Chemical composition and ruminal degradability of white oat (“Avena sativa ” L.) cv. IPR126 under different nitrogen levels

SUMMARY

The present work aims to generate data on chemical composition and degradation profile of IPR 126, fertilized at levels of 0, 180, 360 and 720 kg ha⁻¹ of N as urea, being applied in the implementation and after each cut with an interval of 21 days between cuts. The Dry Matter (DM), ash, Ether Extract (EE), Crude Protein (CP), Neutral and Acid Detergent Fiber (NDF and ADF), Lignin (LIG), Neutral and Acid Detergent Insoluble Protein (NDIP and ADIP) and Total and Soluble Carbohydrates (TC and CHOs) were determined, and we estimate the degradation kinetics parameters: maximum volume and specific rate of gas production by the degradation of soluble fractions of rapid digestion ((Vf₁ and k₁); maximum volume and specific rate of gas production by the degradation of potentially degradable insoluble fraction of slow digestion (Vf₂ and k₂) and latency (λ), belonging to the two-compartment logistic model. The experimental design was a randomized block design and structure of R suitable matrix for each parameter was chosen from the difference between the CorrectedAkaike Information Criterion values (AICc) represented by delta r (Δr). The fertilization level caused a linear increase in CP content, and linear decrease in TC content. The parameter λ varied quadratically with the level of fertilization. The other nutrients and parameters showed no significant variance in the treatments. The asymptotic phase of protein concentration was not reached, even using high doses of nitrogen.

Keywords:
fertilization; food science; forage crops; gas production kinetics