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The objective was to explore publications on the effects of genotype × environment interaction (GEI) in livestock farming. The dataset used for this analysis came from the Web of Science (WOS) database, and the search was carried out from the first article identified in the WOS database until the search date (August 17, 2023). A set of minimum parameters was defined, and then the data was processed using the VOSviewer® software. To generate visual representations in VOSviewer, fractional counting was used, in which the contribution of each article is divided proportionally based on the number of co-authors. Consequently, if an article has three authors, the weight of each author is calculated as 1/3. Brazil and the United States lead research on GEI, while India, China, and Uruguay are emerging countries on the subject. The most cited journals on GEI include the Journal of Animal Science, Journal of Dairy Science, Animal, Livestock Science, Journal of Animal Breeding and Genetics, and Revista Brasileira de Zootecnia. In Brazil, the research groups are at the forefront of publications related to GEI. Ongoing climate changes over the years have likely led to further investigations into this matter. In the Brazilian context, research groups from the São Paulo State University (UNESP), College of Agricultural and Veterinary Sciences ­ Jaboticabal, and the Faculty of Veterinary Medicine and Animal Science at the University of São Paulo (FZEA/USP, Campus Pirassununga) have played a prominent role in advancing this area of study. Furthermore, our bibliometric analysis revealed future trends in GEI publications, including an increasing integration of genomic information into research.(AU)

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We investigated the impact of weaning at 30, 75, and 180 days of age on performance, body measurements, and rumen development (using the ß-hydroxybutyrate biomarker) of beef calves until 190 days of age. A total of 64 Brangus calves were assigned to three treatments: hyper-early (W30), weaned at 32±0.89 days of age (n = 22, 10 males and 12 females); early (W75), weaned at 77±0.95 days of age (n = 20, 12 males and eight females); and conventional (W180), weaned at 183±0.82 days of age (n = 22, 13 males and nine females). Body weight (BW), average daily gain (ADG), ß-hydroxybutyrate (ßHBA), and morphometric measurements were evaluated. These variables were influenced by an interaction between treatment and days and were not affected by the sex of calves. The W30 calves experienced weight loss from 30 to 40 days of age compared with the W75 and W180 calves. Consequently, at day 75, W30 animals were lighter and had lower body length, thoracic circumference, withers height, and croup height compared with the W75 and W180 calves. However, no significant differences in BW were observed among treatments at 85 days of age. Additionally, W30 calves exhibited higher ADG and a moderate correlation with ßHBA levels. Weaning calves at 30 days of age may negatively affect their performance until the sixth week after weaning, but there is no impairment in performance at 190 days of age.(AU)

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The environment is vital to the agricultural sector since it can cause adversities throughout the entire productive chain. This study evaluated the geographical distribution of zebu breeds in Brazil and correlated their occurrence with environmental variables and the human development index. Herds of purebred zebu cattle (Bos indicus) in Brazil were classified as beef, dairy, and dual-purpose breeds, and all breeds were spatialized in the ArcGIS program. Environmental (precipitation, temperature, relative humidity index) and the human development index (HDI) were examined. We conducted regression and logistic analyses. Zebu cattle showed a lower distribution in the Northeastern states compared to other locations, possibly due to harsh weather conditions, namely long periods of high temperatures and lower precipitation, directly affecting local livestock. Beef breeds were evenly spread throughout the country in regions influenced by environmental variables of higher precipitation, normalized difference vegetation index (NDVI), temperature, relative humidity (RH), and temperature humidity index (THI), as well as properties without smallholder farmers and rivers and streams with riparian vegetation. The regions for dual-purpose and dairy breeds were predominantly cultivated with cutting forages (e.g., sugarcane - Saccharum officinarum), with the integration of crops, livestock and/or forestry (i.e., combining different activities in the same area) and areas with a rotational grazing system (i.e., grazing management), indicating a higher occupation in fertile lands. The Gir breed, the only dairy breed evaluated in this study, was seen in establishments with smallholder farmers, characterized by small to medium farms, and in regions at higher altitudes.

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This study aimed to estimate genetic parameters for jumping measures in the Brazilian Sport Horses breed, looking to see which jump characteristics can be evaluated early and that present favorable genetic correlations (ϒg) with measures of later sports performance. Data were available for the results of jumping competitions on the Brazilian Sport Horses. Two traits were calculated: Classification (CLASS) of the animal (taking into consideration obstacle height, number of competitors, type of competition (regional, national, international) and final score (SCOREF) taking into consideration the weight of the competition, height of the obstacles and score for the placement and type of event. Heritabilities were low for the full database (0.00 and 0.07 for CLASS and SCOREF, respectively), but higher when only young horses were considered (0.09 and 0.67, respectively). Genetic correlations between these traits and subjective functional traits (using a scale of 0 to 10) measured at stallion approval for reproduction showed that Power was favorable for indirect selection for both traits (-0.85 for CLASS and 1.00 for SCOREF). Jump also showed a favorable correlation for SCOREF (0.53) but unfavorable for CLASS (1.00). Considering the importance of Temperament and the absence of unfavorable genetic correlations between it and competition results it was concluded that this trait can be maintained among the selection objectives of Brazilian Sport Horses. Suggestions are made for further genetic studies with this breed, and possible modifications in the evaluation regulations to improve data quality.

Este estudo estimou parâmetros genéticos para avaliações de salto em cavalos da raça Brasileiro de Hipismo, buscando características passíveis de serem avaliadas precocemente e que estejam geneticamente correlacionadas (ϒg) com resultados posteriores em competições esportivas. Para os resultados de competições de salto duas características foram consideradas: Classificação (CLASS) do animal (considerando alturas dos obstáculos; número de competidores; tipo de competição: regional, nacional ou internacional) e escore final (SCOREF) (considerando peso da competição, altura dos obstáculos e escore para a colocação e tipo de evento). Herdabilidades foram baixas (0,00 e 0,07 para CLASS e SCOREF, respectivamente) quando o banco de dados foi considerado como um todo. Foram mais elevadas quando apenas a categoria Cavalos Novos foi considerada (0,09 e 0,67, respectivamente). Correlações genéticas entre estas características e avaliações funcionais subjetivas (em escala de 0 a 10) tomadas em aprovações de garanhões para reprodução mostraram relação genética favorável à seleção indireta entre Potência e resultados de competição (-0,84 para CLASS e 1,00 para SCOREF). Salto também apresentou correlação favorável com SCOREF (0,53), porém desfavorável com CLASS (1,00). Considerando a importância do Temperamento e ausência de correlações genéticas desfavoráveis desta com resultados de competição, conclui-se que esta característica deve ser mantida entre os objetivos de seleção de cavalos Brasileiro de Hipismo. Sugestões de estudos genéticos futuros para a raça e para possíveis modificações no regulamento das avaliações, foram feitas visando a melhoria da qualidade dos dados.

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The aim of this study was to explore spatial genetic structure patterns in cattle breeds adapted to local conditions in Brazil. We georeferenced 876 animals of ten breeds raised in Brazil kept in the Genebank of Brazilian Agricultural Research Corporation (Embrapa) by sample locations using the QGIS 2.4.0 software. The Mantel tests, spatial autocorrelation, and Monmonier tests were performed. The distances for spatial correlation tests ranged from 5 to 15 classes. The results indicated genetic discontinuities in cattle breeds from the Midwest, South, and Southeast of the country. Correlation between genetic and geographic distance was low, but significant. The Monmonier Maximum Distance Algorithm indicated an initial subdivision of Curraleiro and then Pantaneiro from the other breeds. In another subdivision, Criollo, Mocho Nacional, and Caracu were grouped. Genetic discontinuity was observed beyond 431 km, the minimum sampling distance between populations for conservation purposes.

Resumo

The aim of this study was to explore spatial genetic structure patterns in cattle breeds adapted to local conditions in Brazil. We georeferenced 876 animals of ten breeds raised in Brazil kept in the Genebank of Brazilian Agricultural Research Corporation (Embrapa) by sample locations using the QGIS 2.4.0 software. The Mantel tests, spatial autocorrelation, and Monmonier tests were performed. The distances for spatial correlation tests ranged from 5 to 15 classes. The results indicated genetic discontinuities in cattle breeds from the Midwest, South, and Southeast of the country. Correlation between genetic and geographic distance was low, but significant. The Monmonier Maximum Distance Algorithm indicated an initial subdivision of Curraleiro and then Pantaneiro from the other breeds. In another subdivision, Criollo, Mocho Nacional, and Caracu were grouped. Genetic discontinuity was observed beyond 431 km, the minimum sampling distance between populations for conservation purposes.(AU)

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Food Safety is an important topic for public health and international trade in food. Residues of veterinary drugs and environmental contaminants in animal products can cause diseases and acute toxicity in organisms exposed to these substances. This study evaluated official monitoring data of veterinary drug residues from the Brazilian Ministry of Agriculture, Livestock and Supply in tissues of poultry and swine in the period between 2002 and 2014 to check for hidden patterns in the occurrence of six common drugs (Closantel, Diclazuril, Nicarbazin, Sulfaquinoxaline, Doxycycline and Sulfamethazinein). The analysis of data was performed by using two machine learning methods: decision tree and neural networks, in addition to visual evaluation through graphs and maps. Contamination rates were low, varying from 0 to 0.66%. A spatial distribution pattern of detections of substances by region was identified, but no pattern of temporal distribution was observed. Nevertless, regressions showed an increase in levels when these substances were detected, so monitoring should continue. However, the results show that the products monitored during the study period presented a low risk to public health.(AU)

A Segurança Alimentar é um tema importante para a saúde pública e o comércio internacional de alimentos. Resíduos de medicamentos veterinários e contaminantes ambientais em produtos de origem animal podem causar doenças e toxicidade aguda em organismos expostos a essas substâncias. Este estudo avaliou dados oficiais de monitoramento de resíduos de medicamentos veterinários do Ministério da Agricultura, Pecuária e Abastecimento em tecidos de aves e suínos no período de 2002 a 2014 para verificar padrões ocultos na ocorrência de seis medicamentos comuns (Closantel, Diclazuril, Nicarbazina, Sulfaquinoxalina, Doxiciclina e Sulfametazina). A análise dos dados foi realizada por meio de dois métodos de aprendizado de máquina: árvore de decisão e redes neurais, além da avaliação visual por meio de gráficos e mapas. As taxas de contaminação foram baixas, variando de 0 a 0,66%. Foi identificado um padrão de distribuição espacial das detecções de substâncias por região, mas nenhum padrão de distribuição temporal foi observado. No entanto, as regressões mostraram um aumento nos níveis quando essas substâncias foram detectadas, portanto, o monitoramento deve continuar. No entanto, os resultados mostram que os produtos monitorados durante o período do estudo apresentaram baixo risco à saúde pública.(AU)

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Bos taurus taurus and Bos taurus indicus cattle subspecies present different capabilities in coping with situations of elevated temperatures, the latter being more tolerant to heat stress. Thus, some breeding programs crossed these subspecies to produce a high producing yet heat-tolerant breed (Girolando). Nineteen Holstein (H100) and 19 Girolando cows [(½ Holstein × Gir (H50) and ¾ Holstein × Gir (H75)] with similar milk production were used in a six-day experiment to evaluate the consequences of heat stress due to shade deprivation on their physiological, blood and milk traits. Cows were exposed to a non-shaded environment between morning (06:00h; GMT -3:00) and evening milking (14:30h; GMT -3:00) with access to water ad libitum. Procedures were conducted before morning and evening milkings. Physiological parameters related to mechanisms of heat dissipation were measured, as well as the milk composition. Blood traits were evaluated. The temperature-humidity index (THI) was calculated. Statistical procedures included analysis of variance, correlation, and principal factors. THI was elevated during the trial and negatively impacted physiological, milk, and blood parameters in H100, H75, and H50. Alterations in physiology, milk stability, milk composition, and blood traits were more pronounced in H100. Holstein cows presented changes in physiological parameters in a more pronounced manner and in some milk and blood traits related to the reduced capability of this breed in dealing with elevated THI. The similarity in milk production levels excludes this parameter as a justification for differences in heat tolerance, with genetic composition being the main reason for these results.

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Bos taurus taurus and Bos taurus indicus cattle subspecies present different capabilities in coping with situations of elevated temperatures, the latter being more tolerant to heat stress. Thus, some breeding programs crossed these subspecies to produce a high producing yet heat-tolerant breed (Girolando). Nineteen Holstein (H100) and 19 Girolando cows [(½ Holstein × Gir (H50) and ¾ Holstein × Gir (H75)] with similar milk production were used in a six-day experiment to evaluate the consequences of heat stress due to shade deprivation on their physiological, blood and milk traits. Cows were exposed to a non-shaded environment between morning (06:00h; GMT -3:00) and evening milking (14:30h; GMT -3:00) with access to water ad libitum. Procedures were conducted before morning and evening milkings. Physiological parameters related to mechanisms of heat dissipation were measured, as well as the milk composition. Blood traits were evaluated. The temperature-humidity index (THI) was calculated. Statistical procedures included analysis of variance, correlation, and principal factors. THI was elevated during the trial and negatively impacted physiological, milk, and blood parameters in H100, H75, and H50. Alterations in physiology, milk stability, milk composition, and blood traits were more pronounced in H100. Holstein cows presented changes in physiological parameters in a more pronounced manner and in some milk and blood traits related to the reduced capability of this breed in dealing with elevated THI. The similarity in milk production levels excludes this parameter as a justification for differences in heat tolerance, with genetic composition being the main reason for these results.(AU)

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The trade in live animals between India and Brazil dates from the late nineteenth century when European travellers traded animals of Indian origin for display in zoos. Considering the origin of coffee and sugar cane, as well as the expertise related to mineral evaluation, we need to consider that India was involved in important economic cycles of Brazil, even indirectly. This virtuous flow of trade has been maintained and intensified throughout modern history, especially after these two nations gained political independence from their colonisers, thereby becoming independent in mercantile affairs. This paper addresses the main points related to the use of animals of Indian origin in Brazil. We revisit some of the historical aspects of the process of colonisation of Brazil, as well as the importation of animals from India. The restrictions imposed on this process due to the occurrence of diseases in cattle and buffalo in India will be examined. At the end of the text, emphasis will be given to the risks of introducing exotic diseases into Brazil.

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The use of new feed resources, particularly local agroindustrial byproducts, such as banana, may be an option for replacing those traditionally used for sheep feed to reduce production costs. Thus, the aim of this study was to evaluate the dietary effects of replacing corn bran with banana leftovers on performance, carcass, non-carcass components, meat traits, and fatty acid profile of Santa Inês lambs. Twenty-four Santa Inês female lambs with an average weight of 23.73 kg were fed diets containing 60 % coast cross hay and 40 % concentrate (30 % corn bran and 10 % soybean meal). Treatments consisted of corn bran replaced by banana leftovers at rates of 0, 25, 50, and 75 % on a dry matter basis. The experiment lasted 120 days. Animals were slaughtered and carcasses and non-carcass components were evaluated. The half-carcasses were weighed and sectioned into commercial cuts. The 12th and 13th ribs were dissected to collect bones, muscle and fat proportions. Cooking loss, color, shear force and sarcomere length were measured. Fatty acid profiles were obtained by gas chromatography. Hot and cold carcass weight, leg, neck, lung, loin eye area, fat thickness, initial sample weight of the 12th and 13th ribs, fat and bone, presented a negative linear effect of banana leftovers replacing corn in the diet. Loin, fat thickness, cooking loss and carcass redness showed a negative quadratic effect, while full and empty abomasum, full omasum, sarcomere length and yellowness presented a positive quadratic effect. Replacement of up to 75 % of corn bran by banana leftovers did not interfere in the intake, performance, meat traits and the fatty acid profile of lambs. The use of banana leftovers may be an alternative for reducing animal production costs.

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Traditional livestock productivity is hard to estimate, since it depends on a gamut of animal production indicators that are difficult to measure for many farms. Thus, we propose an analytical method for estimating productivity and understanding the importance of animal production indicators under different full-cycle cattle production systems in Brazil. To evaluate the impact of these indicators, equations were derived from a comutational model of herd evolution for estimating the output parameters of the system as follows: productivity per hectare (PH) and offtake rate (COR), as a function of the indicators; calving rate (CR), mating age (AM), age of slaughter (AS) and stocking rate (SR). For this analysis, twenty-seven scenarios (simulation data) of low to high productivity were used, resulting from the combination of the following factors and levels: 1) calving rate of 50, 65 and 80 %; 2) mating age of heifers of one, two and three, years of age; and 3) age at slaughter of one, two and three year old steers. The scenario with the highest impact for each parameter and the indicator of highest impact for each scenario were identified for the production conditions in the region. Under most scenarios, a reduction in mating age had a greater impact on the productivity indexes compared to a reduction in slaughter age. Appropriate management of available technologies enables farmers to compare the marginal impacts of specific indicators on full-cycle production systems for beef cattle.

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The allometric growth of male and female naturalized pig breeds (Nilo, Piau, Moura, and Monteiro) was evaluated regarding hip height, snout length, and head length using the allometric equation. Body measurements generally show later growth in relation to the snout length and earlier growth in relation to the head length and hip height. When comparing breeds of pigs, female Moura animals showed later growth of the characteristics linked to muscle (thoracic circumference, body length, and longitudinal diameter) than of head length. Nilo females showed characteristics such as shoulder length, rump length and interschiadic distance earlier than snout length. There were differences between the breed and gender in terms of development times for the different parts of the body, showing that breeding systems and use of these animals have to be specific for each breed.

O crescimento alométrico de raças de suínos naturalizados (Nilo, Piau, Moura e Monteiro), machos e fêmeas, foi avaliado em relação à altura do quadril, comprimento do focinho e comprimento da cabeça, usando-se a equação alométrica. As medidas do corpo geralmente apresentam um crescimento mais tardio em relação ao comprimento do focinho e precocemente em relação ao comprimento da cabeça e altura do quadril. Ao comparar as raças de suínos, as fêmeas da raça Moura apresentaram características relacionadas com o crescimento muscular (circunferência torácica, comprimento do corpo e diâmetro longitudinal) mais tardiamente ao comprimento da cabeça. Fêmeas Nilo apresentaram características do comprimento do ombro, comprimento da garupa e a distância interesquiática mais precoce em relação ao comprimento do focinho. Foram encontradas diferenças entre a raça e o sexo no tempo de desenvolvimento para as diferentes partes do corpo, mostrando que os sistemas de criação e utilização desses animais devem ser específicos para cada raça.

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Gossypol easily pairs with lysine side chains and enzymes involved in the cellular growth process. The effect of gossypol (a compound present in cotton co-products) in ruminant metabolism and meat quality is not yet clear. This study was undertaken in order to evaluate the effects of cotton co-products in lamb muscle proteome. Twenty-four Santa Inês ram lambs, 5-months old (20.6 ± 1.9 kg), were randomly assigned to four treatments: control (without cottonseed), whole cottonseed, cottonseed meal and high oil cottonseed meal. At 95 days into the experiment, lambs were slaughtered and samples from Longissimus dorsi were collected. Proteins were extracted and analyzed by 2-D electrophoresis. Spots showing a significant effect from the treatment (the “treatment effect”) and present in more than 90 % of the samples were identified using mass spectrometry. Cotton co-products decreased the abundance of aldehyde and malate dehydrogenases, creatine kinase M-type and Adenosine triphosphate (ATP) synthase. They also increased four proteins related to muscle contraction. Thus, feeding cotton co-products to lambs changed the abundance of important muscle proteins. A cotton co-product diet induced a negative impact on the energy supply of muscle cells and, consequently, the abundance of ATP dependent proteins (contractile apparatus) increased, probably in order to offset and maintain muscle function. These proteomic changes can promote our understanding of alterations in the sensorial properties of meat due to cotton co-product diets in further investigations.

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The South region of Brazil differs from the others due to its high milk production rates. Production heterogeneity, climate and soil diversity, and environmental and socioeconomic circumstances contribute to differentiate political-administrative regions. In this study, we aimed to spatialize the production, environmental, and socioeconomic factors that best discriminate bovine milk production in the states of the South of Brazil. Multivariate analyses were performed to discriminate both the studied variables and the mesoregion and cities of these states. The Western Catarinense and Northwestern Rio-grandense mesoregions showed the highest production indices, but they were discriminated at a low level (35.76 %). The formation of clusters showed that Casca, Marau, and Santo Cristo from the Northwestern Rio-grandense and Concordia, Coronel Freitas, Palmitos, and São Lourenço do Oeste from the Western Catarinense mesoregion had higher production indices. The municipal clusters were discriminated at a high level by production (98.24%) and by environmental and socioeconomic (72.75%) factors. Production variables were the most important for local clusters discrimination. The specificities and peculiarities to each region were evidenced through the heterogeneity of production and environmental and socioeconomic factors. Therefore, it is necessary to design and implement specific technological innovations to each region to maximize productive efficiency and minimize adverse environmental effects in dairy herds.

A região Sul se diferencia das demais por ter maior produtividade de leite. A heterogeneidade da produção, a diversidade edafoclimática e ambiental, e as distintas realidades socioeconômicas contribuem para diferenciar as regiões político-administrativas. Objetivou-se espacializar os fatores produtivos e os fatores ambientais e socioeconômicos que melhor discriminam a produção de leite de vaca nos estados do Sul do Brasil. Análises multivariadas foram realizadas para discriminar tanto as variáveis em estudo quanto as mesorregiões e municípios destes estados. As mesorregiões Oeste Catarinense e Noroeste Rio-grandense apresentaram os melhores índices de produção, mas foram discriminadas em baixo nível (35,76%). A formação de cluster por municípios mostrou que Casca, Marau e Santo Cristo da mesorregião Noroeste Rio-grandense e Concórdia, Coronel Freitas, Palmitos e São Lourenço do Oeste da mesorregião Oeste Catarinense apresentaram melhores índices produtivos. Os clusters municipais foram discriminados em alto nível pelos fatores produtivos (98,24%) e pelos fatores ambientais e socioeconômicos (72.75%). As variáveis produtivas foram as mais importantes na discriminação dos clusters municipais. As especificidades e peculiaridades específicas a cada região foram evidenciadas por meio da heterogeneidade dos fatores produtivos, ambientais e socioeconômicos. Portanto, faz-se necessário conceber e implementar inovações tecnológicas específicas à cada região para maximizar a eficiência produtiva e minimizar os efeitos ambientais adversos em rebanhos leiteiros.

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Air transportation is one of the most important means to introduce illegally imported animal-origin products into a country. Studies have demonstrated that these items pose a risk of disseminating diseases. São Paulo Guarulhos International Airport (GRU / SBGR) is the main international airport in Brazil in terms of people movement and it has the largest number of seizures of animal-origin products. The aim of the present work was to describe the dynamics of the seizure of illegally imported animal-origin products in baggage from international flight passengers at GRU / SBGR Airport in Brazil. Five hundred and eighty-nine different flights from 43 airlines, arriving from 117 countries were analyzed between 2006 and 2009. The total number of seized items increased from 2006 to 2009 and a single flight from France had the highest number of seizures, followed by flights from South Africa and Germany. Countries were grouped into regions or continents to facilitate the analysis. This grouping was based on historical and cultural ties rather than geographical aspects. Seafood was the most frequently seized product, followed by dairy products, as well as processed and raw meat.

O transporte aéreo é um dos meios mais importantes de introdução ilegal de produtos de origem animal importados em um país e estudos têm demonstrado que esses itens representam um risco para a disseminação de doenças. O Aeroporto Internacional de São Paulo - Guarulhos (GRU / SBGR) é o principal aeroporto internacional no Brasil em termos de movimento de pessoas e tem o maior número de produtos de origem animal apreendidos. O objetivo do presente trabalho é realizar análise descritiva da dinâmica de apreensão de produtos de origem animal importados ilegalmente em bagagens de passageiros de voos internacionais no Aeroporto GRU / SBGR. Foram analisados 589 diferentes voos de 43 companhias aéreas, que chegaram de 117 países entre 2006 e 2009. O montante total de itens apreendidos aumentou entre 2006 a 2009 e um voo da França teve o maior número de apreensões, seguido de voos da África do Sul e Alemanha. Países foram agrupados em regiões ou continentes para facilitar a análise. Este agrupamento foi baseado em laços históricos e culturais em vez de relações geográficas. Frutos do mar foi o tipo de produto mais apreendido, seguido por produtos lácteos e carnes processadas e cruas.

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The objective of this trial was to evaluate carcass quality in 74 Santa Ines hair ewes aged 6 to 48 months. Slaughter occurred after fasting and electroshock, followed by dissection of the jugular veins and carotid arteries. Hot carcass weight, hot carcass yield, carcass length, skin thickness, shoulder, neck, loin, belly, rib and leg weights and percentages, leg length, and girth were measured. The rib eye area, color (by CIELAB system), shear force, and cooking loss were also measured. The data were analyzed using SAS procedures for analysis of variance, regressions, correlations, and principal components. Hot carcass weight was 15.75 kg and yield was 43.65%. Younger animals had higher leg yield while yields of loin and shoulder increased as age increased. The meat was darker in older animals. As age increased, both the quantity of commercial cuts decreased and the loss of quality traits, such as color, cooking loss, and shear force, increased; therefore, slaughter should be performed before 30 months of age.

O objetivo deste trabalho foi avaliar a qualidade da carcaça em 74 ovelhas Santa Inês deslanadas com idades entre 6 a 48 meses. O abate ocorreu após jejum e eletrochoque, seguido de dissecção das veias jugulares e artérias carótidas. As avaliações realizadas foram peso de carcaça quente, rendimento de carcaça quente, comprimento de carcaça, espessura da pele, pesos e percentagens de ombro, pescoço, lombo, fralda, costelas e pernil e comprimento e perímetro do pernil. A área de olho de lombo, a cor usando o sistema CIELAB, a força de cisalhamento e a perda por cocção também foram avaliados. Os dados foram submetidos às análises de variância, regressões, correlações e de componentes principais utilizando o pacote estatístico SAS. O peso de carcaça quente foi 15,75 kg e o rendimento de carcaça foi de 43,65%. Os animais mais jovens apresentaram maior rendimento de pernil enquanto os rendimentos de lombo e ombro aumentaram com a idade. A carne foi mais escura em animais mais velhos. Com o aumento da idade, ocorreu redução na quantidade dos cortes comerciais e aumento das perdas de características de qualidade como cor, perda por cocção e força de cisalhamento; portanto, o abate deve ser realizado antes de 30 meses de idade.

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The objective of this study was to develop an equation to determine the apparent metabolizable energy (AME) and metabolizable energy corrected for nitrogen balance (AMEn) using a physical-based classification of corn. A total of 5,055 samples were taken from bulk cargo trucks, over a five-year period. The parameters studied were the variables related to the physical characteristics of grains. The density of maize was evaluated, and AME and AMEn were calculated. The average value for AME was 3,375 kcal/kg, and two groups were formed of high quality and low quality for all samples. Stepwise regression analysis was then carried out using grain quality to estimate AME and AMEn, and the validation of the equations was carried out with 6,490 independent samples. The average value for density was 767.7 kg/m3. The multiple regressions used to estimate AME and AMEn as a function of humidity, density, and physical composition of corn kernels showed that moisture was included for AME, but not for AMEn. The equations presented high coefficients of determination (R2) for AME (0.994) and AMEn (0.987). The discriminant analyses correctly classified 98% of the high-quality samples and 96.69% of low-quality samples, so the error was smaller than the expected. The calculated equations were shown to be good at discriminating between samples of high and low quality of corn according to its physical composition, and the most important variables for separation between groups were damaged grain fraction, impurities, burnt, and soft. The correlation between calculated (independent samples) and estimated metabolizable energy and AMEn were, respectively, 0.9942 and 0.9859. The corn energy values can be estimated based on physical evaluation of the grain.(AU)

Resumo

Two experiments were carried out to evaluate the influence of genetic group, pregnancyand animal age on the carcass traits and commercial cut patterns of sheep carcasses. In the first experiment,the effect of pregnancy and genetic group were evaluated on 61 eleven month old Santa Inês ewes and theircrosses with Texel, Dorper and Ile de France. Experiment 2 was carried out with 132 Santa Inêsnulliparous or lambed ewes slaughtered with ages ranging from 6 to 48 months to evaluate the influence ofage on carcass traits. For both experiments, hot carcass weight, cold carcass weight, carcass yield, coldcarcass yield and carcass length were measured, as well as the yields and percentages of shoulder, neck, loin,belly, ribs, leg and leg length and perimeter. In experiment 1, the Santa Inês breed presented similar carcassand cut traits compared to the others genetic groups evaluated, except for fasting body weight. Lambedanimals had lower body condition score than nulliparous females. In experiment 2, fasting body weight,loin, rib and leg weights, as well as the leg perimeter, presented a quadratic effect with increasing age. Idealslaughter age is before 16 months to obtain more expensive cuts.

Foram realizados dois experimentos para se avaliar a influência do grupo genético, da prenheze da idade do animal sobre as características da carcaça e dos cortes comerciais de ovelhas. No primeiroexperimento foi avaliado o efeito da prenhez e do grupo genético em 61 ovelhas Santa Inês e seuscruzamentos com Texel, Dorper e Ilê de France. O experimento 2 foi conduzido com 132 ovelhas SantaInês prenhes e não prenhes abatidas com idades entre 6 a 48 meses para avaliar a influência da idade sobreas características da carcaça. Em ambos os experimentos foram realizadas medidas de peso de carcaçaquente, peso de carcaça fria, rendimento de carcaça quente, rendimento de carcaça fria e comprimento dacarcaça, assim como o rendimento e a percentagem da paleta, pescoço, lombo, fralda, costela e pernil, alémdo comprimento e perímetro do pernil. No experimento 1, a raça Santa Inês apresentou similaridade paraas características da carcaça e dos cortes com os outros grupos genéticos avaliados, exceto para o peso decorpo vazio. As fêmeas que pariram apresentaram menor escore de condição corporal que as fêmeasnulíparas. No experimento 2, o peso vivo em jejum, os pesos do lombo, costela e pernil, bem como acircunferência do pernil apresentaram efeito quadrático com o aumento da idade. A idade de abate idealsitua-se antes dos 16 meses de idade para a obtenção de cortes mais caros.

Resumo

ABSTRACT: The use of lambs from crossing of local with specialized sheep breeds for meat production may lead to higher meat deposition and a smaller fat amount in the carcass, with a more adequate nutritional profile for human consumption. This study investigated the performance, carcass and meat characteristics of lambs from the Morada Nova and Santa Inês locally adapted hair breeds and crosses between Dorper × Morada Nova and Dorper × Santa Inês slaughtered at approximately 35 kg. Morada Nova lambs showed lower (p 0.05) performance compared to the other genetic groups resulting in a higher age at slaughter (p 0.05). Crossbred Dorper × Santa Inês and Dorper × Morada Nova lambs showed better characteristics for meat production with better (p 0.05) conformation as well as leg and carcass compacteness index. Dorper × Santa Inês have a fatty acid profile that is more suitable for human consumption than Dorper × Morada Nova lambs do (p 0.05); however, both had lower (p 0.05) intramuscular lipid content (as measured by ether extract levels from Longíssimus lumborum) compared with purebred lambs. Therefore, when the objective is to obtain lean meat, with improved nutritional profile to reduce risks of cardiovascular disease, the use of breeds and crosses that reduce animal slaughter age, such as the ½ Dorper × ½ Santa Inês crossbred, is an interesting alternative.