Emergence of multidrug-resistant Providencia rettgeri clone in food-producing animals: A public health threat.

The occurrence of carbapenemases encoding genes in Providencia rettgeri is a critical public health concern since this species has intrinsic resistance to several antimicrobials, including polymyxins. The identification of this multidrug-resistant (MDR) pathogen outside the hospital setting has become increasingly frequent, and raises an alert for the global health agencies, as they indicate a possible spread of such pathogens. Herein, we described three MDR P. rettgeri isolates carrying a diversity of antimicrobial resistance genes (ARGs) isolated from stool samples of swine and bovine in Brazil. Molecular analysis revealed that all isolates belonged to the same clone. The whole genome sequencing (WGS) of a representative isolate (PVR-188) was performed by MiSeq Illumina® platform, while the assembling and annotation was achieved using SPAdes and Prooka, respectively. The WGS analyses indicated the presence of ARGs that confer resistance to ß-lactams (bla NDM-1, bla CTX-M-2), quinolones (qnrD1), aminoglycosides (aadA2, aadA1, aph(3')-Via), phenicol (catB2), sulfonamides (sul1, sul2), and trimethoprim (dfrA12, dfrA1). The presence of three plasmid replicons (Col3M, IncQ1, and IncT) was detected, but no phage sequences were found. The phylogenetic analyses confirmed the genomic relationship of the PVR-188 with P. rettgeri isolates recovered from animals and humans in the USA and Malaysia. In conclusion, we report the occurrence of MDR P. rettgeri clone colonizing the gut microbiota of food-producing animals in Brazil, revealing the spread of this pathogen beyond hospital boundaries.

Synergistic interaction of polymyxin B with carvacrol: antimicrobial strategy against polymyxin-resistant Klebsiella pneumoniae.

Objective: The antimicrobial activities of the synergistic combination of carvacrol and polymyxin B against polymyxin-resistant Klebsiella pneumoniae were evaluated. Methods: The methods employed checkerboard assays to investigate synergism, biofilm inhibition assessment and membrane integrity assay. In addition, the study included in vivo evaluation using a mouse infection model. Results: The checkerboard method evaluated 48 combinations, with 23 indicating synergistic action. Among these, carvacrol 10 mg/kg plus polymyxin B 2 mg/kg exhibited in vivo antimicrobial activity in a mouse model of infection, resulting in increased survival and a significant decrease in bacterial load in the blood. Conclusion: Polymyxin in synergy with carvacrol represents a promising alternative to be explored in the development of new antimicrobials.

In this study, we wanted to find a new way to fight a bacteria called Klebsiella pneumoniae, which is not easily killed by medication. We mixed two drugs, carvacrol and polymyxin B, to see if they would work together to fight the bacteria. We found that the mixed treatment helped to kill the bacteria. We also tried this mixed treatment in sick mice, and they got better. Our study shows that this mixed treatment might be a new way to fight bacteria that are hard to kill with regular drugs. Next, we hope to learn more about how it works.

Antimicrobial activity of cinnamaldehyde against multidrug-resistant Klebsiella pneumoniae: an in vitro and in vivo study.

The emergence and spread of multidrug-resistant (MDR) Klebsiella pneumoniae strains have increased worldwide, posing a significant health threat by limiting the therapeutic options. This study aimed to investigate the antimicrobial potential of cinnamaldehyde against MDR-K. pneumoniae strains in vitro and in vivo assays. The presence of resistant genes in MDR- K. pneumoniae strains were evaluated by Polymerase Chain Reaction (PCR) and DNA sequencing. Carbapenem-resistant K. pneumoniae strains show the blaKPC-2 gene, while polymyxin-resistant K. pneumoniae presented blaKPC-2 and alterations in the mgrB gene. Cinnamaldehyde exhibited an inhibitory effect against all MDR- K. pneumoniae evaluated. An infected mice model was used to determine the in vivo effects against two K. pneumoniae strains, one carbapenem-resistant and another polymyxin-resistant. After 24 h of cinnamaldehyde treatment, the bacterial load in blood and peritoneal fluids decreased. Cinnamaldehyde showed potential effectiveness as an antibacterial agent by inhibiting the growth of MDR-K. pneumoniae strains.

Antimicrobial and antibiofilm activities of desloratadine against multidrug-resistant Acinetobacter baumannii.

Aim: The antimicrobial and antibiofilm activities of the antihistamine desloratadine against multidrug-resistant (MDR) Acinetobacter baumannii were evaluated. Results: Desloratadine inhibited 90% bacterial growth at a concentration of 64 µg/ml. The combination of desloratadine with meropenem reduced the MIC by twofold in the planktonic state and increased the antibiofilm activity by eightfold. Survival curves showed that combinations of these drugs were successful in eradicating all bacterial cells within 16 h. Scanning electron microscopy also confirmed a synergistic effect in imparting a harmful effect on the cellular structure of MDR A. baumannii. An in vivo model showed significant protection of up to 83% of Caenorhabditis elegans infected with MDR A. baumannii. Conclusion: Our results indicate that repositioning of desloratadine may be a safe and low-cost alternative as an antimicrobial and antibiofilm agent for the treatment of MDR A. baumannii infections.

Exploring the Bacteriome and Resistome of Humans and Food-Producing Animals in Brazil.

The epidemiology of antimicrobial resistance (AMR) is complex, with multiple interfaces (human-animal-environment). In this context, One Health surveillance is essential for understanding the distribution of microorganisms and antimicrobial resistance genes (ARGs). This report describes a multicentric study undertaken to evaluate the bacterial communities and resistomes of food-producing animals (cattle, poultry, and swine) and healthy humans sampled simultaneously from five Brazilian regions. Metagenomic analysis showed that a total of 21,029 unique species were identified in 107 rectal swabs collected from distinct hosts, the highest numbers of which belonged to the domain Bacteria, mainly Ruminiclostridium spp. and Bacteroides spp., and the order Enterobacterales. We detected 405 ARGs for 12 distinct antimicrobial classes. Genes encoding antibiotic-modifying enzymes were the most frequent, followed by genes related to target alteration and efflux systems. Interestingly, carbapenemase-encoding genes such as blaAIM-1, blaCAM-1, blaGIM-2, and blaHMB-1 were identified in distinct hosts. Our results revealed that, in general, the bacterial communities from humans were present in isolated clusters, except for the Northeastern region, where an overlap of the bacterial species from humans and food-producing animals was observed. Additionally, a large resistome was observed among all analyzed hosts, with emphasis on the presence of carbapenemase-encoding genes not previously reported in Latin America. IMPORTANCE Humans and food production animals have been reported to be important reservoirs of antimicrobial resistance (AMR) genes (ARGs). The frequency of these multidrug-resistant (MDR) bacteria tends to be higher in low- and middle-income countries (LMICs), due mainly to a lack of public health policies. Although studies on AMR in humans or animals have been carried out in Brazil, this is the first multicenter study that simultaneously collected rectal swabs from humans and food-producing animals for metagenomics. Our results indicate high microbial diversity among all analyzed hosts, and several ARGs for different antimicrobial classes were also found. As far as we know, we have detected for the first time ARGs encoding carbapenemases, such as blaAIM-1, blaCAM-1, blaGIM-2, and blaHMB-1, in Latin America. Thus, our results support the importance of metagenomics as a tool to track the colonization of food-producing animals and humans by antimicrobial-resistant bacteria. In addition, a network surveillance system called GUARANI, created for this study, is ready to be expanded and to collect additional data.

Conselhos de fiscalização profissional e proteção da sociedade / Professional supervisory boards and protection of society / Consejos de supervisión profesional y protección de la sociedad

Resumo A República Federativa do Brasil, ao reconhecer o valor da liberdade do exercício profissional e o dever de proteger a sociedade, delegou aos conselhos profissionais atividades típicas de poder de fiscalização ética e técnica de pessoas que exercem determinadas profissões. A essa função típica de Estado são somados ainda o exercício de um serviço público e o papel de zelar pelo bom prestígio da profissão. Os conselhos de fiscalização profissional cumprem essas funções de forma legítima, democrática, eficaz e com incontestável valor social. Para que essas entidades continuem exercendo suas missões institucionais, é necessário defender seu reconhecimento como pessoas jurídicas de direito público, detentoras do poder de fiscalização.

Abstract The Federative Republic of Brazil, in recognizing the value of freedom of professional practice and the duty to protect society, delegated to professional councils activities typical of ethical and technical supervision of people who exercise certain professions. To this typical function of the State are also added the exercise of a public service and the role of ensuring the good prestige of the profession. Professional supervisory boards fulfill these functions in a legitimate, democratic, effective way and with undeniable social value. For these entities to continue exercising their institutional missions, it is necessary to defend their recognition as legal entities of public law, holders of supervisory power.

Resumen La República Federativa de Brasil, reconociendo el valor de la libertad de ejercicio profesional y el deber de proteger a la sociedad, delegó en los consejos profesionales actividades típicas de poder de supervisión ética y técnica de las personas que ejercen ciertas profesiones. A esta función típica del Estado se añaden el ejercicio de un servicio público y el papel de velar por el buen prestigio de la profesión. Los consejos profesionales de supervisión desempeñan estas funciones de manera legítima, democrática, efectiva y con un valor social innegable. Para que estas entidades puedan continuar ejerciendo sus misiones institucionales, es necesario defender su reconocimiento como personas jurídicas de Derecho Público, titulares de la facultad de supervisión.

In vitro and in vivo antibacterial activity assays of carvacrol: A candidate for development of innovative treatments against KPC-producing Klebsiella pneumoniae.

Dissemination of carbapenem-resistant Klebsiella pneumoniae poses a threat to the successful treatment of bacterial diseases and increases the need for new antibacterial agents development. The objective of this study was to determine the antimicrobial activity of carvacrol against multidrug-resistant K. pneumoniae. Carbapenemase production was detected by MALDI-TOF. The PCR and sequencing showed that the blaKPC-2, blaOXA-48, blaNDM-1, blaCTX-M-8 genes were present in carbapenem-resistant K. pneumoniae strains. The polymyxin-resistant K. pneumoniae strain exhibited alterations in mgrB gene. The antimicrobial activity of carvacrol was evaluated in vitro using broth microdilution and time-kill methods. For this, carbapenem-resistant K. pneumoniae and polymyxin-resistant strains, were evaluated. The in vitro results showed that carvacrol had antimicrobial activity against all isolates evaluated. The survival curves showed that carvacrol eradicated all of the bacterial cells within 4 h. The antimicrobial effect of carvacrol in vivo was determined using a mouse model of infection with Klebsiella pneumoniae carbapenemase (KPC). The treatment with carvacrol was associated with increased survival, and significantly reduced bacterial load in peritoneal lavage. In addition, groups treated with carvacrol, had a significant reduction in the total numbers of white cell and significantly increased of platelets when compared to the untreated group. In vivo and in vitro studies showed that carvacrol regimens exhibited significant antimicrobial activity against KPC-producing K. pneumoniae, making it an interesting candidate for development of alternative treatments.

Antimicrobial activity of plant extracts against carbapenem-producing Klebsiella pneumoniae and in vivo toxicological assessment.

The global spread of multidrug-resistant strains has prompted the scientific community to explore novel sources of chemicals with antimicrobial activity. The aim of the study was to examine the antimicrobial activity in vitro of 28 extracts against carbapenem-producing Klebsiella pneumoniae, individually and in combination with antibiotics and in vivo toxicological assessment of the most active product. The multi-resistant K. pneumoniae strain was submitted for phenotypic and molecular characterization. The antibacterial activity of 28 plant extracts was evaluated alone and in combination with antibiotics against this strain through the agar disk diffusion. Of these, 16 extracts showed synergism against carbapenem-producing K. pneumoniae, being that B. crassifolia extract exhibited synergism with three antibiotics. Based on this assessment, B. crassifolia-extract-induced toxicity on Swiss male mice was evaluated by administering this extract and subsequently determining apoptosis and splenic phagocytosis using the comet and micronucleus assays. The results of this study showed that B. crassifolia extract had synergistic activity promising and groups treated with B. crassifolia exhibited no genotoxic or mutagenic activity, indicating that B. crassifolia extract exerted beneficial effects and appeared safe to use at the studied concentrations.

Development and reproductive performance of Hereford heifers of different frame sizes up to mating at 14-15 months of age

Body development and reproductive performance of a hundred forty-two 14 to 15-month-old heifers, classified at weaning according to frame size as small, medium, and large, were evaluated. The parameters evaluated were: body weight, hip height, body condition score, weight gain, ovarian activity, and pregnancy rate. At weaning, body weight and hip height were significantly different among frame scores, (small ­ 133.0 kg, 92.2 cm; medium ­ 158.5 kg, 96.6 cm; and large ­ 185.2 kg; 100.2 cm). After weaning, heifers grazed together on natural pastures during the autumn and on ryegrass (Lolium multiflorum La.) during the winter and spring. Frame score differences remained until the beginning of the breeding season (BS), starting on average at 14 months of age. Weight gain between weaning and the beginning of BS was not different among frame scores (0.740 kg/day, on average). Body weights at the beginning of the BS were significantly different, of 255.7 kg (53.3% of the mature weight) for small heifers, 285.0 kg (59.4%) for medium heifers, and 307.6 kg (64.1%) for large heifers. Ovarian activity at the beginning of the BS was not different among the three groups. The average weight gain values during the BS of 0.492, 0.472, and 0.421 kg/day for small, medium, and large heifers, respectively, were significantly different. Pregnancy rates were not different among groups (small, 71.4%; medium, 76.4%; and large, 76.5%). Frame score did not influence the reproductive performance of heifers, but the small and medium heifers conceived 29 and 20 days earlier, respectively, than the large heifers.(AU)

Partially Hydrolyzed Guar Gum Increases Ferroportin Expression in the Colon of Anemic Growing Rats.

Studies have reported a positive effect of prebiotics on the bioavailability of iron. This study evaluated the effect of partially hydrolyzed guar gum (PHGG) on iron absorption mechanisms in anemic rats. Male Wistar rats were fed 75g American Institute of Nutrition Rodent Diets for growth, pregnancy and lactation (AIN93-G) without iron for three weeks in order to induce iron deficiency anemia. Then they were fed a control diet (n = 12; without fiber) or a diet with 7.5% of PHGG (n = 12), both without iron. Food intake, body growth and the feed efficiency coefficient (FEC) were measured. The animals were euthanized after two weeks of treatment. The weight of the organs, the pH of the cecal content, and the hepatic iron and ferroportin expression in the cecum, duodenum, and liver were assessed. The intake of PHGG reduced food intake without affecting body growth, and there was a difference between the groups regarding the FEC (p = 0.026), with the highest value found in the PHGG group. The weight of the cecal content increased (p ≤ 0.001) and the pH of the cecal content was significantly lower in the PHGG group. The intake of PHGG significantly increased ferroportin expression in the cecum; however, the difference was not significant in the duodenum and the liver. PHGG seems to have a positive influence on iron absorption through transporter expression, and structural and physiological changes in the colon of anemic growing animals.

Genetic group and horns presence in injuries and economic losses of bovine carcasses / Grupo genético e presença de chifres em lesões e perdas econômicas de carcaças bovinas

Assessment of carcass bruises in steers and cull females, classified during unloading at the slaughterhouse according to genetic dominance in zebu and taurine cattle, and the presence of horns, including polled, horned and mixed batches. We considered horned the batches that included more than 20% of horned animals and mixed the batches that included less than 20% horned animals. The data were collected in a commercial slaughterhouse and included 93 batches, with a total of 2,520 animals, from different regions in Rio Grande do Sul. After evisceration, the bruises were identified and recorded in the different carcass regions: hip, round, ribs, forequarter and loin area per animal and batch. The weights of the removed tissue due to bruising was based on the average weights of various samples of bruises according to their degree of severity. Regarding the number of bruises per animal, no differences (P > 0.05) were observed between genetic groups, however, when comparing the total bruises per batch, differences were observed in all carcass regions, except for the forequarter, with a greater number of injuries in zebu than in taurine carcasses. The individual assessments showed 86.2% (P < .05) more bruises in the ribs region in horned than in polled animals carcasses. Horned batches had higher bruises mean (P < .05) compared to the polled, with increases of 65.1; 131.7 e 132.8 % in total bruises in the carcass, ribs and forequarter, respectively. The mixed batches did not differ from polled and horned batches. Zebu animals were responsible for higher industry loss totaling 1.21 kg, resulting in a economic loss of R $ 15.48 per carcass. The presence of horns resulted in greater carcass loss, 1.13 kg, with economic loss of R $ 16.11 per carcass. The bruises on carcasses are affected by the breed group and presence of horns, with zebu and horned groups leading to greater economic losses for the meat production chain.

Foi realizado um estudo para avaliar as contusões na carcaça de machos castrados e fêmeas de descarte, classificados ao desembarque no frigorífico segundo a predominância genética em taurinos e zebuínos, e a presença de chifres, incluindo mochos, aspados e mistos. Foram considerados aspados os lotes que incluíam mais de 20% de animais aspados, e mistos menos de 20% de animais aspados. Os dados foram coletados em uma empresa frigorífica do RS, por intermédio da análise de 93 lotes, totalizando 2.520 animais, provenientes de diferentes regiões do estado. Após a evisceração, na linha de abate, foram identificadas as contusões e contabilizadas de acordo com as regiões da carcaça: quadril, traseiro, costela, dianteiro e lombo, por animal e total do lote. Os pesos dos tecidos removidos devido às contusões foi baseado nos pesos médios de várias amostragens das contusões de acordo com o grau de severidade das mesmas. Não houve diferenças (P > 0,05) no número de contusões por animal entre os grupos genéticos, porém, quando comparados os totais por lote, observou-se diferenças em todas as regiões da carcaça, com exceção do dianteiro, com maior número de contusões nos zebuínos em relação aos taurinos. Nas avaliações individuais houve aumentos de 86,2% (P < 0,05) de contusões para a região da costela dos animais aspados em comparação aos mochos. Lotes aspados apresentaram maior média (P < 0,05) de contusões em comparação aos mochos com aumento de 65,1; 131,7 e 132,8 % nas contusões totais na carcaça, na costela e no dianteiro, respectivamente. Os lotes mistos não diferiram dos mochos e aspados. A maior perda econômica ocorreu no grupo dos zebuínos, totalizando 1,21 kg/carcaça resultando em R$ 15,48 por carcaça. A presença de chifres resultou em maior perda em kg de carcaça (1,13 kg) com perda econômica de R$ 16,11 por carcaça.[...]

Genetic group and horns presence in injuries and economic losses of bovine carcasses / Grupo genético e presença de chifres em lesões e perdas econômicas de carcaças bovinas

Assessment of carcass bruises in steers and cull females, classified during unloading at the slaughterhouse according to genetic dominance in zebu and taurine cattle, and the presence of horns, including polled, horned and mixed batches. We considered horned the batches that included more than 20% of horned animals and mixed the batches that included less than 20% horned animals. The data were collected in a commercial slaughterhouse and included 93 batches, with a total of 2,520 animals, from different regions in Rio Grande do Sul. After evisceration, the bruises were identified and recorded in the different carcass regions: hip, round, ribs, forequarter and loin area per animal and batch. The weights of the removed tissue due to bruising was based on the average weights of various samples of bruises according to their degree of severity. Regarding the number of bruises per animal, no differences (P > 0.05) were observed between genetic groups, however, when comparing the total bruises per batch, differences were observed in all carcass regions, except for the forequarter, with a greater number of injuries in zebu than in taurine carcasses. The individual assessments showed 86.2% (P < .05) more bruises in the ribs region in horned than in polled animals carcasses. Horned batches had higher bruises mean (P < .05) compared to the polled, with increases of 65.1; 131.7 e 132.8 % in total bruises in the carcass, ribs and forequarter, respectively. The mixed batches did not differ from polled and horned batches. Zebu animals were responsible for higher industry loss totaling 1.21 kg, resulting in a economic loss of R $ 15.48 per carcass. The presence of horns resulted in greater carcass loss, 1.13 kg, with economic loss of R $ 16.11 per carcass. The bruises on carcasses are affected by the breed group and presence of horns, with zebu and horned groups leading to greater economic losses for the meat production chain.(AU)

Foi realizado um estudo para avaliar as contusões na carcaça de machos castrados e fêmeas de descarte, classificados ao desembarque no frigorífico segundo a predominância genética em taurinos e zebuínos, e a presença de chifres, incluindo mochos, aspados e mistos. Foram considerados aspados os lotes que incluíam mais de 20% de animais aspados, e mistos menos de 20% de animais aspados. Os dados foram coletados em uma empresa frigorífica do RS, por intermédio da análise de 93 lotes, totalizando 2.520 animais, provenientes de diferentes regiões do estado. Após a evisceração, na linha de abate, foram identificadas as contusões e contabilizadas de acordo com as regiões da carcaça: quadril, traseiro, costela, dianteiro e lombo, por animal e total do lote. Os pesos dos tecidos removidos devido às contusões foi baseado nos pesos médios de várias amostragens das contusões de acordo com o grau de severidade das mesmas. Não houve diferenças (P > 0,05) no número de contusões por animal entre os grupos genéticos, porém, quando comparados os totais por lote, observou-se diferenças em todas as regiões da carcaça, com exceção do dianteiro, com maior número de contusões nos zebuínos em relação aos taurinos. Nas avaliações individuais houve aumentos de 86,2% (P < 0,05) de contusões para a região da costela dos animais aspados em comparação aos mochos. Lotes aspados apresentaram maior média (P < 0,05) de contusões em comparação aos mochos com aumento de 65,1; 131,7 e 132,8 % nas contusões totais na carcaça, na costela e no dianteiro, respectivamente. Os lotes mistos não diferiram dos mochos e aspados. A maior perda econômica ocorreu no grupo dos zebuínos, totalizando 1,21 kg/carcaça resultando em R$ 15,48 por carcaça. A presença de chifres resultou em maior perda em kg de carcaça (1,13 kg) com perda econômica de R$ 16,11 por carcaça.[...](AU)

Evaluation of the toxicokinetics and apoptotic potential of ethanol extract from Echinodorus macrophyllus leaves in vivo.

This study evaluates the toxicological, genotoxic, mutagenic and apoptotic potential of an in vivo assay from Echinodorus macrophyllus extract (EEM). The acute toxicity test used 02 groups (n = 5) of female Wistar rats: negative control group (saline) and experimental group (2000 mg/kg b.w. EEM), both orally administered (gavage) at single doses and monitored for 14 days. To assess the genotoxic, mutagenic and apoptotic potential, 50 male Swiss mice were divided into 5 groups (n = 10): Group I: negative control (saline solution 0.1 ml/10 g b.w.); Group II: positive control (cyclophosphamide 100 mg/kg b.w.) intraperitoneally administered; groups III-V received EEM at 500, 1000 and 2000 mg/kg b.w., respectively. Groups I, III-V received oral administrations (gavage). The results showed that there was no acute lethality or any signs of acute toxicity, indicating that LD50 is greater than 2000 mg/kg b.w. The groups treated with EEM showed no genotoxic or mutagenic activity and did not induce apoptosis in the liver and kidney. Therefore, EEM showed no acute toxicity and at doses of 500, 1000 and 2000 mg/kg b.w. absence of genotoxicity, mutagenicity and no apoptotic events were observed.

Genetic group and heterosis on morphometric measurements during the growth of male beef cattle / Grupo genético e heterose sobre medidas morfométricas durante o crescimento de bovinos de corte machos

In the present study, the effects of genetic group and heterosis on body measurements of purebreds (Charolais - C and Nellore - N), first-generation crossbreds (G1) (1/2C1/2N and 1/2N1/2C), and second-generation crossbreds (G2) (3/4C1/4N and 3/4N1/4C) males from rotational crossbreeding were evaluated at 8, 12, 18, and 24 months of age. Among the purebreds, the Nellore displayed greater rump height than the Charolais. The Charolais had greater thoracic perimeter than the Nellore, however this difference decreased gradually with advancing age, being equal between the two genetic groups at 24 months. For width of the rump, ischial opening and thoracic perimeter crossbred animals showed higher values than the purebred animals at all ages, but less pronounced at eight months of age. For all morphometric measurements, with exception of rump height, the differences of crossbreds males in relation to the purebreds, were more evident in relation to the Nellore. Heterosis was significant for morphometric measurements in male beef cattle. Morphometric measurements showed high correlation with each other and with body weight, thereby indicating that they are good indicators of body development.

Foram avaliados os efeitos de grupo genético e heterose nas medidas corporais de machos puros (Charolês - C e Nelore - N); mestiços de primeira geração (G1) (½ CN e ½ NC); e mestiços de segunda geração (G2) ( ¾ C » N e ¾ N » C) oriundos de cruzamento rotativo. Os animais foram avaliados aos 8, 12, 18 e 24 meses de idade. Entre as raças puras, o Nelore apresentou maior altura da garupa do que o Charolês em todas idades. O Charolês foi superior ao Nelore em perímetro torácico, porém esta diferença decresceu gradativamente com o avanço da idade, sendo igual entre os dois grupos genéticos aos 24 meses. Para largura da garupa, abertura isquiática e perímetro torácico, os animais mestiços apresentaram valores médios mais elevados do que os machos puros, em todas as idades, porém menos acentuados aos oito meses de idade. Para as medidas avaliadas, com exceção para altura de garupa, as diferenças dos mestiços frente aos puros, foram mais evidentes em relação ao Nelore. A heterose se mostrou significativa para medidas morfométricas de bovinos de corte machos. As medidas corporais possuem alta correlação entre elas e com o peso corporal, sendo bons indicadores de desenvolvimento corporal.

Genetic group and heterosis on morphometric measurements during the growth of male beef cattle / Grupo genético e heterose sobre medidas morfométricas durante o crescimento de bovinos de corte machos

In the present study, the effects of genetic group and heterosis on body measurements of purebreds (Charolais - C and Nellore - N), first-generation crossbreds (G1) (1/2C1/2N and 1/2N1/2C), and second-generation crossbreds (G2) (3/4C1/4N and 3/4N1/4C) males from rotational crossbreeding were evaluated at 8, 12, 18, and 24 months of age. Among the purebreds, the Nellore displayed greater rump height than the Charolais. The Charolais had greater thoracic perimeter than the Nellore, however this difference decreased gradually with advancing age, being equal between the two genetic groups at 24 months. For width of the rump, ischial opening and thoracic perimeter crossbred animals showed higher values than the purebred animals at all ages, but less pronounced at eight months of age. For all morphometric measurements, with exception of rump height, the differences of crossbreds males in relation to the purebreds, were more evident in relation to the Nellore. Heterosis was significant for morphometric measurements in male beef cattle. Morphometric measurements showed high correlation with each other and with body weight, thereby indicating that they are good indicators of body development.(AU)

Foram avaliados os efeitos de grupo genético e heterose nas medidas corporais de machos puros (Charolês - C e Nelore - N); mestiços de primeira geração (G1) (½ CN e ½ NC); e mestiços de segunda geração (G2) ( ¾ C » N e ¾ N » C) oriundos de cruzamento rotativo. Os animais foram avaliados aos 8, 12, 18 e 24 meses de idade. Entre as raças puras, o Nelore apresentou maior altura da garupa do que o Charolês em todas idades. O Charolês foi superior ao Nelore em perímetro torácico, porém esta diferença decresceu gradativamente com o avanço da idade, sendo igual entre os dois grupos genéticos aos 24 meses. Para largura da garupa, abertura isquiática e perímetro torácico, os animais mestiços apresentaram valores médios mais elevados do que os machos puros, em todas as idades, porém menos acentuados aos oito meses de idade. Para as medidas avaliadas, com exceção para altura de garupa, as diferenças dos mestiços frente aos puros, foram mais evidentes em relação ao Nelore. A heterose se mostrou significativa para medidas morfométricas de bovinos de corte machos. As medidas corporais possuem alta correlação entre elas e com o peso corporal, sendo bons indicadores de desenvolvimento corporal.(AU)

Genetic group and heterosis on morphometric measurements during the growth of male beef cattle / Grupo genético e heterose sobre medidas morfométricas durante o crescimento de bovinos de corte machos

In the present study, the effects of genetic group and heterosis on body measurements of purebreds (Charolais - C and Nellore - N), first-generation crossbreds (G1) (1/2C1/2N and 1/2N1/2C), and second-generation crossbreds (G2) (3/4C1/4N and 3/4N1/4C) males from rotational crossbreeding were evaluated at 8, 12, 18, and 24 months of age. Among the purebreds, the Nellore displayed greater rump height than the Charolais. The Charolais had greater thoracic perimeter than the Nellore, however this difference decreased gradually with advancing age, being equal between the two genetic groups at 24 months. For width of the rump, ischial opening and thoracic perimeter crossbred animals showed higher values than the purebred animals at all ages, but less pronounced at eight months of age. For all morphometric measurements, with exception of rump height, the differences of crossbreds males in relation to the purebreds, were more evident in relation to the Nellore. Heterosis was significant for morphometric measurements in male beef cattle. Morphometric measurements showed high correlation with each other and with body weight, thereby indicating that they are good indicators of body development.

Foram avaliados os efeitos de grupo genético e heterose nas medidas corporais de machos puros (Charolês - C e Nelore - N); mestiços de primeira geração (G1) (½ CN e ½ NC); e mestiços de segunda geração (G2) ( ¾ C » N e ¾ N » C) oriundos de cruzamento rotativo. Os animais foram avaliados aos 8, 12, 18 e 24 meses de idade. Entre as raças puras, o Nelore apresentou maior altura da garupa do que o Charolês em todas idades. O Charolês foi superior ao Nelore em perímetro torácico, porém esta diferença decresceu gradativamente com o avanço da idade, sendo igual entre os dois grupos genéticos aos 24 meses. Para largura da garupa, abertura isquiática e perímetro torácico, os animais mestiços apresentaram valores médios mais elevados do que os machos puros, em todas as idades, porém menos acentuados aos oito meses de idade. Para as medidas avaliadas, com exceção para altura de garupa, as diferenças dos mestiços frente aos puros, foram mais evidentes em relação ao Nelore. A heterose se mostrou significativa para medidas morfométricas de bovinos de corte machos. As medidas corporais possuem alta correlação entre elas e com o peso corporal, sendo bons indicadores de desenvolvimento corporal.

Genetic group and heterosis on morphometric measurements during the growth of male beef cattle / Grupo genético e heterose sobre medidas morfométricas durante o crescimento de bovinos de corte machos

In the present study, the effects of genetic group and heterosis on body measurements of purebreds (Charolais - C and Nellore - N), first-generation crossbreds (G1) (1/2C1/2N and 1/2N1/2C), and second-generation crossbreds (G2) (3/4C1/4N and 3/4N1/4C) males from rotational crossbreeding were evaluated at 8, 12, 18, and 24 months of age. Among the purebreds, the Nellore displayed greater rump height than the Charolais. The Charolais had greater thoracic perimeter than the Nellore, however this difference decreased gradually with advancing age, being equal between the two genetic groups at 24 months. For width of the rump, ischial opening and thoracic perimeter crossbred animals showed higher values than the purebred animals at all ages, but less pronounced at eight months of age. For all morphometric measurements, with exception of rump height, the differences of crossbreds males in relation to the purebreds, were more evident in relation to the Nellore. Heterosis was significant for morphometric measurements in male beef cattle. Morphometric measurements showed high correlation with each other and with body weight, thereby indicating that they are good indicators of body development.

Foram avaliados os efeitos de grupo genético e heterose nas medidas corporais de machos puros (Charolês - C e Nelore - N); mestiços de primeira geração (G1) (½ CN e ½ NC); e mestiços de segunda geração (G2) ( ¾ C » N e ¾ N » C) oriundos de cruzamento rotativo. Os animais foram avaliados aos 8, 12, 18 e 24 meses de idade. Entre as raças puras, o Nelore apresentou maior altura da garupa do que o Charolês em todas idades. O Charolês foi superior ao Nelore em perímetro torácico, porém esta diferença decresceu gradativamente com o avanço da idade, sendo igual entre os dois grupos genéticos aos 24 meses. Para largura da garupa, abertura isquiática e perímetro torácico, os animais mestiços apresentaram valores médios mais elevados do que os machos puros, em todas as idades, porém menos acentuados aos oito meses de idade. Para as medidas avaliadas, com exceção para altura de garupa, as diferenças dos mestiços frente aos puros, foram mais evidentes em relação ao Nelore. A heterose se mostrou significativa para medidas morfométricas de bovinos de corte machos. As medidas corporais possuem alta correlação entre elas e com o peso corporal, sendo bons indicadores de desenvolvimento corporal.

Toxicological analysis and anti-inflammatory effects of essential oil from Piper vicosanum leaves.

This study assessed the anti-inflammatory effects of the essential oil from Piper vicosanum leaves (OPV) and evaluated the toxicological potential of this oil through acute toxicity, genotoxicity and mutagenicity tests. The acute toxicity of OPV was evaluated following oral administration to female rats at a single dose of 2 g/kg b.w. To evaluate the genotoxic and mutagenic potential, male mice were divided into five groups: I: negative control; II: positive control; III: 500 mg/kg of OPV; IV: 1000 mg/kg of OPV; V: 2000 mg/kg of OPV. The anti-inflammatory activity of OPV was evaluated in carrageenan-induced pleurisy and paw edema models in rats. No signs of acute toxicity were observed, indicating that the LD50 of this oil is greater than 2000 mg/kg. In the comet assay, OPV did not increase the frequency or rate of DNA damage in groups treated with any of the doses assessed compared to that in the negative control group. In the micronucleus test, the animals treated did not exhibit any cytotoxic or genotoxic changes in peripheral blood erythrocytes. OPV (100 and 300 mg/kg) significantly reduced edema formation and inhibited leukocyte migration analyzed in the carrageenan-induced edema and pleurisy models. These results show that OPV has anti-inflammatory potential without causing acute toxicity or genotoxicity.

Pre and postweaning weight gain on reproductive performance of beef heifers at fourteen months of age / Ganho de peso pré e pós-desmame no desempenho reprodutivo de novilhas de corte aos quatorze meses de idade

The objective of this experiment was to study the development and reproductive performance of sixty-six Charolais crossbred beef heifers bred at fourteen months of age, classified in four groups according to pre and postweaning average daily weight gain (ADG): AA= heifers that showed ADG > .54 kg and .73 kg, respectively; AB= heifers that showed ADG > .54 kg and .73 kg, respectively; BA= heifers that showed ADG .54 kg and > .73 kg, respectively; BB= heifers that showed ADG .54 kg and .73 kg, respectively. Weight at the beginning and end of the breeding period, and the reproductive performance were influenced by ADG of the heifers during pre and postweaning phase. AA heifers showed better development in relation to the other groups, without difference between AB and BA. The AA group was superior to the others except for the reproductive performance of the group AB. Heifers that became cyclical showed higher development during the growing phase and mating period than acyclic heifers. Reproductive performance of heifers was positively correlated with weight and body condition at beginning and end of the mating period. Greater weight during pre and post-weaning improve the reproductive performance of beef heifers.KEYWORDS: body condition; Charolais; estrus; pregnancy; weight at mating.

Foram estudados o desenvolvimento e o desempenho reprodutivo de 66 novilhas mestiças Charolês, acasaladas aos quatorze meses de idade, classificadas em quatro grupos, conforme o ganho de peso médio diário (GMD) pré e pós-desmame: AA= novilhas com GMD superior a 0,54 kg e 0,73 kg, respectivamente; AB= novilhas com GMD superior a 0,54 kg e inferior 0,73 kg, respectivamente; BA= novilhas com GMD inferior a 0,54kg e superior a 0,73 kg, respectivamente; BB= novilhas com GMD inferior a 0,54 kg e 0,73 kg, respectivamente. O peso no início e no final do período de acasalamento, bem como o desempenho reprodutivo das novilhas foi influenciado pelo ganho de peso das novilhas nas fases pré e pós-desmame. O grupo AA mostrou melhor desenvolvimento sobre os demais, não havendo diferença entre os grupos AB e BA.  O grupo AA foi superior aos demais no desempenho reprodutivo com exceção do grupo AB. As novilhas cíclicas apresentaram desenvolvimento superior durante a recria e o período de acasalamento do que as novilhas acíclicas. O desempenho reprodutivo das novilhas correlacionou-se positivamente com peso e condição corporal no início e no final do período reprodutivo. Maiores ganhos de peso nas fases pré e pós-desmame melhoram o desempenho reprodutivo de novilhas de corte.PALAVRAS-CHAVE: Charolês; condição corporal; estro; peso ao acasalamento; prenhez.

PRE AND POSTWEANING WEIGHT GAIN ON REPRODUCTIVE PERFORMANCE OF BEEF HEIFERS AT FOURTEEN MONTHS OF AGE / GANHO DE PESO PRÉ E PÓS-DESMAME NO DESEMPENHO REPRODUTIVO DE NOVILHAS DE CORTE AOS QUATORZE MESES DE IDADE

The objective of this experiment was to study the development and reproductive performance of sixty-six Charolais crossbred beef heifers bred at fourteen months of age, classified in four groups according to pre and postweaning average daily weight gain (ADG): AA= heifers that showed ADG > .54 kg and .73 kg, respectively; AB= heifers that showed ADG > .54 kg and .73 kg, respectively; BA= heifers that showed ADG .54 kg and > .73 kg, respectively; BB= heifers that showed ADG .54 kg and .73 kg, respectively. Weight at the beginning and end of the breeding period, and the reproductive performance were influenced by ADG of the heifers during pre and postweaning phase. AA heifers showed better development in relation to the other groups, without difference between AB and BA. The AA group was superior to the others except for the reproductive performance of the group AB. Heifers that became cyclical showed higher development during the growing phase and mating period than acyclic heifers. Reproductive performance of heifers was positively correlated with weight and body condition at beginning and end of the mating period. Greater weight during pre and post-weaning improve the reproductive performance of beef heifers.KEYWORDS: body condition; Charolais; estrus; pregnancy; weight at mating.

Foram estudados o desenvolvimento e o desempenho reprodutivo de 66 novilhas mestiças Charolês, acasaladas aos quatorze meses de idade, classificadas em quatro grupos, conforme o ganho de peso médio diário (GMD) pré e pós-desmame: AA= novilhas com GMD superior a 0,54 kg e 0,73 kg, respectivamente; AB= novilhas com GMD superior a 0,54 kg e inferior 0,73 kg, respectivamente; BA= novilhas com GMD inferior a 0,54kg e superior a 0,73 kg, respectivamente; BB= novilhas com GMD inferior a 0,54 kg e 0,73 kg, respectivamente. O peso no início e no final do período de acasalamento, bem como o desempenho reprodutivo das novilhas foi influenciado pelo ganho de peso das novilhas nas fases pré e pós-desmame. O grupo AA mostrou melhor desenvolvimento sobre os demais, não havendo diferença entre os grupos AB e BA.  O grupo AA foi superior aos demais no desempenho reprodutivo com exceção do grupo AB. As novilhas cíclicas apresentaram desenvolvimento superior durante a recria e o período de acasalamento do que as novilhas acíclicas. O desempenho reprodutivo das novilhas correlacionou-se positivamente com peso e condição corporal no início e no final do período reprodutivo. Maiores ganhos de peso nas fases pré e pós-desmame melhoram o desempenho reprodutivo de novilhas de corte.PALAVRAS-CHAVE: Charolês; condição corporal; estro; peso ao acasalamento; prenhez.