جستجوی مقالات مرتبط با کلیدواژه « fish meal replacement » در نشریات گروه « شیلات »

Replacement of fish meal by cost effective and sustainable plant resources in the formulation of feed for fish is a viable option to alleviate the current crisis in fish feed industries arising due to high cost and non-availability of fish meal. The present research was aimed to evaluate if fermented leaf meal of the aquatic plant Ipomoea aquatica could be used as a fish meal alternative in the formulation of feed for the catfish Heteropneustes fossilis.  Fresh green leaves of I. aquatica were sun dried and finely ground to make Ipomea leaf meal (ILM), which was then fermented for 12 days by the phytase producing bacteria Stenotrophomonas maltophilia strain KUAKSP1 (GenBank Accession No. KY790423) isolated from rumen of goat. Four iso-proteinous, iso-lipidous and iso-energetic feeds were formulated by replacing 0, 25, 50 and 75% of fish meal by the fermented Ipomoea leaf meal (FILM). Protein digestibility of the feeds was evaluated within 12 days in an indoor experiment in glass aquaria and growth performance of the fish was evaluated after 8 weeks rearing in outdoor cement tanks. H. fossilis grew better on FILM supplemented feed as compared to fish meal based control feed. Maximum apparent protein digestibility (APD) of the feed, maximum weight gain (WG) and specific growth rate (SGR) and minimum FCR of the fish were found in 50% replacement group. However, crude protein (CP) and crude lipid (CL) deposition in the muscle of the fish and activity of protease in the gut was higher in 25% replacement group. It is concluded that H. fossilis accepts and grows well on the plant based FILM supplemented feed. For better growth management of the fish, incorporation of FILM in the feed should be restricted to 25 to 50% of fish meal.

A feeding trial was performed to investigate the effects of the partial replacement of fish meal with distiller’s dried grains with solubles (DDGS) on growth, feed assessment, economic assessment, digestibility of diets, as well as liver and intestinal histology of rainbow trout (Oncorhynchus mykiss). Four isonitrogenous and isocaloric diets were prepared using DDGS in rates of 0%, 10%, 20% and 30% (Control, DDGS10, DDGS20, and DDGS30, respectively) instead of reducing the fish meal content. Triplicate groups of 25 rainbow trout (mean initial weight 19.88±0.02 g) were fed with the diets for 84 days. The results revealed that dietary DDGS30 had the highest final weight and specific growth rate. Feed conversion and protein efficiency rates were similar among the dietary treatments. Economic conversion ratio was reduced depending on DDGS increase in diet that resulted in an increased economic profit index. The apparent digestibility of the diets did not differ significantly among treatments. There were no significant differences in the diameter of hepatocyte nuclei but there was a detected amount of vacuolization in the hepatocyte cytoplasm of fish fed  the dietary DDGS20 and DDGS30 diets. Distal intestine histomorphometric parameters were unaffected by dietary treatments, however, increased lamina propria width was observed as the rate of DDGS increased in diets. These results indicate that DDGS can be added to rainbow trout diets by up to 30% without negatively affecting growth performance, diet digestibility, as well as the histology of  the liver and intestine.

In this study, a feeding trial was conducted to examine the potential of replacing fish meal with brewers yeast in practical diet of goldfish (Carassius auratus). Five isoproteic (37% CP) and isocaloric (3350 kcal/kg) diets were formulated to contain graded levels of brewers yeast. Fish meal protein was replaced by 0%, 15%, 25%, 35%, and 45% of yeast. Each diet was randomly allocated to triplicate groups of 20 fish (initial average weight of 0.56 g fish-1) in glass aquarium (65L). Fish were fed three times per day to apparent satiation for 84 days. At the end of the experiment, weight gain, specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), condition factor (CF), survival rate (SR), hepatosomatic indices (HSI) and body composition of goldfish fry were determined. According to the results, weight gain, SGR, FCR and PER of fish fed the diet including yeast replaced 35% of the fish meal were better than those of fish fed the other diets. There were no significant differences in SR and HSI values among fish fed diets (p>0.05). However, CF among fish fed the experimental diets was significantly differ (p>0.05). Whole body composition was similar among fish fed different diets. The optimal replacement level of fishmeal protein by brewers yeast was determined by second-order polynomial regression to be (y= 2, 2237- 0,0004x2 0,0279x; R² = 0,9977) 34.875%, on the basis of SGR