Need for strengthened efforts to prevent gastric ulcers in slaughter pigs
A recently finished research project investigated the farmer’s possibilities to identify gastric ulcers in pig herds and examined whether adding hemp to the feed might solve the problem. The results show that meal feed seems to be the best strategy if you want to prevent gastric ulcers in pigs.
Studies from 2013 demonstrate that gastric changes and ulcers occur in approx. 30 percent of slaughter pigs and 50 percent of slaughtered sows in Denmark (1). Gastric ulcers may cause increased mortality rates and reduced growth in slaughter pigs, and also constitute economic and animal welfare production problems.
This has resulted in an agreement on ”strengthened efforts to prevent gastric ulcers in slaughter pigs and sows” in connection with the Summit Declaration on Improved Pig Welfare on 13 March 2014.
Since 1998 the Department of Animal Science at Aarhus University has contributed research efforts, e.g. in cooperation with the Danish Pig Research Centre, in relation to the effect of feed grinding and processing, feed composition and feed supplementation on gastric health and the prevalence of ulcers.
Based on this it has been shown that gastric ulcers may be prevented by feeding the pigs coarsely ground feed instead of finely ground or pelletized feed, but however, this may reduce feed utilization and increase feed costs significantly.
In addition to the effect of feed structure, research demonstrates that a permanent allocation of straw may reduce the prevalence of gastric ulcers (2), but it may be difficult for the farmer to manage the amount of straw.
Examination of a new prevention strategy
A recently finished research project – financed by the Pig Levy Fund and carried out by Aarhus University, the Danish Pig Research Centre and the private company Nørding A/S – aimed at procuring an application-oriented strategy to help the farmer identify gastric ulcers in his herd and also to solve the problem by using an old cultivated plant (hemp) in crop rotation.
The pig model established in the project demonstrated a significant accordance between endoscopy examinations performed on a live pig and the clinical examination of the pig’s gastric health after removing the gut.
In addition, the examination showed a marginal effect on the prevention of gastric ulcers when adding hemp shells to pelletized feed. A supplementation of 4 percent hemp cakes to pelletized feed did not prevent the occurrence of gastric ulcers when compared to feeding pelletized feed alone (3).
Severe gastric ulcers can be diagnosed by saliva tests
Based on a metabolomics analysis using LC-MS/MS of saliva samples extracted the day before slaughtering, it was possible to distinguish pigs diagnosed with severe gastric ulcers from pigs that did not have ulcers.
Analyses of the tissue close to the ulcer showed increased inflammation discomfort in pigs with severe ulcers; however, inflammation markers in manure samples extracted before slaughtering did not distinguish between pigs with severe ulcers and pigs without ulcers.
The results will be presented at e.g. the EAAP conference in Belfast later this year.
Need for further knowledge
In order to strengthen the efforts to prevent and heal gastric ulcers without compromising feed utilization we need further knowledge on the pathogenesis of gastric ulcers, including the importance of risk factors and an understanding of the mechanisms involved. This knowledge will be procured by means of a Knowledge synthesis which we expect to publish later this year.
The superiour conclusion of the research efforts in this area so far, is that meal feed seems to be the best strategy in order to prevent gastric ulcers in pigs. However, we expect that further knowledge of the pathogenesis of gastric ulcers in pigs will contribute to the development of new strategies.strategier.
Department of Animal Science, AU
1. Nielsen et al., 2013, Meddelelse 975, VSP.
2. Herskin et al., 2015
3. Pedersen et al. 2016, Meddelelse 1069.