Metabolomics revealed diurnal heat stress and zinc supplementation-induced changes in amino acid, lipid, and microbial metabolism.

Heat stress (HS) dramatically disrupts the events in energy and nutrient metabolism, many of which requires zinc (Zn) as a cofactor. In this study, metabolic effects of HS and Zn supplementation were evaluated by examining growth performance, blood chemistry, and metabolomes of crossbred gilts fed with ZnNeg (no Zn supplementation), ZnIO (120 ppm ZnSO4), or ZnAA (60 ppm ZnSO4 + 60 ppm zinc amino acid complex) diets under diurnal HS or thermal-neutral (TN) condition. The results showed that growth performance was reduced by HS but not by Zn supplementation. Among measured serum biochemicals, HS was found to increase creatinine but decrease blood urea nitrogen (BUN) level. Metabolomic analysis indicated that HS greatly affected diverse metabolites associated with amino acid, lipid, and microbial metabolism, including urea cycle metabolites, essential amino acids, phospholipids, medium-chain dicarboxylic acids, fatty acid amides, and secondary bile acids. More importantly, many changes in these metabolite markers were correlated with both acute and adaptive responses to HS. Relative to HS-induced metabolic effects, Zn supplementation-associated effects were much more limited. A prominent observation was that ZnIO diet, potentially through its influences on microbial metabolism, yielded different responses to HS compared with two other diets, which included higher levels of short-chain fatty acids (SCFAs) in cecal fluid and higher levels of lysine in the liver and feces. Overall, comprehensive metabolomic analysis identified novel metabolite markers associated with HS and Zn supplementation, which could guide further investigation on the mechanisms of these metabolic effects.

Real-time disease surveillance tools for the swine industry in Minnesota.

The ultimate challenge for integrating geographic information systems (GIS) into swine veterinary activities in the United States is to develop systems that deliver effective decision support to practising veterinarians seeking to control hyper-endemic viral diseases such as porcine reproductive and respiratory syndrome (PRRS). Through collaboration with specialist swine veterinarians and state agencies we have developed two tools designed to enable real-time surveillance for swine diseases, based on capture of veterinary clinical data via the internet. The first is an ArcIMS-based Web-mapping application that enables authorised veterinarians to explore high resolution maps of swine premises throughout the state of Minnesota. This is coupled with a database that enables veterinarians to edit or update farm attribute data, including disease status via the internet. The system is generic so that novel or emerging disease syndromes can be incorporated. The second application is an extension to the Rapid Syndrome Validation Project-Animals which was developed for beef cattle to detect changes in disease incidence through recording of patterns of symptoms. The rationale behind these initiatives is that recent technological advances in relevant disciplines provide opportunities for innovation in surveillance that can enhance the capacity of the industry to combat its most pressing disease challenges in a more efficient manner. The acceptance of these novel tools by industry will assist veterinarians and producers in managing common disease problems, and hopefully serve to diminish the historic reluctance of producers to share information about disease status.