Rodrigo Fortes-Silva

Federal University of Viçosa | UFV · Department of Animal Science

This study aimed to evaluate the effect of two protein sources (black soldier fly [Hermetia illucens] meal [BSFM] vs. fish meal [FM]) on intake target “diet preference” in juvenile Nile tilapia (Oreochromis niloticus) by a self-feeding method (trial 1). Growth, body composition, blood parameters, and immunity genes expression were also evaluated to...

The aim of this study was to evaluate the feeding activity and the rhythm of daily locomotor activity of the convict cichlid (Amatitlania sp.) kept in different social groups under a self‐feeding system. A total of 120 animals was distributed among six repetitions of four social groups, as follows: group 1 with one male and one female per tank; gro...

A 127-day experiment was conducted to evaluate the effect of feeding strategies on juvenile tambaqui's (Colossoma macropomum) growth, body composition, haematological and biochemical parameters, excretion pattern and economic indices. Fifteen tanks randomly stocked 150 juvenile tambaqui (82.0 ± 0.8 g, mean ± SEM) subjected to three feeding strategi...

This study aimed to elucidate the effects of selenium-loaded chitosan nanoparticles used as a dietary supplement on Nile tilapia (Oreochromis niloticus) antioxidant and growth responses. First, chitosan-based nanoparticles containing selenium (Se) were synthesized using the ionotropic gelation method and their physicochemical characteristics, contr...

The world tilapia production faces seasonal variations. However, very few nutritional studies have addressed suboptimal temperature. We evaluated the effect of two temperatures (20 or 30 °C) and two vegetable oil blends (one rich in corn oil (COR) and one rich linseed oil (LIN)) on tilapia growth, body composition, and blood parameters using a 2×2...

Diet supplementation with essential oil from sweet basil Ocimum basilicum (EOOB) can increase fi sh growth. So, this study aimed to evaluate the effect of EOOB in the diet on growth performance and plasmatic variables of pirarucu juveniles (Arapaima gigas) submitted to stressful condition (stocking density of 7.56 kg m-3 per tank and limited space)...

This study was undertaken to evaluate the effect of dietary lipid source [linseed oil (LO, rich in 18:3 n−3); corn oil (CO, rich in 18:2 n−6); olive oil (OO, rich in 18:1n−9); and fish oil (FO, rich in LC‐PUFA)] and level (9% L and 18% L) on growth, body composition and selected plasma biochemistry parameters in hybrid catfish (Pseudoplatystoma ret...

This study aimed to investigate the stress response of Sparus aurata specimens fed with nutraceutical aquafeed brewer’s yeast (Saccharomyces cerevisiae) and spirulina (Arthrospira platensis). For that purpose, 96 (169.0 ± 2.8 g) animals were distributed randomly in 12 tanks (8 fish per tank, 4 replicates) and divided in 3 groups (D1, casein/gelatin...

Goblet cells (GCs) and endocrine cells (ECs) play an important role in intestine physiology , and few studies currently exist for Amazonian fishes. This study aimed to quantify the distribution of GCs and ECs producing cholecystokinin-8 and neuropeptide Y, assessed by mucin histochemistry and peptides immunohistochemistry, in the intestine of two A...

The purpose of this study was to assess the effect of different carbohydrate and lipid (CHO/L) ratios on the performance and energy metabolism of hybrid catfish (♂Pseudoplatystoma corruscans × ♀ Pseudoplatystoma fasciatum). One hundred and sixty-eight fish (104.9±16.5 g BW) were distributed into 24 100-L tanks. The experiment was performed using a...

Winter conditions, extended periods of low temperature and limited food availability, impose pressures to develop strategies to cope with such unfavorable environmental conditions. Overwintering strategies may embrace both behavioral and physiological adaptations and result in differential responses. To address the effects of low temperature and fe...

The effect of different energy to protein ratios on voluntary feed intake was investigated in the carnivorous catfish Lophiosilurus alexandri, in order to evaluate their feeding behaviour responses. Two trials were performed. The first trial involved 16 fish distributed among 16 tanks, which were allowed to select one of two experimental encapsulat...

Fish and terrestrial vertebrates usually exhibit daily feeding rhythms that can be associated with daily patterns of digestion dynamics. The classic approach used in feeding studies usually neglects these biological rhythms. Therefore, this study aims to investigate the existence of daily feeding rhythms for tambaqui (Colossoma macropomum), and of...

“Feeding fish continues to be an “art form“, with the farmer, not the fish, estimating “satiety or near-satiety“ and when and how often fish are fed ” (Cho, 1992). Há mais de 20 anos esta afirmação foi publicada em uma respeitada revista desta fascinante área de estudo e, de alguma forma, inúmeros trabalhos tentam responder até hoje a melhor forma...

The aim of this study was to investigate the daily rhythms of hematological, biochemical and enzymatic parameters of the blood of a nocturnal model of fish (Lophiosilurus alexandri) bred in the laboratory (F1). Thirty-six juveniles were stocked in six tanks of a recirculation aquaculture system for 20 days. The fish were exposed to a light:dark cyc...

This study aimed to investigate the existence of day-night differences in the time for anesthesia and recovery in tambaqui exposed to the anesthetic eugenol and the influence of feeding time. Thus, we evaluated: (1) swimming activity; (2) food anticipatory activity (FAA) as a synchronizer of swimming activity and change to susceptibility to anesthe...

We evaluated the daily changes in immunological and hematological factors in tilapia (Oreochromis niloticus) after an immunization period with a subsequent challenge. Experiments were divided into two phases: Phase 1 (immunization): 144 fish were distributed into two groups with 72 fish in six tanks. One group (T1) was immunized, comprising six vac...

Tilapia is one of the most bred species in Brazil because it is resistant to viral, bacterial and parasitic diseases when compared to other cultivated fish. Knowledge about the blood components and their function is important for normal and pathological balance. Different oil sources used to feed breeding males of Nile tilapia (Oreochromis niloticu...

Oyster farming in Brazil is limited by a number of problems, such as lack of sanitary control in production areas. The aim of the present study was to use the multiple correspondence analyses (MCA) to correlate the microbiological quality of oyster production in the state of Bahia, Brazil, by linking it to environment parameters. Samples were rando...

The use of feed additives as probiotics in aquaculture is increasing, but it is still poorly understood. Our aim was to evaluate the effect of two probiotics (Bacillus subtilis 10⁹UFC/g and Saccharomyces cerevisiae 10⁹UFC/g) on growth parameters, body composition, and hematological responses of tambaqui juveniles (Colossoma macropomum) by consideri...

Tropical fish feeding behaviour and food intake are regulated by a number of environmental factors (e.g.: stress in intensive aquaculture; type or seasonality of food), and also by complex homeostatic mechanisms that involve nutritional requirements. When access to food is not restricted, e.g. controlled laboratory conditions, fish growth and behav...

Pirarucu (Arapaima gigas) is a fast-growing, carnivorous species reared commercially in Amazonian countries as Brazil. Lack of a nutritionally balanced and affordable diet is a major constraint in pirarucu aquaculture, and our investigation sought to estimate the dietary protein requirement for this species. Four diets were formulated to contain in...

The aim of this study was to investigate the ability of tambaqui (Colossoma macropomum) to balance the energy (E) and protein (P) ratio by encapsulated diets (without sensory properties). Thirty fish (71.37 ± 2.58 g) were distributed in six 250-litre tanks. Protein (P), carbohydrate (C) and fat (F) were encapsulated separately to ensure the same se...

Objetivou-se com este trabalho avaliar o efeito de níveis de energia no desempenho produtivo e índice reprodutivo de machos e fêmeas de piauçu (Leporinus macrocephalus). Foram utilizadas 600 póslarvas, com peso e comprimento médios iniciais de 0,33 ± 0,11 g e 2,94 ± 0,39 cm respectivamente. Não foram observadas diferenças para os machos no peso fin...

This study aimed to investigate pirarucu’s (Arapaima gigas) ability to trigger a self-feeding system to regulate protein intake between two standard diets that contained 39% and 49% of crude protein. The same system allowed the evaluation of daily feeding and locomotor activity rhythms. Eighteen fish (654.44±26.85g) were distributed into six 250 L...

The aim of this work was to determine whether juvenile and adult European seabass (Dicentrarchus labrax L.), fed ad libitum manually and with self-feeding demand feeders, respectively, were able to discriminate between a fish oil-based diet and a series of diets made with vegetable oils (soybean, linseed, rapeseed and sunflower oil), as well as a f...

The light-dark cycle and feeding can be the most important factors acting as synchronizers of biological rhythms. In this research we aimed to evaluate synchronization to feeding schedule of daily rhythms of locomotor activity and digestive enzymes of tilapia. For that purpose, 120 tilapias (65.0 ± 0.6 g) were distributed in 12 tanks (10 fish per t...

We report feeding studies on hybrid fish (carnivorous × omnivorous) to determine the interactions between protein sources during diet selection trials. We also examined behavioural rhythms (feeding and locomotor activity) using a self-feeding system mounted with a feeder connected to an infrared photocell. Twenty fish (28.20 ± 0.05 g) were distribu...

Minimization of stress during the transportation of live fish is essential in maintaining the welfare and performance of the animals. In order to test the hypothesis that stress during transport of fingerlings of Nile tilapia (Oreochromis niloticus) can be reduced with the aid of the anesthetics menthol, eugenol or benzocaine, we have assessed the...

The role of light and feeding cycles in synchronizing self-feeding and locomotor activity rhythms was studied in white shrimps using a new self-feeding system activated by photocell trigger. In experiment 1, shrimps maintained under a 12:12 h light/dark (LD) photoperiod were allowed to self-feed using feeders connected to a photoelectric cell, whil...

The principles of modern aquaculture encourage the development of fish feeds containing low fish meal content and several types of plant ingredients plus nutrients to avoid depleting global fish stocks and to reduce costs. However, food constituents can affect animal nutrition and feeding behavior, so the effect of different diets on fish behavior...

Background: farming of hybrid catfish is relatively recent in Brazil; consequently, it is necessary to develop practical diet formulations for this fish. Objective: to evaluate the influence of different carbohydrate/lipid ratios (CHO:L) on growth performance, body composition and nutrient utilization of hybrid catfish (Pseudoplatystoma reticulatum...

Background: farming of hybrid catfish is relatively recent in Brazil; consequently, it is necessary to developpractical diet formulations for this fish. Objective: to evaluate the influence of different carbohydrate/lipid ratios(CHO:L) on growth performance, body composition and nutrient utilization of hybrid catfish (Pseudoplatystomareticulatum x...

This study aimed to assess the daily rhythms of locomotor activity and to quantify bacteria populations in the tambaqui digestive tract during light and dark periods. Photoelectric cells and a recording computational system were used to quantify the locomotor activity, and the existing Gram-positive and Gram-negative bacteria populations were evalu...

Rotation and translation of the Earth subject the living organisms to cyclic changes of environmental factors. This study evaluated the effects of photoperiod on growth and gonadal development in Nile tilapia (Oreochromis niloticus). In a completely randomized design experiment, juvenile males were distributed into nine tanks (10 fish per tank) and...

An experiment was conducted with the purpose of evaluating enzyme blends on the performance, carcass traits, and bone mineralization of broilers. In total, 928 one-day-old Cobb 500 male chicks of were used. A completely randomized design with four treatments with eight replicates of 29 birds each was adopted. The evaluated treatments were: 1- Posit...

Background: feed and light are the most important factors affecting the biological rhythms of fish. This work studies fish adaptation to those factors. Objective: to determine the influence of feeding time and dietary starch and lipid levels on growth, body composition, and liver histology of hybridized Brazilian catfish. Methods: two isoenergetic...

Animals do not eat whatever food item they encounter, but choose different foods that best match their requirements. Fish exhibit such “nutritional wisdom” and adapt their feeding behaviour and food intake according to their needs and the nutritional properties of diets. In this paper, we tested the ability of Nile tilapia to select between diets w...

Our objective was to evaluate the capacity of Nile tilapia (Oreochrmis niloticus) to self-select the most nutritious foods when offered with other foods. The fish were offered pairs of macronutrients (protein + carbohydrate, PC; protein + fat, PF; carbohydrate + fat, CF) in three self-feeders and subjected to different challenges: i) the relative p...

As most animals, fish possess an impressive array of behavioral mechanisms to deal with challenges posed by the composition of the food they consume. Such responses can be behavioral, through both food selection and regulation of the amounts eaten, which helps to alleviate the deleterious effects of such nutritional imbalances. The purpose of the t...

Most animals, including fish, are known to possess "nutritional wisdom" which allows them to choose among different incomplete diets to self-compose a nutritionally balanced diet. The purpose of this research was to investigate dietary selection and the capacity of fish to associate between colour code of encapsulated diets and capsule contents. In...

Objetivou-se avaliar a suplementação de vitamina C no desempenho produtivo de tilápias revertidas (Oreochromis niloticus). Foram utilizadas 400 pós-larvas revertidas num delineamento inteiramente ao acaso com cinco tratamentos (0, 50, 100, 150 e 200 mg/kg de vitamina C monofosfato de ácido ascórbico L) numa ração isoprotéica de 36% de PB e isocalór...

The objective of this study was to evaluate the supplementation of Vitamin C in the productive performance of reverted tilapias (Oreochromis niloticus). Four hundred tilapias were used. The experiment was mounted according to a completely randomized design with 5 treatments (0, 50, 100, 150 and 200 mg/kg of vitamin C monophosphate of ascorbic acid...

Genetic parameters to design or optimize breeding programs for these body weights are lacking. To evaluate the potential of mass selection for growth, genetic parameters are required. The goal of this study was estimate genetic parameters of growth characteristics in Nile tilápia (Oreochromis niloticus) in naturals conditions of low temperature. In...

Genetic parameters to design or optimize breeding programs for these body weights are lacking. To evaluate the potential of mass selection for growth, genetic parameters are required. The goal of this study was estimate genetic parameters of growth characteristics in Nile tilápia (Oreochromis niloticus) in naturals conditions of low temperature. In...

Objetivou-se avaliar a suplementação de Vitamina E no desempenho e qualidade de carcaça de tilápia do Nilo (Oreochromis niloticus). Os experimentos foram conduzidos no ranário experimenta do Departamento de Biologia Animal, UFV, Viçosa, Minas Gerais, Brasil, no período de 09/01/ 2005 a 25/04/2005, totalizando 106 dias. Foram utilizadas 400 pós larv...

The effect of vitamin E supplementation on performance and carcass quality of Nile tilapia (Oreochromis niloticus). The research was carried out in the experimental frog raising facilities at the Department of Animal Biology, UFV, Minas Gerais state, Brazil. Four hundred post larva reversed (Oreochromis niloticus) were used for studies. The experim...

Fish do not feed at any time of the day and on whatever food item they encounter in the wild, but they show daily rhythms of feeding activity and dietary selection. The aim of this research was to investigate the daily rhythms of behavior in Nile tilapia self-fed with plant-based diets supplemented with different levels of exogenous phytase (an enz...

Records of 270 meat-type chickens from three lines, 90 of each one, were used to discard variables in a principal component analysis. Data were obtained from meat-type chicken lines of the genetic breeding program of the Universidade Federal de Viçosa. The following traits were evaluated: days at first egg (DFE), egg production rate (EPR) from 22nd...

Objetivou-se avaliar a suplementação de vitamina C no desempenho produtivo de tilápias revertidas (Oreochromis niloticus). Foram utilizadas 400 pós-larvas revertidas num delineamento inteiramente ao acaso com cinco tratamentos (0, 50, 100, 150 e 200 mg/kg de vitamina C monofosfato de ácido ascórbico L) numa ração isoprotéica de 36% de PB e isocalór...

Objetivou-se avaliar a suplementação de Vitamina E no desempenho e qualidade de carcaça de tilápia do Nilo (Oreochromis niloticus). Os experimentos foram conduzidos no ranário experimental do Departamento de Biologia Animal, UFV, Viçosa, Minas Gerais, Brasil, no período de 09/01/2005 a 25/04/2005, totalizando 106 dias. Foram utilizadas 400 pós larv...

O experimento foi conduzido como objetivo de estimar a exigência de lisina total para codornas européias (Coturnix coturnix coturnix) machos de 21 a 49 dias de idade. Foram utilizadas 315 codornas (peso vivo médio de 80 g) alimentadas com rações à base de milho, farelo de soja e farelo de glúten de milho. A ração basal, formulada sem suplementação...

The trial was carried out to estimate the requirements of total lysine for male European quails (Coturnix coturnix coturnix) from 21 to 49 days old. Three hundred and fifteen quails averaging 80 g BW were fed diets with corn, soy crumb and corn gluten crumb. The basal diet was not supplementated with L-lysine, containing 20% of crude protein, 2,900...

Objetivando-se determinar o efeito do nível de energia digestível da dieta no desenvolvimento testicular de piauçu (Leporinus macrocephalus) foram utilizados 600 peixes com peso e comprimento médio inicial de 0,33 ± 0,11 g e 2,94 ± 0,39 cm, respectivamente. Foram realizados quatro tratamentos (2.600, 2.700, 2.800 e 2.900 kcal de ED/kg de ração). Ve...

Objetivou-se comparar a influência do sexo na morfometria e nos índices somáticos de lambari em condições de cultivo. Utilizou-se 270 alevinos de Lambari prata, com peso médio inicial 5,07 ± 0,14 g para machos, e as fêmeas com peso médio inicial de 6,67 ± 0,07 g, com 3 tratamentos: T1-machos na ausência de fêmea e T2-fêmeas na ausência de machos e...

The objective of this study was to evaluate the effect of energy levels on testicular development of the piauçu (Leporinus macrocephalus ). Six hundred fishes, averaging initial weight and length of 0.33 ± 0.11 g and 2.94 ± 0.39, respectively, were utilized. The experiment was carried out according to a completely randomized design, with 4 treatmen...

This study was carried out to compare the influence of sex on Astyanax scabripinnis morfometric and reproductive indexes. Three fingerlings (live weight 5.07 ± 0.14) were assigned to three treatment groups: T1 male only; T2 female only, and T3 both sex. Female parameters measured were trunk length, head length, pre-anal distance, and body height. S...

Foram coletados por rede de arrasto duzentas matrizes e duzentos reprodutores de tilápia do Nilo (Oreochromis niloticus) de uma fazenda na zona rural de viçosa. Os animais foram acomodados em igual densidade em cinco caixas de 5000 mil litros cada. Após 30 dias, foram selecionados 20 casais com base no aspecto saudável e aptidão para reproduzir e f...