Abstract The efficiency of the bacterium Bacillus subtilis and white-rot fungus Phanerochaete chrysosporium on growth performance, blood metabolites, carcass characteristics, meat composition and nutrient digestibility of lambs fed crushed whole palm leaf hay was investigated for 105 d. In Experiment 1 (Growth experiment), twenty-four lambs (29.5 ± 1.25 kg) were divided into four feed-based treatments: (1) concentrate and wheat straw ad libitum (control), (2) palm leaf hay (DPL), (3) palm leaf hay supplemented with 2 g of B. subtilis and P. chrysosporium (DPL2) or (4) palm leaf hay supplemented with 4 g of B. subtilis and P. chrysosporium (DPL4). In Experiment 2 (Digestibility experiment), twelve rams, three from each treatment, were used to study nutrient digestibility using the faecal bag technique. Results of the Experiment 1 showed that the DPL4 showed greater (P=0.049) live-weight gain than the control. The diets containing palm leaf hay showed lower (P=0.001) roughage and total feed intake and higher (P=0.001) feed efficiency than the control. Increased serum total protein, globulin, urea-N, aspartate aminotransferase and alanine aminotransferase (ALT) levels were observed with the DPL4 (P˂0.05). Additionally, diets containing palm leaf hay showed higher ALT levels than the control. The DPL4 increased the hot carcass weight (P=0.006) and dressing percentage (P=0.036), and the diets supplemented with B. subtilis and P. chrysosporium decreased (P˂0.05) the tail fat and all fat levels compared with the DPL treatment. Results of the Experiment 2 showed that nutrient digestibility was lower (P˂0.05) with the DPL and DPL2 than with the control and DPL4. Compared with the control, nutrient digestibility of DPL4 was not affected. It is concluded that replacement of wheat straw with palm leaf hay did not affect the feed utilization or animal performance of the lambs; however, supplementation with B. subtilis and P. chrysosporium at 4 g/lamb daily enhanced the growth performance, and carcass characteristics without any adverse effects on blood metabolites.

中文翻译：

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在沙漠条件下，使用枯草芽孢杆菌和金孢子菌提高棕榈叶干草在羔羊饲料中的利用

摘要 研究了枯草芽孢杆菌和白腐真菌 Phanerochaete chrysosporium 对饲喂压碎的全棕榈叶干草 105 d 的羔羊的生长性能、血液代谢物、胴体特征、肉成分和营养消化率的影响。在实验 1（生长实验）中，将 24 只羔羊（29.5 ± 1.25 kg）分为四种饲料处理：（1）精料和小麦秸秆随意（对照），（2）棕榈叶干草（DPL）， (3) 棕榈叶干草补充了 2 g 枯草芽孢杆菌和 P. chrysosporium (DPL2) 或 (4) 棕榈叶干草补充了 4 g B. subtilis 和 P. chrysosporium (DPL4)。在实验 2（消化率实验）中，12 只公羊，每个处理 3 只，用于使用粪便袋技术研究养分消化率。实验 1 的结果表明 DPL4 显示出比对照更大 (P=0.049) 的活重增加。与对照组相比，含有棕榈叶干草的日粮表现出较低 (P=0.001) 的粗饲料和总饲料摄入量以及较高 (P=0.001) 的饲料效率。观察到 DPL4 的血清总蛋白、球蛋白、尿素氮、天冬氨酸氨基转移酶和丙氨酸氨基转移酶 (ALT) 水平增加（P˂0.05）。此外，含有棕榈叶干草的饮食显示出比对照更高的 ALT 水平。与DPL相比，DPL4增加了热胴体重（P=0.006）和屠宰率（P=0.036），添加枯草芽孢杆菌和P. chrysosporium的日粮降低了（P˂0.05）尾脂肪和所有脂肪水平治疗。实验 2 结果表明养分消化率较低 (P˂0. 05）用DPL和DPL2比用对照和DPL4。与对照相比，DPL4 的养分消化率没有受到影响。结论是用棕榈叶干草代替小麦秸秆不影响羔羊的饲料利用率或动物性能；然而，每天补充 4 克/羊​​的枯草芽孢杆菌和金孢子菌可提高生长性能和胴体特性，而对血液代谢物没有任何不利影响。