Nutritional assessment of Mavuno grass (Urochloa spp.) harvest a different maturity stage and ensiled with molasses or cornmeal.

Two experiments were carried out to evaluate the nutritive value of Mavuno grass (Urochloa spp.) growing in Gómez Farias County, Jalisco, Mexico. In experiment 1, the effect of maturity stage on biomass yields and chemical composition of Mavuno grass was determined. Grass samples were harvested at 45, 60 and 90 days of regrowth. Experiment 2 evaluated the effect of adding an inoculum, molasses or cornmeal on the quality of Mavuno grass ensiled at 90 days of growth. In this study four treatments were evaluated: T1) Pure Mavuno grass (CON), T2) Mavuno grass + inoculum (BIO), T3) BIO + 4% of molasses per kg of green forage (BIOm) and T4) BIO + 8% of cornmeal per Kg (BIOc). The highest amount of green forage (GF) and dry matter (DM) yields per m2 occurred at 90 d of growth, 1.231 Kg/GF/m2 and 0.332 Kg/DM/m2 (p < 0.05). The crude protein (CP) with a value of 18.6% was greater at 45 d (p < 0.05). Neutral detergent fiber (NDF) and acid detergent fiber (ADF) with values 60.13% and 30.10% were found in lower amounts at 45 d (p < 0.05). In experiment 2, the organic matter (OM), CP, ether extract (EE), crude fiber (CF), NDF, ADF, hemicellulose, total carbohydrates (TC), non-fiber carbohydrates (NFC), and ash contents of the Mavuno grass silages were statistically different between the treatments, and adding molasses showed the lowest pH (4.5). The age of regrowth affected the nutritional value of Mavuno grass, although it maintains good nutritional quality until the 90 d of regrowth. The addition of 4% molasses or 8% cornmeal at ensiling of the Mavuno grass showed a moderately positive effect on the pH and silage quality.