DIGESTIBILITY OF VARIOUS FEEDSTUFFS BY POST-JUVENILE CHINOOK SALMON (ONCORHYNCHUS-TSHAWYTSCHA) IN SEA-WATER .1. VALIDATION OF TECHNIQUE
DIGESTIBILITY OF VARIOUS FEEDSTUFFS BY POST-JUVENILE CHINOOK SALMON (ONCORHYNCHUS-TSHAWYTSCHA) IN SEA-WATER .1. VALIDATION OF TECHNIQUE
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DOI：
10.1016/0044-8486(93)90393-d
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发表时间：
1993-05-15
期刊：
影响因子：
4.5
通讯作者：
DOSANJH, BS
中科院分区：
文献类型：
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作者：
HAJEN, WE;BEAMES, RM;DOSANJH, BS
本研究旨在评估用于测量淡水中虹鳟鱼消化率的圭尔夫系统是否适合测定海水中奇努克鲑鱼的消化率。通过圭尔夫系统、剥离技术（每周一次）和肠道解剖从奇努克鲑鱼中收集粪便。圭尔夫程序的验证还涉及评估：(1) 基于总粪便收集的消化率系数与基于间接氧化铬指示剂法的消化率系数，(2) 使用圭尔夫系统时养分浸出的程度，以及 (3) 饮食摄入水平和鱼类处理程度（由于粪便剥离）对圭尔夫法估计养分消化率的影响。在测量表观养分的完全收集法和指示法之间没有发现显着差异消化率。使用通过剥离和解剖直接从鱼中收集的粪便计算出的表观消化率值始终低于使用圭尔夫系统得出的完整收集和指标值。汽提技术产生最低的消化率系数。当粪便暴露在海水中超过6小时时，就会发生养分浸出。这是由于粪便未完全进入收集柱所致。鱼的处理和随之而来的食物摄入量的减少降低了营养物和能量的消化率系数，并增加了鱼的死亡率。结论是，使用 Cr2O3 作为难消化标记的圭尔夫粪便收集系统是海水中奇努克鲑鱼潜在可靠的消化程序。然而，必须小心确保将粪便快速、彻底地清除到收集柱中，以最大程度地减少营养物浸出。
This study was undertaken to assess whether the Guelph system for measuring digestibility in rainbow trout in fresh water was suitable for determining digestibility in chinook salmon held in sea water. Feces were collected from chinook salmon by the Guelph system, the stripping technique (once per week) and intestinal dissection. Validation of the Guelph procedure also involved assessment of: (1) the digestibility coefficients based on total fecal collection versus those based on the indirect chromic oxide indicator method, (2) the extent of nutrient leaching when using the Guelph system, and (3) the effect of level of dietary intake and extent of fish handling (due to stripping of feces) on estimates of nutrient digestibility by the Guelph method.No significant differences were found between the complete collection and indicator methods for measuring apparent nutrient digestibilities. Apparent digestibility values calculated using feces collected directly from the fish by both stripping and dissection were consistently lower than the complete collection and indicator values derived using the Guelph system. The stripping technique yielded the lowest digestibility coefficients. Nutrient leaching occurred when the feces had been exposed to sea water for more than 6 h. This was attributed to incomplete entry of feces into the collection column. Fish handling and concomitant reduction of food intake depressed digestibility coefficients for nutrients and energy and increased fish mortality.It is concluded that the Guelph system of fecal collection involving the use of Cr2O3 as the indigestible marker is a potentially reliable digestibility procedure for chinook salmon in sea water. However, care must be exercised to ensure rapid and complete removal of feces to the collection column to minimize nutrient leaching.