Use of a Prepaid Cellulase Solution for Screening Forage Grass Germplasm for Digestibility

A reliable rapid and inexpensive laboratory procedure is needed to screen native African forage grass species for forage quality. This study determined the potential of using a prepared cellulase solution to assess in vitro dry matter solubility of 22 native Kenyan forage grasses and 18 native warm season grasses from Missouri, USA. A prepared cellulase solution was used for screening the grass species for digestibility using two procedures. One procedure involved digesting grass samples in prepared cellulose solution without any pre-treatment (CSD), and the other procedure used an acid pepsin pretreatment prior to digestion in the prepared cellulose solution (APCS). The CSD procedures in comparison to APCS generally underestimated in vitro dry matter solubility by a rand of up to 23%. The variations were highly species dependent. Although the APCS procedure more time consuming, it made it possible to identify a group of species resolvable into high (42.6-61.4%), medium (36-40%) and low (29-34%) digestibility. With intensified efforts it is possible for one person to obtain in vitro dry matter solubility estimates on up to 200 samples in 30 days with minimal expense. Results of this investigation points to the end need for further research on the potential of the two digestibility procedures for rationalizing numbers in germplasm collection for initial screening