Nutritional and metabolic parameters of sheep fed with extrused roughage in comparison with corn silage

Abstract

The objective of this study was to evaluate the use of extrused roughage on nutritional and metabolic parameters in sheep. Eighteen 3-year-old sheep in metabolic cages were randomly assigned to two treatments: corn silage and extruded roughage. Dry matter intake (DMI) and water intake were calculated as the difference between offered feed and orts left. Ruminal movement was assessed through auscultation of the rumen for five minutes, glycemia and other metabolites through blood collection by jugular venipuncture, and feeding behavior by observation every 5 minutes for 24 hours. DMI per animal, both as a percentage of live weight and in relation to metabolic weight, was higher for animals fed extrused roughage. The extrused roughage treatment also resulted in reduced ruminal movement and higher dry matter digestibility (DMD), glycemia and drinking water intake. Animals fed with extrused roughage reduced the time of rumination and total chewing, thus increasing ingestion, chewing and rumination efficiency. Blood concentrations of glucose and urea were higher in animals fed extrused roughage, while cholesterol concentration was lower. We conclude that the use of extrused roughage promotes improvement in the nutritional parameters of sheep by increasing DMI and DMD, and reducing chewing and rumination times, without causing disorders in energy and protein metabolism.