Chemical composition, in vitro and in situ dry matter digestibility and preference of Quercus resinosa foliage

The objectives of this study were to determine the chemical composition and dry matter digestibility of Quercus resinosa leaves harvested at different seasons of the year and to assess the intake and palatability of lamb diets containing foliage of Q. resinosa. There were three sites of collection, two located in the state of Jalisco and one in the state of Zacatecas, México. The young leaves harvested in spring, had greatest (P <0.05) nutritional value than leaves harvested in other seasons. The in vitro digestibility of organic matter (IVOMD), rapidly degradable fraction (a) and the degradation rate (c) were greater (P <0.05) in leaves harvested in spring and winter. The slowly degradable fraction (b) was greater (P <0.05) in spring, summer and autumn, and lesser in winter. The potential degradation fraction (a + b) and the effective degradability of dry matter were maximized (P <0.05) in spring than in the other seasons. The consumption was similar (P >0.05) among diets with different inclusion levels of leaves, but sheep consumed greater (P <0.05) amounts of diet containing leaves collected in spring. In conclusion, the Q. resinosa foliage contains the nutritional value and the digestibility and palatability that makes it suitable to replace completely the forage in the fattening diets of sheep, being preferable to use leaves harvested in spring and winter.