Exploring novel feed resources in substitution for concentrate feeds is a primary aim for lowering the cost of feeding and a viable strategy to mitigate the shortage of animal feeds. The present experiment was accomplished by in vitro and in vivo assays with the aim to evaluate the potential of Himalayan Elm (Ulmus wallichiana) leaf meal (ELM) as partial substitute to the concentrate feed mixture in total mixed ration (TMR) of sheep. Under in vitro study, graded levels (0, 10, 20, 30, 40 and 50%) of ELM inclusion substituting concentrate feed mixture constituting 40% of the basal TMR were evaluated for degradability of dry matter (DM), organic matter (OM) and neutral detergent fibre (NDF). In vitro degradability of DM, OM and NDF were higher (P < 0.05) with 30% ELM inclusion, and the level was used for sheep feeding study. In the in vivo experiment, a feeding trail was conducted for one month on Corriedale (16) male (23.43 ± 0.47 kg body weight, 13-14 months of age) sheep allotted randomly into two equal groups, offered basal TMR as control (T₀) and TMR containing ELM substituting concentrate mixture at 30% level as treatment (T₁) group. The animals of control and treatment group had similar feed intake (83.91 vs 85.28 g DM/kg W^0.75/day, respectively); however, digestibility (%) of crude protein and neutral detergent fibre was higher (P < 0.05) in T₁ group. Content and the intakes of digestible nutrients (digestible crude protein, total digestible nutrients and metabolisable energy) were similar between the two groups. Animals of both the groups were in positive balance of nitrogen (N), calcium and phosphorus, and were comparable for N and higher (P < 0.05) for Ca and P in the T₁ group. Haemato-biochemical metabolites were within the normal physiological ranges in both the groups with significantly improved (P < 0.01) levels of haemoglobin and haematocrit while reduced values for serum urea N (P < 0.05) and aspartate amino-transferase (P < 0.01) in T₁. Likewise, rumen fermentation metabolites were in normal ranges and comparable between the groups for pH, total volatile fatty acids, N and its fractions in rumen fluid collected at 30 days of experimental feeding. It can be concluded that Elm leaf meal can replace 30% of concentrate feed mixture in the TMR of sheep as substitution improved digestibility of CP and NDF, and balance of Ca and P, without effecting feed intake, rumen fermentation, blood metabolites and live weight.

探索新型饲料资源来代替浓缩饲料是降低饲料成本的主要目的，也是减轻动物饲料短缺的可行策略。本实验通过体外和体内试验完成，目的是评估喜马拉雅榆（Ulmus wallichiana）叶粉（ELM）作为绵羊总混合日粮（TMR）中的浓缩饲料混合物的部分替代品的潜力。在体外研究中，评估了构成基础TMR的40％的ELM夹杂物替代浓缩饲料混合物的分级水平（0、10、20、30、40和50％）的干物质（DM），有机物（OM）的降解性）和中性洗涤剂纤维（NDF）。体外DM，OM和NDF的降解度较高（P  <0.05），ELM含量为30％，该水平用于绵羊饲养研究。在体内实验中，对Corridale（16）雄性（23.43±0.47 kg体重，13-14个月大）绵羊随机分配给两个相等的组进行了一个月的饲养试验，提供了基础TMR作为对照（T ₀）和含ELM的TMR替代浓度为30％的浓缩混合物作为处理（T ₁）组。对照组和治疗组的动物采食量相似（分别为83.91 vs. 85.28 g DM / kg W ^0.75 / day）；然而， T ₁中粗蛋白和中性洗涤剂纤维的消化率（％）更高（P <0.05）组。两组的可消化营养成分（可消化的粗蛋白，总可消化营养成分和代谢能）的含量和摄入量相似。两组动物的氮（N），钙和磷均处于正平衡状态， 在T ₁组中，其氮含量可比且更高（P <0.05）。血象生化代谢物在两个组的正常生理范围内与显著改善（P  <0.01），血红蛋白和血细胞比容的水平，同时减少了对血清尿素氮值（P  <0.05）和天冬氨酸氨基转移酶（P  <0.01） Ť ₁。同样，瘤胃发酵代谢产物在正常范围内，并且在实验进食30天时收集的瘤胃液中的pH，总挥发性脂肪酸，N及其组分之间在组之间可比。可以得出结论，榆木粉可以替代绵羊TMR中30％的浓缩饲料混合物，因为替代品可以改善CP和NDF的消化率以及Ca和P的平衡，而不会影响采食量，瘤胃发酵，血液代谢产物和活体重。