The impact of the use of water bowls and wet/dry feeders on the volume of manure produced has been verified in 15 farms: 5 farms equipped with nipple drinkers (to compare), 5 others equipped with bowl drinkers and the last 5 equipped with wet/dry feeders. The results showed that a reduction of 34% in the volume of manure produced could be obtained with the use of wet/dry feeders compared to nipple drinkers and for the water bowls, this reduction varied from 30 to 40%. An analysis of the results showed that the differences between the bowls and the wet/dry feeders are no statistically significant. The volume capacity of manure storage facilities for farms equipped with bowls and wet/dry feeders could be reduced by 35% compared with a farm equipped with nipple drinker.

The results show no real difference between wet/dry feeders and water bowls in the total volume of manure produced. Means to reduce water wastage have to be considered as the excess manure produced has to be stored and subsequently spread. The extra water coming from spillage contribute only in more dilution of the nutrients in the manure.