Carcass characteristics and meat quality of male pigs submitted to surgical or immunological castration.

The objective of this study was to evaluate carcass characteristics and meat quality of surgically castrated and immunocastrated male pigs. Data were collected from 24 surgically castrated pigs and 24 immunocastrated male entire originating from the commercial line (Agroceres x Topigs), receiving isonutritive diets and were housed in the same experimental shed, slaughtered at 177 days old, with a slaughter weight of 127.8 (± 6.5) and 135.1 (± 7.8) kg, respectively. Carcass and meat quality characteristics such as carcass yield, lean meat yield, fat content, backfat thickness, muscle depth, pH, meat coloring and, drip, thawing and cooking loss, were evaluated. Immunocastrated pigs have heavier carcass, higher meat yield and lower fat thickness when compared to surgically castrated animals. Regarding meat quality, the immunocastrated presented a lighter meat, less reddness and less water holding capacity. In conclusion, this study confirmed that the carcass of male pigs, submitted immunocastration, has lower yield, however, more meat and less fat content, when compared to carcass of male pigs surgically castrated. Meat quality showed peculiar characteristics for immunocastrated pigs, and can be used more for sausage production, since it retains less water and have smaller redness color compared to surgically castrated pigs.

Efficiency of threonine utilization in the growing pigs / Eficiencia del uso de treonina para cerdos en fase de crecimiento

Objective. This study aimed to determine the marginal efficiency of threonine utilization in growing pigs by using the nitrogen balance technique. Materials and methods. Twelve castrated pigs with an average live weight of 72±2 kg were housed in metabolic cages maintained in a temperature controlled room of 22±3°C. The treatments consisted of four diets calculated to meet 30, 45, 60 and 70% of the nutritional requirements of standardized ileal digestible threonine. The amino acids others than threonine were maintained at least 15% above threonine requirements, expressed in terms of ideal levels. The amount of feed supplied was calculate to provide 2.6 times the metabolizable energy requirements for maintenance and adjusted daily according to an expected daily gain rate of 0.8 kg. Results. Pigs consumed 1.65 g kg-1 BW0.75 nitrogen daily, on average and 61% was retained and, as a result, 39% was excreted, being 31% through the feces and the remainder (69%) in the urine. The pigs showed a linear retention of threonine in response to the increase of standardized threonine intake. For each gram of standardized threonine intake 0.37 g were lost during the metabolism. Conclusions. It is concluded that for calculating nutritional requirements of standardized threonine of pigs by the factorial method, it is possible to use the utilization marginal efficiency of 0.63.

Objetivo. El objetivo de este estudio fue determinar la eficiencia marginal del uso de treonina para cerdos en fase de crecimiento, por medio de la técnica de balance de nitrógeno. Material y métodos. Fueron utilizados doce cerdos machos castrados con peso promedio de 72±2 kg alojados en jaulas metabólicas climatizadas a una temperatura ambiente de 22±3°C. Los tratamientos consistieron en cuatro dietas calculadas para 30, 45, 60 y 70% de las necesidades nutricionales de treonina digestible estandarizada. Los demás aminoácidos se añadieron a las dietas para lograr una proporción de al menos 15% de sus necesidades expresadas con relación a la treonina. La cantidad de alimento proporcionado se calculó para suministrar 2.6 veces la energía metabolizable y ajustada todos los dias, según una tasa de ganancia media diaria de 0.8 kg. Resultados. Los cerdos consumieron 1.65 g kg-1 PV0.75 de nitrógeno por dia. En promedio 61% de nitrógeno ingerido se conservó y 39% fue excretado por el animal. El 31% se excretó en las heces y el resto (69%) en la orina. Los cerdos mostraron una retención lineal de treonina, con relación al aumento en la ingesta de treonina digestible estandarizada. Por cada gramo de treonina digestible estandarizada ingerido 0.37 g se perdieron durante el metabolismo. Conclusiones. Se concluye que, para el cálculo de las necesidades nutricionales de treonina digestible estandarizada para cerdos por método factorial, es posible utilizar la eficiencia marginal del uso de treonina a 0.63.

Effects induced by Apis mellifera venom and its components in experimental models of nociceptive and inflammatory pain.

The effects induced by Apis mellifera venom (AMV), melittin-free AMV, fraction with molecular mass < 10 kDa (F<10) or melittin in nociceptive and inflammatory pain models in mice were investigated. Subcutaneous administration of AMV (2, 4 or 6 mg/kg) or melittin-free AMV (1, 2 or 4 mg/kg) into the dorsum of mice inhibited both phases of formaldehyde-induced nociception. However, F<10 (2, 4 or 6 mg/kg) or melittin (2 or 3 mg/kg) inhibited only the second phase. AMV (4 or 6 mg/kg), but not F<10, melittin-free AMV or melittin, induced antinociception in the hot-plate model. Paw injection of AMV (0.05 or 0.10 mg), F<10 (0.05 or 0.1 mg) or melittin (0.025 or 0.050 mg) induced a nociceptive response. In spite of inducing nociception after paw injection, scorpion (Tityus serrulatus) or snake (Bothrops jararaca) venom injected into the dorsum of mice did not inhibit formaldehyde-induced nociception. In addition, AMV (6 mg/kg), but not F<10 (6 mg/kg) or melittin (3 mg/kg), inhibited formaldehyde paw oedema. Concluding, AMV, F<10 and melittin induce two contrasting effects: nociception and antinociception. AMV antinociception involves the action of different components and does not result from non-specific activation of endogenous antinociceptive mechanisms activated by exposure to noxious stimuli.

Pharmacological investigation of the nociceptive response and edema induced by venom of the scorpion Tityus serrulatus.

In this study we characterized the nociceptive response and edema induced by the venom of the scorpion Tityus serrulatus in rats and mice and carried out a preliminary pharmacological investigation of the mechanisms involved in these responses. Intraplantar injection of the venom (1 or 10mug) induced edema and a marked ipsilateral nociceptive response, characterized by thermal and mechanical allodynia and paw licking behaviour. The nociceptive response was inhibited by previous intraperitoneal administration of indomethacin (4mg/kg), dipyrone (200mg/kg), cyproheptadine (10mg/kg) or morphine (5 or 10mg/kg), but not by dexamethasone (1 or 4mg/kg) or promethazine (1 or 5mg/kg). The edema was inhibited by previous treatment with promethazine (5 or 10mg/kg) or cyproheptadine (5 or 10mg/kg), but not by indomethacin (2 or 4mg/kg), dexamethasone (1 or 4mg/kg) or cromolyn (40 or 80mg/kg). Some bioactive amines, including histamine and 5-hydroxytryptamine, were found in the venom in low concentrations. In conclusion, the nociceptive response and edema induced by the venom of T. serrulatus may result from the action of multiple mediators including eicosanoids, histamine and 5-hydroxytryptamine. These results may lead to a better understanding of the host response to potent animal toxins and also give insights into a more rational pharmacological approach to alleviate the intense pain associated with the scorpion envenomation.