Diets based on plants from Brazilian Caatinga altering ruminal parameters, microbial community and meat fatty acids of Santa Inês lambs

Strategies for the sustainable intensification of ruminant production suggest breeding animals adapted to the environment in which they live using local fodders to maximize efficient ruminal fermentation. The purpose of this study was to explore the effects of using Orbignya phalerata (Babassu) and Combretum leprosum (Mofumbo) leaves in ruminal short chain fatty acids (SCFA) and microbial community, as well as finishing performance, carcass characteristics and meat fatty acid profile of Santa Inês hair lambs. The experimental treatments were diets with 50:50 forage:concentrate ratios, using the leaves of the experimental plants as a 33g/100g of dry matter (DM) replacement of Cynodon dactylon (Tifton-85) hay, with three groups: Control (no hay replacement), Babassu and Mofumbo. Twenty-four Santa Inês lambs (body weight=20.0±5.2kg) were used in a randomized experimental design with eight repetitions (5 males and 3 female) per treatment. Ruminal fluid samples of each animal were collected to determine SCFA and microbial community. The male animals were evaluated for finishing performance and carcass characteristics while longissimus lumborum muscle samples were used for determination of fatty acid profile. Interaction between treatment and sex was observed for total SCFA (P<0.05). Treatment affected (P<0.05) propionate, isobutyric, isovaleric and valeric fatty acids. Mofumbo showed a greater relative abundance of rumen fungi and Ruminococcus flavefaciens, and lower Archaea. There was no difference between treatments (P>0.05) for finishing performance and carcass characteristics but meat fatty acid characteristics were affected by treatments. A redundancy analysis based on microbial abundance profile demonstrated two clusters, one cluster with Babassu and Control treatments, and other cluster with Mofumbo, with some variables associated to dissimilarity between clusters. These results indicated that the inclusion of these plants in lamb diets affects ruminal short chain fatty acids and microbial population, without compromising the production potential, carcass characteristics and meat fatty acid profile.