Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bag 49, Hobart, TAS 7001, Australia.
Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bag 49, Hobart, TAS 7001, Australia.
Comp Biochem Physiol A Mol Integr Physiol. 2022 Mar;265:111121. doi: 10.1016/j.cbpa.2021.111121. Epub 2021 Nov 23.
Apparent digestibility and gastrointestinal evacuation rate were measured to assess the potential of five commercially available protein sources for their inclusion in feeds for juvenile slipper lobster, Thenus australiensis. Protein sources tested were fishmeal, krill meal, lupin meal, soybean meal and squid by-product meal. Apparent digestibility of crude protein ranged from 79.6% to 95.3%, with fishmeal protein significantly less digestible than lupin meal, squid by-product meal and soybean meal. Gastrointestinal evacuation rate was estimated from marker replacement, where yttrium oxide replaced ytterbium oxide. Faeces were collected every 3 h for 48 h, and a kinetic model was used to calculate the rate and time for the second marker to replace the first marker. Gastrointestinal evacuation (≥ 95%) was completed between 4 and 6 h with no significant differences among protein sources. Faeces consisted of both markers in equal parts 2.7 to 5.0 h after the feed switch, with lupin meal reaching the midpoint significantly faster than squid by-product meal and reference feed. The present study is the first in crustaceans to examine the relationship between apparent digestibility and gastrointestinal evacuation, showing more digestible protein sources had slower evacuation rates. The combined approach provides deeper insight into crustaceans' digestive physiology and helps understand their ability to digest specific ingredients. Further research is recommended to understand protein requirements in a broader context to verify highly digestible protein sources meet all nutritional requirements.
本研究旨在评估 5 种市售蛋白质源在幼态滑齿龙（Thenus australiensis）饲料中的应用潜力，采用表观消化率和胃肠道排空率进行评估。测试的蛋白质源有鱼粉、磷虾粉、羽扇豆粉、豆粕和鱿鱼下脚料。粗蛋白的表观消化率范围为 79.6%至 95.3%，其中鱼粉蛋白的消化率显著低于羽扇豆粉、鱿鱼下脚料和豆粕。采用示踪剂替换法估计胃肠道排空率，其中氧化钇替代氧化镱。收集粪便每 3 小时一次，共 48 小时，并使用动力学模型计算第二个示踪剂替代第一个示踪剂的速率和时间。4 至 6 小时内完成胃肠道排空（≥95%），不同蛋白质源之间无显著差异。粪便中两种示踪剂的比例相等，在饲料更换后 2.7 至 5.0 小时，羽扇豆粉达到中点的速度明显快于鱿鱼下脚料和参考饲料。本研究首次在甲壳类动物中研究了表观消化率与胃肠道排空之间的关系，表明更易消化的蛋白质源排空速度较慢。这种综合方法提供了对甲壳类动物消化生理学的更深入了解，有助于理解它们消化特定成分的能力。建议进一步研究以更广泛的背景了解蛋白质需求，以验证高消化率的蛋白质源是否满足所有营养需求。
