Impact of maternal protein supplementation during mid or late gestation on skeletal muscle energy metabolism of beef calves / Impacto da suplementação proteica materna durante o terço médio ou terço final da gestação sobre o metabolismo energético do tecido muscular de bezerros de corte

ABSTRACT: This study evaluated the effect of maternal protein supplementation during mid or late gestation on energy metabolism of the skeletal muscle of beef calves. Sixteen pregnant cows were divided into 3 groups: CTRL (not supplemented); MID (supplemented from 30 to 180 days of gestation); and LATE (supplemented from 181 to 281 days of gestation). The supplement contained 30% crude protein. Thirty days after birth, blood and muscle samples of the calves were collected for analyses of gene expression, proteins, and metabolites. No differences (P ≥ 0.15) in birth weight, performance at weaning, or muscle expression of the genes evaluated (P ≥ 0.21) were observed. Calves born to CTRL cows had a lower ratio (P = 0.03) of p-AMPK/AMPK protein in the skeletal muscle. Calves born to MID cows had lower (P = 0.04) glucose concentration than those born to LATE cows. Changes in p-AMPK/AMPK protein, indicated a possible metabolic inflexibility in the skeletal muscle of calves born to CTRL cows. These results indicated that lack of protein supplementation in pregnant cows alter the energy metabolism of their calves and reflect in a metabolic inflexibility.

RESUMO: O objetivo deste estudo foi avaliar o efeito da suplementação proteica materna sobre o metabolismo energético do músculo esquelético de bezerros de corte. Dezesseis matrizes gestantes foram divididas em três grupos: CONTROLE (não suplementado); MÉDIO (suplementados entre 30 e 180 dias de gestação); e FINAL (suplementado entre 181 e 281 dias de gestação). O suplemento continha 30% de proteína bruta e foi fornecido em quantidades totais iguais aos tratamentos. Trinta dias após o nascimento, amostras de sangue e músculo dos bezerros foram coletadas para análises de expressão gênica, abundância de proteínas e metabólitos. Não foram observadas diferenças (P ≥ 0,15) no peso ao nascimento ou parâmetros de desempenho ao desmame, bem como na expressão dos genes avaliados (P ≥ 0,21). Os bezerros nascidos de matrizes do tratamento CONTROLE apresentaram menor proporção (P = 0,03) de proteína p-AMPK/AMPK no músculo esquelético. Os bezerros nascidos de matrizes do tratamento MÉDIO apresentaram concentração de glicose menor (P = 0,04) do que aqueles nascidos de matrizes do tratamento FINAL. Os resultados observados indicam que a ausência de suplementação proteica em matrizes gestantes pode alterar o metabolismo energético da progênie e refletir em uma inflexibilidade metabólica, a qual pode ocasionar limitações quanto à eficiência energética do tecido muscular esquelético e consequentemente, limitar o desempenho da progênie ao longo da fase pós-natal.

Effect of dietary protein: lipid ratio on growth and body composition in bullfrog (Lithobates catesbeianus)

A feeding trial was performed to assess dietary protein:lipid ratios for the grow-out phase of the bullfrog (Lithobates catesbeianus). Nine balanced isoenergetic diets were formulated, combining three different protein levels (300, 400, and 500 g kg−1) with three different lipid levels (50, 100, and 200 g kg−1), designated as P300/50L, P300/100L, P300/200L, P400/50L, P400/100L, P400/200L, P500/50L, P500/100L, and P500/200L. Additionally, a commercial fish feed, commonly used in Mexico to feed bullfrogs, was also tested during the experiment. Growth performance, animal performance parameters, carcass composition, and fatty acid profiles in muscle and liver were evaluated. The feeding trial results showed that all the experimental diets enhanced growth, feed conversion ratio, and frog-leg weight compared with the commercial diet. Bullfrogs had higher growth with 400 and 500 g kg−1 of dietary protein regardless of dietary lipid content. It was also notable that with the P500/200L diet, frogs doubled the weight of those fed the commercial diet. DHA, EPA, and total omega-3 fatty acids were double in muscle and two to eight times higher in the liver compared with the commercial diet. In all cases, the final proximal composition of carcass reflected the diet composition. It is suggested that a diet containing 400 g kg−1 of protein and 50 g kg−1 lipids (protein/lipid ratio: 7.4; gross energy: 18.2 MJ kg−1) is adequate for bullfrog performance during the grow-out phase to achieve market size in a shorter period, thus, reducing farming risks and production costs.

Molecular detection of Sarcocystis spp. in the breast muscle of captive birds from the southern region of Brazil / Detecção molecular de Sarcocystis spp. no músculo peitoral de aves de cativeiro da região sul do Brasil

Studies on diseases of wild birds are essential in the context of public health, as these animals act as sentinels, allowing information regarding a determined geographic area. In addition, birds are food protein sources for animals, and therefore play an important role in the life cycle of the protozoan Sarcocystis spp. This study aimed to identify the Sarcocystis spp. in breast muscle samples of naturally infected captive birds. The breast muscle of 89 birds were sampled, and the DNA amplified by PCR targeting the 18S ribosomal RNA gene to detect Sarcocystis spp. PCR products were sequenced and 5.61% (5/89) samples showed 100% similarity with Sarcocystis spp. (one Cyanoliseus patagonus, one Psittacula krameri, two Pyrrhura frontalis, and one Ramphastos dicolorus). The large number of naturally infected species analyzed by molecular methods allowed the detection of Sarcocystis spp. in different bird species, corroborating the epidemiology of Sarcocystis spp.

Estudos sobre doenças de aves silvestres são essenciais no contexto da saúde pública, pois esses animais atuam como sentinelas, permitindo obter informações sobre uma determinada área geográfica. Além disso, as aves são fontes de proteína alimentar para os animais e, portanto, desempenham um papel importante no ciclo de vida do Sarcocystis. Este estudo teve como objetivo identificar Sarcocystis spp. nos músculos do peito de aves de cativeiro naturalmente infectadas. Os músculos do peito de 89 aves foram coletados, e o DNA amplificado pela PCR do gene RNA ribossômico 18S para detecção de Sarcocystis spp. Os produtos da PCR foram sequenciados e 5,61% (5/89) amostras apresentaram 100% de similaridade com o Sarcocystis spp. (um Cyanoliseus patagonus, um Psittacula krameri, dois Pyrrhura frontalis e um Ramphastos dicolorus). O grande número de espécies naturalmente infectadas analisadas por métodos moleculares permitiu a detecção de Sarcocystis spp. em diferentes espécies de aves, corroborando a epidemiologia de Sarcocystis spp.

Nutrient compositional variation and interrelationship in the muscle of wild and plastic-reared brachyuran

Edible brachyurans are recognized as a popular source of food due to their delicious taste and nutritional quality. This study investigated the nutrient compositional variation and interrelationship in the muscle of wild and plastic-reared Cardisoma armatum. The plastic-reared crab had 27.81 ± 2.29 g 100 g-1protein while crab from the wild contained 22.45 ± 2.65 g 100 g-1protein. The difference in protein content of plastic-reared and its counterpart from the mangrove swamp was not significantly different(p > 0.05). This is also true of other proximate composition except that wild crabs were slightly higher in both crude fat (2.68 ± 0.35 g 100 g-1) and carbohydrate (5.89 ± 3.05 g 100 g-1). Generally, the total energy contributed due to protein, carbohydrate and fat in the tissues of both wild and plastic-reared C. armatumare similar. In the wild crab, contents of calcium (16083.27 ± 2127.90 mg 100 g-1) and phosphorus (1191.42 ± 199.21) were relatively higher, while contents of magnesium (368.69 ± 111.05 mg 100 g-1), sodium (125.30 ± 11.18 mg 100 g-1) and potassium (87.36 ± 7.27 mg 100 g-1) were relatively higher inplastic-reared crabs. All significant mineral ratios in wild and plastic-reared C. amartumfall within acceptable range. The positive relationship in the nutritional quality indicates that changes in proximate composition are associated with changes in mineral contents of the crab tissue.(AU)

Lipid profile and metabolic parameters of tilapia in the finishing phase in earth ponds or using biofloc technology

Tilapia is a species with great growth potential. Its production comes from a semi-intensive system, such as earthen ponds (EP). Recently, biofloc technology (BFT) appears as an option to intensify fish production. The objective of this work was to compare the organosomatic indices, biochemical parameters, and chemical composition of tilapia reared in EP and BFT. Fish were grown for 150 days, with an initial weight of ≅ 2 g and a final weight of ≅ 780 g. Thereafter, tissues and organs were collected to determine organosomatic indices and analyze biochemical parameters, fatty acid, and proximate composition. The carcass yield was higher for tilapia reared in EP than BFT. The production system did not affect the fish fillet yield. The other organosomatic parameters were higher for tilapia reared in BFT. Tilapia reared in EP showed higher content of crude protein and lipids in the fillet. In both production systems, there was no difference in the body lipid profile. Fish in BFT showed a higher concentration of glucose and ammonia in the muscle and amino acids in the liver. Fish reared in EP showed a higher concentration of lactate in the liver compared to those in BFT. In conclusion, the production system alters the metabolism of fish. The biofloc has a considerable amount of fatty acids, which can be considered in the formulation of diets for tilapia in this system.(AU)

Zootechnical performance, degree of steatosis and the genotoxic potential in yellowtail tetra Astyanax lacustris fed with different levels of L-carnitine / Desempenho zootécnico, grau de esteatose e potencial genotóxico de lambaris Astyanax lacustris alimentados com diferentes níveis de L-carnitina

L-carnitine perform a major role in transporting long-chain fatty acids into the mitochondria, where they are oxidized. It has been used in animal diets to decrease fat and increase muscle protein. The aim of this study was to evaluate the zootechnical performance, degree of steatosis in the liver, and genotoxic potential in Astyanax lacustris fed with different levels of L-carnitine (LC). Yellowtail tetra juveniles (n = 140) were distributed in 20 tanks of 70 L, with seven fish in each, in a water recirculation system with controlled temperature (27±0.1°C). The treatments with different levels of L-carnitine supplementation were: 0 (control), 250, 500, 750, and 1000 mg of LC per kg of food. The diets were provided twice a day for 60 days. The results showed that the different levels of LC did not affect (P>0.05) weight gain, survival, viscerosomatic index, and the liver hepatocytes showed a normal appearance. However, the use of LC supplementation showed genotoxic potential with a significant difference (P<0.05) for cell alterations when compared to the control at concentrations above 500mg kg-1.

A L-carnitina exerce um papel importante no transporte de ácidos graxos de cadeia longa até a mitocôndria para serem oxidados e tem sido incorporada em rações para animais com o objetivo de diminuir a deposição de gordura e aumentar a proteína muscular. O objetivo deste trabalho foi avaliar o desempenho zootécnico, o grau de esteatose no fígado e o potencial genotóxico em Astyanax lacustris alimentados com diferentes níveis de L-carnitina (LC). Juvenis de lambari-do-rabo-amarelo (n=140) foram distribuídos em 20 caixas de 70L, sete peixes em cada, em um sistema de recirculação de água com temperatura controlada (27±0,1°C). Os tratamentos com os níveis de suplementação foram: 0 (controle), 250, 500, 750 e 1000 mg de LC kg-1 de ração. As dietas foram fornecidas duas vezes ao dia, durante 60 dias. Os resultados mostraram que os diferentes níveis de LC não influenciaram (P>0,05) o ganho de peso; a sobrevivência, o índice viscerossomático e os hepatócitos do fígado apresentaram-se com aparência normal. No entanto, a suplementação com LC apresentou potencial genotóxico com diferença significativa (P<0,05) para alterações celulares quando comparada ao controle em concentrações superiores a 500mg kg-1.

DGAT and LEP gene polymorphisms and their association with carcass characteristics and the lipid profile of meat from Nellore cattle / Polimorfismo dos genes DGAT e LEP e sua associação com características de carcaça e perfil lipídico da carne de bovinos nelore

The objective of this study was to evaluate the association of polymorphisms in the diacylglycerol acyltransferase (DGAT) and leptin (LEP) genes with the performance, carcass characteristics, meat quality, and lipid profile of Nellore cattle. A total of 100 intact male Nelore cattle were used to analyze the performance, carcass, physicochemical and centesimal composition, and fatty acid profile of beef. To identify the polymorphisms, the PCR­single-strand conformation polymorphism (SSCP) technique was applied to genomic DNA extracted from muscle tissue. The SSCP technique revealed the presence of four band patterns for the DGAT gene (AC, AD, AE and BB) with five alleles (A, B, C, D and E). For the LEP gene, five band patterns (AA, AB, AC, BB and BC) with three alleles (A, B and C) were observed. For the LEP gene, the AB genotype was associated with higher backfat thickness and ribs weight, while the BB genotype was associated with lower ribs yield; higher hindquarter yield was associated with AC and BB genotypes. Higher contents of C17:0, C18:0 and lower contents of C18:2ω6C, total polyunsaturated fatty acids, total ω6 and ratio of polyunsaturated and saturated fatty acids (PUFA/SFA) were verified for the AC genotype of the LEP gene. The AC and AA genotypes of the LEP gene were associated with higher means of C15:0 and C18:1ω9t. For the DGAT gene, the highest C24:0 content was associated with the AE genotype and the lowest with the AD and BB genotypes. Polymorphisms in the DGAT and LEP genes influence carcass parameters and the lipid profile of the meat of Nellore cattle.

Objetivou-se com este estudo avaliar a associação do polimorfismo dos genes da Diacilglicerol Aciltransferase (DGAT) e Leptina ­ (LEP) em relação ao desempenho, características de carcaça, qualidade de carne e perfil lipídico de bovinos Nelore. Para o estudo, foram utilizados um total de 100 bovinos nelores machos inteiros e avaliado os parâmetros de desempenho, composição da carcaça, composição físico-química, centesimal e perfil lipídico da carne. Para identificação dos polimorfismos foi utilizada a técnica de PCR-SSCP a partir da extração do DNA genômico do tecido muscular. A técnica de SSCP revelou a presença de quatro padrões de banda para o gene DGAT (AC, AD, AE e BB) com cinco alelos (A, B, C, D e E) e, para o gene LEP foram verificados cinco padrões de bandas (AA, AB, AC, BB e BC) com três alelos (A, B e C). Para o gene LEP, o genótipo AB foi associado a maior espessura de gordura subcutânea e peso do corte ponta de agulha, enquanto o genótipo BB foi associado a menor rendimento do corte ponta de agulha; maior rendimento do corte traseiro foi associado aos genótipos AC e BB. Maiores teores de C17:0, C18:0 e menores de C18: 2ω6C, total de ácidos graxos poli-insaturados, total de ω6 e a relação de ácidos graxos poli-insaturados e saturados (POL/SAT) foram verificados para o genótipo AC do gene LEP. Os genótipos AC e AA do gene LEP foram associados a maiores médias de C15:0 e C18:1ω9t. Para o gene DGAT, os maiores teores de C24:0 foram associados o genótipo AE e o menores aos genótipos AD e BB. A ocorrência de polimorfismo nos genes DGAT e LEP revelaram influência destes sobre parâmetros de carcaça e perfil lipídico da carne de bovinos Nelore.

Adenocarcinoma pancreático em um gato / Pancreatic adenocarcinoma in a cat

Background: Despite being rare in domestic animals, pancreatic adenocarcinoma is the most common malignant tumor of the feline pancreas. Due non-specificity of clinical signs in cats and the late diagnosis of the neoplasm, it is necessary to understand this disease better, to contribute for the knowledge of its early recognition and treatment. Thus, this study aims to report a case of metastatic pancreatic ductal adenocarcinoma in a cat, focusing on the main clinical aspects, diagnosis, and prognosis of this disease, in addition to the description of the presentation of peritoneal carcinomatosis. Case: A 14-year-old male neutered mixed breed cat, was referred to the Feline Medicine Service (MedFel) of the Hospital de Clínicas Veterinárias (HCV) - Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, with a history of hyporexia, constipation and increased abdominal volume for 3 days, besides mild difficulty in locomotion and progressive weight loss in the last 6 months. On the physical examination, the patient was alert, with a body condition score of 6/9; muscle condition score 1/4 and moderate dehydration of 7%. Popliteal lymph nodes were enlarged, and abdominal distension was evident. Around 200 mL of a slightly cloudy, straw-yellow liquid were drained from the abdominal cavity. After draining the fluid, a new abdominal palpation was performed, and there were fecal retention and a palpable mass in the right hypogastric region. The result of the cytological analysis of the fluid was consistent with a protein-rich transudate, suggesting neoplastic effusion of epithelial origin. Hematological and biochemical changes included leukocytosis due to neutrophilia, monocytosis, lymphopenia, thrombocytosis and azotemia. On abdominal ultrasound, the patient had free fluid in the abdominal cavity, and the gallbladder had discreet of biliary sludge. The intestines showed some corrugated segments with other segments lacking definition of its layers, and without peristaltic movements, suggesting intestinal neoplasia. Pancreas and adrenals were not visualized. On the chest X-ray, moderate opacification of lung fields with a diffuse interstitial pattern was observed, suggesting lung metastasis. The patient presented an acute worsening of the clinical condition and the owner requested euthanasia. The patient was referred for necropsy and based on the macroscopic and microscopic changes, the post-mortem diagnosis was metastatic pancreatic ductal adenocarcinoma with peritoneal carcinomatosis. Discussion: The clinical presentation of cats with exocrine pancreatic neoplasia is nonspecific, as clinical signs are common to several diseases, such as anorexia, vomiting, abdominal pain, weight loss with normal appetite, jaundice, depression, and lethargy. Complementary blood tests also do not provide data that could lead to the suspicion of pancreatic neoplastic disease. In the present case, the diagnosis of metastatic pancreatic ductal adenocarcinoma with peritoneal carcinomatosis was only possible post mortem. The pancreas is a difficult organ to assess adequately using most diagnostic imaging methods, so histopathology is still the method of choice for differentiating pancreatic tissue comorbidities. Therefore, exploratory laparotomy should be instituted to provide tissue samples from the pancreas and its metastases for histopathological diagnosis, whenever ultrasound or other imaging methods indicate suspicious abdominal changes. The literature reports that less than 10% of affected cats treated with complete surgical removal of the mass and chemotherapy alone will survive more than a year, and the average time for untreated cats is only 6 days. The prognosis of this disease is bad and most cats are euthanized, due to rapid clinical worsening. Therefore, diagnosis is essential to determine an adequate prognosis in advanced cases and to support therapeutic decisions or euthanasia.

Productivity and antioxidant activity of mung bean sprouts (Vigna radiata L. ) mediated by some elicitors / Produtividade e atividade antioxidante de brotos de feijão (Vigna radiata L. ) mediada por alguns elicitores

The production of bioactive food is one of the goals of agriculture. Sprouts used for human consumption are an efficient way to increase the intake of essential nutrients, such as minerals, vitamins, and other bioactive compounds. The use of elicitors can increase the nutritional value of these products. Biomass production, phenolic compound content, and antioxidant activity of mung bean sprouts (Vigna radiata L.) after elicitation were examined in this study. Mung bean sprouts were treated with salicylic acid (SA), ascorbic acid (AA), and tocopherol (TOC) at different concentrations and numbers of applications. Shoot and root lengths and dry mass were measured on five-day-old sprouts. Total phenol content and antioxidant activity were determined using the DPPH assay on dried ethanolic extracts. Total soluble protein content and superoxide dismutase activity were measured in frozen hypocotyls. All elicitors stimulated the antioxidant functions of sprouts and, at the highest concentrations, reduced the biometric parameters; therefore, lower concentrations were better. For the first time, a balance between elicitor concentration and application in instalments was achieved to maintain the production of sprouts with enhanced nutritional characteristics.

A produção de alimentos bioativos é um dos objetivos da agricultura. O uso de brotos para consumo humano é uma forma eficiente de aumentar a ingestão de nutrientes essenciais, como minerais, vitaminas e outros compostos bioativos. O uso de elicitores pode aumentar o valor nutricional desses produtos. A produção de biomassa, o conteúdo de compostos fenólicos e a atividade antioxidante de brotos de feijão (Vigna radiata L.) após a elicitação foram examinados neste estudo. Brotos de feijão foram tratados com ácido salicílico (SA), ácido ascórbico (AA) e tocoferol (TOC) em diferentes concentrações e número de aplicações. O comprimento da parte aérea e da raiz e a massa seca foram medidos em brotos com cinco dias de idade. O teor de fenol total e a atividade antioxidante foram determinados usando o ensaio DPPH em extratos etanólicos secos. O conteúdo total de proteína solúvel e atividade da superóxido dismutase foram medidos em hipocótilos congelados. Todos os elicitores estimularam as funções antioxidantes dos brotos e, nas maiores concentrações, reduziram os parâmetros biométricos; assim, concentrações mais baixas foram mais eficientes. Pela primeira vez, foi alcançado um equilíbrio entre a concentração do elicitor e a aplicação em parcelas para incrementar a produção de brotos e aprimorar características nutricionais aprimoradas.

Meat quality of the Berrichon du Cher lambs and its cross-breeds with a native breed / Qualidade da carne dos cordeiros Berrichon du Cher e seus cruzamentos com raça nativa

This study evaluated the meat of lambs from crossbreeding of Polish lowland sheep, heather and rams of the Berrichone du Cher breed (B). The lambs were kept in a medium-intensive feeding system. During fattening, they received haylage and grass hay with the addition of clover, and a mixture of cereal grains with the addition of minerals and vitamins. During the fattening period, all feeds were given at will. The slaughter and cutting of the carcasses were performed in accordance with the technology applicable in the meat industry. In the longissimus lumborum muscle, the content of dry matter, total protein, total fat and ash was determined. In addition, the pH value of 45 minutes and 24 hours after slaughter, as well as the parameters of colour and tenderness of the meat were measured. The content of collagen protein, cholesterol and selected fatty acids was also determined. As a result of the conducted analyzes, the influence of the Berrichone du Cher breed on the improvement of quantitative parameters related to the slaughter value and some parameters related to the physicochemical composition of the hybrid meat was reported.

O objetivo deste estudo foi avaliar como o cruzamento da raça Berrichon du Cher com raças nativas de ovelhas polonesas de baixa altitude e ovelhas de charneca polonesa afeta os parâmetros qualitativos da carne .O maior teor de proteína (19,86 ± 0,36%, P <0,05) em cordeiros foi encontrado no grupo Berrichon du Cher e no grupo de cordeiros ovinos (19,23 ± 0,67%, P <0,05). Por outro lado, o maior teor de colágeno total (1,10 ± 0,21%) e a maior sensibilidade do tecido muscular (10,69 ± 0,74 N cm-2), que também apresentaram o menor diâmetro das fibras musculares (24,01 ± 4,62 µm, P < 0,01) foi encontrado nos cordeiros mestiços Berrichon du Cher e Polish Heath Sheep. Tanto a raça quanto o gênero afetaram significativamente o teor de colesterol na carne de cordeiro e o maior teor de colesterol foi encontrado na carne dos cordeiros Berrichon du Cher. Seu menor teor foi demonstrado na carne de Ovinos da Baixada Polonesa com a diferença de 9,1 mg 100g-1 de tecido muscular. Um dos níveis mais baixos do isômero CLA (C 18: 2 cis-9 trans-11) também foi encontrado no grupo dos cordeiros Berrichon du Cher. Este isômero evita a formação de colesterol. Dependência semelhante em relação ao gênero também foi observada. Os resultados obtidos indicam que as raças nativas são utilizadas em cruzamentos com a raça Berrichon du Cher destinada à engorda, principalmente para melhorar parâmetros quantitativos relacionados ao valor de abate e parâmetros selecionados de propriedades físicas e químicas da carne ovina.

New alternatives for improving and assessing the color of darkcutting beef a review

ABSTRACT Myoglobin (Mb) is a sarcoplasmic heme protein present in muscle cells, which acts as a shortterm oxygen (O2) reserve in the muscle tissue. After slaughtering and exsanguination, Mb is the major pigment that provides the red color in meat. The concentration of Mb together with its redox state are two pivotal factors that determine meat color. The elevated pH of darkcutting beef can affect both physical and biochemical properties resulting in decreased oxygenation. The darkening observed in high ultimate pH (pHu) beef concerns meat processors as color is the initial attribute that impacts on the purchase. Thus, any atypical meat color (i.e., loss of brightness) reduces consumer interest in the product. Several studies have demonstrated that immunological castration is effective in preventing both aggressive behavior and undesirable darkcutting of bull meat. However, little information is available on the effects of processing techniques that limit the oxidation of ferrous iron (Fe2+), Mb or promote metmyoglobin (MMb) reduction in darkcutting beef. Because of the importance of color to fresh beef marketability, this review aimed at overviewing the significance of pHu in beef color and color stability and to discuss new alternatives for improving and assessing the beef color of darkcutting beef, especially in Nellore bulls and their crossbreds, which are widely used in beef cattle production in Brazil.

Selenium supplementation levels and sources in postlarvae Nile tilapia diet / Níveis de suplementação e Fontes de Selênio na Dieta de pós-larvas de Tilápia do Nilo

Fish larviculture exert great influence in the subsequent phases, in which nutrition is a basic prerequisite for success. Therefore, when it is in an intensified production system, it promotes the limitation of some minerals, making it necessary to supplement selenium in diets for post-larvae. The objective of this study was to evaluate selenium levels and sources in post-larvae Nile tilapia diets on muscle performance and histology. A total of 1,260 post-larvae with an initial average weight of 0.010 g were used, distributed in a completely randomized design in a factorial scheme with four supplementation levels (0.6; 0.9; 1.2 and 1.5 mg of Se/Kg) and two sources (sodium selenite and selenium yeast), plus the negative control, with 35 post-larvae Nile tilapia used per experimental unit. The physical-chemical parameters of water quality were within those recommended for tilapia cultivation. Feed consumption (p < 0.05) and hepatosomatic index (p < 0.05) were affected by the source used. Effects of supplemented selenium levels and sources were not observed for the other performance variables. Higher values for final height, final width, specific development rate and protein efficiency rate were found (p < 0.05) when comparing the control diet with diets containing the sodium selenite source. No effects on muscle fiber morphometry were observed (p > 0.05) in the studied variables. It is concluded that 0.6 mg of selenium in the diet, regardless of the source used, met the mineral requirement for post-larvae Nile tilapia.(AU)

A larvicultura de peixes exerce grande influência nas fases subsequentes, onde a nutrição é um prérequisito básico para o sucesso. Portanto, quando está em sistema de produção intensificada, promove a limitação de alguns minerais, sendo necessária a suplementação de selênio em dietas para pós-larvas. Objetivou-se avaliar níveis e fontes de selênio em dietas para pós-larvas de tilápia do Nilo, sobre o desempenho e histologia muscular. Utilizou-se 1260 pós-larvas, peso médio inicial 0,010 g, distribuídas em delineamento inteiramente casualizado, em esquema fatorial com quatro níveis de suplementação (0,6; 0,9; 1,2 e 1,5 mg/kg de Selênio) e duas fontes (Selenito de sódio e Selênio levedura), mais o controle negativo, utilizou-se 35 pós-larvas por unidade experimental. Os parâmetros físico-químicos de qualidade da água, apresentaram-se dentro do recomendado para tilápias. O consumo de ração (p < 0001) e índice hepatossomático (p < 0,05), foram afetados pela fonte utilizada. Para as demais variáveis de desempenho, não foram observados efeitos dos níveis e das fontes de selênio suplementadas. Quando comparada dieta controle as dietas contendo a fonte selenito de sódio verificou-se (p < 0,05) maiores altura final, largura final, taxa de desenvolvimento especifico e taxa de eficiência proteica. Não foram evidenciados (p > 0,05) efeitos sobre morfometria das fibras musculares nas variáveis estudadas. Conclui-se que 0,6mg de selênio na dieta, independente da fonte utilizada atendeu a necessidade do mineral para pós-larvas de tilápia do Nilo.(AU)

Physicochemical characteristics of lamb meat fed with cottonseed associated with calcium lignosulphonate

The physicochemical characteristics of the meat from lambs fed diets containing whole or disintegrated cottonseed, associated or not with calcium lignosulfonate (LignoCaSO3), were evaluated. Thirty non-castrated Dorper x Santa Inês lambs, with an average of 24.9 ± 3.6 kg and four months of age were confined for 60 days in collective stalls and distributed in a completely randomized design with six replications. After slaughter, by means of contrasts, the averages of the parameters of the semimembranous and semitendinosus muscles were analyzed. The cottonseed increased cooking loss and ash, and reduced muscle weight, water holding capacity and red intensity. The disintegration of the cottonseed reduced the shear force in diets without LignoCaSO3, increased the protein and the loss by cooking and reduced the pH in the diets with the additive. The luminosity values increased with the disintegration of the cottonseed in diets with and without LignoCaSO3. The addition of LignoCaSO3increased the weight of the muscle, protein, ash, pH, shear strength and the intensity of red. Moisture, lipids and yellow intensity were not influenced by the diets. Even changing the physical-chemical characteristics, the cottonseed with or without LignoCaSO3does not change the quality of the meat.(AU)

Compensatory growth of Nile tilapia fingerlings subjected to food restriction and re-feeding at low temperatures / Crescimento compensatório de alevinos de tilápia-do-Nilo submetidos à restrição alimentar e realimentação em temperaturas amenas

This study aims to investigate the effect of different periods of fasting and re-feeding on compensatory responses in Nile tilapia fingerlings and the frequency of muscle fiber distribution. A total of 108 Nile tilapia fingerlings with initial weight of 1.64 ± 0.41 g and mean initial length of 3.60 ± 0.39 cm were used for 55 days. The fish were distributed in a water recirculation system in a completely randomized design with three treatments and four replications: Control - CO - (fish fed until apparent satiation throughout the experimental period); fasting 10 - J10 - (fish fed to apparent satiation for 15 days, followed by 10 days of fasting and re-feeding to satiation for 30 days); and fasting 15 - J15 - (fish fed to apparent satiation for 15 days, followed by 15 days of fasting and re-feeding to satiation for 25 days). Fish from the J15 treatment showed unsatisfactory results in terms of productive performance (p<0.05), such as lower final weight, apparent feed conversion, protein efficiency ratio, and survival, while fish from the J10 treatment achieved the same results as those animals kept in the CO treatment with the exception of the variables of relative weight gain and feed intake. Furthermore, food restriction directly influenced the growth of muscle fibers with a diameter smaller than 20 µm (p<0.05), and fish from the J15 treatment had the lowest frequency of fibers in this diameter class. Therefore, this study concludes that food restriction in short periods (10 days) and at low temperatures can present a compensatory growth, as they alter the process of hyperplasia and hypertrophy of muscle fibers without affecting the morphology of the fibers; however, 15 days of fasting under low temperatures do not compensate for growth and delays the hypertrophic growth of muscle fibers.(AU)

O objetivo do presente estudo é investigar o efeito de diferentes períodos de jejum alimentar e realimentação nas respostas compensatórias em alevinos de tilápias-do-Nilo, e a frequência de distribuição das fibras musculares. Foram utilizados 108 alevinos de tilápia-do-Nilo com peso inicial de 1,64±0,41 g e comprimento inicial médio de 3,60 ± 0,39 cm, durante um período de 55 dias. Os peixes foram distribuídos em um sistema de recirculação de água, em delineamento inteiramente casualizado com três tratamentos e quatro repetições: Controle - CO - (peixes alimentados até a saciedade aparente durante todo período experimental); jejum 10 - J10 - (peixes alimentados até a saciedade aparente por 15 dias, seguidos de 10 dias de jejum e realimentação até a saciedade por 30 dias); e jejum 15 - J15 - (peixes alimentados até a saciedade aparente por 15 dias, seguidos de 15 dias de jejum e realimentação até a saciedade por 25 dias). Os peixes do tratamento J15 apresentaram resultados insatisfatórios de desempenho produtivo (p<0,05), como menor peso final, conversão alimentar aparente, taxa de eficiência proteica e sobrevivência, enquanto os peixes do tratamento J10, atingiram os mesmos resultados daqueles animais mantidos no tratamento CO, com exceção das variáveis de ganho em peso relativo e do consumo de ração. A restrição alimentar influenciou diretamente no crescimento das fibras musculares com diâmetro menor que 20 µm (p<0,05), sendo que os peixes do tratamento J15 apresentaram a menor frequência de fibras nesta classe de diâmetro. Conclui-se que a restrição alimentar em curtos períodos (10 dias) e em temperaturas amenas podem apresentar um crescimento compensatório, alterando o processo de hiperplasia e hipertrofia das fibras musculares, sem afetar a morfologia das fibras, entretanto, 15 dias de jejum e sob temperaturas amenas não ocorre uma compensação no crescimento e atrasa o crescimento hipertrófico das fibras musculares.(AU)

Molecular investigations of the effect of thermal manipulation during embryogenesis on muscle heat shock protein 70 and thermotolerance in broiler chickens

The objective of this study was to elucidate the optimum protocol timing of thermal manipulation (TM) during embryogenesis, which underline genetic improvement of muscle thermotolerance acquisition. For the present study, 1,440 fertile eggs were divided randomly and equally into control (37.8 °C with 56% relative humidity) and four thermally manipulated groups (TM1, TM2, TM3, and TM4) subjected to 39 °C for 18 h with 65% relative humidity daily during different embryonic periods. Then, at day 35 post-hatch, all groups were subjected to thermal challenge at 43 °C for 6 h to identify the level of thermotolerance acquisition differences between them. Hsp70 mRNA expression was evaluated by using a relative quantitatively RT-qPCR. Single nucleotide polymorphisms sequence of the Hsp70 gene was evaluated by Sanger's sequencing method. Pectoral and thigh muscles samples were subjected to immunohistochemistry to detect Hsp70. Among TM conditions that were investigated, TM1 (39 °C for 18 h during embryonic days (ED) 7­11) induced a significant improvement in thermotolerance parameters (body temperature and T3 levels) during thermal challenge combined with an increase in the levels of Hsp70 mRNA and its protein with a high stability of nucleotide sequences in both pectoral and thigh muscles. The partial DNA sequence of Hsp70 gene in TM1 was reported, and nucleotide sequences were deposited in NCBI GenBank database with the accession numbers (MK852579) and (MK852580). Thigh muscle thermotolerance acquisition was higher than pectoral muscle during thermal challenge at 43 °C for 6 h. Thus, TM during ED7­11 may improve thermotolerance acquisition without adversely affecting performance.(AU)

Antinutritional effect of lectin from faveira (Parkia platycephala) seeds in tambatinga (Colossoma macropomum x Piaractus brachypomus) / Efeito antinutricional da lectina de sementes de faveira (Parkia platycephala) em tambatinga (Colossoma macropomum x Piaractus brachypomus)

This study investigated the possible antinutritional effects of Parkia platycephala lectin (0, 20, 40, or 60 mg kg-1 of diet) on tambatinga feeding for 60 days as well as methods of inactivating this protein. Weight gain, specific growth rate, and relative weight gain decreased, and the feed conversion rate increased with the increase in dietary lectin. The hepatic glycogen levels of fish fed 60 mg kg-1 were higher than those of fish fed 20 and 40 mg kg-1. Diets containing 40 and 60 mg kg-1 increased muscle glucose levels compared to the control group. Fish-fed diets containing lectin showed reduced muscle glycogen compared to those receiving the control diet. Fish fed 60 mg kg-1 presented lower muscle protein levels than those fed 20 mg kg-1. In vitro tests showed that the hemagglutination activity of lectin was inhibited by d-mannose, d-glucose, and α-methyl-d-mannopyranoside. Thermal treatment at 50­60°C was sufficient to reduce the action of lectin, as well as a pH below and above the 6­7 range. Therefore, the use of P. platycephala meals as a dietary ingredient for tambatinga with no lectin inac-tivation is not recommended as it can negatively affect the fish's biochemical parameters and growth. Acid or alkaline solutions can be an alternative for inactivating the protein and improving its use by fish and other animals.(AU)

Este estudo investigou possíveis efeitos antinutricionais da lectina de Parkia platycephala (0, 20, 40 ou 60 mg kg-1 de dieta) na alimentação de tambatinga por 60 dias, bem como métodos de inativação dessa proteína. O ganho de peso, a taxa de crescimento específico e o ganho de peso relativo diminu-íram, enquanto o índice de conversão alimentar aumentou com o incremento de lectina na dieta. Os níveis de glicogênio hepático dos peixes alimentados com 60 mg kg-1 foram superiores aos dos que ingeriram 20 e 40 mg kg-1. Dietas contendo 40 e 60 mg kg-1 aumentaram os níveis de glicose muscular em comparação com os que receberam a dieta controle. Nos animais cuja dieta continha lectina, redu-ziu-se o glicogênio muscular em comparação com os da dieta controle. Os espécimes alimentados com 60 mg kg-1 apresentaram menor nível de proteína muscular do que aqueles que consumiram 20 mg kg-1. Testes in vitro mostraram que a atividade de hemaglutinação da lectina foi inibida por D-mano-se, D-glicose e α-metil-D-manopiranosídeo. O tratamento térmico entre 50 e 60°C foi suficiente para reduzir a ação da lectina, assim como o pH abaixo de 6 e acima de 7. Portanto, usar farelo de P. pla-tycephala como ingrediente em dieta para tambatinga sem inativação da lectina não é recomendado, pois pode afetar negativamente os parâmetros bioquímicos e o crescimento dos exemplares. Soluções ácidas ou alcalinas podem ser uma alternativa para inativar a proteína e melhorar sua utilização em peixes e outros animais.(AU)

Effect of one-time high load exercise on skeletal muscle injury in rats of different genders: oxidative stress and mitochondrial responses

Purpose: To evaluate the impact of one-time high load exercise on skeletal muscle injury and analysis its mechanism in different genders. Methods: Twenty-four male and 24 female rats were divided randomly into four groups respectively: control, 0 h, 6 h, and 24 h after exercise. The activities of creatine kinase (CK), lactate dehydrogenase (LDH), and myohemoglobin (MYO) in serum, the expression level of oxidative stress markers, mitochondrial respiratory chain complex enzyme, and the apoptosis related protein in quadriceps were detected. Results: The results showed that the activities of CK, LDH and MYO in serum increased immediately after exercise and restored faster in female rats. More obvious structural disorder and apoptosis in male rats were showed. Malondialdehyde (MDA) and superoxide dismutase (SOD) were increased while catalase (CAT) and glutathione (GSH) were decreased in male rats. SOD, CAT and GSH were increased in female rats. Mitochondrial complex enzyme activity was decreased in males and increased in females. Conclusions: The skeletal muscle injury in both genders of rat could be induced by one-time high load exercise due to the mitochondrial respiratory enzyme dysfunction and oxidative stress, which was relatively mild and recovered quicker in female rats.

Effect of growth and carcass traits on likelihood of early pregnancy in Nellore heifers raised at intensive nutritional plan

This study evaluated the influence of the quantitative traits measured by real-time ultrasound (adjusted longissimus muscle area [AdjLMA], adjusted rump fat thickness [AdjRFT], and adjusted marbling [AdjMAR]) as well as age at first breeding [AFB] and adjusted weight [AdjWeight], on the probability of occurrence of early pregnancy (EP) in 55 Nellore heifers, and also performed an economic analysis. All calves received supplementation in creep-feeding (ad libitum), and at weaning (average age= 210 ± 30 days; average weight= 241 ± 33 kg) until first breeding by artificial insemination (May to November) all heifers were managed in the same group (two paddocks of 25 ha each evenly covered with Urochloa Marandu Grass) and received protein-energy supplementation (1% of average BW per animal/day). The quantitative variables were collected immediately after timed artificial insemination (average age= 392 ± 27 days; average weight= 431.90 kg), and the pregnancy diagnosis was completed at 30 days following insemination. For economic analysis, two systems were compared (age at first breeding at 13 and 24 months). The greater adjusted weight on the first breeding increased the probability of occurrence of early pregnancy, while the greater adjusted longissimus muscle area reduced. In addition, intensive meat production systems provide greater economic return throughout cow-calf operation.(AU)

New alternatives for improving and assessing the color of dark–cutting beef – a review

Myoglobin (Mb) is a sarcoplasmic heme protein present in muscle cells, which acts as a short–term oxygen (O2) reserve in the muscle tissue. After slaughtering and exsanguination, Mb is the major pigment that provides the red color in meat. The concentration of Mb together with its redox state are two pivotal factors that determine meat color. The elevated pH of dark–cutting beef can affect both physical and biochemical properties resulting in decreased oxygenation. The darkening observed in high ultimate pH (pHu) beef concerns meat processors as color is the initial attribute that impacts on the purchase. Thus, any atypical meat color (i.e., loss of brightness) reduces consumer interest in the product. Several studies have demonstrated that immunological castration is effective in preventing both aggressive behavior and undesirable dark–cutting of bull meat. However, little information is available on the effects of processing techniques that limit the oxidation of ferrous iron (Fe2+), Mb or promote metmyoglobin (MMb) reduction in dark–cutting beef. Because of the importance of color to fresh beef marketability, this review aimed at overviewing the significance of pHu in beef color and color stability and to discuss new alternatives for improving and assessing the beef color of dark–cutting beef, especially in Nellore bulls and their crossbreds, which are widely used in beef cattle production in Brazil.

New alternatives for improving and assessing the color of dark­cutting beef ­ a review

Myoglobin (Mb) is a sarcoplasmic heme protein present in muscle cells, which acts as a short­term oxygen (O2) reserve in the muscle tissue. After slaughtering and exsanguination, Mb is the major pigment that provides the red color in meat. The concentration of Mb together with its redox state are two pivotal factors that determine meat color. The elevated pH of dark­cutting beef can affect both physical and biochemical properties resulting in decreased oxygenation. The darkening observed in high ultimate pH (pHu) beef concerns meat processors as color is the initial attribute that impacts on the purchase. Thus, any atypical meat color (i.e., loss of brightness) reduces consumer interest in the product. Several studies have demonstrated that immunological castration is effective in preventing both aggressive behavior and undesirable dark­cutting of bull meat. However, little information is available on the effects of processing techniques that limit the oxidation of ferrous iron (Fe2+), Mb or promote metmyoglobin (MMb) reduction in dark­cutting beef. Because of the importance of color to fresh beef marketability, this review aimed at overviewing the significance of pHu in beef color and color stability and to discuss new alternatives for improving and assessing the beef color of dark­cutting beef, especially in Nellore bulls and their crossbreds, which are widely used in beef cattle production in Brazil.(AU)