Predicting the nutritive value of the olive leaf (Olea europaea): digestibility and chemical composition and in vitro studies

Eight tests of olive leaf digestibility were carried out with sheep. The olive leaves were collected using different procedures (four samples of leaves from dried branches and another four of leaves removed from chopped branches and dried) and stored for varying times. Marked differences in OMD were observed between the two types of procedures and between different times of storage. The greatest loss of nutritive value was in the chopped samples. In the leaves from dried branches, with storage periods longer than 9 months, the digestible organic matter content ranged between 431 and 448 g kg−1 OM, while in the chopped samples, the value ranged between 360 g kg−1 OM (in a sample stored for only 1 month) and 177 g kg−1 OM (in a sample with obvious signs of fermentation). mple set was used together with another, evaluated prior to this work, to study the prediction of in vivo digestibility (OMD, DMD and CPD) from chemical and biological (dry matter disappearance after in vitro incubation with rumen liquor–pepsin or pepsin–cellulase solutions) parameters. In the case of OMD, the best predictions were obtained with the pepsin–cellulase method (r=0.91, RSD=4.6) and NDF (r=−0.91, RSD=4.6).