Apparent digestible protein,energy and amino acid availability of three plant proteins in Florida pompano,Trachinotus carolinus L. in seawater and low‐salinity water

Two experiments were conducted with Florida pompano, Trachinotus carolinus L. at 3 and 28 g L^?1 salinity to determine apparent crude protein digestibility (ACPD), energy digestibility (AED) and amino acid availability (AAAA) from soybean meal (SBM), soy protein isolate (SPI) and corn gluten meal (CGM). Mean AAAA was similar to ACPD. In fish adapted to 3 g L^?1 salinity, they were 81.2% and 81.9% (CGM), 93.6% and 92.2% (SBM), 93.8% and 93.1% (SPI) for AAAA and ACPD respectively. In fish adapted to 28 g L^?1, they were 84.5% and 83.4% (CGM), 86.5% and 87.1% (SBM), and 83.4% and 85.0% (SPI) for AAAA and ACPD respectively. The AED was highest for SPI and lowest for SBM and inversely related to carbohydrate. The ACPD, AED and AAAA of soy products appeared to be lower in high salinity, whereas CGM was unaffected. The data suggest that SBM, SPI and CGM should be further evaluated as partial fishmeal replacements in Florida pompano diets. Application of the generated coefficients can be used to develop well‐balanced, low‐cost diets for Florida pompano reared in low salinity or seawater.     

MOLYBDENUM IN THE LOWER LIAS OF ENGLAND AND WALES IN RELATION TO THE INCIDENCE OF TEART

An explanation is offered for the fact that the toxic levels of molybdenum occurring in the Lower Lias soils of Somerset have not been found in soils of Glamorgan, apparently derived from the same zones of the Lower Lias. This is attributable to the parent rock being free of the abnormally high levels of molybdenum found in Somerset, which in turn probably results from the Glamorgan Lias having been laid down close to the contemporary coastline.
Soils high in molybdenum are to be expected in the Vale of Marshwood (Dorset), but owing to the topography of this district they probably occur in such small pockets as to cause no serious trouble.     

Incorporation of plant protein feedstuffs into fish meal diets for rainbow trout increases phosphorus availability

Individual plant protein feedstuffs were incorporated into a diet containing fish meal and fed to rainbow trout to determine apparent and true phosphorus availability (APA and TPA, respectively). The plant protein feedstuffs evaluated were soybean, canola and peanut meals; each was incorporated at 200 g kg^–1 of dry matter. The average initial weight of fish was 68 g and the water temperature was maintained at 15°C. Concentrations of macronutrients were constant in diets. Incorporation of plant protein feedstuffs significantly increased APA and TPA values. The APA values were 19.5% for fish meal and 39.5%, 40.2%, and 38.5% for the diets containing soybean meal, canola meal, and peanut meal, respectively. Similarly, the TPA values for the combination of fish meal and plant protein feedstuff were 43.4%, 42.1% and 40.6% for diets containing soybean, canola and peanut meals, respectively, which were significantly higher than values for fish meal (21.5%). Calculation of APA and TPA values for individual feedstuffs resulted in values for the plant protein ingredients of over 100%. We speculate that the increased APA and TPA values were the result of decreasing total dietary phosphorus concentrations or dilution of the calcium concentrations from bone in fish meal.     

Fish meal replacement with solvent‐extracted soybean meal or soy protein isolate in a practical diet formulation for Florida pompano (Trachinotus carolinus,L.) reared in low salinity

Two 8‐week growth trials were conducted with juvenile Florida pompano, Trachinotus carolinus fed 0–1000 g kg^?1 replacement of fish meal (FM) protein with soybean meal (SBM) or soy protein isolate (SPI). Practical‐type diets were formulated with at least 360 g kg^?1 digestible protein and 24 mg kJ^?1 digestible protein/digestible energy. Weight gain and efficiency were not different between 0 and 800 g kg^?1 FM protein replacement with SBM. Regression of weight gain and protein productive value suggested a conservative level of SBM substitution was 380 g kg^?1 FM protein. It appeared that lysine could be limiting beyond 400 g kg^?1 FM replacement. No significant differences were detected in fish fed 0 and 200 g kg^?1 FM protein replacement with SPI. A decrease in weight gain and efficiency parameters occurred at 400 g kg^?1 protein replacement, and fish fed a replacement of 600 g kg^?1 or greater with SPI exhibited signs of starvation. A third trial indicated intake and growth were significantly reduced (P < 0.0001) in fish fed 600 g kg^?1 relative to 0 g kg^?1 FM protein replacement with SPI. Poor palatability of diets containing 400 g kg^?1 or more FM protein replacement with SPI appeared to be the causative factor for poor performance.