Reduction in lignin content and increase in the antioxidant capacity of corn and sugarcane silages treated with an enzymatic complex produced by white rot fungus.

The objective was to evaluate the effect of the addition of 0, 10, 20, and 30 mg.kg-1 of natural matter of a lignocellulosic enzymatic complex produced by the white rot fungus on the chemical composition, cumulative gas production in vitro, and antioxidant compounds of corn and sugarcane silages. After being chopped and treated with the enzymatic complex, the plants were packed in vacuum-sealed bags. After 60 days, the mini silos were opened and the samples were dried in a forced ventilation oven at 55 °C for analysis of the proposed parameters. The experiment was conducted in a completely randomized design with four replicates per treatment. In the corn silage, there was a linear reduction in the lignin concentration. In the sugarcane silage showed a reduction of 12% in the lignin concentration, a linear reduction in the hemicellulose content, and a decrease of 8% in the cellulose concentration compared to the control treatment. The lignin monomers had linear increases in the syringyl:guaiacil ratio. This reflected on significant increases in the concentration of the non-fibrous carbohydrates and the A + B1 fraction of the carbohydrates, and a reduction in the C fraction. The in vitro gas production increased, the time of colonization and initiation of in vitro fermentation linearly decreased in both silages. The phenolic compounds and the antioxidant capacity increased linearly with the addition of the enzymes in both silages. The addition of the lignocellulolytic enzymes to the silages caused changes in the cell wall, resulting in improvements in the in vitro fermentative parameters, besides the additional effect on the antioxidant capacity. There was an effect of the addition of the enzymes on the evaluated fodder, and the best concentration was, on average, 20 mg kg-1 MN for corn silage and 10 mg kg-1 NM for sugarcane silage.

Nitrogen metabolism, digestive parameters, and protein requirements for the maintenance of buffalo growth.

The objectives of this study were to evaluate the effect of crude protein (CP) levels in the diet of growing female buffaloes on nitrogen metabolism and estimate protein requirements for maintenance. Four female buffaloes were used, cannulated in the rumen, with an average initial body weight (BW) of 355 ± 3.5 kg, in a Latin square (4 × 4) with four animals and four levels of CP in the diet (70, 90, 110, and 130 g/kg dry matter (DM)) composed of corn silage and concentrate. The increase in protein intake with increasing levels of dietary CP resulted in a higher concentration of ammonia in the rumen and higher ruminal disappearance of PB. However, omasal flow of protein increased linearly as did the efficiency of microbial protein synthesis. The CP levels affected DM intake and other nutrients positively, but there was no effect on nutrient total digestibility. Nitrogen (N) balance, when expressed relative to N intake, had an average value of 48.5 % observed across. The protein requirement for the maintenance of growing female buffaloes was 4.6 g CP/kg BW(0.75).