Wet distiller's grains in diets for feedstuff Nellore cattle: ruminal metabolism

Abstract

With the search for renewable energy sources, the production of biofuels has increased worldwide. This increase has generated a large amount of by-products, such as WDG "wet destiller's grains". This has aroused considerable interest in the livestock sector, mainly due to its high protein value, making it an interesting alternative feedstuff with the possibility of reducing production costs. However, studies have to be carried out regarding their effects on ruminal parameters and limits of inclusion in zebu diets. In this sense, the present study aims to evaluate the effect of partial or total substitution of soybean meal by WDG in diets for Nelore cattle, on ingestive behavior, DM and nutrients intakes, digestibility of DM and nutrients, production and quality of in vitro greenhouse gases, pH, NH3-N and ruminal SCFA. Eight adult Nellore cattle (PC = 650 kg) will be used, which will be distributed, two by two, in a replicated (4 × 4) Latin square design, with four periods of 21 days, and four treatments containing 0, 15, 30 or 45% WDG. The diets will be composed in the ratio roughage:concentrate ratio of 20:80, of Tifton hay, corn cracked grain, soybean meal and mineral-vitamin premix. In the treatment with 45% WDG, the soybean meal will be totally replaced. The data will be analyzed using PROC MIXED of the SAS. Contrasts will be used to compare control treatment and WDG-containing treatments, as well as to evaluate the linear and quadratic effect of by-product inclusion. It will be considered a significance of 5% and a tendency of 10%. (AU)