Avaliação nutricional e produtiva da aveia branca (Avena sativa L.) IPR126 sob diferentes períodos de descanso

Abstract

The present study aiming to determine the best management to production of oat (Avena sativa L.) IPR 126 in order to produce quality forage for ruminants in the southwest region of Parana. Four periods between harvests were used: 14, 21, 28 and 35 days, distributed in randomized blocks with four replicates for each treatment. The variables evaluated were: the dry matter production of each harvest period, and the concentration of Neutral Detergent Insoluble Fiber (NDF), Acid Detergent Insoluble Fiber (ADF), lignin, dry matter (DM), ash, ether extract (EE) and in vitro digestibility of dry matter obtained by measurement of gas production. The profile of gas production was adjusted to the logistic bi-compartimental mathematical model of Schofield. The variables and the parameters of the adjusted gas production curves were analyzed as repeated measurements (each treatment was evaluated more than once over time) through the PROC MIXED of SAS (version 9.0) and the restricted maximum likelihood (REML) as the method of estimation of parameters. Four structures of variance and covariance were tested: VC: (variance components); CS: (compound symmetry); AR (1): (auto regressive of first order) and UN: (unstructured). The structure of the R matrix was chosen considering the lowest value of the corrected Akaike information criterion (AICC). Regression analysis was performed for the variables: DM, CP, EE, NDF, ash, and for the parameter k2 of the bicompartimental model. DM and NDF concentrations increased linearly, CP and the estimations of the parameter k2 reduced linearly and the EE concentration showed a cubic behavior in function of the age of harvest. FDA, lignin and other parameters of the Schofield model were not influenced by the age o harvest.