A new pectinase produced from Aspergillus terreus compared with a commercial pectinase enhanced feed digestion, milk production and milk fatty acid profile of Damascus goats fed pectin-rich diet

Pectinase hydrolyses pectin and increases the utilization of agriculture byproducts as feeds for ruminants. A newly developed pectinase from Aspergillus terreus was compared with a commercially available pectinase at 600 IU/kg feed on feed utilization and lactational performance of Damascus goat fed orange byproduct silage and sugar beet pulp based diet (i.e., pectin-rich diet) for 12 weeks. Thirty (one week postpartum) Damascus goats stratified by previous milk production, body weight and parity were divided into three experimental groups. Does were fed a control diet containing concentrates, orange byproduct silage, sugar beet pulp and wheat straw at 50:20:20:10, respectively without a supplement (control treatment) or supplemented with a newly developed pectinase (new treatment) or commercial pectinase (commercial treatment). With similar feed intake, the new pectinase increased (P<0.01) nutrient digestibility and milk production efficiency more than the other treatments. Out of all the blood parameters, only serum glucose was affected by the treatments with the highest (P=0.025) value noted for the new pectinase. Similarly, the new pectinase increased daily milk production (P<0.005) and the concentrations of milk components compared to the other two treatments. Additionally, pectinase (both the commercial and new) inclusion increased (P<0.05) the concentrations of total conjugated linoleic acid and unsaturated/saturated fatty acids ratio, and decreased atherogenic index (P=0.01) compared with control treatment. It is concluded that the supplementation of the diet of lactating goats with pectinase at 600 IU/kg feed will enhance feed digestion and milk production. The newly developed pectinase performed better than the commercial pectinase.