Deleterious Effects of Polypropylene Microplastic Ingestion in Nile Tilapia (Oreochromis niloticus).

The effect of daily ingestion of polypropylene microplastic on the health of tilapia, Oreochromis niloticus, was evaluated. 60 fish (± 200 g) were placed in 6 aquariums (n = 10, 100 L each), constituting the following treatments: Control (without the addition of polymer), fed with 100 and 500 µg of polypropylene/kg of body weight (b.w.), respectively. After 30 days of feeding, the animals were submitted to blood collection for hemogram and biochemical study and later euthanized for gut microbiological analysis, somatic index of liver, spleen, heart, kidney, stomach, and intestine. In the serum biochemical study, an increase in cholesterol and serum Aspartate Aminotransferase (AST) activity levels was observed in animals treated with 500 µg of polypropylene. Tilapia-fed polypropylene in the diet showed an increase in thrombocyte and total leukocyte counts, marked by a significant increase in the number of circulating lymphocytes. The results of the somatic study revealed a significant increase in the stomach, liver, and heart of tilapia fed with the polymer. Increase in the number of Gram-negative microorganisms and decrease in mesophilic aerobic microorganisms were observed in the gut of fish exposed to the polymer, including a dose-response effect was observed for these analyses. Therefore, tilapias fed daily with diets containing polypropylene for 30 consecutive days showed deleterious effects, resulting in systemic inflammatory disturbs by altering liver functions, leukocyte profile, and organ morphometry, as well as changes in the intestinal microbiota. Such results demonstrate the impairment of fish health, highlighting the need for further studies that evaluate the impact of microplastics on aquatic organisms.

Molecular evidence for stimulation of methane oxidation in Amazonian floodplains by ammonia-oxidizing communities.

Ammonia oxidation is the rate-limiting first step of nitrification and a key process in the nitrogen cycle that results in the formation of nitrite (NO2 -), which can be further oxidized to nitrate (NO3 -). In the Amazonian floodplains, soils are subjected to extended seasons of flooding during the rainy season, in which they can become anoxic and produce a significant amount of methane (CH4). Various microorganisms in this anoxic environment can couple the reduction of different ions, such as NO2 - and NO3 -, with the oxidation of CH4 for energy production and effectively link the carbon and nitrogen cycle. Here, we addressed the composition of ammonium (NH4 +) and NO3 --and NO2 --dependent CH4-oxidizing microbial communities in an Amazonian floodplain. In addition, we analyzed the influence of environmental and geochemical factors on these microbial communities. Soil samples were collected from different layers of forest and agroforest land-use systems during the flood and non-flood seasons in the floodplain of the Tocantins River, and next-generation sequencing of archaeal and bacterial 16S rRNA amplicons was performed, coupled with chemical characterization of the soils. We found that ammonia-oxidizing archaea (AOA) were more abundant than ammonia-oxidizing bacteria (AOB) during both flood and non-flood seasons. Nitrogen-dependent anaerobic methane oxidizers (N-DAMO) from both the archaeal and bacterial domains were also found in both seasons, with higher abundance in the flood season. The different seasons, land uses, and depths analyzed had a significant influence on the soil chemical factors and also affected the abundance and composition of AOA, AOB, and N-DAMO. During the flood season, there was a significant correlation between ammonia oxidizers and N-DAMO, indicating the possible role of these oxidizers in providing oxidized nitrogen species for methanotrophy under anaerobic conditions, which is essential for nitrogen removal in these soils.

Vaginal cytology in mares in the different stages of the estral cycle associated with the seasons of the year / Citologia vaginal em éguas nas diferentes fases do ciclo estral associadas as estações do ano

The reproductive biotechnologies directly assist in the development of different methods of reproductive evaluation. The objective of this study was to develop a new method to determine the estrous cycle phase in equine females through vaginal cytology throughout the seasons, as well as to establish an estimate of inflammatory cells present in the vagina. Six mares were evaluated at different ages without a defined breed and reproductive activity and were subjected to ultrasound evaluation of the reproductive system and cytological analysis of the vaginal region. In the summer, there was a predominance of keratinized epithelial cells in the estrus and intermediate in the diestrus. In the autumn, there was a predominance of keratinized cells in estrus and parabasal cells in estrus and diestrus. In anestrus (winter), a greater number of parabasal cells was identified in relation to the other cell types. In estrus (spring), there was a predominance of parabasal and intermediate cells. Conversely, in diestrus, parabasals were found in greater numbers. The evaluation of inflammatory cells of the vaginal epithelium of mares showed greater activity in the summer; however, there are no reference values for healthy animals in the literature, and it is necessary to conduct studies on the subject. It is concluded that there is an influence of cyclicity on the vaginal epithelium of the equine species, varying according to the season. Additionally, vaginal cytological evaluation is an important complementary tool in the diagnosis of vaginitis in mares, requiring further research on the subject.(AU)

As biotecnologias reprodutivas auxiliam diretamente no desenvolvimento de diferentes métodos de avaliação repro-dutiva. O objetivo deste estudo foi desenvolver um novo método para determinar a fase do ciclo estral em fêmeas equinas através da citologia vaginal ao longo das estações, bem como estabelecer uma estimativa das células inflamatórias presentes na vagina. Seis éguas foram avaliadas em diferentes idades, sem raça definida e em atividade reprodutiva, e foram submetidas à avaliação ultrassonográfica do aparelho reprodutor e análise citológica da região vaginal. No verão, houve predomínio de células epiteliais queratinizadas no estro e intermediárias no diestro. No outono, houve predomínio de células queratinizadas no estro e células parabasais no estro e diestro. No anestro (inverno), foi identificado maior número de células parabasais em relação aos demais tipos celulares. No estro (primavera), houve predomínio de células parabasais e intermediárias. Por outro lado, no diestro, os parabasais foram encontrados em maior número. A avaliação das células inflamatórias do epitélio vaginal de éguas mostrou maior atividade no verão; entretanto, não há valores de referência para animais saudáveis na literatura, sendo necessário a rea-lização de estudos sobre o assunto. Conclui-se que há influência da ciclicidade no epitélio vaginal da espécie equina, variando de acordo com a estação do ano. Além disso, a avaliação citológica vaginal é uma importante ferramenta complementar no diagnóstico da vaginite em éguas, necessitando de mais pesquisas sobre o assunto.(AU)

Influence of Vitrification Device, Warming Protocol, and Subsequent In Vitro Culture on Structural Integrity of Testicular Fragments from Adult Domestic Cats.

The objective of the study was to evaluate the integrity of cat testicular tissues after vitrification with different devices followed by different warming conditions. The influence of vitro culture for 24 hours after warming also was examined. Testicular tissues from adult domestic cats were dissected in small fragments that were vitrified using Cryotop® or threaded on fine needles, warmed (directly at 37°C or with a preliminary 10 seconds exposure to 50°C), and/or cultured in vitro for an additional 24 hours. For each treatment group, tissues were assessed based on histology, apoptosis, and sperm DNA integrity. Results showed that fragments of testicular tissues were efficiently cryopreserved (maintaining the quality of all cell types) with vitrification with Cryotop followed by direct warming at 37°C, and additional culture of 24 hours at 38.5°C. These encouraging results are paving the road to optimize preservation protocols and use them for systematic banking of tissues from genetically valuable felids.

Vitrification of cat ovarian tissue: Does fragment size matters?

The aim of the present study was to investigate whether or not the size of the ovarian fragment influences its resistance to cryostorage. For that purpose, ovaries were collected from 34 queens (various breeds, age 1-5 year) by routine ovariectomy, transported to the laboratory and then sectioned in different sizes (3 mm × 3 mm × 3 mm, 5 mm × 3 mm × 3 mm and 7 mm × 3 mm × 3 mm) and randomly assigned to a control (GC3, GC5 and GC7, respectively) or vitrified (GV3, GV5 and GV7, respectively) groups. Vitrified-warmed fragments were evaluated by histomorphology and immunohistochemistry (for apoptotic rates by using cleaved caspase-3). Histological examination reveals that 72.97% of the follicles in GV3 and 72.58% in GV5 were normal while only 42.86% of the follicles in GV7. The main morphological alteration presented in all groups was a detachment of the epithelial cells. Similarly, immunohistochemistry evaluation using caspase 3 revealed a small proportion of apoptotic cells in GV3 (8.43%) while in GV7 30.43% of the cells expressed cleaved caspase-3. These findings indicate that fragments sectioned in 3 mm × 3 mm × 3 mm (27 mm3 ) seem more adequate for perfusion of the cryoprotectant, causing less damage to the cell after vitrification-warming.

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.

Cat epididymal semen cryopreserved with and without vitamin E: effect on sperm parameters and lipid peroxidation.

The aims of this study were to investigate: 1) if the addition of α-tocopherol (vitamin E) in three concentrations (0.3, 0.6 and 0.9 mM) is able to preserve spermatozoa integrity after thawing and 2) the effect of α-tocopherol supplementation on lipid peroxidation. Fifty four domestic cats were used in this study constituting 18 pools (3 cats per pool). Each pool was submitted at four experimental groups: group 0 (control) - epididymal sperm were frozen with a commercial Botucrio® extender; group 0.3, group 0.6 and group 0.9 - the extender was supplemented with 0.3, 0.6 and 0.9 mM of α-tocopherol, respectively. Each semen sample was evaluated for motility, progressive forward motility, morphology, sperm viability (plasma membrane integrity-PMI), hypo-osmotic swelling test (HOST), before and after thawing. The evaluation of lipid peroxidation reaction by Thiobarbituric Acid Reactive Substances (TBARS) test was performed on thawed semen only. Results demonstrated that there was no significant difference between control and the three α-tocopherol groups with regards to motility and progressive motility after thawing (P > 0.05). As expected, in fresh samples viability was significantly higher than in all the cryopreserved groups in which there was no positive influence of any of the α-tocopherol concentration used. Lipid peroxidation was higher in the supplemented groups 0.6 and 0.9 mM of α-tocopherol than in control and in 0.3 mM group. In conclusion, the addition of α-tocopherol to the commercial extender had no positive influence on reduction of lipid peroxidation. This topic deserves further investigations to better understand the effect of cryopreservation procedures on epididymal spermatozoa and to establish adequate strategies to counteract sperm cryodamages.

Cat epididymal semen cryopreserved with and without vitamin E: effect on sperm parameters and lipid peroxidation

The aims of this study were to investigate: 1) if the addition of α-tocopherol (vitamin E) in three concentrations (0.3, 0.6 and 0.9 mM) is able to preserve spermatozoa integrity after thawing and 2) the effect of α-tocopherol supplementation on lipid peroxidation. Fifty four domestic cats were used in this study constituting 18 pools (3 cats per pool). Each pool was submitted at four experimental groups: group 0 (control) epididymal sperm were frozen with a commercial Botucrio® extender; group 0.3, group 0.6 and group 0.9 the extender was supplemented with 0.3, 0.6 and 0.9 mM of α-tocopherol, respectively. Each semen sample was evaluated for motility, progressive forward motility, morphology, sperm viability (plasma membrane integrity-PMI), hypo-osmotic swelling test (HOST), before and after thawing. The evaluation of lipid peroxidation reaction by Thiobarbituric Acid Reactive Substances (TBARS) test was performed on thawed semen only. Results demonstrated that there was no significant difference between control and the three α-tocopherol groups with regards to motility and progressive motility after thawing (P > 0.05). As expected, in fresh samples viability was significantly higher than in all the cryopreserved groups in which there was no positive influence of any of the αtocopherol concentration used. Lipid peroxidation was higher in the supplemented groups 0.6 and 0.9 mM of α-tocopherol than in control and in 0.3 mM group. In conclusion, the addition of α-tocopherol to the commercial extender had no positive influence on reduction of lipid peroxidation. This topic deserves further investigations to better understand the effect of cryopreservation procedures on epididymal spermatozoa and to establish adequate strategies to counteract sperm cryodamages.(AU)

Cat epididymal semen cryopreserved with and without vitamin E: effect on sperm parameters and lipid peroxidation

The aims of this study were to investigate: 1) if the addition of α-tocopherol (vitamin E) in three concentrations (0.3, 0.6 and 0.9 mM) is able to preserve spermatozoa integrity after thawing and 2) the effect of α-tocopherol supplementation on lipid peroxidation. Fifty four domestic cats were used in this study constituting 18 pools (3 cats per pool). Each pool was submitted at four experimental groups: group 0 (control) – epididymal sperm were frozen with a commercial Botucrio® extender; group 0.3, group 0.6 and group 0.9 – the extender was supplemented with 0.3, 0.6 and 0.9 mM of α-tocopherol, respectively. Each semen sample was evaluated for motility, progressive forward motility, morphology, sperm viability (plasma membrane integrity-PMI), hypo-osmotic swelling test (HOST), before and after thawing. The evaluation of lipid peroxidation reaction by Thiobarbituric Acid Reactive Substances (TBARS) test was performed on thawed semen only. Results demonstrated that there was no significant difference between control and the three α-tocopherol groups with regards to motility and progressive motility after thawing (P > 0.05). As expected, in fresh samples viability was significantly higher than in all the cryopreserved groups in which there was no positive influence of any of the αtocopherol concentration used. Lipid peroxidation was higher in the supplemented groups 0.6 and 0.9 mM of α-tocopherol than in control and in 0.3 mM group. In conclusion, the addition of α-tocopherol to the commercial extender had no positive influence on reduction of lipid peroxidation. This topic deserves further investigations to better understand the effect of cryopreservation procedures on epididymal spermatozoa and to establish adequate strategies to counteract sperm cryodamages.

Determining the daily digestible protein intake for Nile tilapia at different growth stages / Determinação da ingestão diária de proteína digestível para tilápia-do-Nilo em diferentes fases de crescimento

This study aimed to estimate the utilization efficiency and optimal intake of digestible protein to maximize weight gain and feed conversion in Nile tilapia juveniles at different development stages. Four trials, each lasting 45 days, were performed using sexually inverted Nile tilapia juveniles with an initial average weight of 2.01 g (phase A), 14.26 g (phase B), 59.96 g (phase C), and 149.11 g (phase D). The experimental design was completely randomized with five treatments and four replicates. The levels of digestible protein ranged from 175 to 425 g kg-1 (phase A), 163 to 390 g kg-1 (phase B), 150 to 360 g kg-1 (phase C), and 138 to 330 g kg-1 (phase D). The maximum responses in terms of weight gain were obtained with protein intakes (digestible protein) of 88, 328, 713, and 855 mg fish-1 day-1, respectively, for phases A, B, C, and D. The maximum feed conversion ratio was obtained with protein intakes of 78, 272, 697, and 793 mg fish-1 day-1, respectively, for phases A, B, C, and D. The protein utilization efficiency was 52, 51, 51, and 50% for phases A, B, C, and D, respectively.(AU)

Objetivou-se estimar a eficiência de utilização e a ingestão ótima de proteína digestível para maximizar o ganho de peso e a conversão alimentar de juvenis de tilápia do Nilo em diferentes fases de crescimento. Cada um dos quatro ensaios durou 45 dias, utilizando-se juvenis revertidos sexualmente com peso médio inicial de 2,01g (fase A), 14,26 g (fase B), 59,96 g (fase C) e 149,11 g (fase D). O delineamento adotado foi o inteiramente ao acaso, com cinco tratamentos e quatro repetições. Os níveis de proteína digestível variaram de 175 a 425 g kg-1 (fase A), de 163 a 390 g kg-1 (fase B), de 150 a 360 g kg-1 (fase C) e de 138 a 330 g kg-1 (fase D). As máximas respostas para ganho de peso foram estimadas com ingestões de proteína de 88, 328, 713 e 855 mg peixe-1 dia-1 nas fases A, B, C e D, respectivamente. Para maximizar a conversão alimentar estimaram-se ingestões de proteína de 78, 272, 697 e 793 mg peixe-1 dia-1 para as fases A, B, C e D, respectivamente. As eficiências de utilização da proteína encontradas para as fases A, B, C e D, foram 52, 51, 51 e 50%, respectivamente.(AU)

Determining the daily digestible protein intake for Nile tilapia at different growth stages / Determinação da ingestão diária de proteína digestível para tilápia-do-Nilo em diferentes fases de crescimento

This study aimed to estimate the utilization efficiency and optimal intake of digestible protein to maximize weight gain and feed conversion in Nile tilapia juveniles at different development stages. Four trials, each lasting 45 days, were performed using sexually inverted Nile tilapia juveniles with an initial average weight of 2.01 g (phase A), 14.26 g (phase B), 59.96 g (phase C), and 149.11 g (phase D). The experimental design was completely randomized with five treatments and four replicates. The levels of digestible protein ranged from 175 to 425 g kg-1 (phase A), 163 to 390 g kg-1 (phase B), 150 to 360 g kg-1 (phase C), and 138 to 330 g kg-1 (phase D). The maximum responses in terms of weight gain were obtained with protein intakes (digestible protein) of 88, 328, 713, and 855 mg fish-1 day-1, respectively, for phases A, B, C, and D. The maximum feed conversion ratio was obtained with protein intakes of 78, 272, 697, and 793 mg fish-1 day-1, respectively, for phases A, B, C, and D. The protein utilization efficiency was 52, 51, 51, and 50% for phases A, B, C, and D, respectively.

Objetivou-se estimar a eficiência de utilização e a ingestão ótima de proteína digestível para maximizar o ganho de peso e a conversão alimentar de juvenis de tilápia do Nilo em diferentes fases de crescimento. Cada um dos quatro ensaios durou 45 dias, utilizando-se juvenis revertidos sexualmente com peso médio inicial de 2,01g (fase A), 14,26 g (fase B), 59,96 g (fase C) e 149,11 g (fase D). O delineamento adotado foi o inteiramente ao acaso, com cinco tratamentos e quatro repetições. Os níveis de proteína digestível variaram de 175 a 425 g kg-1 (fase A), de 163 a 390 g kg-1 (fase B), de 150 a 360 g kg-1 (fase C) e de 138 a 330 g kg-1 (fase D). As máximas respostas para ganho de peso foram estimadas com ingestões de proteína de 88, 328, 713 e 855 mg peixe-1 dia-1 nas fases A, B, C e D, respectivamente. Para maximizar a conversão alimentar estimaram-se ingestões de proteína de 78, 272, 697 e 793 mg peixe-1 dia-1 para as fases A, B, C e D, respectivamente. As eficiências de utilização da proteína encontradas para as fases A, B, C e D, foram 52, 51, 51 e 50%, respectivamente.

Determining the daily digestible protein intake for Nile tilapia at different growth stages / Determinação da ingestão diária de proteína digestível para tilápia-do-nilo em diferentes fases de crescimento

This study aimed to estimate the utilization efficiency and optimal intake of digestible protein to maximize weight gain and feed conversion in Nile tilapia juveniles at different development stages. Four trials, each lasting 45 days, were performed using sexually inverted Nile tilapia juveniles with an initial average weight of 2.01 g (phase A), 14.26 g (phase B), 59.96 g (phase C), and 149.11 g (phase D). The experimental design was completely randomized, with five treatments and four replicates. The levels of digestible protein ranged from 175 to 425 g kg-1 (phase A), 163 to 390 g kg-1 (phase B), 150 to 360 g kg-1 (phase C), and 138 to 330 g kg-1 (phase D). The maximum responses in terms of weight gain were obtained with protein intakes (digestible protein) of 88, 328, 713, and 855 mg fish-1 day-1, respectively for phases A, B, C, and D. The maximum feed conversion ratio was obtained with protein intakes of 78, 272, 697, and 793 mg fish-1 day-1, respectively for phases A, B, C, and D. The protein utilization efficiency was 52, 51, 51, and 50% for phases A, B, C, and D respectively.

Objetivou-se estimar a eficiência de utilização e a ingestão ótima de proteína digestível para maximizar o ganho de peso e a conversão alimentar de juvenis de tilápia-do-nilo em diferentes fases de crescimento. Cada um dos quatro ensaios durou 45 dias, utilizando-se juvenis revertidos sexualmente com peso médio inicial de 2,01g (fase A); 14,26 g (fase B); 59,96 g (fase C) e 149,11 g (fase D). O delineamento adotado foi o inteiramente ao acaso, com cinco tratamentos e quatro repetições. Os níveis de proteína digestível variaram de 175 a 425 g kg-1 (fase A), de 163 a 390 g kg-1 (fase B), de 150 a 360 g kg-1 (fase C) e de 138 a 330 g kg-1 (fase D). As máximas respostas para ganho de peso foram estimadas com ingestões de proteína de 88, 328, 713 e 855 mg peixe-1 dia-1 nas fases A, B, C e D respectivamente. Para maximizar a conversão alimentar estimaram-se ingestões de proteína de 78, 272, 697 e 793 mg peixe-1 dia-1 para as fases A, B, C e D respectivamente. As eficiências de utilização da proteína encontradas para as fases A, B, C e D foram 52, 51, 51 e 50% respectivamente.

Determining the daily digestible protein intake for Nile tilapia at different growth stages / Determinação da ingestão diária de proteína digestível para tilápia-do-nilo em diferentes fases de crescimento

This study aimed to estimate the utilization efficiency and optimal intake of digestible protein to maximize weight gain and feed conversion in Nile tilapia juveniles at different development stages. Four trials, each lasting 45 days, were performed using sexually inverted Nile tilapia juveniles with an initial average weight of 2.01 g (phase A), 14.26 g (phase B), 59.96 g (phase C), and 149.11 g (phase D). The experimental design was completely randomized, with five treatments and four replicates. The levels of digestible protein ranged from 175 to 425 g kg-1 (phase A), 163 to 390 g kg-1 (phase B), 150 to 360 g kg-1 (phase C), and 138 to 330 g kg-1 (phase D). The maximum responses in terms of weight gain were obtained with protein intakes (digestible protein) of 88, 328, 713, and 855 mg fish-1 day-1, respectively for phases A, B, C, and D. The maximum feed conversion ratio was obtained with protein intakes of 78, 272, 697, and 793 mg fish-1 day-1, respectively for phases A, B, C, and D. The protein utilization efficiency was 52, 51, 51, and 50% for phases A, B, C, and D respectively.

Objetivou-se estimar a eficiência de utilização e a ingestão ótima de proteína digestível para maximizar o ganho de peso e a conversão alimentar de juvenis de tilápia-do-nilo em diferentes fases de crescimento. Cada um dos quatro ensaios durou 45 dias, utilizando-se juvenis revertidos sexualmente com peso médio inicial de 2,01g (fase A); 14,26 g (fase B); 59,96 g (fase C) e 149,11 g (fase D). O delineamento adotado foi o inteiramente ao acaso, com cinco tratamentos e quatro repetições. Os níveis de proteína digestível variaram de 175 a 425 g kg-1 (fase A), de 163 a 390 g kg-1 (fase B), de 150 a 360 g kg-1 (fase C) e de 138 a 330 g kg-1 (fase D). As máximas respostas para ganho de peso foram estimadas com ingestões de proteína de 88, 328, 713 e 855 mg peixe-1 dia-1 nas fases A, B, C e D respectivamente. Para maximizar a conversão alimentar estimaram-se ingestões de proteína de 78, 272, 697 e 793 mg peixe-1 dia-1 para as fases A, B, C e D respectivamente. As eficiências de utilização da proteína encontradas para as fases A, B, C e D foram 52, 51, 51 e 50% respectivamente.

Diferentes níveis protéicos na dieta de girinos de rã-touro (Lithobates catesbeianus) e seus efeitos sobre o tecido hepático / Different protein levels in the diet of bullfrog tadpoles (Lithobates catesbeianus) and its effects on the liver tissue

Para verificação da ocorrência de alterações morfológicas no fígado, foram coletados dez animais de cada dieta, no 30º dia (1º período experimental) e no 60º dia (2º período experimental), sendo esse, o último dia do período experimental e início do clímax da metamorfose. Os girinos foram distribuídos em delineamento experimental inteiramente casualizado (DIC) com três tratamentos: dieta experimental com 32,68% de proteína bruta e duas dietas comerciais com 37,92% e 57,53% de proteína bruta. Os órgãos coletados foram fixados em solução de Bouin e depois submetidos às práticas da rotina histotecnológica e coradas com hematoxilina - Eosina (HE). Na avaliação microscópica do fígado foram encontradas diversas alterações morfológicas como: Desorganização e vacuolização de hepatócitos, infiltrado inflamatório mononuclear periportal, multifocal e difuso, infiltrado inflamatório eosinofílico, congestão, hemorragia, hemólise e necrose. As alterações hepáticas encontradas neste estudo sugerem que as dietas utilizadas para os girinos de rã-touro, não atenderam suas necessidades dietéticas, afetando a homeostasia dos mesmos, comprometendo assim, sua sanidade.(AU)

To verify the occurrence of liver morphological changes, bullfrog tadpoles were fed three diets: an experimental diet with 32.68% crude protein and two commercial diets with 37.92% and 57.53% crude protein. Tadpoles were distributed into a completely randomized design (CRD) with three treatments and four replications. Liver samples were collected twice, on the 30th and 60th day of the experiment. Tadpole livers were fixed in Bouin's solution, then subjected to routine histotechnology procedures, and stained with hematoxylin - eosin (HE). Microscopic evaluation of liver tissue showed several morphological changes like disorganization and vacuolization of hepatocytes; periportal, multifocal and diffuse mononuclear inflammatory infiltrate, eosinophilic inflammatory infiltration, congestion, hemorrhage, hemolysis and necrosis. The liver changes found in this study suggest that diets used for bullfrog tadpoles, did not meet their dietary needs, what affected their homeostasis, thus compromising their health.(AU)

Diferentes níveis protéicos na dieta de girinos de rã-touro (Lithobates catesbeianus) e seus efeitos sobre o tecido hepático / Different protein levels in the diet of bullfrog tadpoles (Lithobates catesbeianus) and its effects on the liver tissue

Para verificação da ocorrência de alterações morfológicas no fígado, foram coletados dez animais de cada dieta, no 30º dia (1º período experimental) e no 60º dia (2º período experimental), sendo esse, o último dia do período experimental e início do clímax da metamorfose. Os girinos foram distribuídos em delineamento experimental inteiramente casualizado (DIC) com três tratamentos: dieta experimental com 32,68% de proteína bruta e duas dietas comerciais com 37,92% e 57,53% de proteína bruta. Os órgãos coletados foram fixados em solução de Bouin e depois submetidos às práticas da rotina histotecnológica e coradas com hematoxilina - Eosina (HE). Na avaliação microscópica do fígado foram encontradas diversas alterações morfológicas como: Desorganização e vacuolização de hepatócitos, infiltrado inflamatório mononuclear periportal, multifocal e difuso, infiltrado inflamatório eosinofílico, congestão, hemorragia, hemólise e necrose. As alterações hepáticas encontradas neste estudo sugerem que as dietas utilizadas para os girinos de rã-touro, não atenderam suas necessidades dietéticas, afetando a homeostasia dos mesmos, comprometendo assim, sua sanidade.(AU)

To verify the occurrence of liver morphological changes, bullfrog tadpoles were fed three diets: an experimental diet with 32.68% crude protein and two commercial diets with 37.92% and 57.53% crude protein. Tadpoles were distributed into a completely randomized design (CRD) with three treatments and four replications. Liver samples were collected twice, on the 30th and 60th day of the experiment. Tadpole livers were fixed in Bouin's solution, then subjected to routine histotechnology procedures, and stained with hematoxylin - eosin (HE). Microscopic evaluation of liver tissue showed several morphological changes like disorganization and vacuolization of hepatocytes; periportal, multifocal and diffuse mononuclear inflammatory infiltrate, eosinophilic inflammatory infiltration, congestion, hemorrhage, hemolysis and necrosis. The liver changes found in this study suggest that diets used for bullfrog tadpoles, did not meet their dietary needs, what affected their homeostasis, thus compromising their health.(AU)

Nonlinear models for morphometric analysis in Bullfrog Tadpoles / Análise morfométrica através de modelos não-lineares para girinos de rã-touro

Biometric relationships are important to illustrate the growth of animals. When adjusted using nonlinear models, these relationships can provide important information that contributes to the improvement of breeding techniques. In this study, morphometric data as a function of weight obtained in four experiments involving bullfrog tadpoles were adjusted using Gompertz, Logistic, Von Bertalanffy and Brody nonlinear models and the best-fit model was determined. After fitting the parameters to the different models in each experiment, the models were compared based on confidence intervals ( = 0.05). The following criteria were used for selection of the best model: biological interpretation, residual mean square, coefficient of determination, graphic analysis, and number of iterations. Standard and total length data as a function of tadpole weight converged in the four models. The Logistic and Gompertz models had no biological interpretation for some datasets. The Brody model provided the lowest residual mean square and number of iterations for the variables studied in all experiments. The Brody relative growth rate (K) was lower for total length when compared to standard length, indicating a greater initial growth in standard length. The Brody model was the best to describe the growth in standard and total length of bullfrog tadpoles as a function of weight.(AU)

As relações biométricas são importantes para ilustrar o processo de crescimento dos animais. Estas, quando ajustadas a modelos não-lineares, podem revelar informações importantes para a melhoria das técnicas de criação. O conjunto de dados morfométricos em função do peso, de quatro experimentos com girinos de rã-touro, foram ajustados aos modelos não-lineares de Gompertz, Logístico, Von Bertalanffy e Brody, com objetivo de verificar o melhor ajuste. Após a adequação dos parâmetros para os diferentes modelos em cada experimento seguiu-se com a comparação dos mesmos, por meio dos intervalos de confiança ( = 0,05). Os critérios para selecionar os modelos foram: interpretação biológica, quadrado médio do resíduo, coeficiente de determinação, análise gráfica e o número de iterações. Os dados de comprimentos padrão e total em função do peso dos girinos convergiram nos quatro modelos. Os modelos Logístico e Gompertz não apresentaram interpretação biológica para alguns conjuntos de dados. O quadrado médio do resíduo e número de iterações em todos os experimentos e variáveis estudadas apresentaram os menores valores para o modelo de Brody. Os valores de K dos modelos de Brody para comprimento total, quando comparados ao padrão, apresentaram-se menores, indicando que os animais apresentaram um crescimento inicial maior em comprimento padrão.(AU)

Nonlinear models for morphometric analysis in Bullfrog Tadpoles

SUMMARY Biometric relationships are important to illustrate the growth of animals. When adjusted using nonlinear models, these relationships can provide important information that contributes to the improvement of breeding techniques. In this study, morphometric data as a function of weight obtained in four experiments involving bullfrog tadpoles were adjusted using Gompertz, Logistic, Von Bertalanffy and Brody nonlinear models and the best-fit model was determined. After fitting the parameters to the different models in each experiment, the models were compared based on confidence intervals ( = 0.05). The following criteria were used for selection of the best model: biological interpretation, residual mean square, coefficient of determination, graphic analysis, and number of iterations. Standard and total length data as a function of tadpole weight converged in the four models. The Logistic and Gompertz models had no biological interpretation for some datasets. The Brody model provided the lowest residual mean square and number of iterations for the variables studied in all experiments. The Brody relative growth rate (K) was lower for total length when compared to standard length, indicating a greater initial growth in standard length. The Brody model was the best to describe the growth in standard and total length of bullfrog tadpoles as a function of weight.

RESUMO As relações biométricas são importantes para ilustrar o processo de crescimento dos animais. Estas, quando ajustadas a modelos não-lineares, podem revelar informações importantes para a melhoria das técnicas de criação. O conjunto de dados morfométricos em função do peso, de quatro experimentos com girinos de rã-touro, foram ajustados aos modelos não-lineares de Gompertz, Logístico, Von Bertalanffy e Brody, com objetivo de verificar o melhor ajuste. Após a adequação dos parâmetros para os diferentes modelos em cada experimento seguiu-se com a comparação dos mesmos, por meio dos intervalos de confiança ( = 0,05). Os critérios para selecionar os modelos foram: interpretação biológica, quadrado médio do resíduo, coeficiente de determinação, análise gráfica e o número de iterações. Os dados de comprimentos padrão e total em função do peso dos girinos convergiram nos quatro modelos. Os modelos Logístico e Gompertz não apresentaram interpretação biológica para alguns conjuntos de dados. O quadrado médio do resíduo e número de iterações em todos os experimentos e variáveis estudadas apresentaram os menores valores para o modelo de Brody. Os valores de K dos modelos de Brody para comprimento total, quando comparados ao padrão, apresentaram-se menores, indicando que os animais apresentaram um crescimento inicial maior em comprimento padrão. O modelo de Brody foi o mais indicado para descrever o comprimento padrão e total em função do peso para girinos de rã-touro.

Nonlinear models for morphometric analysis in Bullfrog Tadpoles / Análise morfométrica através de modelos não-lineares para girinos de rã-touro

Biometric relationships are important to illustrate the growth of animals. When adjusted using nonlinear models, these relationships can provide important information that contributes to the improvement of breeding techniques. In this study, morphometric data as a function of weight obtained in four experiments involving bullfrog tadpoles were adjusted using Gompertz, Logistic, Von Bertalanffy and Brody nonlinear models and the best-fit model was determined. After fitting the parameters to the different models in each experiment, the models were compared based on confidence intervals ( = 0.05). The following criteria were used for selection of the best model: biological interpretation, residual mean square, coefficient of determination, graphic analysis, and number of iterations. Standard and total length data as a function of tadpole weight converged in the four models. The Logistic and Gompertz models had no biological interpretation for some datasets. The Brody model provided the lowest residual mean square and number of iterations for the variables studied in all experiments. The Brody relative growth rate (K) was lower for total length when compared to standard length, indicating a greater initial growth in standard length. The Brody model was the best to describe the growth in standard and total length of bullfrog tadpoles as a function of weight.

As relações biométricas são importantes para ilustrar o processo de crescimento dos animais. Estas, quando ajustadas a modelos não-lineares, podem revelar informações importantes para a melhoria das técnicas de criação. O conjunto de dados morfométricos em função do peso, de quatro experimentos com girinos de rã-touro, foram ajustados aos modelos não-lineares de Gompertz, Logístico, Von Bertalanffy e Brody, com objetivo de verificar o melhor ajuste. Após a adequação dos parâmetros para os diferentes modelos em cada experimento seguiu-se com a comparação dos mesmos, por meio dos intervalos de confiança ( = 0,05). Os critérios para selecionar os modelos foram: interpretação biológica, quadrado médio do resíduo, coeficiente de determinação, análise gráfica e o número de iterações. Os dados de comprimentos padrão e total em função do peso dos girinos convergiram nos quatro modelos. Os modelos Logístico e Gompertz não apresentaram interpretação biológica para alguns conjuntos de dados. O quadrado médio do resíduo e número de iterações em todos os experimentos e variáveis estudadas apresentaram os menores valores para o modelo de Brody. Os valores de K dos modelos de Brody para comprimento total, quando comparados ao padrão, apresentaram-se menores, indicando que os animais apresentaram um crescimento inicial maior em comprimento padrão.

Nonlinear models for morphometric analysis in Bullfrog Tadpoles

SUMMARY Biometric relationships are important to illustrate the growth of animals. When adjusted using nonlinear models, these relationships can provide important information that contributes to the improvement of breeding techniques. In this study, morphometric data as a function of weight obtained in four experiments involving bullfrog tadpoles were adjusted using Gompertz, Logistic, Von Bertalanffy and Brody nonlinear models and the best-fit model was determined. After fitting the parameters to the different models in each experiment, the models were compared based on confidence intervals ( = 0.05). The following criteria were used for selection of the best model: biological interpretation, residual mean square, coefficient of determination, graphic analysis, and number of iterations. Standard and total length data as a function of tadpole weight converged in the four models. The Logistic and Gompertz models had no biological interpretation for some datasets. The Brody model provided the lowest residual mean square and number of iterations for the variables studied in all experiments. The Brody relative growth rate (K) was lower for total length when compared to standard length, indicating a greater initial growth in standard length. The Brody model was the best to describe the growth in standard and total length of bullfrog tadpoles as a function of weight.

RESUMO As relações biométricas são importantes para ilustrar o processo de crescimento dos animais. Estas, quando ajustadas a modelos não-lineares, podem revelar informações importantes para a melhoria das técnicas de criação. O conjunto de dados morfométricos em função do peso, de quatro experimentos com girinos de rã-touro, foram ajustados aos modelos não-lineares de Gompertz, Logístico, Von Bertalanffy e Brody, com objetivo de verificar o melhor ajuste. Após a adequação dos parâmetros para os diferentes modelos em cada experimento seguiu-se com a comparação dos mesmos, por meio dos intervalos de confiança ( = 0,05). Os critérios para selecionar os modelos foram: interpretação biológica, quadrado médio do resíduo, coeficiente de determinação, análise gráfica e o número de iterações. Os dados de comprimentos padrão e total em função do peso dos girinos convergiram nos quatro modelos. Os modelos Logístico e Gompertz não apresentaram interpretação biológica para alguns conjuntos de dados. O quadrado médio do resíduo e número de iterações em todos os experimentos e variáveis estudadas apresentaram os menores valores para o modelo de Brody. Os valores de K dos modelos de Brody para comprimento total, quando comparados ao padrão, apresentaram-se menores, indicando que os animais apresentaram um crescimento inicial maior em comprimento padrão. O modelo de Brody foi o mais indicado para descrever o comprimento padrão e total em função do peso para girinos de rã-touro.

Fecal collection methods for the determination of protein digestibility in bullfrogs / Métodos de coleta de fezes para determinação da digestibilidade proteica em rã-touro

Adequate methods for the determination of protein digestibility in bullfrogs are important for the understanding of nutrient utilization. Therefore, this study evaluated two methods of feces collection: intestinal dissection and fecal decantation, using cylindric-conical tanks. Frogs were fed with a commercial diet (45% crude protein) which was ground and supplemented with 0.5% chromium oxide III. The frogs were fasted 48h before force-feeding (5% of the animal's live weight). For the decantation method, the animals were sacrificed 36 h after force-feeding and feces were collected directly from the large intestine. For the sedimentation method, feces were collected when they appeared in the tubes attached to the front end of the cylindric tanks. No significant difference (P>0.05) in the apparent digestibility coefficients of crude protein for dietary was observed between the methods tested (74.0% and 76.4% for the dissection and decantation methods, respectively). In conclusion, both methods can be used for the determination of protein digestibility of bullfrog feeds.(AU)

A avaliação de metodologias adequadas para a determinação da digestibilidade proteica em rã-touro é de grande importância para o entendimento do aproveitamento dos nutrientes. Neste estudo, foram avaliados dois métodos de coleta de fezes, um por dissecação intestinal e outro por decantação de fezes, utilizando-se aquários de coleta de fezes para peixes. Os animais receberam uma ração comercial (45% PB), a qual foi moída e adicionado 0,5% de óxido de crômio III. As rãs permaneceram 48 horas em jejum antes da alimentação forçada (5% do peso vivo das rãs). No método de dissecação, os animais foram sacrificados 36 horas após a alimentação forçada e as fezes coletadas diretamente do intestino grosso. No método de decantação, as fezes foram coletadas assim que apareciam nos tubos fixados na extremidade anterior dos aquários cilíndricos. Verificou-se que não houve diferença significativa (P>0,05) nos coeficientes de digestibilidade aparente da proteína bruta (CDAPB) da ração entre as metodologias testadas, sendo de 74,0% e 76,4%, respectivamente, para o método de dissecação e decantação. Concluiu-se que ambas as metodologias podem ser utilizadas para a determinação da digestibilidade proteica de alimentos para rã-touro.(AU)