Impact of the precipitation on yield and chemical composition of oat (Avena sativa L.) hay forage grown in the northwestern Chihuahua, Mexico.

Objective: Assess yield and quality of oat hay growing under five rainfall scenarios: optimal, 503 mm (R-101%); middle, 277 mm (R-55%) and 260 mm (R-52%); critical, 180 mm (R-36%) and 140 mm (R-30%) of precipitation in northwestern of Chihuahua, Mexico. Design/Methodology/Approach: The data corresponds to a previous study of oat varieties planted under rainfed conditions and harvested at dough grain maturity stage. The data analyzed employed the analysis of variance. The variables dry matter yield (DMY), total digestible nutrients yield (TDNY), relative feed value (RFV), crude protein yield (CPY), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) were studied. Results: Yield and chemical content differed significantly (P<0.001) by the effect of rainfall scenario The DMY and TDNY decreased as much as 43.5 and 41.6% in oats grown under critical rainfall scenario with respect to an optimal rainfall scenario (P<0.001). Likewise, NDF, ADF and ADL contents decreased (P<0.001) by 5, 10 and 13%, respectively. The CP content varied due to the rainfall scenario (P<0.001), but it was not correlated with this factor (r=0.218, P=0.069). Study Limitations/Implications: In the state of Chihuahua, oats are grown under rainfed conditions; however, the increasingly prolonged periods of drought make it necessary to develop and evaluate new drought-resistant oat varieties. Findings/Conclusions: In this region, oats grown under rainfall scenarios of up to 52% of the optimal (500 mm) yield acceptable amounts of dry matter with sufficient nutritive value for feeding cattle.