Artur N. Rombenso

Comparison of Traditional and Fermented Soybean Meals as Alternatives to Fish Meal in Hybrid Striped Bass Feeds

Abstract Soybean meal is one of the most common fish meal alternatives used in aquafeeds because of its high protein density, favorable amino acid profile, comparatively low price, and widespread availability. However, palatability issues and antinutritional factors limit soybean meal inclusion, particularly in feeds for carnivorous fishes. Various processing strategies, including fermentation, may offer some advantage in terms of reducing or eliminating antinutritional factors while enhancing protein content, improving protein absorption rate, and feed intake. Accordingly, we assessed production performance of juvenile hybrid Striped Bass (White Bass Morone chrysops × Striped Bass M. saxatilis) fed diets containing 30% menhaden fish meal, or reduced or fish-meal-free feeds (0, 5, or 10% fish meal) containing traditional soybean meal (47.5% crude protein) or PepSoyGen fermented soybean meal (52.0% crude protein) as the principal sources of dietary protein. Each dietary treatment was fed to quadruplicate t...

Traditional and Fermented Soybean Meals as Ingredients in Feeds for White Seabass and Yellowtail Jack

AbstractSoybean meal is commonly used as a protein source in aquafeeds, but its benefits can be limited by its digestibility and the presence of antinutritional factors. Fermentation may address both of these issues, thereby improving utilization of soybean meal by carnivorous fish. We compared the production performance of juvenile White Seabass Atractoscion nobilis and Yellowtail Jack Seriola lalandi that were fed diets containing fish meal, or graded levels of traditional soybean meal or fermented soybean meal. These diets were also compared to reduced or fish-meal-free feeds based on soy protein concentrate, poultry byproduct meal, or algal meal (spirulina Spirulina spp.). Complete fish meal replacement yielded poor performance in both species, regardless of the alternative protein source used. White Seabass performed well on diets containing blends of fish meal and traditional or fermented soybean meals or soy protein concentrate; similar results were observed in Yellowtail Jack, though performance w...

Feeding Rate and Frequency Affect Growth of Juvenile Atlantic Spadefish

Abstract The Atlantic spadefish Chaetodipterus faber is an excellent candidate for aquaculture development, but success will depend on the identification of proper feeds and feeding regimens for this species. Accordingly, we evaluated the growth performance of juvenile Atlantic spadefish (3.60 ± 0.03 g [mean ± SE]) fed at rates of 3, 5, or 7% of body weight (BW) per day, either in a single feeding (1×) or in three equal feedings (3×). Weight gain, specific growth rate, feed conversion ratio, and feed intake were significantly affected by both feeding rate and frequency. Weight gain and the specific growth rate increased significantly with feeding rate, and growth was generally greater and more efficient in the 3× groups than in the 1× groups. Fish fed at higher feeding rates accumulated significantly more lipid within the body and had associated decreases in moisture, protein, and ash content, but carcass composition was unaffected by feeding frequency. We suggest that the growth of juvenile Atlantic spad...

Outbreak of mortality among cage-reared cobia (Rachycentron canadum) associated with parasitism

This study reports a disease outbreak among juvenile cobia (Rachycentron canadum) farmed in cages in the state of Rio de Janeiro, Brazil, caused by the dinoflagellate Amyloodinium ocellatum and the monogenean Neobenedenia melleni. Two thousand five hundred fish were stocked at 0.4 kg/m3 in a set of 12 m3 tanks, in autumn (mean weight 15.0 ± 7.3 g) and in winter (mean weight 43.0 ± 5.6 g). Freshwater baths were administered as a routine treatment, as the symptoms were detected followed by two collection samples. Firstly in May 2011 (n = 5) and secondly in September 2011 (n = 10). In the first sample, the prevalence of N. melleni on the body surface was 100% and the mean intensity was 42.0 ± 1.7, while in the second sample the prevalence was 60% with a mean intensity 3.0 ± 0.2 and mean abundance 1.8 ± 0.4. Amyloodinium ocellatum was only found in the second sample, at a prevalence 100% and mean intensity 46.8 ± 3.4. The cause of fish mortality was possibly associated with a decrease in fish resistance after the first contact with monogenean parasites, allied with respiratory difficulty caused by the presence of A. ocellatum in the gills.

Oxytetracycline does not cause growth promotion in finfish1

Until recently, use of antibiotics to enhance terrestrial animal growth performance was a common, U.S. Food and Drug Administration (FDA)-approved, but controversial practice. There are no FDA-approved production claims for antibiotic drug use in fish, but it is a common misconception that antibiotics are widely used for this purpose in U.S. aquaculture. Antibiotics are not thought to be effective growth promoters in fish, but there is little quantitative data available to address whether there are growth-promoting effects that might incentivize the use of antibiotics in this way, despite legal prohibitions. Therefore, this study was conducted to determine if oral administration of oxytetracycline, an antibiotic with known growth-promoting effects in terrestrial livestock, has a similar effect when applied to channel catfish Ictalurus punctatus, hybrid striped bass Morone chrysops × M. saxatilis, Nile tilapia Oreochromis niloticus, or rainbow trout Oncorhynchus mykiss. Oxytetracycline products with production claims are typically applied at doses substantially lower than the approved therapeutic doses for the same products. Medication (0, 0.24, or 1.2 g oxytetracycline dihydrate kg-1 feed) and feeding rates (3% BW d-1) were selected to achieve target daily doses of 0, 16, or 80 mg kg-1 fish representing control, subtherapeutic, and therapeutic treatments. Replicate groups of fish (N = 4) were fed accordingly for 8 wk. Overall, oral administration of oxytetracycline did not affect survival or promote growth of the selected taxa, with no significant differences observed for weight gain, feed conversion ratio, or specific growth rate (P > 0.05 in all cases). Few differences were observed in organosomatic indices and in the frequency of tissue abnormalities; where present, these differences tended to suggest a negative effect of long-term dietary exposure to oxytetracycline. These data demonstrate that there is no benefit to dietary supplementation with oxytetracycline for nontherapeutic purposes in a range of economically important finfish species. As such, our results indicate there is little incentive to misuse oxytetracycline products for purposes of growth promotion in U.S. aquaculture.