Information provided courtsey Ontario Pork

Variation
Birth weight variation should be reduced to 10 - 15 per cent by the time pigs are marketed - a feat which can be achieved through good management, say University of Guelph researchers.

The common variation at birth is about 25 per cent. But Prof. Cate Dewey and Angel de Grau, Department of Population Medicine, have found that management practices used throughout the production cycle -- especially in the early stages-- can contribute significantly to reducing variation.

"There is a lot of variation across farms in Ontario, mostly attributable to management styles," says de Grau. "Ultimately, time and care needs to be given to piglets in the early days of life to ensure that they grow well."

Dewey and de Grau weighed more than 4,000 pigs from nine commercial farms in Southern Ontario. The pigs were weighed at birth, at weaning and at seven, 14 and 20 weeks of age.

Different management styles
The farms represented a wide variety of management styles. They ranged in size from 150 - 1,200 sows. Disease status ranged from high health status to herds where many swine pathogens were present.

Their study was conducted in three stages. The first stage looked at factors affecting variation in weaning weights. The average weights at birth and at weaning were 1.61 kg and 5.89 kg, respectively. Weaning age ranged from 14 to 29 days, depending on individual farm policies. Birth weight, weaning age and the size of the litter accounted for 25 per cent of the variation in weaning weights (pigs from small litters showed improved weaning).

In farms with continuous flow management, variation was magnified from birth to weaning. Weaning weights were significantly lower than in all-in all-out managed farms.

Larger, lighter litters
The researchers say larger litter sizes and lighter birth weights have become increasingly common. That means it's important to improve management strategies to reduce neonate weight variations. Also, because birth weight is the main determinant of weaning weight, ways of enhancing birth weight without sacrificing litter size (and losing money) should be pursued, he says.

Minimizing variation
To minimize variation, de Grau recommends the sow be fed well and the piglets are healthy. He also suggests providing an alternative source of feed for piglets to access if the sow is sick. Results showed that farms that offered an alternative had better pigs at weaning.

Spot the errors? Up-side down and leaking

Improving performance
Next, nursery pig performance was examined. In this stage, factors such as disease, environment, genetics and nutrition have a significant impact on growth. Dewey and de Grau found that the age piglets were injected with iron was a significant factor affecting growth rate. Animals given iron at four days of age or later showed better growth. Weaning weight was also important -- a higher weaning weight was associated with better growth -- as was the number of pigs when nursing the sow.

Something so simple as water
The researchers also found that providing extra water in the pen promoted better growth. "Water was a very important factor in this stage," says de Grau. "Farms that provided water in the pens had heavier pigs. Many farmers don't think that piglets need water because they drink milk, but they'll drink water even a few hours after birth."

Disease management
Finally, factors associated with grower-finisher pig performance were looked at. Disease management was crucial in this phase. Dewey and de Grau say the presence of disease is probably the leading cause of variation in growth rates in this stage and that disease can decrease a pig's genetic potential by up to 50 per cent.

All-in, All-out is King (Where have you heard that before!)
The researchers say all-in all-out management is extremely important for controlling disease. Farms with continuous flow management had a much higher incidence of disease and showed significantly more weight variation.

"The bottom line is that pigs need good care right from the beginning," says de Grau. "Small things like making sure there is extra water in the pen in the early stages to broader practices that take all precautions against disease can really help minimize variation."

This research was sponsored by Ontario Pork and the Ontario Ministry of Agriculture, Food and Rural Affairs. For more information, contact Jean Howden at 1-877-ONT-PORK or [email protected].

Further information on all these topics is available on-line, just a click away, in our exclusive Pig health database. Just click the relevant link in the left hand navigation bar.

Source: Ontario Pork, September 2001