Thin sow syndrome affects sows worldwide. The effects of this disease are weight loss and anoestrus. The classically condition results from a combination of Parasitism (helminth or mange), low environmental temperatures and inadequate feed intake, particularly during lactation. Weight loss at this time may never be regained. Parasitism is less important when therapy is routinely carried out.
- Causes of Thin sow syndrome >
- Effects of Thin sow syndrome >
- Diagnosis of Thin sow syndrome >
- Treatment & Control of Thin sow syndrome >
Causes of Thin sow syndrome
The condition results from a combination of classically Parasitism (helminth or mange), low environmental temperatures and inadequate feed intake, particularly during lactation. Weight loss at this time may never be regained.
Parasitism is less important when therapy is routinely carried out. In outdoor pig populations, low environmental temperatures are important. Outdoor sows require at least 200 kg more feed per sow per year than indoor animals. Indoors, thin sows in sow stalls should be kept at 22 ° C and sows in moderate condition at 21 ° C. Lower temperatures may be tolerated in the presence of bedding. Temperatures below this require extra feed to maintain weight gain in sow stationed.
Feed intake is the most important cause. Feed intake may be affected by:
- Bullying,
- Disease,
- A high environmental temperature in the farrowing accommodation, or
- An over fat condition at farrowing.
Sows should be in condition score 3 / 4 or 6 / 10 (fat depth at P2 16-20 mm) at farrowing and may fall to condition score 2-2.5 / 4 or 4 / 10 (fat depth 12 mm P2) after lactation. Unless these criteria are met, total weaning weight of the litter will be reduced, return to oestrus will be delayed and egg numbers will be reduced to give small subsequent litters.
Effects of Thin sow syndrome
In extreme cases:
- Emaciation may occur in 30-90% of sows and boars in a herd,
- Associated with hypothermia (36.5-38 ° C, 97-100 ° F),
- Depraved appetites,
- Restlessness,
- Apathy and later,
- Difficulty in rising
- Skin may be dirty and greasy
- There may be surface Abrasions, especially pressure sores in Lactating sows crated.
As the condition progresses, failure to return to oestrus and permanent infertility may occur.
Where accurate to individual feeding condition is not practised and bullying occurs, individual animals in a group can be Clinically affected.
Sows in less than optimum condition are frequently found in winter where temperature control is not practised. Suboptimal condition or even thin sows may be found during the recovery period from disease such as influenza and this may be more extreme in lean breeds.
Clinical signs of suboptimal condition include increased weaning to service intervals, small litters and low weaning weights. Piglets or sows in suboptimal condition may be restless and demand milk more frequently.
Diagnosis of Thin sow syndrome
Thin sows may be identified by systematic observation and condition scoring of the herd. Ultrasound is particularly useful for quantitative measurement as scoring is more difficult in older animals due to their conformation.
As sows should gain at least 12.5 kg body weight between partitions, regular weighing can identify animals in sub-optimal condition. Pressure sores in sows at weaning also indicate poor condition.
Some production parameters can be used to detect thin sows:
- Where gilt conditioning and nutrition in lactation is inadequate,
- The second litter is the same size or smaller than the first,
- Born low numbers may reflect overall sow condition at service.
Extended weaning to service intervals and low weaning weights may be due to poor body condition. The causes of poor sow condition should be established. It should be established that adequate quantity of feed and nutrient density is being supplied to each individual especially during lactation and until implantation 10-14 days after service. Parasitism can be ruled out by inspection and sampling for faecal sampling for mange and worm eggs and coccidia. The influence of disease may be established by inspection, clinical examination or consultation of the recent history of the herd of the animals concerned.
Treatment & Control of Thin sow syndrome
There is no treatment.
- The effects of thin sows on litter weaning weights can be reduced by supplementary feeding of the litter.
- The effects on numbers born when sows may be reduced or screams are in poor condition by delaying service until the next oestrus (herd inventory projections permitting).
- Ensure that adequate quantities of food are given to all affected animals and that individual feeding is possible.
- In loose housing systems, feeding crate or electronic sow feeding may be required.
- Environmental temperatures should be restored to normal and mange or anthelminthic treatment should be considered.
- Adequate feed intake during lactation and early pregnancy should maintain the weight of the sow and increase it by 10-15 kg between litters by increasing the energy content of Lactating rations with fat feeding or three times daily during lactation.
- It may be necessary to weigh sows after weaning in order to Ensure that adequate weight gain has occurred between lactation, to assign them to groups at an appropriate level for feeding through pregnancy or to feed individually to condition.
- Management systems which low protein feed rations can increase relative to lean gilt Ensure adequate fat levels and production during the second parity.
