Objective: This study aimed to determine the effects of stress during slaughter of beef cattle on physiological parameters, carcass, and meat quality at a Federal Inspection Type slaughterhouse located in the southeast of Mexico.Methods: A total of 448 carcasses of male Zebu×European steers with an average age of 36 months were included. Carcass assessment of presence of bruises and bruise characteristics was carried out on each half-carcass. Blood variable indicators of stress (packed cell volume, neutrophil to lymphocyte ratio, glucose, cortisol concentration) and meat quality parameters (pH, color, shear force, drip loss) were evaluated.Results: Of the 448 carcasses evaluated, 81% of the carcasses showed at least one bruise; one bruise was detected in 36.6% and two bruises in 27.0% of animals. Of the 775 bruises found, 69.2% of the bruises were grade 1 in region 3. Of the 448 carcasses studied, 69.6% showed hyperglycemia (6.91 mmol/L); 44.3% and 22.7% showed high (74.7 ng/mL) and extremely high (108.8 ng/mL) cortisol levels, respectively, indicative of inadequate handling of animals during preslaughter and slaughter. Of the carcasses evaluated, 90.4% had a pH ≥5.8 with an average of pH 6.3. In both pH groups, meat samples showed L* values >37.0 (81.6%) and a shear force >54.3 N; meat pH≥5.8 group showed a drip loss of 2.5%. These findings were indicative of dark, firm, and dry (DFD) meat. According to principal component analysis, grades 1 and 2 bruises in region 3 and grade 1 bruises in region 5 were highly associated with cortisol, drip loss, and color parameters b* and h* and were negatively associated with L*, a*, and C*.Conclusion: The bruises probably caused by stress-inducing situations triggered DFD meat. Appropriate changes in handling routines in operating conditions should be made to minimize stress to animals during the slaughter process to improve animal welfare and meat quality.

Evidence indicates that the atmospheric and oceanic processes that occur in response to increased greenhouse gases in the broad-scale climate system may already be changing the ecology of infectious diseases. Recent studies have shown that climate also influences the abundance and ecology of pathogens, and the links between pathogens and changing ocean conditions, including human diseases such as cholera. Vibrio cholerae is well recognized as being responsible for significant mortality and economic loss in developing countries, most often centered in tropical areas of the world. Within the marine environment, V. cholerae is found attached to surfaces provided by plants, filamentous green algae, copepods, crustaceans, and insects. The specific environmental changes that amplified plankton and associated bacterial proliferation and govern the location and timing of plankton blooms have been elucidated. Several studies have demonstrated that environmental non-O1 and non-O139 V. cholerae strains and V. cholerae O1 El Tor and O139 are able to form a three-dimensional biofilm on surfaces which provides a microenvironment, facilitating environmental persistence within natural aquatic habitats during interepidemic periods. Revealing the influence of climatic/environmental factors in seasonal patterns is critical to understanding temporal variability of cholera at longer time scales to improve disease forecasting. From an applied perspective, clarifying the mechanisms that link seasonal environmental changes to diseases’ dynamics will aid in developing strategies for controlling diseases across a range of human and natural systems.

The effects of increasing proportions of soybean soapstock (SSS) in laying hen diets on egg quality parameters and on the fatty acid (FA) composition of the yolk were studied. One hundred sixty Babcock B-300 x laying hens, 20 wk of age, were allotted to 5 dietary treatments comprising a control diet (D5) with soybean oil at 100% or SSS in proportions of 25% (D1), 50% (D2), 75% (D3), and 100% (D4) replacing the oil source in commercial-type diets throughout the 15-wk laying period. Egg quality parameters were recorded weekly. Four pooled yolks for each treatment were collected at 0, 9, and 15 wk, and their FA profiles were determined. Egg weight, shell thickness, shape index, and Haugh unit were not influenced by dietary treatment. The concentrations of saturated FA (SFA) in yolks were generally kept at a constant level, regardless of the percentage of SSS in the hen diets. Total monounsaturated FA (MUFA) content did not vary over the course of the experiment, except for C14:1. After 15 wk of feeding, the total polyunsaturated FA (PUFA) n-3 increased in yolks of all diets. Among the long-chain PUFA, the percentage of C20:4 (arachidonic acid) was less affected. Inclusion of 100% SSS allowed production of eggs with similar PUFA/SFA and n-6/n-3 ratios when compared with eggs from hens fed D5. As SSS represents one-third of the oil cost, its inclusion in layer diets could represent an important economic benefit.