Poultry by-product meal as dietary protein source for dourado, Salminus brasiliensis: an economic appraisal

The dourado, Salminus brasiliensis, a large, carnivorous, Neotropical, Characin, is highly regarded for fish farming and sport fishing alike. However, studies on the farming and husbandry of dourado are still scarce. This study evaluated the performance of dourado fed diets formulated so as to contain increasing levels of poultry by-product meal as a replacement for fish meal and aimed to identify the maximum level of replacement to maximize profit. The trial was set up in a closed recirculation system with controlled water quality (temperature 27 °C, dissolved oxygen 6.5 mg L–1, pH 7.4, and ammonia 0.25 mg L–1). Juvenile fish were stocked in tanks in a completely randomized design, acclimatized to system conditions and experimental diets, and then fed twice a day for 66 days with extruded, nutritionally complete diets (40 % digestible protein and 4020 kcal kg–1 digestible energy), formulated to contain 0, 20, 40, 60, 80 or 100 % poultry meal as a surrogate protein source for fish meal. Performance parameters – average weight gain, specific growth rate, feed consumption, feed conversion rate, protein efficiency rate, productive value of protein, energy retention rate, survival rate – did not differ (p > 0.05). To minimize the effects of influential data, the robust regression method was used and profit maximization analysis revealed that replacing 33.3 % of dietary fishmeal by poultry by-product meal maximizes profit in the farming of dourado

Poultry byproduct meal as surrogate protein source in diets for dourado, Salminus brasiliensis (CUVIER, 1816)

Alguns peixes carnívoros, como o salmão e a truta, são produzidos mundialmente com rações nutricionalmente completas contendo elevados níveis de farinha e óleo de peixe em função da excelente qualidade nutricional destes ingredientes. A estagnação dos estoques pesqueiros e a demanda crescente por estes ingredientes fazem com que o custo com alimentação de peixes carnívoros seja cada vez mais elevado. Nutricionistas vêm então buscando substituir a farinha e o óleo de peixe nas dietas comerciais, sem prejudicar o desempenho dos peixes confinados. O dourado, Salminus brasiliensis, é um Characiforme ictiófago neotropical de grande porte que apresenta um grande potencial para a aquicultura: excelente qualidade de carne e boa aceitação do mercado consumidor, refletidos em elevado valor comercial, sendo ainda procurado para a pesca esportiva. Entretanto, os estudos sobre o uso da espécie em piscicultura comercial são ainda rudimentares. Os objetivos deste estudo foram avaliar o desempenho do dourado alimentado com dietas contendo a farinha de vísceras em substituição à farinha de peixe e determinar o nível máximo de substituição da farinha de peixes que permitisse a maximização do lucro. O experimento foi realizado em um sistema de recirculação de água com controle de temperatura (26,78 ± 2,21 ºC), oxigênio dissolvido (6,44 ± 1,03 mg L-1), pH (7,40 ± 0,28) e amônia total (0,05), foi observada a presença de dados influentes ou atípicos, que viciaram os resultados da regressão. Para diminuir a influência destes dados na curva da regressão, foi adotado o método da regressão robusta. A análise de maximização do lucro determinou que o nível ótimo de substituição de farinha de peixe por farinha de vísceras de aves foi de 33,29 %.Carnivorous fish such as trout and salmon are raised on complete feeds, containing large quantities of fish oil and fishmeal, the best quality feed ingredient there is. The stagnation of natural fish stocks and the increasing demand for such feedstuffs makes the cost of carnivorous fish diets increasingly high. Nutritionists are thus in search of alternative ingredients to replace fishmeal in commercial diets without hampering fish performance. The dourado, Salminus brasiliensis, is a Neotropical, large ichthyophagous Characin, highly regarded for fish farming and sport fishing alike because of its prized flesh, high acceptance and market value. However, studies on the farming and husbandry of dourado are still rudimentary. This study evaluates the performance of dourado fed diets formulated to contain increasing levels of poultry byproduct meal in replacement of fish meal and determining the maximum level of replacement of fishmeal that maximizes profit. Trial was set up in a closed loop system, controlled temperature (26.78 ± 2.21 ºC), dissolved oxygen (6.44 ± 1.03 mg L-1), pH (7.40 ± 0.28), and total ammonia (0.05), so to decrease the effects of influent data, the robust regression method was used and the profit maximization analysis revealed that replacing 33.29% of dietary fishmeal by poultry byproduct meal maximizes profit in the farming of dourado

Effects of Miscanthus grass as a fiber source in pet diets on extrusion processing and diet utilization by dogs and cats

Doctor of PhilosophyDepartment of Grain Science and IndustryGreg AldrichGastrointestinal health, digesta passage, regularity and consistency of elimination, and energy dilution of the diet can be affected by dietary fiber. Cellulose and beet pulp have been common fibers used in pet foods. Pet owners and pet food companies are in search of alternatives. Miscanthus grass is an ingredient produced from the dried canes of Miscanthus giganteus, a C4 grass grown for its high fiber content; however, it has not previously been evaluated in pet foods. Thus, the objectives were to determine the effect of Miscanthus grass on processing, nutrient utilization, hairball management, and fermentation end products. Pet foods were produced in a pilot scale extruder (E525, Extru-Tech, Sabetha, KS), dried to less than 10% moisture, then coated with chicken fat and flavor enhancer. Extrusion parameters (preconditioner and barrel water and steam addition, preconditioner discharge temperature, screw speed, die pressure, diet temperature, knife speed, specific mechanical energy, total mass flow, and wet bulk density) and kibble characteristics (kibble length, diameter, volume, density, sectional expansion ratio index, hardness, and compression energy) were evaluated for dog and cat foods produced with 10% Miscanthus grass, cellulose, or beet pulp. Miscanthus grass and cellulose dog diets required less specific mechanical energy. Additionally, these two canine diets were less dense than the beet pulp containing diet. Pet foods were fed to dogs and cats to evaluate nutrient digestibility and stool quality. Generally, dry matter, organic matter, and gross energy digestibility were lower for animals fed Miscanthus grass and cellulose diets than beet pulp diet. However, crude protein digestibility was higher for animals fed Miscanthus grass and cellulose diets compared to beet pulp diet. In both dog and cat studies, feces were softer when animals were fed the beet pulp diet. For cats, hairball management was evaluated by feeding a diet with 10% Miscanthus grass versus a non-fiber containing control diet. Most parameters evaluated (fecal hairball count, hair masses per day, average hairball size, total hair weight) were not affected by inclusion of Miscanthus grass, but there was a trend for more hair collected on the strainer (P = 0.0884), less total hair per gram of dry feces, and less hair masses per gram of dry feces (P < 0.05). Finally, to evaluate the effects of colonic fermentation an in vitro model used canine feces as the inoculum. Five fiber sources (Miscanthus grass, cellulose, beet pulp, pea fiber, and sorghum bran) were incubated (0, 4, 8, 12h) to determine organic matter disappearance and short chain fatty acid production. Beet pulp had a higher concentration of acetate, propionate, butyrate, and total volatile fatty acids compared to all other fiber sources. Sorghum bran produced the highest amount of isobutyrate and isovalerate compared to other test fibers. Miscanthus and cellulose were very poorly fermented and generally did not differ from each other. Therefore, Miscanthus grass is an alternative fiber source that compares favorably to cellulose in dogs and cat foods without affecting processing parameters, nutrient utilization, and fermentation end products

The Time Course of Inflammatory Biomarkers Following a One-Hour Exercise Bout in Canines: A Pilot Study

There is little information available to describe the inflammatory consequences of and recovery from moderate-intensity exercise bouts in hunting dogs. The purpose of the current study is to generate pilot data on the appearance and disappearance of biomarkers of inflammation and inflammation resolution following a typical one-hour exercise bout in basset hounds. Four hounds were set out to find a scent and freely adopted running or walking over wooded terrain for approximately one hour. Venous blood samples were obtained before the exercise and at 1, 2, 4, 6, and 10 h following cessation of exercise and were analyzed for biomarkers of inflammation (prostaglandin E2 (PGE2), nitric oxide (NO), interleukin 1&beta; (IL-1&beta;)) tumour necrosis factor-&alpha; (TNF-&alpha;)), and inflammation resolution (resolvin D1 (RvD1)). There was an increase in inflammation one hour after the exercise, shown by a significant increase in PGE2. Following this peak, PGE2 steadily declined at the same time as RvD1 increased, with RvD1 peaking at six hours. This pilot study provides evidence that dogs that undergo an hour of hunt exercise experience transient inflammation that peaks one hour after the end of exercise; inflammation resolution peaks six hours after the end of exercise. Future studies should seek to further understand the distinct and combined roles of PGE2 and RvD1 in dog adaptation to exercise stress

Poultry by-product meal as dietary protein source for dourado, Salminus brasiliensis: an economic appraisal

ABSTRACT: The dourado, Salminus brasiliensis, a large, carnivorous, Neotropical, Characin, is highly regarded for fish farming and sport fishing alike. However, studies on the farming and husbandry of dourado are still scarce. This study evaluated the performance of dourado fed diets formulated so as to contain increasing levels of poultry by-product meal as a replacement for fish meal and aimed to identify the maximum level of replacement to maximize profit. The trial was set up in a closed recirculation system with controlled water quality (temperature 27 °C, dissolved oxygen 6.5 mg L−1, pH 7.4, and ammonia 0.25 mg L−1). Juvenile fish were stocked in tanks in a completely randomized design, acclimatized to system conditions and experimental diets, and then fed twice a day for 66 days with extruded, nutritionally complete diets (40 % digestible protein and 4020 kcal kg−1 digestible energy), formulated to contain 0, 20, 40, 60, 80 or 100 % poultry meal as a surrogate protein source for fish meal. Performance parameters – average weight gain, specific growth rate, feed consumption, feed conversion rate, protein efficiency rate, productive value of protein, energy retention rate, survival rate – did not differ (p > 0.05). To minimize the effects of influential data, the robust regression method was used and profit maximization analysis revealed that replacing 33.3 % of dietary fishmeal by poultry by-product meal maximizes profit in the farming of dourado