Research identifies sound mucking-out technique
September 16, 2009
Ammonia generation is greater in horse stables if they are completely mucked out every day, German research has found.
Mucking out completely on a daily basis should not be undertaken in horse stables, German researchers have found.
They also found that wheat straw outperformed straw pellets and wood shavings as stable bedding.
The researchers set out to compare different types of bedding and mucking out regimes used in horse stables on the production of particle matter and biogenic gases - carbon dioxide, nitrous oxide, and especially ammonia.
Three separate experiments were undertaken, each carried out in an enclosed stable with five single boxes housing four horses.
Measuring instruments were set up in the middle of one side of the stable.
In the first experiment, the three types of bedding material were assessed according to their ammonia generation. Each type of bedding was used for two weeks, with three repetitions of the experiment.
The average ammonia concentrations were lowest for wheat straw - 3.07 milligrams per cubic metre of air, plus or minus 0.23mg per cubic metre - compared with 4.79 for straw pellets (which showed an identical level of variation to wheat straw) and a level of 4.27 for wood shavings, which showed a slightly lower level of variation.
In the second part of the experiment, the effects of the mucking out regimes on the generation of ammonia and particles from wheat straw were examined using three different daily methods:
* No mucking out.
* Complete mucking out.
* Partial mucking out, in which only the faeces were removed.
Average ammonia concentrations differed significantly between all three mucking-out regimes, the researchers found.
"The highest values were recorded when the stalls were mucked out completely every day," they wrote.
No mucking out at all resulted in ammonia levels about 15 per cent lower than when the stalls were mucked out completely. Ammonia levels in partial mucking out were, on average, 32 per cent lower than what they were with complete mucking out.
No mucking out at all delivered the lowest average level of particle matter in the air among the three different strategies.
In the third phase of the experiment, the researchers evaluated gas and airborne particle generation for a six-week period without mucking out.
"The ammonia values were found not to constantly increase during the course of the six-week period," the said.
"The average weekly values for particle matter also did not constantly increase but varied between approximately 90 and 140 micrograms/m.
"It can be concluded from the particle and gas generation patterns found in the results of all three experiments that wheat straw was the most suitable bedding of the three types investigated, and that mucking out completely on a daily basis should not be undertaken in horse stables."
The study, entitled "Gas and particle concentrations in horse stables with individual boxes as a function of the bedding material and the mucking regime", was carried out out by K. Fleming, E.F. Hessel and H.F. Van den Weghe, from the Department for Animal Sciences, Division Process Engineering, at Georg-August University of Goettingen, in Vechta, Germany.
Their findings appear in the Journal of Animal Science.