Depopulation and Repopulation Problems

The following are some examples how repopulations have encountered problems.

Inadequate planning
Pathogens not recognised – Brachyspira hyodysenteriae is one example where failure to recognize its presence will result in too short a down-time	Unrealistic pathogen removal associated with pathogens in the same district too close to the farm. Note the location of the “isolation” unit	The presence of wild pigs in the vicinity and poor fencing.
New stock are infected with pathogens – mange can be an example	In adequate removal of previous stock dead animals	Inadequate review of surrounding wildlife
Inadequate preparation
Pipes and gates may contain feaces on the inside	Gates require to be fixed before cleaning. Note particularly under the gate	Inadequate repair of buildings – holes in the walls and large cracks
Destroy and remove all broken equipment	Electrics that are impossible to clean unless fixed	Poor farm security during and after cleaning

Greed
Keeping “old” medicines on the farm – even unopened should be suspected	Keeping old equipment – teething, tail dockers, iron injectors	Slap markers are a classic to remain on the farm
Keeping boots – the favourite slippers for example.	Attempting to clean overalls	Keeping other equipment which has been in direct contact with the previous pigs
Inadequate cleaning
Examine cleaned area extremely carefully	Water unclean with feaces from previous groups	Examine floor for faeces – ask the vet to check the building
Even small pieces of faeces need to be manually removed	Under the slatted floor can be extremely difficult to clean	Remember all areas where dirt can hide – inside curtains for example
Cobwebs - manually clean especially when around electrics	Evidence of the previous pig farm may be clear – an AI top	Old feed on farm in bags and in feed bins and pipelines.

Poor repair of farm facilities
Down pipes left unfixed are a rodent risk	Waterers which are leaking	Feeders with holes
Floors which are worn – especially under waterer and feeders	Ventilation systems broken – blocked attic inlets for example	Insulation which requires replacement
Post-repopulation problems
Inadequate rodent and vermin control programmes	Biosecurity rules broken by stockpeople – slaughterhouse visit	Introduction of pathogens remember pigs are the number on risk
Congenital tremor – this can be a risk as new gilts are not introduced to “farm viruses” which are not removed	Mulberry Heart – with the increased growth rate increase Vit E to the weaners	Slippery floors – associated with the extremely good cleaning. Can result in damage to gilt’s or weaned sow’s hips
In-adequate gilts numbers provided or selected	Poor selection of gilts associated with pressure of the ‘sale’ – in particular check backs, legs and teats	Poor feeding control resulting in breeding of overweight or too young gilts
Over-optimistic gilt reproduction resulting in empty farrowing crates	Too many gilts bred, again resulting in poor pig flow – poor weaners	Pre-weaning diarrhoea – poor gilt immunology
Overweight/fat finishing pigs as growth rates are unexpected.	Careless breach of biosecurity -bringing pork products onto the farm	In the long term parity crashes with high stillborn rates etc associated with older sows who were retained with poor culling programmes.

Depopulation and subsequent repopulation can be a great success if the process if fully planned, orchestrated and then implemented.

The major reasons for problems are failing to set formal goals and then setting out to complete these goals. Remember that the repopulation is about gilts and if they are rushed the consequences are far reaching.

Coordinate the gilt growth, introduction, flow and future care with all members of the health team.

Finally, remember, not all “pathogens” can be eliminated – Erysipelothrix rhusiopathiae; some are brought rapidly back onto the farm – Bordetella bronchiseptica and is some cases perhaps the organism should not be eliminated as its absence makes new stock introduction impossible and movement of the produced stock difficult – Haemophilus parasuis for example.