Feeding methionine hydroxyl analogue chelated trace minerals reduces mineral excretion to the environment in broiler chickens

This study investigated the effects of feeding mineral methionine hydroxyl analogue chelates (MMHAC) zinc (Zn), copper (Cu) and manganese (Mn) (MINTREX® Zn:Cu:Mn, Novus International, Inc.) and high dietary inorganic Cu level on growth performance, nutrient digestibility, carcass yield, excreta nitrogen (N) and mineral level, environmental conditions, bone parameters and welfare status of Ross 308 males. A total of 384 one-day-old chicks were randomly distributed to four dietary treatments with eight replicates of 12 birds per pen per treatment. The treatments consisted of (1) ITM ZnSO4 110 ppm, CuSO4 16 ppm, MnO 120 ppm (ITM), (2) MMHAC Zn 40 ppm, Cu 10 ppm, Mn 40 ppm (MMHAC10), (3) ITM ZnSO4 110 ppm, TBCC 125 ppm, MnO 120 ppm (TBCC125), and (4) MMHAC Zn 40 ppm, Cu 30 ppm, Mn 40 ppm (MMHAC30). There were three feeding phases, including starter (days 0-10), grower (days 10-21) and finisher (days 21-42). Growth performance was calculated per feeding phase. Data were analysed using R Commander with P-value ≤ 0.05 considered significant. The results showed that broilers fed the MMHAC10, MMHAC30 and TBCC125 diets tended to have higher FI with the highest FI observed for TBCC125 treatment (P = 0.052), and higher weight gain with the highest weight gain observed for MMHAC30 group (P = 0.063) compared to the ITM control group over the entire study. Although, a significant difference was not obtained, birds fed MMHAC10 had numerically higher overall liveability and European productivity index (EPI) over the entire study compared to the other groups. Thigh and drumstick weight were higher in birds fed MMHAC30 compared to the ITM control group at day 42 (P = 0.050). At days 10, 16, 21, 28 and 42, feeding MMHAC at both levels significantly decreased Zn and Mn levels while feeding TBCC125 increased Cu level in the excreta compared to the other dietary treatments (P < 0.001). Also, birds fed the MMHAC30 diet had higher Cu digestibility compared to those fed the MMHAC10 and ITM diets at day 21 (P < 0.01). Whereas, litter conditions, levels of air gases (ammonia, carbon dioxide and methane), bone parameters and welfare indicators were generally similar between the dietary treatments. Thus, it can be concluded that dietary supplementation of MMHAC at the reduced levels could serve as a nutritional strategy to improve growth performance and carcass yield while maintaining litter quality, bone health and welfare status and reducing Zn, Cu and Mn excretion of broilers into the environment, therefore reducing the environmental impacts of broiler production.

本研究探究了饲粮添加蛋氨酸羟基类似物螯合矿物质（mineral methionine hydroxy analogue chelates, MMHAC）锌（Zn）、铜（Cu）与锰（Mn）产品（MINTREX® Zn:Cu:Mn，诺伟司国际公司（Novus International, Inc.）），以及高剂量无机铜饲粮，对罗斯308（Ross 308）雄性肉鸡生长性能、养分消化率、胴体性能、排泄物氮（N）与矿物质含量、环境状况、骨骼参数及福利状态的影响。试验共选取384只1日龄雏鸡，随机分为4个饲粮处理组，每组设置8个重复饲养栏，每栏饲养12只肉鸡。4个处理组分别为：(1) ITM组：添加硫酸锌110 ppm、硫酸铜16 ppm、一氧化锰120 ppm；(2) MMHAC10组：添加MMHAC锌40 ppm、铜10 ppm、锰40 ppm；(3) TBCC125组：添加硫酸锌110 ppm、TBCC 125 ppm、一氧化锰120 ppm；(4) MMHAC30组：添加MMHAC锌40 ppm、铜30 ppm、锰40 ppm。试验分为3个饲喂阶段：育雏期（0~10日龄）、育成期（10~21日龄）与育肥期（21~42日龄），并按各饲喂阶段分别计算生长性能指标。试验数据采用R Commander软件进行统计分析，以P值≤0.05作为差异显著的判定标准。整个试验周期内，与ITM对照组相比，饲喂MMHAC10、MMHAC30及TBCC125饲粮的肉鸡采食量（Feed Intake, FI）呈升高趋势，其中TBCC125组采食量最高（P=0.052）；同时各组增重也呈升高趋势，MMHAC30组增重最高（P=0.063）。尽管未达到统计学显著水平，但MMHAC10组肉鸡的全程存活率与欧洲生产效率指数（European Productivity Index, EPI）在所有组中数值最高。42日龄时，与ITM对照组相比，MMHAC30组肉鸡的大腿与小腿重量显著升高（P=0.050）。在10、16、21、28及42日龄，与其他饲粮处理组相比，两个MMHAC添加组的排泄物中Zn和Mn含量均显著降低，而TBCC125组排泄物Cu含量显著升高（P<0.001）。此外，21日龄时，饲喂MMHAC30饲粮的肉鸡Cu消化率显著高于MMHAC10组与ITM组（P<0.01）。各组肉鸡的垫料状况、空气污染物含量（氨气、二氧化碳与甲烷）、骨骼参数及福利指标均无显著差异。综上，饲粮添加低剂量MMHAC可作为一种营养调控策略，在改善肉鸡生长性能与胴体性能的同时，维持垫料品质、骨骼健康与福利状态，并降低肉鸡排泄物中Zn、Cu、Mn的排放量，从而减轻肉鸡生产对环境的负面影响。