YIELD AND QUALITY OF FORAGE VARIETIES OF OATS ACCORDING TO PLANTING SYSTEM AND MATURITY STAGE AT CUTTING

Abstract

Oat forage (Avena sativa L.) is widely used in livestock feeding systems at the northwestern region of Chihuahua State, México. The effect of variety, planting system, and maturity stage at cutting on yield and chemical composition of oat forage were evaluated on seven varieties planted under rainfed conditions, in furrow diking and plane surfaces, in five locations at the northwestern region of Chihuahua state. Harvest was done at three crop growth stages: boot (BS), dough grain (DS) and physiological maturity of grain (PMS). Yield in kg ha^-1 of hay dry matter (DM) and its chemical composition (%) were measured; digestible dry matter (DDM, %) and net energy for lactation (NEL, Mcal kg^-1) were estimated. Treatments were distributed into a sub-sub-split experimental arrangement in a completely randomized blocks design; locations were the replications, main plots were planting systems, medium size plots were stages of maturity at cutting, and large plots were varieties. Planting system did not affect hay dry matter yield (P = 0.20) or chemical composition (P > 0.05). As the cutting stage approached PMS, DM yield linearly (P < 0.05) increased (2247, 3120 and 4475 kg ha^-1 for BS, DS and PMS, respectively), while crude protein decreased nonlinearly (P < 0.05). A significant effect of the maturity x variety interaction (P < 0.01) on crude protein was detected. As harvest approached PMS, fiber fractions decreased (P < 0.05), while DDM and ENL increased linearly (P < 0.05). Oat hay chemical composition improved towards maturity of grain due to a decrease in fiber, without significant differences among varieties.