Total mixed ration silages based on elephant grass with the addition of agro-industrial byproducts

The present study aimed to evaluate the fermentative profile and losses in total mixed ration silages based on elephant grass (Pennisetum purpureum Schum.) with the addition of agro-industrial byproducts. The experiment was conducted at Campus II, CCA/UFPB, Areia – PB, in a completely randomized design with six repetitions per treatment, totaling 30 experimental units. The agro-industrial byproducts used were pineapple residues, passion fruit peel, sisal mucilage, refinazil, corn bran, soybean meal, and cottonseed cake. Elephant grass constituted the basal forage of the diet. The treatments were as follows: T1: elephant grass + cottonseed cake + refinazil; T2: elephant grass + cottonseed cake + refinazil + pineapple residues; T3: elephant grass + cottonseed cake + refinazil + passion fruit peel; T4: elephant grass + cottonseed cake + refinazil + sisal mucilage; T5: elephant grass + corn bran + soybean meal. The silos remained closed for 68 days. The data were subjected to analysis of variance and Tukey's test, with a 5% significance level. The dry matter content of the silages varied from 32 to 44%. Regarding pH, treatments T2, T4, and T5 presented values above 4.5, while the others remained within the ideal range. No significant differences were observed between treatments regarding lactic acid bacteria (LAB) at the opening of the silages. The elephant grass silages including cottonseed cake and refinazil (T1 and T2) showed promise, with moderate losses and satisfactory presence of lactic acid bacteria. On the other hand, treatments that included passion fruit peel (T3) and sisal mucilage (T4) presented unfavorable conditions, with higher losses and significant presence of mold-forming microorganisms. Notably, the treatment with corn bran and soybean meal (T5) demonstrated adequate fermentation, with a significant increase in lactic acid bacteria, suggesting it to be a viable option for the production of elephant grass silage.