Ferreira H C, Hannas M I, Albino L F T, Rostagno H S, Neme R, Faria B D, Xavier M L, Rennó L N
Department of Animal Science, Universidade Federal de Viçosa - UFV, Viçosa, Minas Gerais, Brazil.
Department of Animal Science, Universidade Federal de Viçosa - UFV, Viçosa, Minas Gerais, Brazil
Poult Sci. 2016 Aug 1;95(8):1848-57. doi: 10.3382/ps/pew076. Epub 2016 Apr 2.
Three experiments were conducted to evaluate the effect of β-mannanase BM: supplementation on the performance, metabolizable energy, amino acid digestibility, and immune function of broilers. A total of 1,600 broilers were randomly distributed in a 4 × 2 factorial arrangement (4 nutritional levels × 0 or 500 g/ton BM), with 10 replicates and 20 broilers per pen. The same design was used in the energy and digestibility experiments with 8 and 6 replicates, respectively, and 6 broilers per pen. The nutritional levels : NL : were formulated to meet the nutritional requirements of broilers : NL1 : ; reductions of 100 kcal metabolizable energy : NL2 : ; 3% of the total amino acids (NL3); and 100 kcal metabolizable energy and 3% total amino acids (NL4) from NL1. The serum immunoglobulin (Ig) concentration was determined in two broilers per pen, and these broilers were slaughtered to determine the relative weight of spleen, thymus, and bursa of Fabricius. Throughout the experiment, the lower nutritional levels reduced (P < 0.05) body weight gain : BWG : and increased (P < 0.05) feed conversion : FCR : for the NL4 treatment. The BM increased (P < 0.05) the BWG values and improved (P < 0.05) the FCR of the broilers. The apparent metabolizable energy corrected for nitrogen balance (AMEn) values were reduced (P < 0.05) for NL2 and NL3. The BM increased (P < 0.05) the AMEn values and reduced (P < 0.05) the excreted nitrogen. NL3 and NL4 reduced (P < 0.05) the true ileal digestibility coefficients (TIDc) of the amino acids cystine and glycine, and BM increased (P < 0.05) the TIDc for all amino acids. The addition of BM reduced (P < 0.05) the relative weights of the spleen and bursa. NL2 increased (P < 0.05) the Ig values, whereas BM reduced (P < 0.05) the serum IgA, IgG, and IgM values of the broilers. This study indicates that using suboptimal nutrient levels leads to losses in production parameters, whereas BM-supplemented diets were effective in improving performance, energy values, and TIDc levels of amino acids and immune response of broilers.
进行了三项试验以评估添加β-甘露聚糖酶（BM）对肉鸡生产性能、代谢能、氨基酸消化率及免疫功能的影响。总共1600只肉鸡按4×2析因设计（4种营养水平×添加或不添加500克/吨BM）随机分组，每组10个重复，每个栏舍20只鸡。能量和消化率试验采用相同设计，分别有8个和6个重复，每个栏舍6只鸡。营养水平（NL）按满足肉鸡营养需求进行配制：NL1；代谢能降低100千卡（NL2）；总氨基酸减少3%（NL3）；以及在NL1基础上代谢能降低100千卡且总氨基酸减少3%（NL4）。测定每个栏舍两只肉鸡的血清免疫球蛋白（Ig）浓度，并宰杀这些肉鸡以测定脾脏、胸腺和法氏囊的相对重量。在整个试验期间，较低的营养水平使NL4处理组的体重增重（BWG）降低（P<0.05），饲料转化率（FCR）升高（P<0.05）。添加BM使肉鸡的BWG值升高（P<0.05），FCR得到改善（P<0.05）。NL2和NL3组经氮平衡校正的表观代谢能（AMEn）值降低（P<0.05）。添加BM使AMEn值升高（P<0.05），排泄氮减少（P<0.05）。NL3和NL4降低了（P<0.05）氨基酸胱氨酸和甘氨酸的真回肠消化率系数（TIDc），而添加BM使所有氨基酸的TIDc升高（P<0.05）。添加BM使脾脏和法氏囊的相对重量降低（P<0.05）。NL2使Ig值升高（P<0.05），而添加BM使肉鸡血清IgA、IgG和IgM值降低（P<0.05）。本研究表明，使用次优营养水平会导致生产性能参数下降，而添加BM的日粮能有效改善肉鸡的生产性能、能量值、氨基酸TIDc水平及免疫反应。
