The Pig Farmer Survey 2003 found that one in three farmers was unaware that reduced protein diets can reduce slurry production from pigs by 10% while nearly two in three were unaware that it can also reduce water consumption. About 2/3 of protein fed to pigs is lost, half of which escapes into the air as ammonia gas while the other half is spread in slurry or manure. When managed properly, ‘precision protein feeds’ can reduce nitrogen in slurry by 14-22%. Other research has found that as slurry is reduced by 10%, so is the ammonia that is emitted into the air.
The survey found that one in three pig farmers estimated the cost of complying with Nitrate Vulnerable Zone regulations to be more than ₤5,000/year. Research has shown however, that a slightly higher feed cost was balanced by significant savings on slurry, storage and transport together with the reduction in water costs.
Under pollution controls (PPC) for intensive pig farms this method represents the ‘best available technique’ (BAT) because it brings benefit to the farmers and the environment. Guidance to farmers on PPC is available on the Environmental Agency’s website. The Pollution Prevention and Control (Wales and England) Regulations 2000 are designed to prevent and eliminate pollution at the source through the efficient use of natural resources. They apply to all farms with 40,000 birds, 750 sows or 2,000 production pigs. PPC covers most aspects of farming activity including the handling of raw materials and waste, intensive rearing of pigs, manure management planning, the spreading of solid manure and slurry, energy use, accident management as well as monitoring and reporting.