This experiment aimed to investigate the effects of substituting barley grain with discarded dates on intake and digestibility, nitrogen (N) utilization and fermentation characteristics of sheep fed Atriplex hay-based diets. Four Barki sheep (50.9 ± 2.93 kg of body weight (BW)) fitted with rumen cannula were used in a 4 × 4 Latin Square design with 23-day periods. Four isonitrogenous (~140 g crude protein (CP)/kg of dry matter (DM)) experimental diets were formulated with Atriplex hay, and dietary sugar content was increased by replacing barley grain with discarded dates (the proportions of discarded dates in the diet were 0, 93, 187 and 280 g/kg DM). Nutrient intakes were not influenced by diet. Organic matter, CP and neutral detergent fibre digestibility increased (p < 0.05) linearly and DM digestibility tended to increase with increased dates inclusion. Ruminal pH and molar proportion of butyrate increased (p < 0.05) linearly with increasing levels of dates inclusion, whereas ruminal ammonia-N decreased (p < 0.05) linearly. Total volatile fatty acid concentration was unaffected. Microbial protein synthesis (MCP) increased linearly and efficiency of microbial protein synthesis tended to increase as discarded dates increased. Total N intake was not affected by diets whereas, urinary N, urea-N and total N execrations linearly decreased (p < 0.05) with higher amounts of dates in the diets. Blood urea-N tended to decrease with increasing levels of dates. It could be concluded that replacing 100% barley grain with discarded dates as a source of soluble carbohydrates can enhance the utilization of N in Atriplex hay-based diet and consequently improve digestibility and MCP.

中文翻译：

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以弃枣替代大麦粒的羊饲喂 Atriplex 干草日粮的干物质摄入量、消化率、氮利用和发酵特性

本实验旨在研究用废弃枣子代替大麦谷物对饲喂Atriplex干草日粮的绵羊采食量和消化率、氮 (N) 利用率和发酵特性的影响。四只装有瘤胃插管的 Barki 羊（体重 50.9 ± 2.93 kg）用于 4 × 4 拉丁方设计，周期为 23 天。用Atriplex 干草配制了四种等氮（~140 g 粗蛋白 (CP)/kg 干物质 (DM)）实验日粮，并通过用丢弃的枣（日粮中丢弃的枣的比例）代替大麦粒来增加日粮糖含量分别为 0、93、187 和 280 g/kg DM)。营养摄入量不受饮食影响。有机物、粗蛋白和中性洗涤纤维的消化率增加 ( p < 0.05) 线性和 DM 消化率随着日期的增加而增加。瘤胃pH和丁酸盐摩尔比例随着枣包合物水平的增加呈线性增加（p  < 0.05），而瘤胃氨氮呈线性下降（p  < 0.05）。总挥发性脂肪酸浓度不受影响。微生物蛋白质合成（MCP）线性增加，微生物蛋白质合成效率随着丢弃日期的增加而增加。总氮摄入量不受饮食影响，而尿氮、尿素氮和总氮摄入量呈线性下降（p < 0.05) 日粮中枣的含量较高。血尿素-N 趋于随着枣含量的增加而降低。可以得出结论，用废弃的枣代替 100% 的大麦作为可溶性碳水化合物的来源，可以提高以干草为基础的日粮中 N 的利用率，从而提高消化率和 MCP。