The United States organic poultry industry is currently facing a limitation on dietary inclusion of synthetic methionine (Met). This study investigated Brazil nut protein powder (BNPP), spray-dried egg white (SDEW), and spray-dried egg blend (70:30 albumen: yolk) (SDEB) as alternatives to synthetic Met in organic laying hen diets. A total of 270 Hy-Line Brown laying hens was fed 5 diets from 22 to 38 wk of age, with 6 replicates of 3 adjacent cages per diet and 3 hens per cage. Diets included a commercial control (COM) (non-organic with standard CP and synthetic Met), an organic control (ORG) (with no synthetic Met, but higher CP to meet Met requirements), and 3 organic treatment diets with no synthetic Met, but including BNPP, SDEW, or SDEB at levels to meet Met requirements. Egg production and quality, body weight (BW), feed intake, and manure nutrients and ammonia were assessed. Data were analyzed using the PROC MIXED procedure of SAS, with Tukey's test used for multiple mean comparisons, and P ≤ 0.05 was deemed statistically significant. Body weight was greatest for the COM diet, and feed conversion improved for hens fed egg-based diets compared to controls. Egg weight and production did not differ between COM and treatment diets. The SDEW diet had greater albumen height and Haugh units compared to ORG and BNPP diets and greater percent albumen compared to COM and BNPP diets. Specific gravity was greatest for BNPP fed hens. Manure DM and potash were highest from COM and BNPP diets, respectively. Both egg-based diets increased ammonia flux relative to the COM diet. The BNPP and egg-based diets were lower in cost for $/metric tonne, $/dozen eggs, and $/kg of eggs compared to the ORG diet. The ingredients assessed herein could, therefore, cost-effectively replace synthetic Met in organic hen diets without negatively impacting egg production.

中文翻译：

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巴西坚果粉和喷雾干燥的蛋粉可作为有机蛋鸡饮食中合成蛋氨酸的替代品。

美国有机家禽业目前在饮食中包含合成蛋氨酸（Met）的含量受到限制。这项研究调查了巴西坚果蛋白粉（BNPP），喷雾干燥的蛋清（SDEW）和喷雾干燥的鸡蛋混合物（70:30蛋白：蛋黄）（SDEB）作为有机蛋鸡日粮中合成Met的替代品。总共为270头Hy-Line Brown蛋鸡饲喂了22至38周龄的5种日粮，每批日粮3头母鸡和3头母鸡进行6次重复饲养。饮食包括商业对照（COM）（具有标准CP和合成Met的非有机食品），有机对照（ORG）（不含合成Met，但具有更高的CP以满足Met要求）和3种不含合成Met的有机饮食，但要满足Met要求的水平包括BNPP，SDEW或SDEB。产蛋量和质量，体重（BW），采食量，并评估肥料中的养分和氨气。使用SAS的PROC MIXED程序分析数据，并使用Tukey检验进行多次均值比较，并且P≤0.05被认为具有统计学意义。体重对于COM饮食而言是最大的，与对照相比，饲喂蛋基饮食的母鸡的饲料转化率得到了改善。蛋重和产量在COM和治疗日粮之间没有差异。与ORG和BNPP日粮相比，SDEW日粮具有更高的蛋白高度和Haugh单位，与COM和BNPP日粮相比，SDEW日粮具有更高的蛋白百分比。BNPP饲喂母鸡的比重最大。粪便中的DM和钾肥分别来自COM和BNPP日粮。两种蛋基饮食相对于COM饮食均增加了氨通量。BNPP和以蛋为基础的饮食的成本较低，每公吨，十个鸡蛋，和$ / kg鸡蛋相比，ORG饮食。因此，本文评估的成分可以经济有效地替代有机母鸡日粮中的合成蛋氨酸，而不会对蛋的生产产生负面影响。