Characteriztion of Quercus persica, Quercus infectoria and Quercus libani as ruminant feeds

The nutritive value of three species of oak trees leaves was assessed by chemical analysis as well as by an in situ and in vitro gas production method. The chemical composition (g/kg DM basis) of three species, Quercus persica, Q. infectoria and Q. libani were 951, 927, 946 organic matter (OM); 115, 92, 123 crude protein (CP); 532, 540, 512 neutral detergent fiber (NDFom); 317, 300, 331 acid detergent fiber (ADFom); 98, 103, 95 lignin (lignin(sa)); 8.9, 11.7, 19.2 water soluble carbohydrates (WSC); 78, 115, 104 total phenols; 73, 109, 100 total tannins (TT); 14, 15, 12 condensed tannin (CT); and 46, 87, 62 hydrolysable tannin (HT). Protein precipitable phenolics (PPP) were respectively 160, 190 and 230 (g/kg total phenols). Effects of tannins on in vitro gas production, in vitro organic matter digestibility (OMD), metabolisable energy (ME) and effective DM digestibility (ED) were assessed by polyethylene glycol (PEG) tannin bioassay. Among species, Q. Libani had the highest gas production. This species also had the highest (P<0.05) increase in gas production, OMD and ME due to the addition of PEG. Using this in situ method the soluble component (A), insoluble but fermentable component (B), the degradation rate of B (c), the potential degradability (A + B) and the effective degradability (ED) of the oak leaves were influenced (P<0.05) by species, PEG treatment and interaction of species and PEG treatment. Adding PEG to Quercus species suggests that these feeds have potential as small ruminant feeds.