Balanced pig diets overcome effects of Swedes GPban
By Jessica Buss
FOCUSING on correctly balanced pig diets has helped Swedish producers overcome their countrys ban on in-feed antibiotics.
Leif Goransson of the Swedish Pig Centre, Lantmannen told the University of Nottingham Feed Manufacturers Conference that the main consequences of banning in-feed antibiotics (growth promoters) had been seen in the post-weaning period. After the ban on their use in 1986, there was a two-fold increase in post-weaning diarrhoea.
Daily liveweight gain of piglets weaned at four to five weeks old – Swedish law prevents weaning before four weeks – also fell.
"Producers became used to solving problems with antibiotics in the diet and forgot about management and breeding," said Dr Goransson. Use in medicated diets of the prescription-only antibiotic, Olaquinadox, to treat scour had halved by 1993 since its inclusion as a general feed additive before the ban.
Changes to piglet diets since the ban have included reducing crude protein levels, but still supplying adequate essential amino acids. Decreasing the crude protein in post-weaning diets increased piglet daily liveweight gain and improved feed conversion from diets of the same energy level (see table).
"Lower protein diets also reduce the ammonia in the air and make slurry drier," he said.
Providing water soluble fibres in the diet, such as 5% sugar beet pulp, also reduced post-weaning scour. All diets now contain an acidifier and when feeding was restricted to 2-3% of bodyweight a day in the first week to 10 days after weaning diarrhoea was reduced.
Zinc oxide had also reduced scour levels and increased daily liveweight gains, but recent environmental concerns could restrict its use in the future.
It was also common practice to use an all-in, all-out housing to reduce the disease challenges found in continuous flow units.
"We have also learnt the importance of feeding the sow correctly.If we can produce heavy pigs at weaning we have more chance of keeping them healthy," he said.
\ Dr Goransson.
Results from trials using different kinds of probiotics and feed enzymes were too inconsistent for practical use, he said.
Reducing the crude protein of post-weaning diets lifts daily lw gain.
Decreasing protein levels in post-weaning diets
Managing without in-feed antibiotics:
• Reduce crude protein in diet.
• Offer water soluble fibre source.
• Include zinc oxide in rations.
• Restrict feed for 10 days post weaning.
Avoparcin feed ban
The antibiotic feed additive, avoparcin, is to be banned from use in Europe.
The Roche-manufactured avoparcin product, Avotan, has been used in diets for 20 years to improve feed digestion and absorption by controlling bacteria that cause damage to animals intestines.
It is currently used by an estimated 80% of UK poultry producers, and about 30% of UK pig and cattle producers.
The EU decided to ban the product "as a precautionary measure", because of rising fears that use of antibiotics in agriculture could cause cross resistance to antibiotics used to treat humans.