Performance, carcass and meat quality of pigs submitted to immunocastration and different feeding programs.

The feed restriction of pigs aims to improve the nutrient utilization of the diet, reduce carcass fat and increase lean meat. Immunocastration is a painless, reversible technique that improves animal welfare, decreases boar taint in meat, leading to lower fat deposition and increases lean meat. This study aimed at evaluating either feeding (restricted) programs (FP) and castration categories (surgically castrated × immunocastration) in terms of pig performance, carcass traits and meat quality. Castration category and FP did not influence marbling, initial pH and drip loss in loin and ham. However, immunocastrated pigs presented lighter loins and hams with lower ultimate pH, compared to the surgically castrated pigs. The FP with lower feed volume resulted in higher ultimate pH. Immunocastrated males had a higher live weight than those surgically castrated. Also, the more the feed supply decreased, the better the feed conversion. Immunocastrates had lower carcass yields, however these pigs had their backfat thickness decreased and lean meat increased in the carcass, without affecting the loin depth.

Determination of ractopamine residue in tissues and urine from pig fed meat and bone meal.

In many countries, ractopamine hydrochloride (RAC) is allowed to be used in animal production as a ß-agonist, which is an energy repartitioning agent able to offer economic benefits such as increased muscle and decreased fat deposition, feed conversion improvement and an increase in average daily weight gain. However, some countries have banned its use and established strict traceability programmes because of pharmacological implications of ß-agonist residues in meat products. In Brazil, commercial RAC is controlled (5-20 mg kg-1) and only added to pig diet during the last 28 days before slaughter. However, the control is more difficult when co-products, like meat and bone meal (MBM), which can be produced from RAC treated animals, are part of the feed composition. Therefore, a study was undertaken to evaluate the presence of RAC residue concentrations in urine and tissues of gilts (n = 40) in four dietary groups: 0%, 7%, 14% and 21% (w/w) of MBM-containing RAC (53.5 µg kg-1). The concentration of RAC residues in MBM, pig tissues and urine was determined by LC-MS. Low RAC concentrations were detected in muscle, kidney, liver and lungs (limit of detection = 0.15, 0.5, 0.5 and 1.0 µg kg-1, respectively); however, no RAC residues were quantified above the limit of quantification (0.5, 2.5, 2.5 and 2.5 µg kg-1, respectively). In urine, the RAC concentration remained below 1.35 µg L-1. These data suggest that MBM (containing 53.5 µg kg-1 RAC) added to diet up to 21% (w/w) could hamper the trade where RAC is restricted or has zero-tolerance policy.

Development of a readily applied method to quantify ractopamine residue in meat and bone meal by QuEChERS-LC-MS/MS.

A QuEChERS method of ractopamine (RCT) residue detection in swine meat and bone meal (MBM) samples was demonstrated. Samples were hydrolyzed with protease and ß-glucuronidase prior to QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction and clean-up. Samples were analyzed in a Liquid Chromatography (equipped with ACE 5 C18 column under gradient elution) coupled with a triple quadrupole mass spectrometer operating in positive electrospray ionization mode (using multiple reaction monitoring, MRM). The method was validated for its specificity, decision limit (CCα), detection capability (CCß), recovery, repeatability, reproducibility, linearity, limits of detection (LODs), quantification (LOQs), and stability according to international guidelines (European Commission Decision 2002/657/EC). Recoveries ranged from 96.3 to 107.0%. Repeatability and reproducibility showed both RSD<5.7% and 3.1%, respectively. LODs and LOQs were 1.91 and 6.36 ppb, respectively. CCα and CCß values were 1.91 and 2.37 ppb, respectively. RCT showed good stability for spiked samples and real samples when the concentration was higher, otherwise at lower concentration stability was lower. The proposed method can be successfully applied on a regular basis for the determination of RCT in MBM, demonstrating the usefulness of the method as a tool for compliance monitoring in regulatory laboratories.

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.