In vitro organic matter digestibility and crude protein content of Panicum maximum Jacq. cv. Tobiatã under water stress

Abstract

In vitro organic matter digestibility (IVOMD) and crude protein content (CP) were determined in Panicum maximum Jacq. cv. Tobiatã grown in pots and subjected to water stress. The soil water conditions were: U₁ = 45% (field capacity), U₂ = 29% and, U₃ = varying from 37% to 27% of soil water content. The evaluations were made at 7,14,21 and 28 days after the imposition of soil the water status. The basic treatment design was a factorial combination of soil water condition x period of evaluation. A complete randomized design with three replications was used. The IVOMD coefficient was similar (P > 0.01) in the first three evaluations periods but higher (P < 0.01) for U₂ (68.3%) and U₃ (67.1%) plants in relation to U₁ (58.8%) plants in the last period. Although similar (P > 0.01) during the first evaluation, from the second evaluation period onwards, CP content of U₂ (19.2%, 14.3% and 10.6%) and U₃ (17.2%, 12.3% and 11.3%) plants was higher (P < 0.01) than that of U₁ (13.9%, 6.9% and 4.5%) plants.