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Twenty Holstein cows at 168 ± 87 d in milk (mean ± SD) were assigned to a 4 × 4 Latin square design with a 2 × 2 factorial arrangement to evaluate the effects of 2 storage lengths (30 or 90 d) and the presence of sodium benzoate (control or 0.2% as fed) on the nutritive value of reconstituted sorghum grain silages (RSGS). For each treatment, dry ground sorghum grain was rehydrated to 35% moisture and ensiled in 200-L plastic drums. The treatments were RSGS stored for 30 d without sodium benzoate ( 30CON), RSGS stored for 30 d with sodium benzoate (30 BEN), RSGS stored for 90 d without sodium benzoate (90 CON) and RSGS stored for 90 d with sodium benzoate (90 BEN). Diets contained 16.3% RSGS. Silages stored for 90 d had higher concentrations of 1,2-propanediol, soluble protein, and ammonia nitrogen than did those stored for 30 d. Sodium benzoate reduced ethanol and ethyl-ester formation. Silages stored for 90 d had higher starch (89.3 vs. 86.9%) and protein (57.1 vs. 54.0%) digestibility compared with silages stored for 30 d. The ruminal acetate-to-propionate ratio tended to be lower in RSGS stored for 90 d than in RSGS stored for 30 d (3.75 vs. 3.34). Milk yield increased from 30.0 kg/d in cows fed RSGS stored for 30 d to 31.2 kg/d in cows fed RSGS stored for 90 d, without a change in dry matter intake (23.5 kg/d on average). Hence, feed efficiency and milk N efficiency also had tendencies to increase in cows fed RSGS stored for 90 d. Sodium benzoate did not alter cow performance but slightly increased plasma glucose (65.2 vs. 63.6 mg/dL). In conclusion, increasing the storage period of RSGS from 30 to 90 d improved starch and protein digestibility, milk yield, and feed efficiency.

An experiment was conducted in the Sheep Farming Laboratory at the Federal University of Santa Maria to examine the effect of different levels of replacement of sorghum silage with soybean pre-cleaning by-product (SPCB) on nutrient intake, performance and feeding behavior; as well as to undertake an economic analysis of feeding finishing lambs in a feedlot system. The study involved 32 uncastrated Texel × Ile de France crossbred male lambs weaned at 60 days of age. Treatments consisted of diets in which the roughage source (sorghum silage) was replaced with SPCB at the levels of 0, 33.5, 66.5 or 100% (DM basis). A 45:55 roughage:concentrate ratio was used (DM basis). The diets were composed of a roughage feed based on sorghum silage and/or SPCB, and a concentrate consisting of crushed maize, soybean meal and limestone. In addition, mineral salt was freely available to the animals. The lambs were slaughtered upon reaching the pre-established live weight of 35 kg. Intake on a DM basis showed a quadratic response (P ≤ 0.05) in all forms it was evaluated and expressed, except for the NDF fraction, which increased linearly (P ≤ 0.05) with SPCB inclusion. Average daily weight gain was not significantly influenced (P > 0.05) by the different SPCB levels, averaging 292 g/day. As regards the feeding behavior characteristics evaluated, the number of daily feeding bouts increased linearly (P ≤ 0.01) with the SPCB content of the diets. Total feed cost decreased linearly (P ≤ 0.01), whereas the profit per kilogram of gain and profit obtained per day in the feedlot period increased linearly (P ≤ 0.01) with SPCB inclusion. The use of soybean pre-cleaning by-product as the roughage source in the finishing of feedlot lambs proved to be a viable alternative in both the productive and economic terms.