How is wash water used? Water for washing includes water used to pre- soak or soak pens as well as the water used
to pressure wash pens, floors, crates and feeders. A variety of methods for soaking can
be used including flooding the pits, spraying by hand or with a garden sprinkler, or use of
a permanently installed greenhouse irrigation system. It may be obvious that flooding
uses the most water and results in no better softening than can be attained by sprinkling
less water.
Pressure washing is noisy and messy. Ensure that protective equipment including
hearing protection and a rain suit are used during pressure washing
How much water is wasted in a 5000 head barn?
In the 1998 PSCI Satellite Conference, Dr. S. Lemay noted that water wastage has been
documented to exceed 40% of the water provided by a nipple drinker. This would mean
that a 5000 head finishing barn would need an additional 5.5 million litres of annual
storage capacity just for the wasted drinking water.
Throughout this article, we will assume a comparable scale of operation for each phase.
A farrowing facility with 108 crates that is turned 13 times per year (refilled every 4
weeks) will produce about 14,000 nursery piglets. Likewise, a 5000 place feeder barn
turned 2.8 times per year will accommodate 14,000 pigs.
What is the extra cost of waste water disposal in a 5000 head barn?
The cost of spreading the additional slurry volume represents another expense due to
wasted drinking water. Based on a typical slurry dispersal charge of $1.55 per cubic
meter (about 0.6 cents per gallon), the drinking water wasted during finishing amounts to
$0.61 per pig sold.
Management of drinking water can improve feed intake.
This brief article is not intended to address the nutritional aspects of water, but just to
remind readers that restricting water intake is false economy. An example of this is
provided by a project done by the VIDO Swine Technical Group that has shown that top
dressing gilt feed with extra water results in greater feed intake. Two groups of about
600 gilts each were provided water using a typical nipple drinker. One group had
additional water provided as top dressing on feed by using a hose on an automatic timer.
This graph shows that the gilts that were provided extra water consumed an average of
6.2 kg of feed per day whereas the group of gilts with just the nipple drinker consumed a
daily average of 5.4 kg (15% improvement).
Survey of wash water use. Another major contributor to slurry volume is wash water. In order to get an estimate of
the amount of wash water that is actually used in current production systems, the VIDO
Swine Technical Group under took a survey study. Producers in western Canada who
were associated with the group provided the sites used. The survey sites included each of
the three main production stages and were characterised as farrowing, nursery or
finishing.
Wash water for farrowing, nursery and finishing facilities. The average amount of time for washing these farrowing facilities was 15 minutes (range
from 7 to 29 minutes) per crate using a volume of 152 litres of water (range 85 to 318).
The wash water temperature (warm versus cold) did not affect the length of time needed
to wash these facilities. Most of them (85%) were washed with warm water which is not
as unpleasant as washing with cold water.
Assuming that each of the 108 crates in this example crate is washed once per cycle, then
a total of 1404 crate washings occur during the year. Washing the farrowing crates
contributes 18.7 litres of wash water per pig sold.
Washing the nursery pens takes approximately 1 minute per pig and uses a volume of 10 litres per
piglet.
Washing the finishing barn takes longer and uses more water per pig than any other stage of production. The average washing time 1.8 minutes per pig, was about twice as long as was spent while washing the nursery. There was considerable variation in washing time (1.1 to 4.8 minutes per pig).
The amount of water used to wash the finishing barn (average of 80 litres per pig)
represents three-quarters of the total (110 litres per pig) used in all three production
stages.
One of the biggest messages to come out of the survey was the very large range of wash
water volume used in different finishing operations. As you can see from the graph
below, the amount of water used ranged from 21 to 246 L/pig.
In conclusion, the points to remember are: