ABSTRACT. The purpose of the current study was to evaluate the in vitro fermentation (IVRF) and apparent in vivo digestibility (AIVD) of diets formulated with four inclusion levels of babassu mesocarp meal (BMM) (0.0; 7.5; 15.0 and 22.5%) in ewe lambs. The IVRF test was performed through the "Hohenheim Gas Test" technique, following a randomized complete block design, with four blocks (rumen fluids from four different bovines). Gas production was measured at 3, 6, 9, 12, 24, 48, 72, and 96 hours after incubation. For the AIVD trial, 20 ewe lambs were used in a completely randomized design with five replicates. The animals were housed in metabolic cages during the digestibility test. Diets with BMM showed lower fermentation levels than those without BMM. The BMM reduced the gas production per incubation time and dry matter effective degradability (DMED), possibly due to its chemical characteristics, or even to the influence of other factors, such as physical properties. The BMM negatively influenced the AIVD of DM. Thus, it can be stated that, despite being a starch source, BMM reduces ruminal fermentation parameters when included in ruminant diets, negatively interfering with diet digestibility. Therefore, its use should be cautious.

Objetivou-se com o experimento demonstrar a composição bromatológica e avaliar a cinética de fermentação e degradabilidade ruminal efetiva in vitro, por meio da técnica "Hohenheim Gas Test", da farinha do mesocarpo do babaçu I® e II® (FMBI e FMBII) e de rações com diferentes níveis de inclusão. Foram conduzidos dois ensaios: um com os subprodutos puros e milho e outro com rações com inclusões da FMBI e FMBII nas seguintes proporções: 0; 7,5; 15,0 e 22,5% da matéria seca total. O delineamento foi o de blocos casualizados sendo seis blocos no primeiro e cinco no segundo ensaio. Os tempos de mensuração dos gases produzidos foram 3; 6; 9; 12; 24; 48; 72 e 96 horas. As farinhas FMBI e FMBII apresentaram composições bromatológicas diferentes, em relação aos constituintes da fibra (FDN, FDA e Lignina). As farinhas FMBI e FMBII apresentaram padrões de cinética de fermentação inferiores aos padrões de fermentação do milho grão. Com o aumento da proporção de FMBI e FMBII na ração, reduz-se a produção de gases por tempo de incubação. Em virtude do exposto, pode-se afirmar que as farinhas do mesocarpo I e II, apesar de serem fontes de amido, não apresentaram fermentação ruminal semelhante à fonte amilácea padrão, o grão de milho.

The objective of the experiment was to demonstrate the bromatological composition, and evaluate the fermentation kinetics and effective ruminal degradability in vitro, using the "Hohenheim Gas Test" technique, of babassu mesocarp flour I® and II® (FMBI and FMBII) and of feeds at different levels of inclusion. Two trials were carried out: one of pure byproducts and corn, and another of feeds with inclusions of FMBI and FMBII in the following proportions: 0, 7.5, 15.0 and 22.5% of the total dry matter. The experimental design was of randomized blocks, with six blocks in the first trial and five in the second. Measurement times for the gases produced were 3, 6, 9, 12, 24, 48, 72 and 96 hours. The FMBI and FMBII flours showed different bromatological composition for the fibre components (FDN, FDA and Lignin). The FMBI and FMBII flours also showed patterns for fermentation kinetics inferior to the fermentation patterns of corn grain. Increasing the ratio of FMBI and FMBII in the feed reduces gas production for time of incubation. In view of the above, it can be said that mesocarp flours I and II, despite being sources of starch, did not present ruminal fermentation similar to corn grain, the standard source of starch.