Effect of digestible protein on intermediate metabolism, hepatic enzyme activities, energy reserves, and growth performance of pacu (Piaractus mesopotamicus) in the finishing growth phase.

This study investigated the effect of different levels of digestible protein (DP) on blood metabolites, hepatic enzyme activity of glycolysis and amino acid metabolism, energy reserves, and the production characteristics of pacu (Piaractus mesopotamicus) during the finishing growth phase. Six semi purified and isoenergetic diets, containing 16.3, 20.1, 23.8, 27.2, 31.5, and 34.8% of balanced DP, provided with essential amino acid balance, were hand-fed to pacu (1100.0 ± 10.3 g, initial weight) three times daily for 7 weeks. The experiment consisted of six treatments, with three randomly arranged replicates (tanks) per treatment. The data obtained from this experiment were analyzed by one-way analysis of variance (ANOVA), and significant differences (p < 0.05) between treatments were determined using Tukey's test. Blood metabolites, except serum ammonia and the hepatic enzymes activities of glycolysis and amino acid metabolism, except hexokinase activity were affected (p < 0.05) by balanced DP. The energy reserve indices, except hepatic total lipid content, were also found associated (p < 0.05) with balanced DP. The test diets significantly (p < 0.05) affected growth performance parameters. Higher dietary proteins led to a greater energy uptake by fish from the protein in feed. Overall, fish fed the intermediate level (23.8%) of balanced DP with digestible energy of 17.95 MJ kg-1 showed better production traits and physio-biochemical health markers. This information could help nutritionists and farmers to develop nutritionally balanced and economically and environmentally sustainable aquafeed for promoting healthy and sustainable production of pacu in intensive culture systems.

Dynamics of Growth and Egg Traits in Three Dietary Balanced Protein Scenarios Applied for Laying Hens.

The objective of this study was to evaluate laying hens from 8 to 102 weeks old, regarding their changes in performance, body composition, and egg components produced in three scenarios of nutrition. Three treatments designed to contain different levels of balanced protein (BP) were randomly assigned to the experimental units, performing ten replicates per treatment with 20 birds each. A standard feed was formulated to meet hen requirements and the ideal ratio between essential amino acids. Then, two experimental feeds were formulated to contain 20% above or below the dietary BP used in the standard feed. The responses evaluated were cumulated feed intake (g), daily feed intake (g/day), body weight (g), body composition (g of protein, fat, and ash), hen-housed egg production (%/hen-housed), egg production (%), egg weight (g), egg mass (g), and egg components (percentages of yolk, albumen, and eggshell). The dietary BP influenced the body composition, egg production, egg weight, and egg mass of white laying hens. The increase in dietary BP was related to an increase in body contents and egg weight, whereas hens consuming the low dietary balanced protein presented a lower body weight, leaner, and produced smaller eggs.

Effect of feed restriction on the maintenance energy requirement of broiler breeders.

OBJECTIVE: This study aimed to evaluate the effect of the ad libitum and restricted feeding regimen on fasting heat production (FHP) and body composition. METHODS: Twelve Hubbard broilers breeders were selected with the same body weight and submitted in two feeding regimes: Restricted (T1) with feed intake of 150 g/bird/d and ad libitum (T2). The birds were randomly distributed on the treatments in two runs with three replications per treatment (per run). The birds were adapted to the feed regimens for ten days. After that, they were allocated in the open-circuit chambers and kept for three days for adaptation. On the last day, oxygen consumption (VO2) and carbon dioxide production (VCO2) were measured by 30 h under fasting. The respiratory quotient (RQ) was calculated as the VCO2/VO2 ratio, and the heat production (HP) was obtained using the Brower equation (1985). The FHP was estimated throughout the plateau of HP 12 hours after the feed deprivation. The body composition was analyzed by dual-energy X-ray absorptiometry scanning at the end of each period. Data were analyzed for one-way analysis of variance using the Minitab software. RESULTS: The daily feed intake was 30 g higher to T2 (p<0.01) than the T1. Also, the birds of the T2 had significatively (p<0.05) more oxygen consumption (+3.1 L/kg0.75/d) and CO2 production (+2.2 L/kg0.75/d). That resulted in a higher FHP 359±14 kJ/kg0.75/d for T2 than T1 296±17.23 kJ/kg0.75/d. In contrast, the RQ was not different between treatments, with an average of 0.77 for the fasting condition. In addition, protein and fat composition were not affected by the treatment, while a tendency (p<0.1) was shown to higher bone mineral content on the T1. CONCLUSION: The birds under ad libitum feeding had a higher maintenance energy requirement but their body composition was not affected compared to restricted feeding.

Efficacy of Benzocaine, Eugenol, and Menthol as Anesthetics for Freshwater Angelfish.

For the production and commercialization of ornamental fish species, it is indispensable to collect biometric data that facilitate the selection of animals for trade and genetic improvement of the stock. However, during the handling process, fish receive more stress if proper anesthetics are not used. Thus, application of appropriate anesthetics is an important tool for minimizing stress in animals. The objective of this study was to determine the effective concentrations of benzocaine, eugenol, and menthol for achieving anesthesia in Freshwater Angelfish Pterophyllum scalare and to develop induction and recovery response curves for different concentrations of these anesthetics. In total, 75 fish were exposed to five concentrations of the three anesthetics in a completely randomized design: benzocaine at 60, 85, 110, 135, and 160 mg/L; eugenol at 40, 80, 120, 160, and 200 mg/L; and menthol at 50, 75, 150, 200, and 250 mg/L. Each concentration (5 fish/concentration) consisted of five replicates, with each replicate represented by a single fish. The results indicated that the tested substances met the criteria of anesthetic efficiency. The effective concentrations of benzocaine, eugenol, and menthol for the anesthesia of Freshwater Angelfish were identified as 89.25, 90.6, and 92.1 mg/L, respectively.

An overview of the ongoing insights in selenium research and its role in fish nutrition and fish health.

In the present review, the ongoing researches about selenium research in fish nutrition have been comprehensively discussed. Selenium research is getting popularity in fish nutrition as it is required for the normal growth and proper physiological and biochemical functions in fish. Its deficiency or surplus amounts create severe problems in fish. It is available as inorganic form, organic form, and nano form. In fish, most of the previous research is about the selenium requirements for fish by using only one selenium source mainly the inorganic one. Selenium shows maximum biological activity and bioavailability when it is supplied in proper form. However, to differentiate the more bioavailable and less toxic form of selenium, sufficient information is needed about the comparative bioavailability of different selenium forms in different fish species. In fish, important data about the new forms of selenoproteins is still scarce. Therefore, it is necessary to focus on the determination and elucidation of the new selenoproteins in fish through the utilization of recent approaches of molecular biology and proteomics. The adaptation of these new approaches will replace the old fashioned methodologies regarding the selenium research in fish nutrition. Moreover, the use of molecular biology and proteomics-based new approaches in combination with selenium research will help in optimizing the area of fish nutrition and will improve the feed intake, growth performance, and more importantly the flesh quality which has a promising importance in the consumer market.

Parasitic infections in ornamental cichlid fish in the Peruvian Amazon.

The aim of this study was to evaluate the prevalence and seasonal distribution of the main parasite species in Amazonian ornamental cichlids that affect their trade. The study was conducted from August 2007 to September 2009. We sampled 3042 specimens from 9 different species, of which 9.47% had at least one type of external parasite. 81.25% of the cases occurred in the dry season. Crenicichla anthurus (28.57%) was the most parasitized, followed by Aequidens diadema (26.32%), Pterophyllum scalare (22.69%), Cichlasoma sp. (9.52%), Apistogramma sp. (3.88%) and Symphysodon aequifasciatus (3.66%). Monogenea was the most abundant group of parasites, occurring in 66.67% of the cases, of which 96.88% occurred in the dry season. This parasite infested 95.68% of Pterophyllum scalare, 76.67% of Apistogramma sp, 33.33% of Cichlasoma sp. and 23.81% of Symphysodon aequifasciatus cases. Ichthyophthirius multifiliis infested 100% of Aequidens diadema, 76.19% of Symphysodon aequifasciatus, 66.67% of Cichlasoma sp, 41.67% of Crenicichla anthurus and 23.33% of Apistogramma sp cases. Myxosporidia infested 58.33% of Crenicichla anthurus. Trichodina infested 4.32% of Pterophyllum scalare. The prevalence of these parasites is related to the season, preferred habitat, fish behavior, individual susceptibility and handling of animals during transportation by fishermen.

Parasitic infections in ornamental cichlid fish in the Peruvian Amazon / Infestação parasitária em ciclídeos ornamentais da Amazônia de Peru

The aim of this study was to evaluate the prevalence and seasonal distribution of the main parasite species in Amazonian ornamental cichlids that affect their trade. The study was conducted from August 2007 to September 2009. We sampled 3042 specimens from 9 different species, of which 9.47% had at least one type of external parasite. 81.25% of the cases occurred in the dry season. Crenicichla anthurus (28.57%) was the most parasitized, followed by Aequidens diadema (26.32%), Pterophyllum scalare (22.69%), Cichlasoma sp. (9.52%), Apistogramma sp. (3.88%) and Symphysodon aequifasciatus (3.66%). Monogenea was the most abundant group of parasites, occurring in 66.67% of the cases, of which 96.88% occurred in the dry season. This parasite infested 95.68% of Pterophyllum scalare, 76.67% of Apistogramma sp, 33.33% of Cichlasoma sp. and 23.81% of Symphysodon aequifasciatus cases. Ichthyophthirius multifiliis infested 100% of Aequidens diadema, 76.19% of Symphysodon aequifasciatus, 66.67% of Cichlasoma sp, 41.67% of Crenicichla anthurus and 23.33% of Apistogramma sp cases. Myxosporidia infested 58.33% of Crenicichla anthurus. Trichodina infested 4.32% of Pterophyllum scalare. The prevalence of these parasites is related to the season, preferred habitat, fish behavior, individual susceptibility and handling of animals during transportation by fishermen.

O objetivo deste estudo foi avaliar a prevalência e distribuição sazonal das principais espécies de parasitas em ciclídeos ornamentais amazônicos que afetam seu comércio. O estudo foi realizado entre agosto de 2007 e setembro de 2009. Foram amostrados 3042 espécimes de 9 espécies diferentes, das quais 9,47% tinham pelo menos um tipo de parasita externo. Na estação seca, ocorreram 81,25% dos casos. Crenicichla anthurus (28,57%) foi o mais parasitado, seguido por Aequidens diadema (26,32%), Pterophyllum scalare (22,69%), Cichlasoma sp. (9,52%), Apistogramma sp. (3,88%), e Symphysodon aequifasciatus (3,66%). Monogenea foi o grupo mais abundante de parasitas, ocorrendo em 66,67% dos casos. Na estação seca, ocorreram 96,88% deles. Este parasita infestou 95,68% dos casos em Pterophyllum scalare, 76,67% em Apistogramma sp., 33,33% em Cichlasoma sp. e 23,81% em Symphysodon aequifasciatus. Ichthyophthirius multifiliis infestou 100% dos casos em Aequidens diadema, 76,19% em Symphysodon aequifasciatus, 66,67% em Cichlasoma sp., 41,67% em Crenicichla anthurus e 23,33% em Apistogramma sp.; Myxosporidia infestou 58,33% dos casos em Crenicichla anthurus; Trichodina infestou 4,32% dos casos em Pterophyllum scalare. A prevalência desses parasitas está relacionada com a época do ano, hábitat preferido, comportamento dos peixes, suscetibilidade individual e manejo dos animais durante o transporte pelos pescadores.

Induced reproduction and early development histology of Oscar Astronotus ocellatus (Agassiz, 1831).

Oscar (Astronotus ocellatus) is an important fish from the Amazon Basin that has great potential for fish farming, human consumption, sport fishing and fish keeping. This study aimed to evaluate the effect of two hormonal treatments on the induction of artificial reproduction in broodstock and to describe the histological development of embryos and larvae. Broodstocks were selected and induced using two different hormones: (i) extract of carp pituitary (ECP); and (ii) synthetic human chorionic gonadotropin (hCG). Spawnings were transferred to hatcheries, collected at pre-established times, processed and analysed by histology. Astronotus ocellatus did not respond well to induced reproduction. From 16 couples of breeding fish, only five out of the eight females released oocytes after the hormonal action time, three with hCG and two with ECP; just one male responded positively to hCG. Oscar eggs were oval, and semi-adhesive, the yolk contained granules, and egg diameter was approximately 1.65 ± 0.057 to 1.98 ± 0.038 mm. Development from the initial collection (IC) point until the total absorption of the yolk lasted 315 h, at an average temperature of 27.45 ± 2.13°C. Several events marked embryonic and larval development, including the formation of the optic cup, forebrain, otic vesicle and cephalic divisions. The newly hatched larvae had non-pigmented eyes, and a closed mouth and anus, as well as the presence of adhesive glands on the head. Larval development was characterized by formation of the heart, liver, gaseous bladder, gills, pronephros, brain, fins and also the digestive tract. These results provide important information for the rearing and reproduction of A. ocellatus.

Early development of Betta splendens under stereomicroscopy and scanning electron microscopy.

Betta splendens is a very important ornamental species. The current paper describes the embryonic and larval development of B. splendens under stereomicroscopy and scanning electron microscopy. Eggs and larvae from natural spawning were collected at different developmental stages at previously established intervals and analysed. The eggs of B. splendens are yellowish, clear, spherical, demersal, translucent and telolecithal with a large amount of yolk. Between 0-2 h post-initial collection (hpIC), the eggs were at the egg cell, first cleavage and morula stages. The blastula stage was identified at 2-3 hpIC and the early gastrula phase was observed at 3-4 hpIC with 20% epiboly, which was finalized after 13-18 hpIC. When the pre-larvae were ready to hatch, the appearance of somites and the free tail were observed, at 23-25 hpIC. At 29 hpIC, the majority of larvae had already hatched at an average temperature of 28.4 ± 0.2°C. The newly hatched larvae measured 2.47 ± 0.044 mm total length. The mouth opened at 23 h post-hatching (hPH) and the yolk sac was totally absorbed at 73 hPH. After 156 hPH, the heart was pumping blood throughout the entire larval body. The caudal fin, operculum and eyes were well developed at 264 hPH. When metamorphosis was complete at 768 hPH, the larvae became juveniles. The current study presents the first results about early development of B. splendens and provides relevant information for its reproduction, rearing and biology.

Descrição do potencial de retenção de nitrogênio em frangas de postura por diferentes metodologias: mínima retenção / Description of the potential for nitrogen retention in pullets by different methodologies: minimum retention

Objetivou-se com esta pesquisa descrever o potencial de retenção de nitrogênio por duas técnicas: abate comparativo e balanço de nitrogênio. Também se objetivou comparar os modelos ajustados para cada técnica e estimar as exigências de mantença para frangas de postura. Os ensaios foram realizados no período de 14 a 28, 56 a 70 e 98 a 112 dias de idade, utilizando 168 frangas. Os ensaios tiveram sete tratamentos e oito repetições. Os tratamentos consistiram de níveis de proteína variando de 75 a 435gkg-1 de matéria seca. As variáveis coletadas pelo abate comparativo foram nitrogênio ingerido e depositado e, pela técnica do balanço de nitrogênio, ingestão e excreção de nitrogênio. O intercepto da relação exponencial entre nitrogênio excretado e ingerido foi considerado a exigência de mantença. Os modelos ajustados foram comparados pelo teste da razão de máxima verossimilhança. As técnicas comparadas descreveram de forma diferente a exigência de mantença de nitrogênio. Para o abate comparativo, a exigência de mantença foi estimada em 342, 372 e 543mg/kgPC0,67 e para o balanço de nitrogênio foi de 342, 225 e 284mg/kgPC0,67, para os período de 14 a 28, 56 a 70 e 98 a 112 dias de idade, respectivamente.

The objectives of this study were to describe the potential for nitrogen retention by two techniques: comparative slaughter and nitrogen balance; compare the adjusted models for each technique and estimate the maintenance requirement for pullets. Assays were performed during 14 to 28, 56-70 and 98 to 112 days of age, using 168 pullets. The design was completely randomized with seven treatments and eight replications. Treatments consisted of protein levels ranging from 75 to 435gkg-1 of dry matter. The variables were collected by comparative slaughter and nitrogen ingested and deposited in nitrogen balance technique intake and nitrogen excretion. The intercept of the exponential relationship between ingested and excreted nitrogen was considered a requirement for maintenance. The adjusted models were compared by using the maximum likelihood ratio. The techniques described differently compared the requirement for maintenance of nitrogen. For comparative slaughter requiring maintenance was estimated at 342, 372 and 543mg/kgPC0,67 and for nitrogen balance was 342, 225 and 284mg/kgPC0,67 for the period of 14 to 28, 56-70 and 98 to 112 days of age, respectively.

Early development of Astronotus ocellatus under stereomicroscopy and scanning electron microscopy.

Astronotus ocellatus, popularly known as Oscar, is a cichlid fish from the Amazon basin (Brazil) with a great potential for fish farming. The aim of this research is to describe the morphology of eggs and larvae of A. ocellatus under stereomicroscopy and scanning electron microscopy. Eggs from natural spawnings were taken to hatcheries, collected at previously established time periods and then analysed. Oscar's eggs are demersal, adhesive and fragile to touch, with a slightly oval shape. The fertile eggs are yellowish in colour and when unfertilized are a white opaque colour. In the initial collection (IC), the majority of eggs were found to be at the gastrula phase with 30% epiboly. At 12 h after the IC, the formation of the embrionary axis and somites was observed, followed by differentiation of the tail and of the head. Fifteen hours after the IC, the emergence of the optic and otic vesicles, and of adhesive glands and the yolk pigmentation was observed. Larval hatching took place between 46 and 58 h after the first collection, at an average temperature of 27.45 ± 2.13°C. The larval stage was characterized by the development of the heart, fins, branchial apparatus, neuromasts, taste buds and adhesive glands on the head. Larval development to yolk absorption took a period of 257 h. These results provide important information for reproduction, rearing and preservation of A. ocellatus.

Mananoligossacarídeos em dietas para frangos de corte / Mannanoligosaccharides in diets for broilers

Objetivou-se avaliar dietas contendo mananoligossacarídeos (MOS) como aditivo alternativo aos promotores de crescimento por meio do estudo da morfometria do intestino e do desempenho de frangos de corte. Para tanto, 1280 pintos de corte foram distribuídos em delineamento inteiramente casualizado com quatro tratamentos (controle negativo, CN: dieta isenta de antibiótico; controle positivo, CP: dieta contendo antibiótico e duas dietas, MOS 1 e MOS 2, nas quais foram adicionadas ao CN duas fontes distintas de MOS) e oito repetições, sendo a unidade experimental composta por 40 aves. Para submeter as aves ao desafio sanitário, foi formulada uma dieta basal com milho, farelo de soja e farinha de carne e ossos. Adotou-se cama reutilizada, limpeza dos bebedouros duas vezes por semana e oferta semanal de água contaminada com cama. Foram avaliadas altura de vilo e profundidade de cripta do duodeno, jejuno e íleo, consumo da dieta, peso médio, ganho de peso e conversão alimentar das aves. Houve melhora na profundidade de cripta no jejuno e na altura de vilo no íleo das aves alimentadas com dietas contendo MOS. A adição de MOS, independente da fonte, resultou em melhor conversão alimentar em relação às aves do CN, sendo similares às aves do CP. Os mananoligossacarídeos podem ser utilizados como aditivo alternativo aos promotores de crescimento em dietas para frangos de corte, porém, dependendo da fonte, esta pode acarretar em pequenas diferenças no desempenho das aves.

This study aimed to evaluate mannan oligosaccharides (MOS) as an alternative additive to growth promoters in broiler diets by studying the morphology of the intestine and the performance. For this purpose, 1280 broiler chicks were distributed in a completely randomized design with four treatments (negative control, NC: diet free of antibiotics; positive control, PC: diet with antibiotic and two diets, MOS 1 and MOS 2, in which were added to NC two distinct sources of MOS) and eight repetitions, and the experimental unit consisted of 40 birds. To submit birds to the challenge, a basal diet was formulated with corn, soybean meal and meat and bones meal, was adopted used litter, cleaning of water troughs twice a week and were offered weekly water contaminated with litter. The variables evaluated were villus height and crypt depth of duodenum, jejunum and ileum, feed intake, weight, body weight gain and feed conversion ratio. There was improvement in crypt depth in jejunum and in villus height in ileum of birds fed diets containing MOS. The addition of MOS, regardless of source, resulted in improvement in feed conversion ratio than birds of NC, and were similar to the birds of PC. The mannan oligosaccharides can be used as an alternative additive to growth promoters in diets for broiler chickens, but depending on the source, this can result in small differences in bird performance.

Crescimento e desempenho de linhagens de aves pescoço pelado criadas em sistema semi-confinado / Growth and performance of naked neck broiler reared in free-range system

Este trabalho foi realizado para avaliar o crescimento e desempenho de duas linhagens de aves pescoço pelado. Foram utilizadas 400 aves, distribuídas em um delineamento inteiramente casualizado, os tratamentos consistiram de um esquema fatorial 2 x 2 (linhagens x sexo), com cinco repetições de 20 aves cada. Foram utilizadas aves Pescoço Pelado das linhagens Sasso e ISA Label. As aves receberam rações formuladas à base de milho e de farelo de soja para atender às exigências nutricionais. Foi determinado o ganho de peso (GP), o consumo de ração (CR) e a conversão alimentar (CA) aos 28, 56 e 84 dias de idade e o rendimento de carcaça e de partes aos 84 dias de idade. Não foi observada interação entre sexo e linhagem (P>0,05) para nenhuma das variáveis de desempenho analisadas. Para CR e GP houve diferenças significativas (P<0,05) entre as linhagens e entre os sexos nos três períodos. As aves da linhagem Sasso apresentaram desempenho superior à ISA Label. Em relação aos parâmetros descritos da equação de Gompertz, as aves da linhagem Sasso apresentaram maior peso à maturidade (Pm) e tempo em que a taxa de crescimento é máxima (t*) e menor taxa de maturidade (b), indicando que as aves da linhagem ISA Label foram mais precoces para atingir a idade de máximo crescimento. As fêmeas demonstraram melhor aptidão para rendimento de peito e os machos para o rendimento de coxa e de sobra-coxa.

A trial was carried out to evaluate the growth and performance of naked neck birds. Four hundred birds were distributed into four treatments in factorial arrangement (2 strains x 2 genders), with five replicates of 20 birds each. The naked neck strains evaluated were Sasso and ISA Label. The birds were fed a diet formulated with corn and soybean meal according to the nutritional requirements. Food intake, body weight gain and food conversion were determined at 28, 56, and 84 days as well as the yield of carcass and cuts at 84 days. No interaction was observed between gender and strain (P>0.05). Food intake and body weight gain were different (P <0.05) between the strains and between the genders. Sasso strain presented higher performance than ISA Label. The parameters estimated for Gompertz equation, the weigh at maturity (Wm) and time that the growth rate is maximum (t*) were higher and maturity rate (b) was lower for Sasso strain than those of Isa Label strain. These results indicated that the Isa Label was more precocious than Sasso strain. The females showed better breast yield while the males showed better thigh and drumstick yield.