João Radünz Neto

Farelo de soja na alimentação de alevinos de jundiá (Rhamdia quelen)

The present study was conducted to evaluate different protein sources in practical diets for South American catfish fingerlings (Rhamdia quelen). Two experiments, lasting 42 days each one, were carried out by using 320 fishes with initial average weight of 1.18 ± 0.28grams and 4.00 ± 0.18 grams, respectively, distributed into 16 experimental units in a water recirculating system, where each experiment was tested with four treatments and four replications. In the first experiment, four isoproteic (34% crude protein) and isocaloric (3,500 Kca/kg digestible energy) diets were tested. Diet A1 contained sugar cane yeast, soybean meal, and meat and bone meal, while in the other diets (A2, A3 e A4) one of those sources was suppressed. Diet A2 (sugar cane yeast and soybean meal) promoted the highest weight gain (P<0.01). The protein sources from diet A2 were used in a second experiment, where the effect of replacing sugar cane yeast with soybean meal at growing levels (75%, 87.5% e 100%) was tested on a diet (B1) containing the same levels of inclusion of both sources (36.4 %). Diet B1 provided better growth and daily weight gain in this second feeding trial (P<0.01).

DESENVOLVIMENTO E COMPOSIÇÃO CORPORAL DE ALEVINOS DE JUNDIÁ (Rhamdia quelen) ALIMENTADOS COM DIETAS CONTENDO DIFERENTES FONTES DE LIPÍDIOS

Three sources of lipids, canola oil (T1), cod liver oil (T2), and swine fat (T3), were tested in experimental rations for juveniles of jundia (Rhamdia quelen), representing 5% of their diet. A completely randomized design with three treatments (T) and three repetitions was used. The performance and the carcass yield were not affected by the three lipids. The lipids sources influenced the protein (high value on T1) and fat (high value on T3) deposition in the carcass.

Avaliação de diferentes fontes protéicas sobre o desempenho inicial de larvas do jundiá Rhamdia quelen

The experiment was carried out to evaluate the survival and growth of catfish larvae Rhamdia quelen with different sources of protein during the first three weeks of life. Five treatments, with three replications, were tested. A total of 3000 larvae were randomly distributed into 15 groups, maintained under controlled conditions using a termoregulatory water re-use system. The artificial diets tested contained 35% of crude protein and digestible energy varied from 3075 to 3286kcal/kg of dry matter. Granulometry of the ration was 100 to 200m, 200 to 400m and 400 to 600m during the first, second and third week, respectively. The diets were offered ad libitum from 8 am to 8 pm. The treatment 1, containig bovine liver and yeast (Saccharomyces cerevisae), resulted in the highest (P < 0.05) survival rate (61%). The remaining treatments: 2 (soybean, yeast), 3 (soybean, bovine liver), 4 (soybean, corn) and 5 (soybean, meat, corn) did not differ significantly among each other, resulting in low survival rates (1.17 to 10.19%). Larvae of T1 were significantly longer (16.46mm) at 21 days of age than the others. It can be concluded that feeding ration containing bovine liver plus yeast results in could be a good performance of catfish larvae.

Efeito de níveis crescentes de levedura de álcool em rações contendo fígado bovino sobre a performance de larvas de jundiá (Rhamdia quelen)

The present study was developed with the purpose of evaluating the effects of different protein levels in initial performance of Rhamdia quelen larvae during the first three weeks of life. The sample contained 3000 larvae distributed in fifteen groups, maintained in controlled conditions of culture and utilizing termoregulatory water re-use system. Five crescent levels of yeast (T1 50%, T2 60%, T3 70%, T4 80% and T5 90%) were used in rations in substituition of bovine liver. Levels of crude protein and digestible energy varied 41,36% to 26,56% CP and from 3197 to 2789 kcal ED/kg. The granulometry of tested food was of 100 a 200m, 200 a 400m and 400 a 600m for three experimental weeks respectively. Food distribution provided at ease between 8 Am and 8 Pm. Within the net protein used in this research, there was found a positive effect for the highest protein levels for total, standard lenght and individual weight while, it was observed a negative effect over the larval survival of jundia Rhamdia quelen.

Alimentação do jundiá com dietas contendo óleos de arroz, canola ou soja

O objetivo deste trabalho foi avaliar a influencia de oleos vegetais no desenvolvimento corporal e composicao do file de jundias. Foram testadas seis dietas (32%PB), sendo avaliados oleos de arroz, canola ou soja com 5 ou 10% de inclusao, durante 90 dias. Os peixes (180, peso inicial=71,0±0,8g) foram distribuidos ao acaso em 18 caixas (280L) de um sistema de recirculacao de agua, com temperatura controlada. Para avaliacao de desempenho, estimaram-se variaveis como peso, comprimentos totais, padrao, altura caudal, sobrevivencia, taxa de crescimento especifico, fator de condicao, consumo diario, conversao alimentar aparente e rendimento de partes comestiveis. Alem disso, foram avaliadas a composicao centesimal e taxas de deposicao de proteina e gordura nos files. Nao houve diferencas entre os oleos e os niveis sobre o crescimento dos peixes; entretanto, os jundias alimentados com 10% de oleo depositaram mais gordura no file. Conclui-se que os oleos de canola, arroz e soja proporcionam bom crescimento e rendimento de partes comestiveis. As dietas contendo oleo de canola, com 5% de inclusao, possibilitam menor deposicao de gordura no file.

Protein sources and digestive enzyme activities in jundiá (Rhamdia quelen)

Digestive enzymes activity influence feed utilization by fish, and its understanding is important to optimize diet formulation. This study reports the digestive enzyme activities of jundia juveniles fed diets with protein sources. Fish were fed six experimental diets for 90 days: MBY (meat and bone meal + sugar cane yeast), SY (soybean meal + sugar cane yeast), S (soybean meal), MBS (meat and bone meal + soybean meal), FY (fish meal + sugar cane yeast) and FS (fish meal + soybean meal), and then sampled every 30 days and assayed in two intestine sections for digestive enzymes - trypsin, chymotrypsin and amylase - activities; gastric protease was assayed in the stomach. Digestive and hepatosomatic index, intestinal quotient, digestive tract length and weight gain were also measured. Trypsin and chymotrypsin activities were higher (p < 0.0001) in fish fed diets containing animal protein sources (MBY, MBS, FY and FS diets). Alkaline proteases were negatively affected by dietary soybean meal in the SY and S diets. Amylase activity had greater variation between diets and intestine sections. Fish fed MBY and MBS diets showed higher gastric protease activity (p < 0.0001). Weight gains were higher in fish fed the MBS and FS diets (p < 0.05). Highest values (p < 0.05) of digestive tract length were observed in fish fed MBS and FY diets, but no correlation with enzymes activities was found. Hepatosomatic index (HSI) was affected by diet composition. Dietary composition influenced digestive enzymes activities of jundia.

Cultivo de jundiás alimentados com dietas com casca de soja ou de algodão

The objective of this work was to evaluate the effect of crude fiber on growth, digestive parameters, and yield and carcass quality of jundia (Rhamdia quelen) juveniles in net cages. The experimental design was completely randomized in a 2x3 factorial scheme (two sources - soy and cotton hull - and three levels of crude fiber: 4, 7 and 10%), with three replicates. Four hundred and fifty fishes (129.11± 7.8 g) were randomly distributed in 18 net cages (1 m3), at densities of 25 fish per cage, in 0.1 ha earth fishpond. The following parameters were evaluated: weight, total length, weight gain, biomass, survival, carcass and fillet yield, chemical composition of fillet, digestive and hepato-somatic indexes, intestinal quotient. No difference was detected in the growth performance. Fish fed with soy hull diets presented more fat and mineral accumulation on fillets. The sources and fiber levels tested do not affect jundias performance.

Comparative study on effects of dietary with diphenyl diselenide on oxidative stress in carp (Cyprinus carpio) and silver catfish (Rhamdia sp.) exposed to herbicide clomazone

The study investigated the capacity of diphenyl diselenide [(PhSe)2] (3.0mg/kg), on reduce the oxidative damage in liver, gills and muscle of carp and silver catfish exposed to clomazone (192h). Silver catfish exposed to clomazone showed increased thiobarbituric acid-reactive substance (TBARS) in liver and muscle and protein carbonyl in liver and gills. Furthermore, clomazone in silver catfish decrease non-protein thiols (NPSH) in liver and gills and glutathione peroxidase and ascorbic acid in liver. (PhSe)2 reversed the effects caused by clomazone in silver catfish, preventing increases in TBARS and protein carbonyl. Moreover, NPSH and ascorbic acid were increased by values near control. The results suggest that (PhSe)2 attenuated the oxidative damage induced by clomazone in silver catfish. The clomazone no caused an apparent situation of oxidative stress in carp, showing that this species is more resistant to this toxicant. Altogether, the containing (PhSe)2 diet helps fish to increase antioxidants defenses.

Substituição parcial ou total de óleo de canola por lecitina de soja em rações para larvas de jundiá (Rhamdia quelen), pisces, Pimelodidae

This report was carried out at the Animal Sciences Department - Fish Culture Sector of the Federal University of Santa Maria, RS, Brazil, in a system for larvae raising with thermoregulation and recirculation of water, in order to assess the replacement of canola oil for soy lecithin in the feeding of south american catfish (Rhamdia quelen) larvae during their 21 days of life. In the experiment, seven treatments with three replications were tested by using different proportions of canola oil (0-5%) and soybean lecithin (0-4%), added to a diet prepared with beef liver and sugar canne yeast. The best results were obtained in treatment containing 2% of soy lecithin, in which catfish larvae presented 80.25% survival rate, 184.89mg average individual weight and 28.03mm total length, what significantly differs from the other treatments. According to the results obtained in the experiment, it is concluded that soy lecithin (2%) is more efficient as a lecithin - canola oil combination in south american catfish larvae nutrition.

DIFERENTES FONTES DE LIPÍDIOS TESTADAS NA CRIAÇÃO DE LARVAS DE JUNDIÁ (Rhamdia quelen), PISCES, PIMELODIDAE

The present study was developed in order to evaluate the influence of different sources of fat on the Rhamdia quelen larvae performance. It was carried out at the Animal Husbandry Department - Fish culture Section of the Federal University of Santa Maria, using a system of larvae culture with thermoregulation and recirculation of water. There were seven (7) treatments, with three replicates each one and the different sources of fat tested during 21 days were: canola oil, soybean oil, cod liver oil, sunflower oil or corn oil incorporated in the rate of 5% of a basal diet (liver and yeast). The treatment with canola oil resulted in a 94% survival rate, and larvae with 19.97mm of total length and 54,3mg of individual body weight. According to the results obtained in the experiment, it was concluded that canola and cod liver oil are more efficient as fat supplement in Rhamdia quelen larvae nutrition.