Assessment of manure and digestive tract content from slaughterhouses as a pathway for weeds and plant pests
Report no: 2016: 55
Culture plants are exposed to many different pests. Only a small number of pests survive in animal stomach and in manure. Among these are a few who have limited geographic coverage today, and they can expand their area through the proliferation of gastric contents and manure from slaughterhouses for farmland.
The most serious pests that can spread with slaughterhouse waste is wild oats, potato wart fungus, potato cyst nematodes and cockspur grass. However, it is uncertainty related to the probability of cockspur grass to survive through the digestive tract and manure.
This is the key message in a risk assessment from the Norwegian Scientific Committee for Food Safety (VKM).
Plant pests evaluated
The Norwegian Food Safety Authority (NFSA) commissioned the Norwegian Scientific Committee for Food Safety (VKM) to assess if the current practice, that manure and digestive tract content from slaughterhouses are spread on adjacent farms, is a pathway for spread of plant pests to new agricultural areas.
The assessment deals with manure from ruminants (cows, sheep and goats), pigs and horses. Poultry is not considered in the assessment, as they are fed concentrate only.
There is no import to Norway of animals for slaughter in domestic slaughterhouses. About half the ingredients used in concentrate production is imported. The import of hay and cereal straw is very limited.
The weed species evaluated were restricted to vigorous and competitive weed species, invasive alien species, and species with hard seeds that are known to be robust under anaerobic conditions.
A huge number of plant pathogenic fungi, viruses and bacteria were considered in the assessment.
Only phytophageous insects and mites that feed on plants that are likely to be eaten by grazing animals or harvested, were considered.
VKM´s panel on plant health was responsible for the risk assessment.