How can different livestock strategies improve the quality and safety of food? (subproject 4)

The livestock work packages of the QLIF project focus on the development of improved strategies for: (a) the control of endo- and ectoparasites and bacterial zoonoses in pigs and poultry, (b) maintaining udder health and reducing enteric pathogen shedding in dairy cows, (c) improving feeding regimes for poultry and pig production systems, (d) health status of pigs.

Endoparasites in poultry

The experiments with different layouts of hen runs showed that the prevalence of endoparasites (e.g. Heterakis and Ascaridia) is strongly influenced by the size of the run and the density of hens. Unfortunately, what has been defined so far as an ‘ideal’ run is not good enough, as only a very low hen density could reduce the average faecal egg counts.

Bioactive compounds

Bioactive compounds in fodder plants, such as inulin (in dried chicory roots) appear to be very effective against nodular worm of pigs but not against roundworms. In contrast, no reduction of endoparasites could be observed in poultry fed with anthelminthic plant products. Positive results were obtained by diatomaceous earth (86% silica, 5% sodium, 3% magnesium and 2% iron) on poultry ectoparasites, an effect which was equal to natural acaricides.

Mastitis prevention

In co-operation with farmer groups, mastitis prevention strategies were developed on dairy farms. As the knowledge of the farmers on preventive management measures and on non-antibiotic therapies is generally low, the co-operation between farmers and veterinarians let to a considerable improvement of udder health status.

Some farmers were able to reduce the use of antibiotics to zero and in parallel to improve milk quality, including somatic cell count. In addition, a novel teat sealant was successfully tested and recommendations were made for sealants, homeopathic treatments and targeted antibiosis.

A successful case study comparing three calf rearing methods showed that suckling methods did not have a negative effect on milk quality (somatic cell counts). This is important evidence as mother cows and calves are more robust and less disease susceptible if they are allowed a longer and more natural suckling period.

Grain legumes as feed supplementation for pigs

Feeding experiments with pigs showed that supplementation of feed with synthetic amino acids can be replaced by use of home-grown grain legumes. Although the pig performance suffered, the intramuscular fat content (IMF) increased, resulting in a better meat quality and economic performance was therefore not affected negatively. In an on-farm study in Germany and Austria, experimental groups of pigs were fed during the fattening period with high proportions of grain legumes (36 and 40% respectively) in order to verify the on-station results. The grain legumes consisted of lupines, faba beans and peas. Although results are impressive so far, more knowledge on the digestibility of protein, amino acids and energy in organically grown protein crops is urgently needed.

Feed supplementation with probiotics

Feed supplementation with probiotic bacteria (Lactic Acids Bacteria, LAB) can significantly decrease the risk of gastrointestinal infections and diarrhoea caused by enteric bacterial pathogens.

In the QLIF project, we investigated the synergistic effect of adding oligosaccharides and lactose containing whey. These ‘nutribiotics’ were tested after weaning and for piglets challenged with Salmonella. Although some effects on growth performance were significant, initial culture based tests indicate that Salmonella populations were not reduced. In a next stage, the probiotics will be tested on growing-finishing pigs and more sensitive molecular tests are being employed to test the impact of treatments on microbial diversity and Salmonella populations in the upper intestine of pigs.

For a more detailed description of the work carried out under subproject 4 see Spoolder et al., 2007.

Reference