Abstract 96

Capper,-BS; Thomson,-EF; Rihawi,-S

Overseas Development Natural Resources Institute, 56/62 Grays Inn Road, London WC1X 8LU, UK.

Animal-Feed-Science-and-Technology. 1989, 26: 1-2, 105-118; 19 ref.

Voluntary intake and digestibility trials using Awassi sheep were conducted with straw from 7 barley varieties and a landrace from Syria. Two straws were allocated to each of four 4 X 4 Latin squares and one straw in each square was also supplemented with barley grain (average 169 g/head daily) or cottonseed cake (average 130 g/head daily). Organic matter intakes (OMI) for the 7 varieties ranged from 31.0 to 45.9 g kg - 0.75 day - 1 and were correlated (P < 0.05) with straw yield (r = 0.82) and days from sowing to maturity (r = 0.78). Organic matter digestibility (OMD) ranged from 43.0 to 47.7% and was less important than voluntary intake in determining straw feeding value. For the landrace, straw OMI and OMD were 47.5 g kg - 0.75 day - 1 and 49.8%, respectively. Supplementation with barley grain improved straw OMI from 34.9 to 41.7 g kg - 0.75 day - 1 for a 2 rowed variety (P < 0.05) but did not improve OMI of straw from three 6-rowed varieties. Cottonseed cake supplementation improved straw OMI for all 4 varieties tested (P < 0.05) but OMI was lower (P < 0.05) for one 6-rowed variety (43.5 g kg - 0.75 day - 1) compared with the 3 other varieties (55.6, 54.4 and 55.7 g kg - 0.75 day - 1). The results suggest the presence of variety X supplementation interactions for straw OMI. Within the barley/sheep farming system practiced in semi-arid areas of west Asia the selection of barley varieties with superior grain yield and straw quality could have an important impact on sheep production.