With the weather turning warmer and fields firming up, producers are turning their thoughts to field work with less attention often paid to the pigs in production facilities. In the past couple of weeks I’ve seen many dairy producers hauling manure prior to beginning any field work.
In this region of the US, the vast majority of swine manure is fall applied. This reduces the risk of compaction on wet fields and eases the labor crunch as planting time approaches. However, there are producers who have to apply some manure in the spring, especially those with drinkers that waste a lot of water and generate a lot of extra volume to be disposed of.
Note that I said disposed of for the wasted water, rather than utilized which is what we should be saying when we talk about collected feces and urine. Wasted water is expensive. Generally you can figure it costs about $0.015/gal to transport and inject manure, either with draglines or with tankers. Thus you want as much of the product to be rich in the nutrients associated with feces and manure and as little wasted water (no nutrients) as possible.
Twenty years ago I did my first research regarding the impact of drinkers on pig performance and manure volume. As you might expect, with gate mounted nipple drinkers, water use was 40-50% higher than with wet/dry feeders. While I didn’t do a head-to-head comparison, water-to-feed ratio data I collected suggested that the difference between wean-finish bowl drinkers and nipple drinkers would be similar.
The industry recognizes this as the vast majority of sites now utilize some sort of water saving drinking device. I seldom see nipple drinkers in production facilities.
However I often see water wastage in the form of leaking drinkers. To see how much water comes from a leaking drinker, I set my kitchen faucet to drip at 90 drips per minute. When I captured the drips, it worked out to 7.6 gal/day. This is 1.5 5 gallon buckets of waste if you have a drinker leaking at this rate. Keep in mind that at 90 drips per minute I could still count the drips so many leaking drinkers are wasting more than this.
At $0.015 per gallon to dispose of the manure (in addition to filling up manure storage devices faster than intended) this 90 drip per minute rate costs $0.11/day in added disposal expense. Leaking drinkers have a cost and it can add up quickly!
It is true that wet feeders typically use less water. That is why we routinely pump pond water into our barn with wet feeders to be able to thin the manure so it can be pumped. That costs money too so maybe not all water wasted by nipple drinkers is bad.
I’ve heard/seen the complaint of manure being too ‘dry’ if we get too good at conserving water. Years ago almost all manure was transferred using vaccuum wagons and producers quickly found that they needed to use slurry pumps as less water was wasted by drinkers.
Another instance where wasted water is necessary is pull plug systems going to lagoons. If you get the manure too ‘dry’ you have flow problems of the material to the lagoon. In addition, lagoons work better with more dilution.