Qualitative characteristics of meat from confined crossbred heifers fed with lipid sources

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Strategies to promote farm animal welfare in Latin America and their effects on carcass and meat quality traits

Several initiatives, including research and development, increasing stakeholders' awareness and application of legislation and recommendation, have been carried out in Latin America to promote animal welfare and meat quality. Most activities focused on the impact of pre-slaughter conditions (facilities, equipment and handling procedures) on animal welfare and meat quality. The results are encouraging; data from Brazil, Chile and Uruguay showed that the application of the improved pre-slaughter handling practices reduced aggressive handling and the incidence of bruised carcasses at slaughter in cattle and pigs. These outcomes stimulated some to apply animal welfare concepts in livestock handling within the meat production chain as shown by the increasing demand for personnel training on the best. To attend this demand is important to expand local studies on farm animal welfare and to set up (or maintain) an efficient system for knowledge transfer to all stakeholders in the Latin America meat production chains. However, it is clear that to promote the long-term progress in this field is important to deliver practical solutions, assuring that they match the technical and financial conditions of those who are the target of training programs. (C) 2012 Elsevier Ltd. All rights reserved.

Relative development of tissues, commercial meat cuts and live weight components in Saanen goats

Objetivando avaliar o desenvolvimento relativo dos componentes do peso vivo (PV), dos cortes comerciais e dos tecidos da carcaça, utilizaram-se 40 cabritos Saanen. Os animais foram abatidos ao atingir 5,0; 12,5; 20,0; 27,5 e 35,0 kg de PV e a carcaça foi seccionada em paleta, pescoço, 1ª a 5ª costelas, 6ª a 13ª costelas, peito/fralda, lombo e perna. A perna foi dissecada em ossos, músculos e gordura. Utilizou-se a equação alométrica Y=aXb para estimar o desenvolvimento relativo. O crescimento do tecido ósseo foi precoce, o do tecido muscular intermediário e o da gordura crescimento tardio, uma vez que a gordura subcutânea é depositada mais tardiamente. Os cortes comerciais apresentaram coeficiente de alometria isogônico, com exceção do corte da 6ª a 13ª costelas e do peito/fralda. O desenvolvimento da carcaça e dos não-componentes da carcaça acompanhou o peso de corpo vazio. Cabritos com 35 kg de PV possuem proporção de músculos e relação músculo:osso adequadas, mas apresentam proporção de gordura maior que a observada nos animais abatidos com 20 kg de PV.

Evaluation of corn cultivars harvested at two cutting heights for ensilage

Objetivou-se neste estudo avaliar as características agronômicas, a composição químico-bromatológica e a digestibilidade de 11 cultivares de milho (Zea mays) colhido em duas alturas de corte. As cultivares D 766, D 657, D 1000, P 3021, P 3041, C 805, C 333, AG 5011, FO 01, CO 9621 e BR 205 foram avaliadas quando colhidas 5 cm acima do solo (baixa) e 5 cm abaixo da inserção da primeira espiga (alta). O experimento foi delineado como blocos casualizados, com três repetições, arranjados em esquema fatorial 11 x 2. Os cultivares apresentaram produções semelhantes de matéria seca de forragem e de grãos. As porcentagens das frações colmo, folha, palha, sabugo e grão diferiram entre os cultivares, assim como os teores de matéria seca da planta inteira no momento da colheita. Considerando a planta inteira, apenas os teores de energia bruta, nitrogênio da fração fibra em detergente neutro e a digestibilidade in vitro da fibra em detergente neutro e detergente ácido não diferiram entre os cultivares. O aumento da altura de corte melhorou a qualidade da forragem, devido à redução das frações colmo e folha e dos teores dos constituintes da parede celular.

Quantitative and qualitative characteristics of the non-carcass components and the meat of lambs fed sunflower seeds and vitamin E

The objective of this investigation was to evaluate the weight and percentage of the non-carcass components and the mineral content (macro minerals and trace minerals), crude protein, ether extract, moisture and vitamin E of the heart, liver, tongue, lungs, reticulum, kidneys and meat from the longissimus dorsi of lambs in feedlot finishing. Thirty-two non-castrated Ile de France male lambs, fed diets containing sunflower seeds and vitamin E from 15 to 32 kg of body weight were allotted in a completely randomized design in a 2 × 2 factorial arrangement. The weight of the gastrointestinal tract was higher in the lambs fed diets containing vitamin E (10%). No difference was observed in the liver as to the mineral matter, crude protein, ether extract, moisture (2.01; 20.03; 2.39 and 74.78 g/100 g, respectively), the macro minerals and trace minerals, except iron. In the tongue, lungs, reticulum, kidneys and meat there was no in fluence of diets in the studied variables. The liver and the meat presented different values of crude protein (20.01 and 18.34 g/100 g, respectively), and the heart (1.03 mg/100 g) showed a higher content of vitamin E. High contents of manganese, zinc and copper were observed in the liver. The evaluated non-carcass components were nutritionally equal to the sheep meat, once, in addition to their high yield in relation to the body weight at slaughter, the non-carcass components are sources of nutrients.

Ractopamine hydrochloride in formulated rations for barrows or gilts from 94 to 130 kg

Foi realizado um experimento com o objetivo de avaliar o desempenho, a composição de carcaça e a viabilidade econômica do uso de 5 e 10 ppm de cloridrato de ractopamina (RAC) em rações formuladas para suínos machos castrados ou para fêmeas dos 94 aos 130 kg. Utilizaram-se 60 suínos, distribuídos em delineamento de blocos ao acaso, em arranjo fatorial 3 × 2, composto de três níveis de ractopamina e dois sexos. Não houve interação significativa entre a ractopamina e o sexo para as variáveis analisadas. Observou-se, nos animais que receberam ractopamina, maior peso final, ganho de peso médio diário e conversão alimentar. As fêmeas apresentaram menor peso final, consumo médio diário de ração e conversão alimentar. Para rendimento de carcaça, área de olho-de-lombo e rendimento de carne na carcaça, o nível de 10 ppm foi superior ao controle. A ractopamina, independentemente do nível utilizado, reduziu a espessura de toucinho e melhorou o rendimento de filezinho, pernil e carne no pernil. As fêmeas apresentaram maior rendimento de carne na carcaça, menor espessura de toucinho, maior flexibilidade da barriga e menor espessura de toucinho da barriga. As carcaças de suínos sob suplementação com ractopamina apresentaram melhor índice de bonificação, receita bruta e receita líquida. Houve redução no custo total e aumento no índice de bonificação das carcaças das fêmeas, o que melhorou a receita líquida. Dessa forma, a suplementação com 5 ppm de ractopamina é suficiente para melhorar o desempenho, a composição de carcaça e o rendimento de cortes da carcaça de suínos machos castrados e fêmeas. Além disso, a suplementação com 5 ou 10 ppm de ractopamina, nas condições estudadas, é economicamente viável, e o abate de fêmeas aos 130 kg, mais rentável que o de machos castrados.

Production of polysaccharidases in different carbon sources by Leucoagaricus gongylophorus Moller (Singer), the symbiotic fungus of the leaf-cutting ant Atta sexdens linnaeus

Leucoagaricus gongylophorus, the fungus cultured by the leaf-cutting ant Atta sexdens, produces polysaccharidases that degrade leaf components by generating nutrients believed to be essential for ant nutrition. We evaluated pectinase, amylase, xylanase, and cellulase production by L. gongylophorus in laboratory cultures and found that polysaccharidases are produced during fungal growth on pectin, starch, cellulose, xylan, or glucose but not cellulase, whose production is inhibited during fungal growth on xylan. Pectin was the carbon source that best stimulated the production of enzymes, which showed that pectinase had the highest production activity of all of the carbon sources tested, indicating that the presence of pectin and the production of pectinase are key features for symbiotic nutrition on plant material. During growth on starch and cellulose, polysaccharidase production level was intermediate, although during growth on xylan and glucose, enzyme production was very low. We propose a possible profile of polysaccharide degradation inside the nest, where the fungus is cultured on the foliar substrate.

Evaluation of the adequacy of diflubenzuron and dechlorane in toxic baits for leaf-cutting ants (Hymenoptera : Formicidae) based on formicidal activity

Studies assessing the characteristics of active ingredients (AIs) of toxic baits for leaf-cutting ants are still scarce, although the need for a delayed action of these compounds on adult workers has been well accepted (mortality <= 15% at 24 h and <= 90% at 21 days). Therefore, we determined the insecticidal action of two AIs used in commercial baits, diflubenzuron and dechlorane, over time in workers, and discussed the control of colonies in relation to the existing literature. Dechlorane presented excellent insecticidal activity with a delayed action at all concentrations tested, although its commercial use has been prohibited due to its organochlorine nature. In contrast, diflubenzuron did not cause significant mortality or symptoms of intoxication, indicating that the successful cases reported with the use of baits containing this AI were in fact due to an accidental contamination with dechlorane. We comment about the ineffectiveness of diflubenzuron on alternative targets, i.e., young forms and the mutualistic fungus, supporting the concept that the AI needs to a have a delayed action on adult workers.

Larval isolation and brood care in Acromyrmex leaf-cutting ants

The larvae of leaf-cutting ants are maintained within the fungus gardens of their colonies and are fed pieces of fungus by the adult workers. However, little else is known about the nature of the worker-larva interaction in these ecologically important ants. To examine whether workers can gauge the needs of individual larvae, we isolated larvae without adult workers for different lengths of time. We then placed workers with the larvae and recorded the type and frequency of the subsequent behaviours of the workers. Workers scraped the mouthparts of larvae, ingested their faecal fluid, fed them with fungal hyphae, transported them around the fungus garden and, most frequently, licked their bodies. The workers were also observed to 'plant' fungal hyphae on the bodies of larvae. Workers interacted more frequently with larvae that had been isolated without workers than with those that had not, but there was no effect of the length of isolation. The results suggest that the interactions are complex, involving a number of behaviours that probably serve different functions, and that workers are to some extent able to assess the individual needs of larvae.

Filamentous fungi found on foundress queens of leaf-cutting ants (Hymenoptera: Formicidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Geographic Distribution and Population Estimate of Leaf-cutting Ants of the Genus Acromyrmex (Hymenoptera: Formicidae) in Southwestern Bahia

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Growth of the Symbiotic Fungus of the Grass-cutting Ant Atta capiguara (Hymenoptera: Formicidae): Effect of Grass Extracts

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Selectivity of Workers of the Grass-Cutting Ants Atta bisphaerica and Atta capiguara (Hymenoptera: Formicidae) to Vegetable Oils

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Digging effort in leaf-cutting ant queens (Atta sexdens rubropilosa) and its effects on survival and colony growth during the claustral phase

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nest Digging by Leaf-Cutting Ants: Effect of Group Size and Functional Structures.

Leaf-cutting ant workers dig underground chambers, for housing their symbiotic fungus, interconnected by a vast quantity of tunnels whose function is to permit the entrance of food (leaves), gaseous exchanges, andmovement of workers, offspring, and the queen. Digging is a task executed by a group of workers, but little is known about the group effect and group-constructed functional structures. Thus, we analyzed the structures formed by worker groups (5, 10, 20, and 40 individuals) of the leaf-cutting ant, Atta sexdens rubropilosa, for 2 days of excavation. The digging arena was the same for the 4 groups, with each group corresponding to a different density. Our results verified a pattern of tunneling by the workers, but no chamber was constructed. The group effect is well known, since the 40-worker group dug significantly more than the groups of 5, 10, and 20. These groups did not differ statistically from each other. Analysis of load/worker verified that workers of the smallest group carried the greatest load. Our paper demonstrates the group effect on the digging of nests, namely, that excavation is proportional to group size, but without emergence of a functional structure such as a chamber.