RESUMO

The objective of this study was to determine the effect of pre-slaughter time about some blood constituents used as stress indicators in the evaluation of animal welfare in cattle. In the practice of ethology, animal welfare is assessed through physiological and behavioral indicators. For the determination of serum biomarkers of animal stress, a total of 180 animals was used, divided into two major groups according to the time of pre-slaughter. In the acceptable group, the animals had a pre-slaughter time up to 24 hours and in the not acceptable group the pre-slaughter time was greater than 24 h. These two groups were split up into three animal categories (males, females and castrated males). In this study, 30 samples were collected from each animal category of the two groups, acceptable and not acceptable, totaling 180 samples. Samples were separated for analysis of muscle enzymes creatine kinase and lactate dehydrogenase (CK and LDH), glucose and cortisol. Physiological values, regardless of the animal category and pre-slaughter time, were higher than the normal values of reference, expressing the prior management effect on animal welfare. The data clearly show a need to update and adapt the entire production chain to animal welfare practices, with the objective of producing competitive quality meat in the world market.(AU)

O objetivo do estudo foi avaliar o efeito do tempo de pré-abate sobre alguns constituintes sanguíneos utilizados como indicadores de estresse na avaliação do bem-estar animal em bovinos. Na prática da etologia, o bem-estar animal é avaliado por meio de indicadores fisiológicos e comportamentais. Para a determinação sérica de biomarcadores de estresse animal utilizaram-se 180 animais, divididos em dois grupos de acordo com o tempo de pré-abate: até 24 horas ou acima de 24 horas. Esses dois grupos subdividiram-se em três categorias animais (machos não-castrados, machos castrados ou fêmeas). Foram coletadas 30 amostras de cada categoria animal nos dois grupos, totalizando 180 amostras. Foram separadas amostras para análise de enzimas musculares creatina quinase e lactato desidrogenase (CK e LDH), glicose e cortisol. Os valores fisiológicos, independentemente da categoria animal e do tempo de pré-abate, foram superiores aos valores de referência, expressando o efeito do manejo prévio sobre o bem-estar dos animais. Os dados evidenciam claramente a necessidade de atualização e adequação de toda a cadeia produtiva às práticas de bem-estar animal, com o objetivo de produzir carne de qualidade competitiva no mercado mundial.(AU)

Assuntos

RESUMO

Background: The Brazilian tapir (Tapirus terrestris), considered the largest land mammal in South America, is a vulnerable species in terms of its degree of conservation. In captivity, its health is evaluated through behavioral and physical observation and laboratory exams, and in some cases, chemical restraint, to reduce stress. Dissociative anesthetics and sedatives are used for the sedation of these animals, and few studies have reported the use of dexmedetomidine and its effects when associated with other drugs in chemical containment protocols; therefore, this work reports its use, in conjunction with ketamine and midazolam, in a young Brazilian tapir. Case: A male Brazilian tapir, male, weighing 89 kg, 1 and a half year old, housed at CETAS in Rio Branco, Acre, was chemically restrained with dexmedetomidine (7 µg/kg), ketamine (1.5 mg/kg), and midazolam (0.2 mg/kg) for venous blood collection, oral and rectal mucosal swabs, and microchipping. The protocol was administered intramuscularly to the right triceps brachii, after physical restraint. After 5 min of application, the animal assumed sternal recumbency and presented reflux. After 15 min, the patient was placed in the right lateral decubitus position. During collection, heart rate (48 ± 10 bpm), respiratory frequency (29 ± 1 mpm), rectal temperature (38.1 ± 0.18°C), oxyhemoglobin saturation (97 ± 1%), and electrocardiographic tracing were recorded. The tapir showed deep sedation, immobility, good muscle relaxation, discreet medial palpebral reflex, and bilateral rotation of the eyeball. After 40 min of protocol administration, sedative reversal was performed intramuscularly with 14 µg/kg atipamezole. Five min after administration, the tapir showed signs of mild sedation. After 10 min, he assumed the quadrupedal position, remained in this position for 8 min, and gently resumed the sternal decubitus. After only 20 min, he resumed the quadrupedal position, with mild ataxia and good muscular and conscious tone. After 50 min, the patient was discharged from anesthesia. Discussion: Domestic horses are phylogenetically close to tapirs, so the choice of drugs and doses of the protocol used was based on their use in horses, and on studies carried out with tapirs as well. Despite being docile and passive, the tapir was not conditioned and did not allow the manipulation and collection of samples collaboratively; therefore, it was chemically contained. The physical restraint performed did not generate satisfactory immobilization of the tapir, resulting in agitation and stress and causing the needle to break. The reflux presented by the tapir minutes after sedation and at recovery was induced by dexmedetomidine, and only the undigested banana pieces were offered to the animal. Reflux plus stress from extensive fasting and suboptimal physical restraint was responsible for the change in the tapir's eating behavior, with possible stress gastritis 24 h after chemical restraint. Only one study reported the use of dexmedetomidine in tapirs, associated with continuous infusions of ketamine, midazolam and guaiacol glyceryl ether for moderate to long-term field procedures. Sedative reversal of dexmedetomidine by atipamezole reduced the recovery time and the risk of death from cardiorespiratory depression. The anesthetic combination used was effective, promoting immobility, muscle relaxation, and stability of the physical parameters evaluated, with rapid and gentle induction and an adequate level of sedation for the objective, good sedative reversal, and anesthetic recovery.

Assuntos

RESUMO

Strategies to improve beef nutritional value, mainly fatty acid composition, have been a major goal for the scientific community. The use of different oil contents, mostly those rich in unsaturated fatty acids, can be interesting for cost reduction, as well as cattle performance and meat quality improvements. This study assessed the influence of diets containing increasing linseed oil levels (1.0, 3.8, and 5.2% DM) on performance, carcass traits, and meat quality of feedlot-finished Nellore x Canchim steers and heifers. The experiment was carried out in a randomized block design and arranged in a mixed 3 x 2 factorial scheme. Increasing oil levels linearly decreased dry matter intake (DMI) (P < 0.05) and hence improved feed efficiency (P < 0.05), regardless of sexual condition. A beneficial effect of increasing the inclusion of linseed oil was the reduction DMI. Steers had a higher weight at slaughter (P < 0.05) and heifers had greater backfat thickness (P < 0.05). The concentrations of most fatty acids were changed by the linseed oil levels studied (P < 0.05). Dietary inclusion of linseed oil improved beef quality by reducing (P < 0.05) the n-6:n-3 ratio by 1.3 points per percentage point increase in linseed oil level in the finishing diet of both sexes.(AU)

Estratégias para melhorar os aspectos nutricionais da carne bovina, principalmente sua composição em ácidos graxos, têm se tornado uma meta importante para a comunidade científica. O uso de diferentes níveis de óleo, rico em ácidos graxos insaturados, pode ser uma estratégia interessante para redução de custos com melhoria no desempenho e na qualidade da carne. Este estudo avaliou a influência de dietas contendo níveis crescentes de óleo de linhaça (1,0; 3,8 e 5,2% MS) no desempenho, características de carcaça e qualidade da carne de novilhos e novilhas Nelore x Canchim terminados em confinamento. O delineamento foi em blocos casualizados em esquema fatorial 3 x 2 em modelo misto. Um aumento nos níveis de óleo diminuiu linearmente o consumo de matéria seca (CMS) (P < 0,05) e, consequentemente, melhorou a eficiência alimentar (P < 0,05), independentemente da condição sexual. Um efeito benéfico do aumento da inclusão do óleo de linhaça foi a redução no CMS. Os novilhos apresentaram maior peso ao abate (P < 0,05) e as novilhas apresentaram maior espessura de toucinho (P < 0,05). A concentração da maioria dos ácidos graxos foi alterada pelos níveis de óleo de linhaça (P < 0,05). A inclusão de óleo de linhaça melhora a qualidade da carne ao reduzir (P < 0,05) a razão n-6: n-3 em 1,3 pontos para cada aumento de ponto percentual de óleo de linhaça na dieta de terminação de ambos os sexos.(AU)

Assuntos