ABSTRACT Protein and amino acid (AA) availability of three protein meals of expected different quality were evaluated in young growing and adult mink. Lamb meal (LM), poultry meal (PM) or fishmeal (FM) were used as main protein sources in three extruded diets investigated by determining apparent total tract digestibility (ATTD) and nitrogen balance in 12 growing mink males aged 8–11 weeks in a Latin square design. In adult mink, ATTD of the diets was determined. The diets had lower protein content than recommended for growing mink, protein contributing 23% of total metabolisable energy (ME), to ensure differences in growth response. The LM diet with expected low protein quality revealed lower content of essential AA than the PM and FM diets. The ATTD of major nutrients and essential AA was significantly affected by diet, with the poorest values for LM, intermediate for PM and the highest values for FM. Mink kits revealed lower ATTD values than adults for protein, AA and especially fat, resulting in lower dietary ME content for kits than for adults. The mean difference was greatest for the LM diet with lowest ATTD and smallest for the FM diet with the highest ATTD. Nitrogen retention and growth rate differed significantly among diets and was lowest for diet LM and highest for diet FM, respectively. Different dietary essential AA contents and ATTD, especially of methionine, were the main factors to explain the difference in growth response. Generally, plasma essential AA concentrations did not clearly reflect the different dietary supply and the different growth response. The study shows that a recommended level of 0.31 g apparent total tract digestible methionine per MJ ME covers the minimum requirement with a safety margin. To obtain optimal growth, the lower digestive capacity in young mink kits should be considered when choosing feed ingredients.

中文翻译：

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成年和成长中的水貂不同质量蛋白质粉的氨基酸可用性（Neovison vison）

摘要 在幼小和成年水貂中评估了三种不同质量的蛋白质粉的蛋白质和氨基酸 (AA) 可用性。羊肉粉 (LM)、家禽粉 (PM) 或鱼粉 (FM) 被用作三种挤压饲料中的主要蛋白质来源，该研究通过测定 12 只 8-11 周龄生长水貂雄性的表观总消化率 (ATTD) 和氮平衡进行研究。拉丁方形设计。在成年水貂中，测定了日粮的 ATTD。这些日粮的蛋白质含量低于推荐用于生长的水貂，蛋白质占总代谢能 (ME) 的 23%，以确保生长反应的差异。具有预期低蛋白质质量的 LM 饮食显示出比 PM 和 FM 饮食更低的必需 AA 含量。主要营养素和必需氨基酸的ATTD受饮食影响显着，LM 的值最差，PM 的中间值和 FM 的最高值。水貂套件显示的蛋白质、AA 尤其是脂肪的 ATTD 值低于成人，导致套件的膳食 ME 含量低于成人。平均差异对于具有最低 ATTD 的 LM 饮食来说最大，对于具有最高 ATTD 的 FM 饮食来说最小。不同饮食之间的氮保留和生长速度有显着差异，分别是饮食 LM 最低和饮食 FM 最高。不同的膳食必需氨基酸含量和ATTD，尤其是蛋氨酸，是解释生长反应差异的主要因素。一般来说，血浆必需氨基酸浓度不能清楚地反映不同的饮食供应和不同的生长反应。研究表明，推荐水平为 0。每个 MJ ME 31 g 表观总消化道可消化蛋氨酸涵盖了具有安全裕度的最低要求。为了获得最佳生长，在选择饲料原料时应考虑幼貂的消化能力较低。