RESUMO

Colonies of leaf-cutting ants of the genus Atta need to collect large quantities of vegetal substrate in their environment to ensure their growth. They do so by building and extending over time a foraging network that consists of several underground tunnels extending above ground by physical trails. This paper presents a longitudinal study of the foraging network of two mature colonies of the grass-cutting ant Atta capiguara (Gonçalves) located in a pasture in central Brazil. Specifically, we investigated whether the extension of the foraging area of the colonies required to reach new resources occurs by building new and longer underground tunnels or by building new and longer physical trails. Each nest was surveyed at intervals of approximately 15 days during 1 year. At each survey we mapped the position of the tunnel entrances and foraging trails at which activity was observed. In addition, we assessed the excavation effort of the colonies since the last survey by the number and distance to the nest of new tunnel entrances, and the physical trail construction effort by the number and length of newly built physical trails. Our study reveals that in A. capiguara the collection of new resources around the nest required to ensure the continuous growth of the colonies is achieved mainly through the excavation of new underground tunnels, opening at greater distance from the nest, not through the building of longer aboveground physical trails.

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RESUMO

O objetivo desta pesquisa foi avaliar o efeito da suplementação privativa, com concentrado ou leguminosa, sobre as características da carcaça e dos componentes corporais de cordeiros lactentes mantidos em pastejo de azevém. Foram utilizados 27 cordeiros lactentes, distribuídos nos tratamentos que corresponderam aos sistemas de alimentação: cordeiros lactentes mantidos em pasto de azevém, cordeiros lactentes mantidos em pasto de azevém e suplementados com concentrado em comedouro privativo (creep feeding) e cordeiros lactentes mantidos em pasto de azevém e suplementados com leguminosa no pasto privativo (creep grazing). O concentrado era composto por milho, farelo de soja e calcário calcítico, e a leguminosa utilizada foi o trevo-branco. O delineamento experimental foi o inteiramente ao acaso. Os resultados foram submetidos à análise de variância, e as médias comparadas pelo teste de Tukey a 5% de significância. O conteúdo do trato gastrintestinal juntamente com bile e urina e a proporção de esôfago foram maiores (P<0,05) nos cordeiros mantidos em pasto de azevém. As proporções de fígado e intestino grosso foram maiores (P<0,05) nos cordeiros suplementados com concentrado. Os sistemas alimentares testados produzem carcaças com características semelhantes. A suplementação, com leguminosa ou concentrado, altera os componentes corporais de cordeiros lactentes mantidos em azevém.(AU)

This research objective was to evaluate the effect of private supplementation with concentrated or legumes, on the carcass characteristics and body components from suckling lambs kept on ryegrass pasture. Twenty seven suckling lambs were used, with about 17 days of age and weighing 9,91±0,594kg, which were distributed in the treatments that corresponded to feeding systems: suckling lambs kept on ryegrass pasture, suckling lambs kept on ryegrass pasture and supplemented with concentrated in private feeder (creep feeding) and suckling lambs kept on ryegrass pasture and supplemented with legume in the private pasture (creep grazing). The concentrate supplement was composed by corn, soybean meal and limestone, and was supplied ad libitum. The supplementary pasture was white clover legume. The experimental design was completely randomized, where the results were submitted to analysis of variance and means compared by Tukey test at 5% of significance level. The gastrointestinal+bile+urine content and the proportion of esophagus were higher (P<0,05) in lambs kept on ryegrass. The liver and large intestine proportions were higher (P<0,05) in lambs supplemented with concentrate. The tested alimentary systems produce carcasses with similar characteristics. The supplementation with legume or concentrate cause changes in body components of suckling lambs grazing ryegrass.(AU)

Assuntos

Assuntos

RESUMO

O objetivo deste estudo foi avaliar as características de carcaça e dos componentes não carcaça de cordeiros terminados em confinamento, com diferentes proporções de caroço de algodão na dieta. Foram utilizados 45 cordeiros, machos, não castrados, da raça Ile de France. Os tratamentos foram constituídos por níveis de inclusão de caroço de algodão na matéria seca (MS) da dieta total (0%; 10%; 20%; 30% ou 40%), sendo a dieta composta por silagem de milho (Zea mays L.), grão de milho triturado (Zea mays L.), farelo de soja (Glycine max L.), caroço de algodão (Gossypium hirsutum L.), calcário calcítico e sal mineral, em proporção de volumoso:concentrado de 40:60. Os animais foram abatidos com peso de abate preestabelecido. O peso de carcaça quente e o peso de carcaça fria, bem como o índice de quebra ao resfriamento, o índice de compacidade, a conformação e o estado de engorduramento da carcaça, não foram influenciados (P>0,05) pelo nível de inclusão de caroço de algodão na dieta. As características de rendimento de carcaça quente e rendimento de carcaça fria diminuíram linearmente (P≤0,05) à medida que se incluiu caroço de algodão na dieta. Com relação à medida de espessura de gordura de cobertura, pode-se observar que houve comportamento quadrático crescente e, em relação à variável área de olho de lombo, o comportamento observado foi o linear decrescente. Quanto às proporções dos cortes comerciais da carcaça, o peso de perna diminuiu linearmente (P≤0,05) enquanto a porcentagem de perna foi influenciada de forma quadrática (P≤0,05) pela inclusão de caroço de algodão nas dietas. O trato gastrointestinal cheio e o conteúdo do trato gastrointestinal aumentam linearmente (P≤0,05) com o incremento do nível de inclusão de caroço de algodão na dieta. Algumas das características de carcaça e dos componentes não carcaça tiveram influência negativa da elevação do teor de fibra e de lipídios da dieta à medida que se incluiu caroço de algodão na dieta total.(AU)

The objective of this study was to evaluate the carcass and non carcass components characteristics of lambs finished in feedlot with different proportions of cottonseed on the diet. Forty five lambs, non castrated males, from Ile de France race. The treatments were constituted by levels of inclusion of cottonseed on dry matter (DM) of the total diet (0%; 10%; 20%; 30% or 40%), being the diet composed by corn silage (Zea mays L.), ground corn grain (Zea mays L.), soybean meal (Glycine max L.), cottonseed (Gossypiumhirsutum L.), limestone and mineral salt in a roughage: concentrate proportion of 40:60. The animals were slaughtered with a pre- established slaughter weight. The hot and cold carcass weight, as well as the carcass chilling index, the compactness index, the conformation and the fattening state of the carcass were not influenced (P> 0.05) by the level of inclusion of cottonseed on the diet. The hot and cold carcass yield decreased linearly (P≤ 0.05) as the cottonseed was included on the diet. Regarding the subcutaneous fat thickness it is possible to observe that there was a crescent quadratic behavior and in relation to the rib eye area variable, the behavior observed was linear decrescent. Regarding the proportions of the commercial cuts of the carcass, the leg weight decreased linearly (P≤ 0.05) while the percentage of leg was quadratic influenced (P≤ 0.05) by the inclusion of cottonseed on the diets. The full gastrointestinal tract and the gastrointestinal tract content increased linearly (P≤ 0.05) with the increase on the level of inclusion of cottonseed on the diet. Some of the carcass and non carcass components characteristics had negative influence of level fiber content and dietary lipids as it included cottonseed in the total diet.(AU)

Assuntos

RESUMO

O objetivo deste estudo foi avaliar as características de carcaça e dos componentes não carcaça de cordeiros terminados em confinamento, com diferentes proporções de caroço de algodão na dieta. Foram utilizados 45 cordeiros, machos, não castrados, da raça Ile de France. Os tratamentos foram constituídos por níveis de inclusão de caroço de algodão na matéria seca (MS) da dieta total (0%; 10%; 20%; 30% ou 40%), sendo a dieta composta por silagem de milho (Zea mays L.), grão de milho triturado (Zea mays L.), farelo de soja (Glycine max L.), caroço de algodão (Gossypium hirsutum L.), calcário calcítico e sal mineral, em proporção de volumoso:concentrado de 40:60. Os animais foram abatidos com peso de abate preestabelecido. O peso de carcaça quente e o peso de carcaça fria, bem como o índice de quebra ao resfriamento, o índice de compacidade, a conformação e o estado de engorduramento da carcaça, não foram influenciados (P>0,05) pelo nível de inclusão de caroço de algodão na dieta. As características de rendimento de carcaça quente e rendimento de carcaça fria diminuíram linearmente (P≤0,05) à medida que se incluiu caroço de algodão na dieta. Com relação à medida de espessura de gordura de cobertura, pode-se observar que houve comportamento quadrático crescente e, em relação à variável área de olho de lombo, o comportamento observado foi o linear decrescente. Quanto às proporções dos cortes comerciais da carcaça, o peso de perna diminuiu linearmente (P≤0,05) enquanto a porcentagem de perna foi influenciada de forma quadrática (P≤0,05) pela inclusão de caroço de algodão nas dietas. O trato gastrointestinal cheio e o conteúdo do trato gastrointestinal aumentam linearmente (P≤0,05) com o incremento do nível de inclusão de caroço de algodão na dieta. Algumas das características de carcaça e dos componentes não carcaça tiveram influência negativa da elevação do teor de fibra e de lipídios da dieta à medida que se incluiu caroço de algodão na dieta total.(AU)

The objective of this study was to evaluate the carcass and non carcass components characteristics of lambs finished in feedlot with different proportions of cottonseed on the diet. Forty five lambs, non castrated males, from Ile de France race. The treatments were constituted by levels of inclusion of cottonseed on dry matter (DM) of the total diet (0%; 10%; 20%; 30% or 40%), being the diet composed by corn silage (Zea mays L.), ground corn grain (Zea mays L.), soybean meal (Glycine max L.), cottonseed (Gossypiumhirsutum L.), limestone and mineral salt in a roughage: concentrate proportion of 40:60. The animals were slaughtered with a pre- established slaughter weight. The hot and cold carcass weight, as well as the carcass chilling index, the compactness index, the conformation and the fattening state of the carcass were not influenced (P> 0.05) by the level of inclusion of cottonseed on the diet. The hot and cold carcass yield decreased linearly (P≤ 0.05) as the cottonseed was included on the diet. Regarding the subcutaneous fat thickness it is possible to observe that there was a crescent quadratic behavior and in relation to the rib eye area variable, the behavior observed was linear decrescent. Regarding the proportions of the commercial cuts of the carcass, the leg weight decreased linearly (P≤ 0.05) while the percentage of leg was quadratic influenced (P≤ 0.05) by the inclusion of cottonseed on the diets. The full gastrointestinal tract and the gastrointestinal tract content increased linearly (P≤ 0.05) with the increase on the level of inclusion of cottonseed on the diet. Some of the carcass and non carcass components characteristics had negative influence of level fiber content and dietary lipids as it included cottonseed in the total diet.(AU)

Assuntos

RESUMO

O objetivo desta pesquisa foi avaliar o efeito da suplementação privativa, com concentrado ou leguminosa, sobre as características da carcaça e dos componentes corporais de cordeiros lactentes mantidos em pastejo de azevém. Foram utilizados 27 cordeiros lactentes, distribuídos nos tratamentos que corresponderam aos sistemas de alimentação: cordeiros lactentes mantidos em pasto de azevém, cordeiros lactentes mantidos em pasto de azevém e suplementados com concentrado em comedouro privativo (creep feeding) e cordeiros lactentes mantidos em pasto de azevém e suplementados com leguminosa no pasto privativo (creep grazing). O concentrado era composto por milho, farelo de soja e calcário calcítico, e a leguminosa utilizada foi o trevo-branco. O delineamento experimental foi o inteiramente ao acaso. Os resultados foram submetidos à análise de variância, e as médias comparadas pelo teste de Tukey a 5% de significância. O conteúdo do trato gastrintestinal juntamente com bile e urina e a proporção de esôfago foram maiores (P<0,05) nos cordeiros mantidos em pasto de azevém. As proporções de fígado e intestino grosso foram maiores (P<0,05) nos cordeiros suplementados com concentrado. Os sistemas alimentares testados produzem carcaças com características semelhantes. A suplementação, com leguminosa ou concentrado, altera os componentes corporais de cordeiros lactentes mantidos em azevém.(AU)

This research objective was to evaluate the effect of private supplementation with concentrated or legumes, on the carcass characteristics and body components from suckling lambs kept on ryegrass pasture. Twenty seven suckling lambs were used, with about 17 days of age and weighing 9,91±0,594kg, which were distributed in the treatments that corresponded to feeding systems: suckling lambs kept on ryegrass pasture, suckling lambs kept on ryegrass pasture and supplemented with concentrated in private feeder (creep feeding) and suckling lambs kept on ryegrass pasture and supplemented with legume in the private pasture (creep grazing). The concentrate supplement was composed by corn, soybean meal and limestone, and was supplied ad libitum. The supplementary pasture was white clover legume. The experimental design was completely randomized, where the results were submitted to analysis of variance and means compared by Tukey test at 5% of significance level. The gastrointestinal+bile+urine content and the proportion of esophagus were higher (P<0,05) in lambs kept on ryegrass. The liver and large intestine proportions were higher (P<0,05) in lambs supplemented with concentrate. The tested alimentary systems produce carcasses with similar characteristics. The supplementation with legume or concentrate cause changes in body components of suckling lambs grazing ryegrass.(AU)

Assuntos

RESUMO

Objetivou-se avaliar os consumos de matéria seca, nutrientes e desempenho na terminação de cordeiros e borregos submetidos a dietas de alto concentrado de grão de milho ou sorgo. Foram utilizados 32 animais, sendo 16 cordeiros (dente de leite) e 16 borregos (dois dentes) da raça Corriedale. As dietas eram constituídas de feno de aveia- branca (Avena sativa), grão de milho (Zea mays) ou de sorgo (Sorghum bicolor (L.) Moench), farelo de soja (Glycine Max), calcário calcítico, bicarbonato de sódio e monensina. Os cordeiros apresentaram superioridade (P≤0,05) quanto ao CMS (% do PV e g/kg PV0,75), ao CPB (kg/dia, % do PV e g/kg PV0,75), ao CEE (% do PV), ao CFDN e ao CFDA (% do PV e g/kg PV0,75), ao CNDT (% do PV), ao ganho de peso médio diário, à conformação in vivo e à conversão alimentar. Por outro lado, o CEE, o CCHT e o CCNE (kg/dia), o peso vivo inicial, o peso vivo final e o peso vivo ao abate foram superiores (P≤0,05) na categoria dos borregos. Em relação aos grãos avaliados, verificou-se maior (P≤0,05) CEE (kg/dia, % do PV e g/kg PV0,75) e menor (P≤0,05) CFDN (% do PV) e CFDA (kg/dia, % do PV e g/kg PV0,75) para os animais alimentados com dieta de alto concentrado à base de grão de milho em relação àqueles alimentados com grão de sorgo. Os cordeiros apresentam consumos relativos superiores aos borregos, porém sua resposta zootécnica é maior. O uso de dietas de alto concentrado de sorgo ou de milho proporcionou resultados semelhantes.(AU)

This study aimed to evaluate the dry matter, nutrient intake, and performance on feedlot of lambs and hoggets submitted to corn or sorghum high concentrate diets. Thirty-two Corriedale animals, being 16 lambs (milk teeth) and 16 hoggets (two teeth) were used. The diets were composed of white oat hay (Avena sativa), corn (Zea mays) or sorghum grain (Sorghum bicolor (L.) Moench), soybean meal (Glycine Max), limestone, sodium bicarbonate, and monensin. The lambs presented a superiority (P≤0.05) regarding the DMI (% of LW and g/kg LW0.75), CPI (kg/day, % of LW and g/kg LW0.75), EEI (% of LW), NDFI and ADFI (% of LW and g/kg LW0.75), TDNI (% of LW), daily average weight gain, conformation in vivo and feed conversion. On the other hand, the EEI, TCI, and NSCI (kg/day), the initial live weight, final live weight and the live weight at slaughter were superior (P≤0.05) in the hoggets category. In relation to the evaluated grains, a higher (P≤0.05) EEI (kg/day, % of LW and g/kg LW0.75) and a lower (P≤0.05) NDFI (% of LW) and ADFI (kg/day, % of LW and g/kg LW0.75) were verified for the animals fed with high concentrate diets based on corn grain in relation to those fed with sorghum grain. The lambs presented an intake relatively superior to the hoggets, however their zootechnical response is higher. The use of high concentrate diets of sorghum or corn provides similar results.(AU)

Assuntos

RESUMO

Objetivou-se avaliar os consumos de matéria seca, nutrientes e desempenho na terminação de cordeiros e borregos submetidos a dietas de alto concentrado de grão de milho ou sorgo. Foram utilizados 32 animais, sendo 16 cordeiros (dente de leite) e 16 borregos (dois dentes) da raça Corriedale. As dietas eram constituídas de feno de aveia- branca (Avena sativa), grão de milho (Zea mays) ou de sorgo (Sorghum bicolor (L.) Moench), farelo de soja (Glycine Max), calcário calcítico, bicarbonato de sódio e monensina. Os cordeiros apresentaram superioridade (P≤0,05) quanto ao CMS (% do PV e g/kg PV0,75), ao CPB (kg/dia, % do PV e g/kg PV0,75), ao CEE (% do PV), ao CFDN e ao CFDA (% do PV e g/kg PV0,75), ao CNDT (% do PV), ao ganho de peso médio diário, à conformação in vivo e à conversão alimentar. Por outro lado, o CEE, o CCHT e o CCNE (kg/dia), o peso vivo inicial, o peso vivo final e o peso vivo ao abate foram superiores (P≤0,05) na categoria dos borregos. Em relação aos grãos avaliados, verificou-se maior (P≤0,05) CEE (kg/dia, % do PV e g/kg PV0,75) e menor (P≤0,05) CFDN (% do PV) e CFDA (kg/dia, % do PV e g/kg PV0,75) para os animais alimentados com dieta de alto concentrado à base de grão de milho em relação àqueles alimentados com grão de sorgo. Os cordeiros apresentam consumos relativos superiores aos borregos, porém sua resposta zootécnica é maior. O uso de dietas de alto concentrado de sorgo ou de milho proporcionou resultados semelhantes.(AU)

This study aimed to evaluate the dry matter, nutrient intake, and performance on feedlot of lambs and hoggets submitted to corn or sorghum high concentrate diets. Thirty-two Corriedale animals, being 16 lambs (milk teeth) and 16 hoggets (two teeth) were used. The diets were composed of white oat hay (Avena sativa), corn (Zea mays) or sorghum grain (Sorghum bicolor (L.) Moench), soybean meal (Glycine Max), limestone, sodium bicarbonate, and monensin. The lambs presented a superiority (P≤0.05) regarding the DMI (% of LW and g/kg LW0.75), CPI (kg/day, % of LW and g/kg LW0.75), EEI (% of LW), NDFI and ADFI (% of LW and g/kg LW0.75), TDNI (% of LW), daily average weight gain, conformation in vivo and feed conversion. On the other hand, the EEI, TCI, and NSCI (kg/day), the initial live weight, final live weight and the live weight at slaughter were superior (P≤0.05) in the hoggets category. In relation to the evaluated grains, a higher (P≤0.05) EEI (kg/day, % of LW and g/kg LW0.75) and a lower (P≤0.05) NDFI (% of LW) and ADFI (kg/day, % of LW and g/kg LW0.75) were verified for the animals fed with high concentrate diets based on corn grain in relation to those fed with sorghum grain. The lambs presented an intake relatively superior to the hoggets, however their zootechnical response is higher. The use of high concentrate diets of sorghum or corn provides similar results.

Assuntos

RESUMO

Seeds of different plant species constitute an alternative but also significant substrate that leaf-cutting ants use to cultivate their fungus garden. However, how they are processed inside the nest and if their use implies differential allocation of worker size classes are still poorly known. Using laboratory colonies of Acromyrmex subterraneus (Forel) as a model, the behaviors related to the processing of three different seeds (sesame, guava, and grape) as fungus substrate were listed. At the same time, we measured how each worker size class contributed to the execution of these behaviors by registering their respective frequency. It was found that medium-sized (1.2 > head width < 1.6 mm) and minimum-sized (head width <1.1 mm) workers assumed the role of incorporation for sesame and grape seeds, respectively. Major-sized workers (head width >1.7 mm) were concentrated on licking and holding guava seeds. Tegument removal was the only task observed that differs between treatment of seeds and treatment of leaves before their incorporation, as described in the literature. It was verified that different species of seeds imply a differential allocation of worker size classes and the inclusion or exclusion of some tasks from the behavioral repertoire. Regardless of the substrate type, leaf-cutting ant workers follow a coordinated and specialized procedure to cultivate the fungus garden but always maintain a high degree of cooperation.

Assuntos

RESUMO

Um experimento foi conduzido com o objetivo de avaliar as características da carcaça e dos componentes não carcaça de cordeiros nascidos de parto simples ou duplo. Dezesseis cordeiros mestiços Texel × Ile de France, machos não castrados, foram desmamados aos 56 dias de idade e abatidos com aproximadamente 28kg de peso corporal. Imediatamente após o abate, cada componente corporal foi pesado separadamente, sendo as carcaças avaliadas após 24 horas de refrigeração a 2°C. Os cordeiros oriundos de parto simples apresentaram superioridade no peso e nos rendimentos da carcaça, além de maior área de olho de lombo. Por outro lado, proporcionalmente ao peso de corpo vazio, o rúmen é maior em cordeiros nascidos de parto duplo, o que resulta incremento da proporção de conteúdo gastrintestinal ao abate. Os resultados deste estudo indicam que, quando abatidos a um mesmo peso, cordeiros oriundos de parto simples possuem carcaças de melhor qualidade, em comparação a cordeiros nascidos de parto gemelar.(AU)

An experiment was conducted to evaluate the carcass and non-carcass traits of single and twin lambs. Sixteen Texel × Ile de France crossbred, non-castrated male lambs were weaned at 56 days of age and slaughtered at 28kg of body weight. Immediately after the slaughter each body component was individually weighed, while carcasses were evaluated after a 24h period of refrigeration at 2°C. Single lambs presented higher values of carcass weight and carcass dressing percentage. Moreover, the Longissimus muscle area was also greater for single lambs. On the other hand, as a proportion of empty body weight, rumen was greater for twin lambs, increasing their gastrointestinal content at slaughter. The results of this study indicated that at a same slaughter weight single lambs have better quality carcasses in comparison with those from twin lambs.(AU)

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