EFFECT OF 2 YUCCA EXTRACTS ON THE REDUCTI ON OF AMMONIA CONCENTRATIONS

The effects of two commercial yucca extracts on the ammonia release fr om pig slurry have been tested in laboratory and in one fattening hous e. In laboratory, tests were carried on with 4 litre samples whose amm onia production was recorded during 35 days. One of the two products, at the factory recommanded dose of 5 g/l, has successfully lowered the ammonia emission rate of the slurry. In the pig house, the two same p roducts were given in the pigs' diet at the dose of 160 and 200 g/ton of feed. Inside a same building, pigs of one room received feed plus y ucca extracts and those of the second room feed alone; none of the 2 p roducts has significantly reduced the ammonia concentrations recorded on a three month period. One can expect improvements of the yucca extr acts but up to now no guaranty can be given of their efficiency.