The general picture reported by NADIS veterinary surgeons for pig farms in November suggested that herds are starting to come out of problems imposed by movement restrictions due to FMD and the gradual restoration of meat exports is at least allowing herds to cull sows as needed. There was, however, a wide range of problems reported, particularly in breeding stock.

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Gilts
Health and acclimatisation of incoming gilts featured in a number of reports with the familiar pattern of gilts entering a farm to healthy and suffering subsequently. Attention to vaccination regimes prior to delivery was important in addition to avoidance of excessive challenge on arrival. In one instance looking back through the year, approximately 15% of supplied gilts had failed to breed – requiring culling – as a result of health challenge.

Recent reports of gilts failing to cycle properly was also consistent with autumn infertility, which had been anticipated following a summer of poor light levels.

Sows
A number of reports suggested sow mortality has been high in recent months and in most cases this appears to be the result of a failure to cull due to marketing restrictions. Either sows have become overcrowded as culls have not left the farm – leading directly to more injuries requiring euthanasia, or herds have tended to destroy sows that might in the past have been kept to allow recovery before culling.
Infertility was prominent in the monthly reports which relates to sows served from August onwards. Many of these have been assigned to seasonal infertility, although in one case mouldy straw was to blame and in another an infectious infection process (possibly influenza) was thought to have accounted for a dramatic rise in returns.
2nd litter drop was reported as a result of the combined effects of gilts performing extremely well (rearing 11 pigs/litter) and bullying of weaned gilts in yards when mixed with the next group.

Piglets
Very few specific problems were reported in sucking piglets in November. A high stillbirth rate recorded on one farm was thought to be more to do with inaccurate recording – pigs born alive but dying very early. This has implications as to corrective measures.

Scour, as usual, featured with coccidiosis, clostridia and rotavirus reported. Given the widespread use of anticoccidial treatments on pig farms, the continued problems with coccidiosis is perhaps surprising. It should be noted that the timing of the use of Baycox (Bayer) is critical if it is to give lasting protection. When given to pigs below 96 hours of age its effect can be erratic. Ideally it should be given to piglets between 96 and 120 hours of age.

Weaners
Weaner problems were quite sparse within reports although anecdotal comments are coming through from farms using Circovirus vaccines. One of the earliest farms to start this vaccination (in sows), having seen dramatic initial improvements, has started to see an increase in fading pigs after weaning, coinciding with a 0.75 rise in pigs weaned/litter. Inadequate colostrum intake in larger litters at birth was thought to be at the root of this problem.

Chilling problems as a result of variable night time temperatures and inadequate adjustment of air inlets etc was prominent, and in one case a dramatic tail biting problem over the preceding month was ascribed to poor adjustment of air inlets in a newly commissioned building – an unfortunate case of stockmen expecting a ‘new’ building to work perfectly without need for their input.

Finishers
Overstocking in finishing pigs was widely reported with a number of factors contributing.

1. Delays and rollover at slaughter as demand for pig meat declined with the loss of exports in September/October. Farms are still trying to catch up on expected slaughterings. Attempts to reduce slaughter weight have been frustrated by the build up of pigs.
2. Overserving earlier in the year to compensate for infertility problems which then corrected, leading to excessive farrowings (hence too may pigs) which also impacts on weaning age and weight, slowing subsequent growth and causing overstocking.
3. Improvements to health as a result of implementation of Circovirus vaccination, which is having a dramatic effect on mortality levels, with some farms seeing drops of 5-8 percentage age points. These surviving pigs risk overcrowding on the farm.

Problems reported that have been blamed on overcrowding include:

1. Increased pneumonias
2. Late onset PMWS/PDNS
3. Riding injuries

In addition to these problems, enteric disease was prevalent and included colitis/ileitis, occasional cases of Swine Dysentery and one report of acute Salmonellosis causing a severe scour in growing pigs. Gastric ulcers also continue to feature in reports of sporadic on farm post mortem examination.

As we head into winter problems might be anticipated with:

1. Respiratory disease in low air flow environments
2. Interruptions to water supply
3. Continued difficulties resulting from overcrowding
4. Slowed growth as producers are tempted to cut feed costs by using cheaper or less suitable rations

Mark White BVSc DPM MRCVS

NADIS Pig Health Report for October 2007
Heavier Pigs Hitting The Market
Avoid Temptation to Retain Old Sows