Nutritive value of oak browse (Quercus coccifera) foliage for goats at various phenological stages

The nutritive value of oak (Quercus coccifera) was studied at four discrete phenological stages. 1) In early spring, during the season of rapid growth, 2) In late summer, after elongation had seased and stems had hardened. 3) In fall, when secondary growth occured and 4) In winter when growth had seased and plants were dormant. Shrub foliage was harvested daily and offered fresh to goats in metabolism cages. In winter, during separate trials, the effect of an energy rich and a protein rich supplement was tested. For comparative purposes a digestion trial with alfalfa was conducted. In vivo digestibility of kermes oak browse was estimated by the in vitro Tilley and Terry (1963) digestion procedure. Nutrient content (crude protein, total energy, and cell contents) of feed, year around was almost constant despite the variation in browse foliage. This was a result of the selective browsing of goats. Apparent digestibility was drastically reduced after stem elongation had seased and there after was almost constant. Direct in vitro estimates did not precisely predicted the in vivo digestion of browse foliage. However, estimates with the regression equation Y=34,6 + 0,69Xr(exp 2)=76 were sufficiently accurate. Apparent digestibility of crude protein were low all year but spring. The low digestibility of crude protein resulted from low dry matter digestion and the high percentage of metabolical fecal protein. Both digested crude protein and energy of feed were inadequate for meeting maintanance demands of goats, all seasons but spring. Nutrients in feed from spring folliage were sufficient for maintenance and low production but insufficient for lactation. Although, nutrient content of foliage was well above maintenance requirements, intake was well bellow their intake capacities. Forage intake (g/Kg.B.75) was below 60%, as compared to the alfalfa diet all year around but spring. Intake was increased when animals were supplemented. Weight gains were observed when animals were fed alfalfa, foliage from spring collection and when they were supplemented