The Effects of Fermentable Dietary Fiber on Performance and Metabolism of Nile Tilapia (Oreochromis niloticus)

Abstract This study was conducted to evaluate the inclusion of new prebiotics in the diet on performance and metabolism (liver protein, glucose and glycogen) of Nile tilapia. For 60 days, 720 Nile tilapia (3.4 ± 0.60 g) were maintained in 24 polypropylene tanks (280 liters). Fish were fed with experimental diets with addition of 2.5 and 5 g kg-1 of dietary fiber of citrus pulp (DFCP), dietary fiber of linseed (DFL) and Actigen®. The experimental design was completely randomized with a 3x2 factorial arrangement. At the end of the period, there was higher final weight of tilapias fed on diets containing DFCP and DFL, and regardless of prebiotic, the best results in the final weight and length were observed for inclusion of 2.5 g kg-1. There was higher body protein deposition in tilapia fed on diets containing DFCP, without differences from those with inclusion of DFL. Total fat deposition was higher for the lowest level of inclusion (2.5 g kg-1). The digestive somatic index was higher for the diet with inclusion of DFCP, which did not differ from the diet with inclusion of Actigen®. There were higher concentrations of liver glycogen in the diets containing DFCP and Actigen®. Faced with the search for alternative growth promoters, this study confirms the possibility of using the new prebiotics (DFCP and DFL) in nutrition of Nile tilapia, because they showed efficiency equivalent to the prebiotic Actigen®.

Fontes protéicas vegetais na alimentação da carpa húngara / Plant protein sources on common carp feeding

A substituição parcial da farinha de carne suína por farelos vegetais em dietas para juvenis de carpa húngara (Cyprinus carpio) foi avaliada em cinco dietas experimentais: um controle (farinha de carne suína (FCS) como fonte protéica) e quatro dietas vegetais: farelo de soja (FS), farelo de canola (FC), farelo de girassol (FG) ou farelo de linhaça (FL), substituindo 50 por cento da proteína proveniente da FCS. 195 juvenis (43,4±0,4g) foram alimentados duas vezes ao dia (9 e 15 horas) durante 71 dias. Ao final do experimento, maior peso (205,69g), ganho em peso (2,29g dia-1), taxa de crescimento específico (2,2 por cento dia-1) e conversão alimentar (1,74) foram obtidos nas dietas com FCS, seguido dos tratamentos FC e FS que não diferiram entre si. Os peixes alimentados com FCS, FG e FS apresentaram maior gordura corporal. A dieta FL apresentou piores resultados de desempenho, coeficiente de retenção protéica, deposição de proteína e gordura corporal e no filé. Pode-se concluir que a dieta à base de farinha de carne suína proporciona maior crescimento e deposição de proteína em juvenis de carpa húngara, comparada às dietas com farelos vegetais; os parâmetros de carcaça (rendimentos e índices digestivos) não são afetados pelas fontes protéicas da dieta.

This study was conducted to evaluate the partial replacement of porcine meat meal by plant-protein meals in diets for common carp (Cyprinus carpio). Five experimental diets were evaluated: control (FCS), only porcine meat meal as protein source, and four plant-based diets: soybean meal (FS), canola meal (FC), sunflower meal (FG) or linseed meal (FL) replacing 50 percent of protein from porcine meat meal. Juveniles (195, 43.4±0.4g) were fed twice daily (9:00 am and 03:00pm) for 71 days. At the end of the trial, the best weight (205,69g), weight gain (2,29g day-1), specific growth rate (2,2 percent day-1) and food conversion ratio (1,74) were obtained in FCS, followed by FC and FS, that did not differ among each other. Fish fed FCS, FG and FS showed higher body fat. The FL diet had the worst performance, protein retention coefficient, protein and fat deposition in whole body and fillet. It was concluded that a diet based on porcine meat meal provides higher growth and protein deposition in common carp juveniles, compared to diets with plant-protein meals; carcass parameters (carcass and fillet yield and digestive indices) are not affected by the dietary protein sources.

Valor nutricional de forragem de pastagens manejadas durante o período hibernal / Nutritive value of forage of pastures managed during cool-season

O objetivo nesta pesquisa foi avaliar o valor nutritivo, determinando-se a matéria orgânica (MO), digestibilidade in vitro da MO (DIVMO), nutrientes digestíveis totais (NDT), digestibilidade in vitro da matéria seca (DIVMS), proteína bruta (PB) e fibra em detergente neutro (FDN), de quatro sistemas forrageiros (tratamentos), pastejados por vacas da raça Holandesa. Os tratamentos foram constituídos por "coastcross" (Cynodon dactylon L. Pers.) sobresemeada com azevém (Lolium multiflorium Lam. cv. 'Comum'); coastcross sobresemeada com azevém e trevo branco (Trifolium repens L., cv. 'Yi'); azevém mais trevo branco e apenas azevém. Entre 15 de maio e 24 de outubro de 2006, foram conduzidos cinco ciclos de pastejo, sendo avaliada a massa de forragem de pré-pastejo (MF), as composições botânica e estrutural e lotação (L). Para análise do valor nutritivo, foram coletadas amostras de pastejo simulado. O delineamento experimental foi inteiramente casualizado com quatro tratamentos e duas repetições (piquetes). Não foram detectadas diferenças entre os tratamentos para as médias de MF e L. Observou-se que os melhores resultados de valor nutritivo estão associados à biomassa de lâmina foliar de azevém em todas as pastagens. Verificaram-se pequenas diferenças no valor nutritivo entre as pastagens sobresemeadas em comparação ao azevém e trevo branco ou azevém. Os valores médios de MO, DIVMO, NDT, DIVMS, PB e FDN das pastagens foram de 89,52; 69,50; 60,95; 70,96; 23,03 e 51,87 por cento, respectivamente.

This research aimed at evaluating the nutritive value by determining the organic matter (OM), in vitro OM digestibility (IVOMD), total digestibility nutrient (TDN), in vitro dry matter digestibility (IVDMD), crude protein (CP) and neutral detergent fiber (NDF) of four pasture-based system grazed by Holstein cows. The treatments were sod seeding of ryegrass (Lolium multiflorium Lam. cv. 'Common') over coastcross (Cynodon dactylon L. Pers.,); sod seeding of ryegrass plus white clover (Trifolium repens L., cv. 'Yi') over coastcross ryegrass plus white clover or ryegrass. From May 15th to October 24th, 2006, in five grazing periods, the pregraze herbage mass (PM), botanical and structural compositions and stocking rate (SR) were evaluated. Hand-plucked samples were collected to analyze the nutritive value. The experimental design was completely randomized, with four treatments (pastures) and two replications (paddocks). Differences in PM and SR averages were not detected among treatments. Better results of nutritive value were associated of ryegrass leaf lamina biomass in all pastures. Small differences on nutritive value were observed on sod seeding 'coastcross' systems compared to ryegrass plus white clover or ryegrass pastures. The mean values of OM, IVOMD, TDN, IVDMD, CP and NDF of the pastures were 89.52; 69.50; 60.95; 70.96; 23.03 and 51.87 percent, respectively.