Gastric ulcers in fattening pigs from intensive pork production can cause sudden deaths on farm and the grinding intensity of the diet appears to be among the risk factors, according to Maria Grazia Cappai and colleagues at Italy's University of Sassari.

The objective of their study published recently in BMC Veterinary Research was to adopt the latest laboratory tests and thresholds for the ulcerogenic risk assessment of diets from experimental reports and verify the class of risk in relation to gastric lesion prevalence in reared finishers.

Specificity and accuracy of feed safety tests based on the ulcerogenic risk of feed associated with the particle size distribution of diets were calculated on the occurrence of gastric lesions observed at a slaughterhouse: 41 lard-type hogs, fed with two diets [pelleted (n=21 pigs) versus mixed meal (n=20 pigs)], analysed at the laboratory of the University, were involved.

Gross inspection at the abattoir allowed the identification of the development of macroscopic gastric lesions in the pigs (13/21) fed with a pelleted complete diet, ranked in Class 1 (high ulcerogenic risk) on laboratory assessment.

The breakdown of gastric lesion severity was as follows: hyperkeratosis (13/13), mucosal erosions (11/13) and bleeding ulcers (2/13).

This occurrence was compared to the morphology of stomach mucosa from 20 finishers fed with a mixed meal diet, ranked in Class 3 (low ulcerogenic risk), in which no gastric lesions were observed.

Very fine particle mass (<0.4mm) according to cut off thresholds (>36 per cent) for the safety ranking of diets, showed 100 per cent positive predictive value, 100 per cent specificity, 88.1 per cent accuracy and 72.2 per cent sensitivity.

Three factors emerged from the study, concluded the researchers. Firstly, the greater mass (42.6 per cent) of particles under 0.4mm in the pelleted complete diet confirmed the associated risk rank in Class 1 assessed by laboratory procedures, as gastric lesions were selectively observed in 61.9 per cent of finishers fed with the high-risk diet.

Second, in these animals, macroscopic gastric lesions occurred within four weeks and showed a sub-clinical course, independent of severity.

Finally, Cappai and colleagues concluded that proper sieving analysis is necessary to define the proportion of very fine particles in feedstuffs with certainty, as an adequate measure to assess the ulcerogenic risk class of the diet.

Reference

Cappai M.G., M. Picciau and W. Pinna. 2013. Ulcerogenic risk assessment of diets for pigs in relation to gastric lesion prevalence. BMC Veterinary Research, 9:36. doi:10.1186/1746-6148-9-36

Further Reading You can view the full report by clicking here.

March 2013