SEARCH · USGS Science
Results for “Soybean Digest”
Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Cataractous and digestive protease responses of rainbow trout fed autoclaved isolated soybean protein and added methionine
No abstract available at this time.
Lack of surface-associated microorganisms in a mixed species community of freshwater Unionidae
To determine whether unionids contain surface-attached endosymbiotic bacteria, ciliates, or fungi, we used scanning electron microscopy to examine the epithelial surface of various organs within the digestive systems and mantle cavity of temperate river and lake unionids on a seasonal basis. We also cultured material removed from the lumen of these same organs and from the mantle cavity to detect cellobiose-, cellulose-, and chitin- degrading microbes. No true endosymbiotic fauna were observed attached to the surface of the digestive or mantle tissues of any species of unionid. Microbial growth on cellulose or chitin bacteriological media varied by season and habitat, but not by unionid species or source of the isolate. Lake unionids did not contain microbes capable of digesting cellulose or chitin, whereas unionids from the river site did in March and August, but not in December. Since these cultured cellulose- and chitin-degrading bacteria were never found attached to any unionid tissues, they appeared to be transient forms, not true endosymbionts. Microbes capable of digesting cellobiose were found in every unionid collected in all seasons and habitats, but again, no microbes were directly observed attached to unionid tissues. If unionids, like most other vertebrates, lack digestive enzymes required to initiate primary bond breakage, then the lack of cellulolytic and chitinolytic endosymbionts would affect the ability to utilize cellulose or chitin foods. Thus, in captivity dry feeds based on corn, soybeans, or nauplii should be pre-digested to ensure maximum absorption of nutrients by unionids. The lack of celluloytic or chitinolytic endosymbionts should not affect relocation success, though the seasonal role of transient microbes in unionid nutrition requires further investigation.
Assessment of lupin flour as a diet ingredient for rainbow trout (Salmo gairdneri)
Studies were conducted to determine the value of lupin flour as a replacement for full-fat soybean meal (FFSM) in the diet of rainbow trout ( Salmo gairdneri ). Energy and digestibility values for lupin were determined using a metabolism chamber and it was found that trout utilize lupin well. The gross energy, metabolizable energy, and the percent digestibilities of protein and energy for lupin were found to be 4757 kcal/kg, 2797 kcal/kg, 85.2%, and 66.1%, respectively. When plant protein (either FFSM or lupin flour) was used as a supplemental dietary protein source to fish meal, or when the plant protein was the primary dietary protein source, fish fed diets where lupin completely replaced FFSM gained 99–106% of the weight of those fed the FFSM and had statistically equal feed efficiency ratios ranging from 80 to 83%. Although some minor dietary alterations may be needed (e.g., lowering the fat content of the diet) to maintain the economic advantage of lupin over soybean meal, lupin appears to be a useful source of protein for trout and may represent another economical plant protein alternative to fish meal.