Ingestive behaviour and performance of feedlot lambs fed saccharine sorghum and corn silages

This study evaluated the ingestive behaviour and performance of feedlot lambs fed saccharine sorghum and corn silages. Ten animals were randomly selected from a group of 32 uncastrated male Suffolk lambs. The four treatments consisted of diets with 50% of silage made from forage sorghum (BD 1615), two varieties of saccharine sorghum (BRS 506 and BRS 511), and corn (BRS 2223). Ingestive behaviour was observed by a scan sampling method using seven strategically positioned video cameras so as not to interfere with the usual animal behaviour. The animals were observed for three 48-hour periods at 15-day intervals, with a total of 144 hours of observation. Video recordings were then examined to identify the time spent in ruminating, eating, drinking water and idling. Times spent feeding or drinking water were not significantly affected by the treatments. Animals fed forage sorghum silage had higher neutral detergent fibre (NDF) intake (0.41 kg of NDF), thus spent more time ruminating (342 min/day). Rumination time was similar for the BD 1615 and BRS 506 silages and was 85 min/day greater than for the BRS 511 and BRS 2223 silages, which were similar. Average daily gain was greater for BRS 2223 (275 g/day) than for BRS 506 and BRS 511 silages, which were similar (196 g/day). Ingestive behaviour for BRS 511 was similar to that observed for BRS 2223. Ingestive behaviour for BRS 506 was similar to that observed for BD 1615. Average daily gain was related to intake and ruminating efficiency. Keywords: eating, idling, roughage, rumination, sheep (Ovis aires

Screening of pectinase-producing microorganisms with polygalacturonase activity

The aim of this work was to perform the screening of microorganisms, previously isolated from samples of agro-industrial waste and belonging to the culture collection of our laboratory, able to produce polygalacturonases (PG). A total of 107 microorganisms, 92 newly isolated and 15 pre-identified, were selected as potential producers of enzymes with PG activity. From these microorganisms, 20 strains were able to synthesize PG with activities above 3 U mL-1. After the kinetic study, the enzyme activity was increased up to 13 times and the microorganism identified as Aspergillus niger ATCC 9642 and the newly isolated W23, W43, and D2 (Penicillium sp.) after 24 h of fermentation led to PG activities of 30, 41, 43, and 45 U mL-1, respectively. The RAPD analysis demonstrated that the selected strains differs genetically, indicating that no duplication of strains among them in the experiments for polygalacturonases production was verified. © 2010 Springer Science+Business Media, LLC