NADIS disease forecast – pigs (August)

August 2004

By Mark White BVSc DPM MRCVS

Whilst weather conditions do not tend to affect pig producers to the same extent that they do cereal farmers and cattle farmers – particularly the indoor pig industry – the continuing poor summer may well prove a prelude to production problems later in the year. We tend to talk about both summer and autumn infertility. 

However, they are 2 separate and distinct entities. Summer infertility is simply a result of hot weather. Boar semen quality may drop, heat stroke and sunburn can affect sows, particularly in the immediate post service period and hot weather can limit feed intake in lactation, which has a knock on effect to subsequent re-breeding.

Autumn infertility, however, is a rather more vague problem. It tends to affect younger sows more than mature animals; it normally peaks in October; it tends to manifest as returns to service at abnormal times and abortions. 

The timing corresponds to the most rapid decrease in day length and it is presumed that it is this factor which brings out the inherent seasonality in pig reproduction. Furthermore, there is a strong belief that autumn infertility occurs at a higher level following summers of poor light level as we are currently experiencing. 

It, thus, seems that you cannot win.  If we get a long, hot sunny summer, then fertility problems are likely at that time; in a cooler, duller summer, the infertility problems will occur later on!

Adults
For once, this sector was not totally dominated by infertility, although some were still reported. In particular, late drop outs/not in pig sows were reported in one farm to have been finally resolved by servicing the pregnancy testing machine. Second litter drop problems were also highlighted and related to inadequate feeding of gilts during their first lactation.

A number of reports of clinical erysipelas in sows were received; why do producers continue to fail to protect their herds with cheap and effective vaccines? 

This has always classically been regarded as a summer disease so further problems can be expected.

Lameness in sows was also widely reported (arthritis, spinal damage etc) and seems to be the major cause of high recorded sow mortality – many sows having to be shot for these reasons.

Growers
Many problems were reported in the grower pigs with enteric disease dominating. Not only are producers beginning to notice the slowing of growth that has come with the removal of high copper levels but more nutritional type scour is seen in pigs of 40-60kg. 

Moreover, mortality due to torsion of the intestine (twisted guts) may be on the rise; this would be expected if digestibility of the diet is lower, allowing more fermentation in the intestine – the usual precursor to torsion.

Individual cases of PDNS have been more prevalent recently without any reported increase in PMWS.  No reasons have been found for this.

Glassers Disease was also widely seen with many herds finding control increasingly difficult.

Erysipelas, particularly in straw yard finishers, was also regularly reported.

Piglets
Coccidiosis type scour continues to be common and, in warm weather, is not surprising – sows have a tendency to lie wet and dirty in farrowing pens in an attempt to cool off. 

Greasy Pig Disease affecting suckling pigs was reported and can be a serious problem in this age group. The loss of fluid balance that results from extensive skin disease often causes death in young pigs. Joint ill was also widely reported.

In August, watch out for:

• 
  
  Coccidial scours in sucking piglets
  
  
• 
  
  Erysipelas
  
  
• 
  
  Heat stroke and sunburn
  
  
• 
  
  Appetite problems in farrowed sows
  
  
• 
  
  Slowed growth in finishers

While every effort is made to ensure that the content of this forecast is accurate at the time of publication, NADIS cannot accept responsibility for errors or omissions. All information is general and will need to be adapted in the light of individual farm circumstances in consultation with your veterinary surgeon

Copyright © NADIS 2002