Use of phytase and citric acid supplementation on growth performance and nutrient digestibility of Cirrhinus mrigala fingerlings fed on canola meal based diet / Uso de suplementação de fitase e ácido cítrico no desempenho do crescimento e digestibilidade de nutrientes de dedos Cirrhinus mrigala alimentados em dieta à base de refeição de canola

Fishmeal; being a limited and costly feed ingredient is continuously been substituted with locally available plant proteins. However, the occurrence of anti-nutritional factors in plant meal suppresses its potential to be fully replaced. Therefore, in this study we aimed to study the synergistic effects of dietary additives like citric acid and phytase enzyme supplementation on growth performance and nutrient digestibility of Cirrhinus mrigala fingerlings. Canola meal (CM) was used as a test ingredient to replace fishmeal (FM) as; 0%, 25%, 50% and 75%. These four diets were further supplemented by varying levels of phytase (0 and 750 FTU kg-1) and citric acid (0% and 2.5%) to formulate total sixteen test diets as T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15 and T16. Each treatment contained three replicates; applied to fish groups having 15 fingerlings each; following 3×3 factorial arrangement. 1% of chromic oxide was added as an inert marker. Maximum weight gain% (288%) and the lowest value of FCR (1.07) were recorded when fish was fed on diet T12 as compared to fish fed control diet (T1). Similarly, optimum nutrient digestibility values such as crude protein (77%), crude fat (84%) and gross energy (70%) were noted on same level. It was concluded that 50% canola meal can optimally replace fishmeal when supplemented with phytase and citric acid at the levels of 750 FTU kg-¹ and 2.5%, respectively.

A farinha de peixe, por ser um ingrediente alimentar limitado e caro, é continuamente substituída por proteínas vegetais disponíveis localmente. No entanto, a ocorrência de fatores antinutricionais na farinha de plantas suprime seu potencial de ser totalmente substituída. Portanto, neste estudo objetivamos estudar os efeitos sinérgicos de aditivos dietéticos como ácido cítrico e suplementação com enzima fitase sobre o desempenho de crescimento e digestibilidade de nutrientes de alevinos de Cirrhinus mrigala. A farinha de canola (CM) foi usada como ingrediente de teste para substituir a farinha de peixe (FM) como: 0%, 25%, 50% e 75%. Essas quatro dietas foram suplementadas por níveis variados de fitase (0 e 750 FTU kg-1) e ácido cítrico (0% e 2,5%) para formular um total de 16 dietas de teste como T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15 e T16. Cada tratamento continha três repetições; aplicado a grupos de peixes com 15 alevinos cada; seguindo o arranjo fatorial 3 × 3. 1% de óxido crômico foi adicionado como um marcador inerte. % de ganho de peso máximo (288%) e o valor mais baixo de FCR (1,07) foram registrados quando os peixes foram alimentados com dieta T12 em comparação com peixes alimentados com dieta controle (T1). Da mesma forma, valores ótimos de digestibilidade de nutrientes, como proteína bruta (77%), gordura bruta (84%) e energia bruta (70%) foram anotados no mesmo nível. Concluiu-se que 50% da farinha de canola pode substituir de forma ideal a farinha de peixe quando suplementada com fitase e ácido cítrico nos níveis de 750 FTU kg-¹ e 2,5%, respectivamente.

Evaluation of secretory activity in carp pancreatocytes (Cyprinus carpio L. ) when using lactobacillus-based chelate and probiotic supplemental feed complexes / Avaliação da atividade secretora em pancreatócitos de carpa (Cyprinus carpio L. ) ao usar quelato à base de lactobacilos e complexos suplementares de alimentação probiótica

The experimental research was carried out on the juvenile carp (Cyprinus carpio L.). The impact from supplemental feeds consisting of variable concentrations of chelate compounds, biogenic trace elements and probiotic lactobacillus-based product Bacillus subtilis VKPM B-2335 was evaluated. Optical and qualitative parameters of the lactobacillus base were studied in order to identify the major group of substances potentially able to influence the end result. The purpose of this research was to identify changes in the structure of the zymogen granules and their dimensions at which supplemental feeds produce a stimulating effect on the synthesis of zymogens in exogenous cells of the secretory part of pancreas. At the outcome of the study, for the first time, it was possible to prove that the integrated action of chelates and lactobacillus-based probiotics complemented each other. Metal chelate compounds contributed to enlargement of the zymogen granules, if compared to the control values. The bacterial products accelerated production of the zymogen granules in acinar cells diffusely located in carp hepatopancreas.

A pesquisa experimental foi realizada em carpas juvenis (Cyprinus carpio L.). O impacto de suplementos alimentares consistindo em concentrações variáveis de compostos quelatos, oligoelementos biogênicos e produto probiótico baseado em lactobacilos Bacillus subtilis VKPM B-2335 foi avaliado. Parâmetros ópticos e qualitativos da base de lactobacilos foram estudados a fim de identificar o maior grupo de substâncias potencialmente capazes de influenciar o resultado final. O objetivo dessa pesquisa foi identificar mudanças na estrutura dos grânulos de zimogênio e suas dimensões nas quais alimentos suplementares produzem um efeito estimulante na síntese de zimogênios em células exógenas da parte secretora do pâncreas. No resultado do estudo, pela primeira vez, foi possível comprovar que a ação integrada dos quelatos e dos probióticos à base de lactobacilos se complementava. Compostos quelatos metálicos contribuíram para o aumento dos grânulos de zimogênio, se comparados aos valores de controle. Os produtos bacterianos aceleraram a produção dos grânulos de zimogênio nas células acinares localizadas difusamente no hepatopâncreas da carpa.

Presence of bound substrate in lactate dehydrogenase from carp liver.

While attempting to purify UDP-galactose 4-epimerase from carp liver extract at pH 8.0, it was observed that the preparation even after dialysis could reduce NAD to NADH, interfering epimerase assay. The NAD reduction activity and the epimerase were co-eluted in a series of chromatographic steps. Mass spectrometric analysis of semi-purified fraction revealed that carp liver lactate dehydrogenase (LDH) contained bound lactate which was converted to pyruvate in the presence of NAD. The enzyme-bound lactate and the association with epimerase stabilized LDH from trypsin digestion and thermal inactivation at 45°C by factors of 2.7 and 4.2 respectively, as compared to substrate-free LDH. LDH and epimerase do not belong to any one pathway, but are the rate-limiting enzymes of two different pathways of carbohydrate metabolism. Typically, strongly associated enzymes work in combination, such as two enzymes of the same metabolic pathway. In that background, co-purification of LDH and epimerase as reloaded in this study was an unusual phenomenon.

Teores de proteína bruta em dietas práticas para juvenis de carpa capim / Crude protein levels in practical diets for grass carp juveniles

Avaliou-se a resposta de juvenis de carpa capim (Ctenopharyngodon idella) à inclusão de proteína bruta (PB) em dietas práticas, em um experimento com 120 juvenis e 80 dias de duração. As dietas eram compostas por farinha de carne suína, farelo de soja, milho e farelo de trigo com 22, 30, 36 ou 44 por cento de PB. Dez juvenis (153,0±1,5g) por tanque (850L) foram alimentados duas vezes ao dia (3 por cento da biomassa). Foi observado efeito linear positivo da PB para peso final, ganho em peso, taxa de crescimento específico, rendimento de carcaça e filé, coeficiente de retenção proteica, taxa de eficiência proteica, deposição de gordura e proteína e hematócrito. O mesmo efeito também foi observado para triglicerídeos e colesterol total no sangue, indicando que a proteína da dieta foi utilizada como fonte energética. Conversão alimentar aparente e gordura no peixe inteiro apresentaram efeito quadrático, com pontos de máxima em 40,6 e 37,1 por cento de PB, respectivamente. Pode-se concluir que a porcentagem mínima de PB para a carpa capim na fase de recria foi de 44 por cento e que a variação da proteína da dieta promoveu alterações no metabolismo dos juvenis de carpa capim, refletidos nos parâmetros sanguíneos e de carcaça.

The response of grass carp (Ctenopharyngodon idella) juveniles to crude protein (CP) levels in practical diets was evaluated in an experiment with 120 juveniles and 80 days of feeding. The diets containing porcine meat meal, soybean meal, corn and wheat meal, with 22, 30, 36, or 44 percent CP. Ten juveniles (153.0±1.5 g) per tank (850L) were fed twice daily with pelleted feed (3 percent of biomass). Linear effect of CP on final weight, weight gain, specific growth rate, carcass and fillet yield, coefficient of protein retention, protein efficiency rate, deposition of fat and protein, and hematocrit were observed. It was also observed effect on triglycerides and total cholesterol in blood, indicating that dietary protein was being used as energy source. Feed conversion ratio and fat content in whole fish showed quadratic effect, with maximum points at 40.6 and 37.1 percent CP, respectively. The best CP content for grass carp in growing phase was 44 percent, and the variation of protein content in diet changed the metabolism of grass carp juveniles, reflected in blood and carcass parameters.

Effects of ammonia, nitrite and nitrate on hemoglobin content and oxygen consumption of freshwater fish, Cyprinus carpio (Linnaeus).

Lethal effects of nitrogenous compounds ammonia, nitrite and nitrate on freshwater fish Cyprinus carpio were studied and the static LC50 values obtained for these 3 toxicants for 24 hr were 0.80 ppb, 171.36 ppm; 1075.10 ppm and continuous flowthrough LC50 values for 24 hr were 0.72 ppb, 154.31 ppm; 967.63 ppm respectively. The fish were exposed to lethal concentrations to study the changes in hematological parameters and the rate of oxygen consumption. During the period of exposure general decline in the content of hemoglobin was observed. Methemoglobin content increased in case of nitrite exposure consequently the hemoglobin levels decreased drastically. It is also observed that rate of oxygen consumption decreased progressively with the increase of toxicant concentration and duration of the exposure.

Behavioural and hematological responses of Cyprinus carpio exposed to mercurial chloride.

The static bioassay experiments were conducted to study the hematological and behavioural responses of Cyprinus carpio after exposure to mercuric chloride. Three different concentrations i.e. 0.5, 1.0 and 1.5 ppm of mercuric chloride (HgCl2) were used for 8, 16, 24, 48, 72, 96 and 124 hrs for evaluating behavioural responses. Hematological responses were assessed after 60 days exposure to 0.1 ppm of HgCl2. The changes in body colour, movement, sluggishness or activeness, disbalance etc. constituted the observations on behavioural responses. Hematological parameters included total erythrocyte (TEC) and leukocyte (TLC) counts and hemoglobin (Hb) levels. Body colour had changed in all groups after 48 hours. The fish exposed to 0.5 ppm HgCl2 did not show any abnormal activity except colour change throughout the experiment. Though no sign of distress was observed initially in groups exposed to 1.0 and 1.5 ppm HgCl2 but abnormal posturing, disbalance and sluggishness became apparent after 72 hrs and all specimens of 1.5 ppm group had died within 124 hours. TEC and Hb levels decreased whereas TLC increased in both male and female specimens of C. carpio after exposure to 0.1 ppm HgCl2 for 60 days. These observations indicated that mercurial toxicity even at low levels, caused adverse effects on body colour, behavioural responses and hematological parameters like TEC, TLC and hemoglobin levels in C. carpio.

Immunohistochemical Study of the Endocrine Cells in the Pancreas of the Carp,Cyprinus carpio (Cyprinidae)

The regional distribution and relative frequency of some endocrine cells in the pancreas of the carp, Cyprinus carpio Linnaeus, belonging to the family Cyprinidae in the order Cypriniformes, were observed using specific mammalian antisera against insulin, glucagon, somatostatin and human pancreatic polypeptide (hPP) by peroxidase antiperoxidase (PAP) method. The pancreas was divided into four regions (principal and secondary islets, exocrine and pancreatic duct regions). In addition, the pancreatic islet regions were further subdivided into three regions (central, mantle and peripheral regions) and the pancreatic duct regions were subdivided into two regions (epithelial and subepithelial regions). Spherical to spindle or occasionally round to oval shaped immunoreactive (IR) cells were demonstrated in the pancreatic islets, exocrine and pancreatic duct. In the principal islet regions, some cells were also detected in the other regions, most of insulin- and somatostatin-IR cells were located in the central regions, and glucagon- and hPP-IR cells were situated in the peripheral regions. In this regions, insulin-IR cells were most predominant cell types and then, glucagon, somatostatin and hPP in that order. In the secondary islet regions, the regional distribution and relative frequency of these four types of endocrine cells were quite similar to those of the principal islets except for cell clusters consisted of hPP-IR cells that were situated in the peripheral to mantle regions. In the pancreatic duct regions, all four major pancreatic endocrine cells were demonstrated in the inter-epithelial cells and/or basal regions of the epithelial linning. In addition, cell clusters composed of numerous insulin-, moderate glucagon- and somatostatin-IR cells of low frequency were also observed in the subepithelial regions of the pancreatic duct. In the exocrine regions, insulin-, glucagon-, somatostatin- and hPP-IR cells were located in the inter-acinus regions with rare, a few, moderate and moderate frequencies, respectively. In conclusion, the regional distribution and relative frequency of four major pancreatic endocrine cells, insulin-, glucagon-, somatostatin- and hPP-IR cells, in the pancreas of the carp showed general patterns which were observed in other stomachless teleost. However, some species- dependent different distributional patterns and/or relative frequencies were also demonstrated.