Strategies to improve fermentation characteristics of ensiling WDBS-based total mixed ration and partial mixed ration

• Ano de defesa: 2024
• Autor(a) principal: Chengqiang, Wang
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Additives; Aditivos; Aerobic stability; Ensilagem mista; Estabilidade aeróbica; Farelo de destilaria úmido mais solúveis; Mixed ensiling; Silagem ração mista total; Total mixed ration silage; Wet distillers bran plus solubles
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/11/11139/tde-14012025-160436/

Wet distillers bran plus solubles (WDBS), as a byproduct of the corn ethanol industry, has been widely used for ruminant feed due to its high quality fiber and protein concentration. However, the risk of spoilage limits its long-term storage and long-distance transportation. For this reason, two experiments were conducted to evaluate WDBS as the main ingredient in total mixed ration (TMR) and partial mixed ration (PMR) silages. The hypothesis was that different additives applied to TMR (Experiment 1), or different combinations between WDBS and other dry ingredient (Experiment 2) would affect the fermentation quality and losses in TMR and PMR silages. In the first experiment, the TMR was composed of 50% WDBS, 7% tropical grass silage, 9% cottonseed hulls (CH), 12% soybean hulls (SH), 19% ground corn (CORN) and 3% premixed minerals-vitamins, on a DM basis. The following treatments were evaluated: control, Lentilactobacillus buchneri (LB, 5×105cfu/g of fresh matter), sodium benzoate (SB, 1.5 g/kg of fresh matter) and a blend of organic acids (BOA, 2 mL/kg of fresh matter), with four replicates per treatment, stored in 5 L polyethylene buckets for 45 days. TMR silages showed an adequate fermentation pattern, with pH values between 4.36 and 4.38 and acceptable levels of propionic acid (202-568 mg/kg, DM) and butyric acid (109-155 mg/kg, DM). The BOA treatment resulted in the highest concentration of propionic acid and LB in the highest butyric acid, different from the others (p<0.05). The silages had low counts of fungi and yeasts and a higher CFU count for LAB (7.2 log10cfu/g, FM, p<0.05). Dry matter losses were low (1.56%-3.49%) and the BOA treatment was the most efficient in controlling losses (p<0.05). The additives did not modify the aerobic stability of fresh or ensiled TMR. In the second experiment, the following treatments were evaluated: negative control (WDBS: ensiled alone), positive control (TMR: same composition as in the previous experiment), and mixtures of WDBS with cottonseed hulls (CH), in the proportion (85% WDBS: 15% CH); soybean hulls (SH), (81% WDBS: 19% SH), or ground corn (72% WDBS: 28% CORN). Obeying the same inclusion levels of these ingredients in the TMR, on a dry matter basis. The experimental units were 20 L polyethylene buckets containing a kit for effluent collection at the bottom (dry sand covered with plastic screen and cotton fabric). Storage times were 60 and 120 days. TMR treatment showed the highest counts of lactic acid bacteria (p<0.0001). The mold population decreased with storage time (p<0.0001). All treatments achieved low pH (below 4), except TMR treatment, which also resulted in higher concentrations of lactic acid and acetic acid (p<0.05). In addition to TMR, the WDBS+CH combination resulted in the lowest effluent and dry matter losses. The average aerobic stability of all treatments at 60 days was 14 hours higher than at 120 days of ensiling. The TMR and WDBS+CH strategies were the most promising for WDBS storage.