (DM), forage DM, supplement DM, organic matter (OM), crude protein (CP), neutral detergent fibre (NDF), ether extract (EE), or GE were found. However, there was an effect of starch and oil source on intake of EE. There were no interactions between starch level and oil source supplementation with respect to digestibility of DM, OM, NDF, CP, EE, or digestibility energy. Irrespective of the starch level utilised, the addition of soybean grain (oil source) decreased the digestibility of NDF and increased the digestibility of EE. In relation to animal performance, there were no interactions between starch level and oil regarding initial BW, final BW, average daily gain (ADG), gain efficiency, hot carcass weight, dressing, carcass gain, fat depth, or longissimus muscle area. However, the addition of soybean grain (oil source) increased the fat depth independently of the starch level used. There was no interaction between starch-based supplementation level and oil source on CH4 emissions when expressed in g/day, g/kg DM intake, g/kg OM intake, g/kg NDF intake, % of GE intake, g/g EE intake, g/kg ADG, or g/kg of carcass gain. Therefore, the addition of soybean grain (oil source) in supplements, independent of starch level used, was associated with reduced CH4 emissions expressed in g/day. Additionally, soybean grain (oil source) decreased enteric CH4 emissions relative to GE and EE intake and ADG for animals fed high- or low-starch supplements. Soybean grain supplementation is effective at reducing enteric CH4 emissions from Nellore bulls grazing on tropical pasture.