Evaluation of internal markers in digestibility estimation for sheep and goats.

The objective of this study was to compare the indirect methods of obtaining digestibility with the direct method of total fecal collection to estimate the apparent digestibility of nutrients in sheep and goats supplemented with non-protein nitrogen. Five goats and five sheep with no defined racial pattern were used, distributed in two 5 × 5 Latin squares, with split plots, considering the diets as plots and the apparent digestibility determination methodologies as subplots. The diets were composed of buffelgrass hay and the addition, via ruminal infusion, of increasing amounts of nitrogen supplementation in order to gradually raise the CP level of the basal diet in intervals of 2% points, that is, + 2, +4, + 6 and + 8%. Samples of the feeds offered, and the leftovers were collected daily during the five days of collection to determine the nutrient intake, as well as the total collection of feces to determine the apparent digestibility of the nutrients. The amount of fecal dry matter excreted was estimated by the concentration of Indigestible Acid Detergent Fiber (ADFi), Indigestible Neutral Detergent Fiber (NDFi), Indigestible Dry Matter at 244 h (DMi 244 h) and Indigestible Dry Matter at 264 h (DMi 264 h). Among the evaluated markers, DMi 264 h had the lowest accuracy in estimating fecal excretion and nutrient digestibility. For the goat species, the markers ADFi and DMi 244 h proved to be able to adequately predict fecal excretion and digestibility indices, while NDFi stood out for both species. Among the evaluated markers, NDFi is the one that most accurately estimates the nutrient digestibility of the diet for goats and sheep.

Forage cactus as an additive in corn without the cob silages of feedlot sheep diets.

This study aimed to assess the impact of adding forage cactus as an additive to the production of corn silage without the cob on the performance of feedlot sheep and subsequent silage losses. The experimental design was completely randomized, consisting of three treatments: corn silage without cob; 0% = 100% corn plant without the cob; 10% = 90% corn plant without cob + 10% forage cactus; 20% = 80% corn plant without cob + 20% forage cactus. Significant effects were observed for dry matter intake (P = 0.0201), organic matter (P = 0.0152), ether extract (P = 0.0001), non-fiber carbohydrates (P = 0.0007). Notably, nutrient digestibility showed significant differences in organic matter (P = 0.0187), ether extract (P = 0.0095), neutral detergent fiber (P = 0.0005), non-fiber carbohydrates (P = 0.0001), and metabolizable energy (P = 0.0001). Performance variables, including total weight gain (P = 0.0148), average daily weight gain (P = 0.0148), feeding efficiency, and rumination efficiency of dry matter (P = 0.0113), also exhibited significant effects. Consequently, it is recommended to include 20% forage cactus in corn silage, which, based on natural matter, helps meet animals' water needs through feed. This inclusion is especially vital in semi-arid regions and aids in reducing silage losses during post-opening silo disposal.

Blend of secondary metabolites from mesquite to improve nutrient digestibility, microbial protein, efficient use of nitrogen, ruminal parameters, and blood metabolites in sheep.

Although chemical additives are able to improve the efficiency of ruminal fermentation, they can leave residues in the meat. However, a blend of secondary metabolites can improve ruminal fermentation without harming the population welfare. Five levels (0.0, 1.5, 3.0, 4.5, and 6.0 g/day) of a blend of secondary metabolites from mesquite extract in sheep feed to promote increases in the nutritional value, ruminal parameters, nitrogen (N) use efficiency, microbial protein (MP) synthesis, and blood metabolites. Ten intact male Santa Inês sheep with average body weight of 55 ± 9.81 kg were used in a 5 × 5 Latin square design, replicated twice. There was a quadratic response of the digestibility of dry matter (DM), organic matter (OM), crude protein (CP), and total digestible nutrients (TDN). Microbial protein concentrations, MP synthesis efficiency, propionic acid levels, and acetic/propionic acid ratio also showed a quadratic response. The blend promoted a quadratic effect on plasma glucose and lactate levels. On the other hand, it decreased the concentrations of ammoniacal nitrogen, plasma urea, and plasma cholesterol. It is recommended to supply a blend of secondary metabolites at 3.43 g/day.