Barley straw constitutes up to half of the dry-matter intake of Awassi sheep in areas of Syria where the rainfall is 200 to 350 mm. The genotype of barley planted could therefore, through the nutritive value of its straw, significantly affect flock production levels. Selection of suitable barley genotypes may have greater economic potential as a means of improving roughage feeding quality in these areas than chemical or physical processing.The voluntary intake and digestibility of the unsupplemented straw of three genotypes of barley was evaluated with Awassi castrated male sheep. The voluntary organic-matter (OM) intakes of handharvested Beecher, Arabic Abied and ER/Apam straw were 22-2, 34-7 and 27-0 g/kg M" 75 per day and OM digestibility coefficients were 0-39, 0-44 and 0-42. The factors affecting voluntary intake and digestibility appeared to be the proportions of leaf and stem. Beecher straw had less leaf and more stem than the other two genotypes. The chemical composition and in vitro cellulase digestibility of the leaf indicated that it had a higher potential feeding value than stem.ER/Apam appears to be an example of a genotype which under dry environmental conditions combines higher barley grain yields with more acceptable straw feeding value than several other genotypes evaluated.

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Stubble grazing is the main source of nutrients for small ruminants in the Middle East for 3-5 months after cereal harvesting in late May or June. As the flocks are usually mated at this time, poor nutrition may affect the prolificacy of the flocks. However, there have been very few studies of the process of grazing stubble that have defined nutrient intakes and the need for supplementation to sustain particular levels of weight change at mating. An experiment was designed to describe the patterns of removal of different fractions of stubble during grazing at different stocking rates.

The intake of nitrogen and its removal, return, and partition between urine, faeces, and milk was measured over 5 months in Awassi ewes grazing medic pasture or barley. Total faeces and urine were collected in bags carried by the ewes for 5-day collection periods at monthly intervals. Bags were changed in the morning and evening so that excreta produced in the field or in the yards at night were collected separately. Nitrogen was partitioned between the urine and faeces on the basis of the N: ADF ratio of samples of faeces taken directly from the rectum of the animal when the bags were changed. Outputs of excreta and N were very similar in the field and at night in the yard. When N output in the milk was included, 20% more N was removed from the field than was returned. The partitioning of N output between urine and faeces changed markedly during the season and corresponded with changes in the quality of the herbage. Fifty per cent and 65% of the removal of N in faeces and urine, respectively, occurred in the first 2 months of the experiment.