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In recent decades, mortality caused by ostreid herpesvirus (OsHV-1) and a variant (OsHV-1 μvar) has severely impacted the production of Pacific oyster, Crassostrea gigas, chronologically in France, New Zealand (NZ) and Australia (Jenkins et al., 2013; Keeling et al., 2014; Segarra et al., 2010). This study was conceived based on observations made in several commercial hatcheries and research institutes in these countries where vertical transmission of OsHV-1 μvar has been absent or extremely rare. We have collated data from the production of Pacific oysters across these countries to assess the risk associated with breeding oysters from broodstock grown in OsHV-1 μvar-infected waters. The aim is to provide a reference point for regulatory authorities to use when developing or updating biosecurity management policy associated with the hatchery production of Pacific oysters.

High inclusion levels of dehulled lupin (Lupinus angustifolius) in salmonid diets significantly decrease growth rates. This may be caused by the high concentrations of non-starch polysaccharides including oligosaccharide (OS) in lupin. The antinutritive effects of OS have not yet been fully investigated in fish. The objective of this study was to determine the effect of enzyme supplementation of dehulled lupin-based diets on the fish performance. There were two control diets: a fish meal-based diet with no plant protein (FM) and a diet that contained 50% dehulled lupin (L). Four experimental diets based on diet L and containing four different exogenous enzyme supplements were used: diet L(E) (Energex™); diet L(B) (Bio-Feed™ Pro); diet L(α) (Alpha galactosidase™); and diet L(Mix), which contained all the enzymes. Fish were randomly stocked into tanks in duplicate groups of 38 fish, 16.58±0.169 (SE) g, and were fed twice a day for 6 weeks. The supplemented enzymes did not improve weight gain in fish fed lupin-based diets. However, mixed enzyme significantly improved Protein Efficiency Ratio (PER). Apparent digestibility of DM, CP and GE significantly improved in fish-fed L(E) diet. None of the supplemented enzymes affected digestive tract indices or carcass composition. Surprisingly, weight gain was significantly higher in fish-fed L(α), L(E) and L(Mix) diets as compared with FM diet. Feed intake was significantly higher in fish-fed L, L(α) and L(E) diets compared with the FM diet. It is concluded that storing of lupin kernel under a suitable condition may have partially hidden the positive effects of exogenous enzymes through activating the endogenous enzymes

In this experiment, 23% of fish meal protein was replaced with protein from Australian soybean meal (SBM), lupin meal (LM), corn gluten meal (CGM) and meat meal (MM) in nutritionally balanced experimental diets. Growth and growth efficiencies of juvenile Australian short-finned eel Anguilla australis australis (Richardson) elvers (2.23 ± 0.4-g average wet weight) were compared Elvers were fed twice a day to a total of 5% body weight per day for 63 days. Total weight gain (g), specific growth rate (% day-1), protein efficiency ratio (%) and productive protein value (%) were significantly higher (P < 0.05) for elvers fed the MM diet than for those fed the LM diet. There were no differences in diurnal ammonia-nitrogen excretion rates. However, diurnal urea-nitrogen excretion rates were significantly (P < 0.05) affected by diet and rates were two to three times higher for all diets, except CGM, 4 h following the afternoon feed. Diet significantly affected apparent digestibility (AD); ADs of protein for SBM and LM were significantly (P < 0.001) higher than for control diet, CGM and MM; AD of energy for LM was significantly (P < 0.05) lower than for all the other diets. Fish meal protein was replaced by CGM, SBM and MM without compromising growth rates of the Australian short-finned eel. However, whole lupin seed meal (LM) depressed growth and growth efficiencies most likely because of the high indigestible carbohydrate content. © 2005 Blackwell Publishing Ltd.

The utilization of dehulled lupin as a partial replacement for fish meal was studied in diets of rainbow trout. Fish were fed diets with 0%, 10%, 20%, 30%, 40% and 50% of dehulled lupin, at a daily feeding rate of 2% body weight for 8 weeks at 15 ± 0.5 °C. Growth performance generally decreased with increasing dehulled lupin in the diet (R2 = 0.81, P

Development of a formulated pellet to replace ‘bait’ fish in farmed southern bluefin tuna (SBT), Thunnus maccoyii (Castelnau), feeds is in progress; however, inherent difficulties have been encountered in conducting large-scale growth trials to evaluate experimental pellet quality. Consequently, alternative methods are being investigated to develop a suitable feed more rapidly. This work explored whether Atlantic salmon, Salmo salar L., could be used as a ‘surrogate’ species for nutrition research on SBT by screening experimental SBT feeds. Atlantic salmon (initial mean weight 161.4 g) were fed a commercial salmon feed (Com.Sal), a commercial northern bluefin tuna feed (Com.NBT), one of three experimental SBT feeds (CRC-A, -B, -C) or dry pelleted pilchards for 42 days, at which time growth was assessed. In vivo and in vitro protein digestibility of the feeds was also evaluated. Weight gain of Atlantic salmon fed Com.Sal (99.8 g) and Com.NBT (93.5 g) were found to be significantly (P

Supplementary enzymes were added to a diet in order to increase its digestibility and improve the growth achieved by seawater Atlantic salmon, Salmo salar L. The supplementary enzymes were selected to hydrolyse proteins and carbohydrates. Three diets, with fishmeal as the only source of protein (C1), with fishmeal and soybean meal (C2) and diet C2 with supplementary enzymes (C3) were fed to seawater salmon (100g) for 12 weeks at nominal tank rations equivalent to 2·5% body weight per day. Consumption rates of individual fish were measured by radiography. The salmon fed C3 had higher rates of food consumption, significantly higher final weights and rates of growth and lower food conversion efficiencies and maintenance ration than those fed C2. Salmon fed C1 had similar food conversion efficiencies to the C3 fed fish. These results indicate that the addition of supplementary enzymes to diets containing soybean meal improves the growth and food conversion efficiency of salmon.