The impact of weaning age, environment, nutrition and sow parity on piglet performance and microbial diversity
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(A studentship forming part of the Gutwean research)
Research partners: University of Bristol, Rowett Research Institute
Sponsors: Defra, SEERAD, BPEX
Project duration: 2005-2009
In relation to animal production it is plausible to suggest that the immune system may be negatively affected by the high hygiene status adopted by many intensive (indoor) rearing systems and that some of the advantages of extensive (outdoor) rearing systems may result in improved bacterial colonisation and immunological status of outdoor-reared animals. This research project investigated how microbial colonisation is shaped by environment, early colonisation and antibiotic treatment and how bacterial diversity influences the developing immune system of the pig.
To evaluate the impact of the environment on the microbiota, the bacterial composition of the gut in intensively reared animals was compared with animals that were reared extensively.
To investigate the impact of early bacterial colonisation and antibiotic exposure, 24 hour old animals were transferred into sterile isolators and treated with commercially available antibiotics.
In pigs, probiotics have been used to improve growth performance, decrease the incidence of diarrhoea and subsequent mortality rates. Protection from E.coli and salmonella infections by lactobacilli has been reported in the pig. In the intensively reared animals, lactobacilli made up only a small percentage of the whole microbiota. In animals that were treated with antibiotics, lactobacilli were almost completely absent in the gut.
This study showed that the extensive environment favours the expansion of a natural microbiota which is dominated by lactobacilli. This could aid immune events that are beneficial for the host. On the contrary, an increase in hygiene status (from outdoor to indoor environment to isolation and antibiotic administration) leads to a decrease of lactobacilli in the gut mucosa.