Efecto del período de adaptación al consumo de camas de aves, en ovinos y bovinos, sobre la degradabilidad ruminal

Abstract

The effect of an adaptation period to the consumption of broiler litter (BL) on the ruminal degradability (dgr) was evaluated. The dgr of dry matter (DM), total N (TN), protein N (N x 6.25) and uric acid was determined for 6 BL; 3 BL were obtained during the winter months from sheds with earth floor and 3 during the summer months from sheds with concrete floor. The dgr was measured using the Mehrez & Orskov technique (1997) in 3 heifers and 3 male lambs. The BLs were incubated in 9 x 17 cm dracon nylon bags for 2, 4, 8, 12, 18 and 24 hours in sheep and heifers, and also for 48 hours in heifers. The diet gradually changed from 100% alfalfa hay to a mixture of 60% alfalfa hay and 40% BL (DM base) during a period of 21 days. In the lambs, the dgr of DM, TN and N x 6.25 increased, from 59.9, 80.8 and 71.1 to 82.1, 86.1 and 79.2%, respectively due to the adaptation period (P<0.05). Nevertheless, the dgr of uric acid was similar in both groups of lambs (96%). In heifers, the adaptation period was insufficient to increase the dgr of TN, N x 6.25 and uric acid, but it decreased the dgr of DM from 78.5 to 73.5%.