The Impact of Peat Moss Amendments on the Microbial Load in Used Pine Shaving Poultry Litter23 July 2013
Adding peat moss to poultry litter may be a useful amendment for reducing bacteria, yeasts and moulds, according to new research from the US.
As well as pine shavings, alternative litter sources for poultry bedding include sand, pine straw or even peat moss, according to the authors of a paper published in the latest issue of International Journal of Poultry Science. Peat moss has a high absorptive capacity and is naturally acidic, possibly making it a good poultry litter amendment.
The objective of the study - by D.L. Everett of Mississippi State University and others there and at the University of Arkansas - was to determine if microbial populations changed when different levels of peat moss were added to poultry litter.
Experimental treatments included 0, 13 and 20 per cent peat moss, which were added to used pine shavings. A total of 216 male broilers (42 days) were separated into 18 pens (six pens / three treatments).
Control litter samples (100 g) were collected prior to the addition of peat moss and birds (0 days); then litter samples from each pen were collected weekly thereafter for three weeks.
From each litter sample, 10g was diluted in 90 ml of Buttersfield's Phosphate and then serially diluted. For Tryptic soy agar, MacConkey agar and Sabouraud Dextrose agar, 100µl of inoculums was plated in duplicate to detect aerobic bacteria, total coliforms and yeasts/moulds, respectively. Plates were incubated aerobically for 24 hours at 37°C and then counted.
The results indicated that there were no differences between treatments for total aerobic bacterial counts. Initially, an increase in coliforms was detected in treatments that had peat added. By the second week, coliforms were reduced in the peat treatments and a treatment by week interaction was detected (P=0.012). The level of coliforms in litter which had peat added (13 or 20 per cent) was 3.92 and 4.04 log colony-forming units per gramme (cfu/g), respectively.
For the control litter where no peat was added, coliforms were 5.43 log cfu/g of litter.
A treatment by week interaction was detected for yeast and moulds (P=0.0025). Over each week of the experiment, a decrease in the number of yeast and moulds occurred in litter where peat was added. In week 1, yeast and moulds were at 5.22 log cfu/g of litter in the control and 4.42 and 4.54 log cfu/g of litter in the 13 and 20 per cent peat treatments, respectively.
In week 2, the yeast and moulds were 5.43 log cfu/g of litter in the control and 4.0 and 3.88 log cfu/g of litter for the 13 and 20 per cent peat treatments, respectively.
For week 3, the yeast and moulds were 6.03 log cfu/g of litter in the control and 4.82 and 3.72 log cfu/g of litter for the 13 and 20 per cent peat treatments, respectively.
Everett and co-authors concluded that the addition of peat moss may be a useful amendment for reducing bacteria, yeasts and moulds in poultry litter.
Overall, they added, future studies should test the absorptive capacity of peat moss for trapping ammonia and changing the litter pH, which could demonstrate how peat moss is actually reducing bacteria and yeast/mould growth in poultry litter.
Everett D.L., Y. Vizzier-Thaxton, C.D. McDaniel and A.S. Kiessume. 2013. The impact of peat moss amendments on the microbial load in used pine shaving poultry litter. Int. J. Poult. Sci., 12 (4):202-205.
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