P&SS Info # 318

The use of alum (aluminum sulfate) in broiler litter management can improve profitability while reducing some of the environmental threats posed by litter.

Research has demonstrated that the use of alum by the poultry industry can significantly improve production. Demonstrations in Tennessee have shown that treating broiler litter between grow-outs with alum can also significantly lower ammonia levels in poultry houses (Figure 1). Lower in-house ammonia levels can improve the health and performance of the poultry, as well as protect workers.

An additional, but important, environmental advantage from alum use is the significant reduction in soluble phosphorus and heavy metals in the runoff from land where litter is applied.

How Alum Works

When alum is mixed with broiler litter, it reacts with the moisture in the litter to reduce ammonia volatilization and tie up the soluble phosphorus. It is not necessary to apply alum to fresh litter. For the best results, alum should be applied to litter between flocks, starting after the first flock but before the second flock. Application should be made before each subsequent flock. This will give maximum control of ammonia when the birds are young and most sensitive to atmospheric ammonia. Higher rates will control ammonia for longer periods than lower rates, as well as tie up more phosphorus. This is also evidence that pathogens, including E. coli and Salmonella, will be reduced (Moore et al., 1998).

Rates

A rate of 100 to 200 lbs. alum per 1,000 square feet is recommended to treat broiler litter. In most Tennessee broiler houses, this is between one and two tons of alum per house per grow out. The higher rate (200 lbs. alum per 1,000 square feet) will control both ammonia and significantly reduce soluble phosphorus in the litter. The lower rate (100 lbs. alum per 1,000 square feet) will control ammonia during the first few weeks of a grow-out, but will have less of an effect on reducing the soluble phosphorus in the litter (Figure 2).

Rate selection for your operation will depend on your current building, how well it is currently ventilated and managed and the moisture content of the litter. The higher alum rate is recommended in buildings where there is more ammonia volatilization, typical of litter with more moisture.

Application Methods

There are three steps you can take to ensure that alum is applied safely and most effectively in your house:

1. The house must first be de-caked or tilled with rototiller.
2. Alum should be broadcast using a de-caker or drop spreader used to spread fertilizer (Figure 3).
3. Before birds are re-introduced in the house, any alum spills or other concentrated areas should be lightly raked into the litter. This is to avoid consumption by the young chicks.

Precautions

Alum controls ammonia volatilization by acidifying the litter. It is a dry acid and should be treated with respect. During handling, wear gloves to prevent skin irritation or burns. When applying alum, it is vital that all personnel wear goggles for eye protection as well as a dusk mask to prevent inhalation of alum dust that can be in the air for several minutes after application (Figure 4).

After the alum has been applied, walk through the building and break up any large lumps of alum that may have been left on the surface. Within four or five weeks after treatment, the litter will no longer be acid and no extra precautions are needed for handling litter during clean-out.

Cost of Alum

For some producers, cost will be a major factor in determining what rates to use. The costs of using alum in your operation may be offset by improved productivity and reduced energy costs. Demonstrations in Arkansas have shown a benefit-to- cost ratio of 1.96 (Moore et al., 1999) using two tons of alum per house between grow-outs over six grow-outs.

Alum can be purchased directly from General Chemical Corporation (1-800-631-8050) or from your local agricultural supplier. Alum currently costs about $200 to $250 per ton. It is sold in 50 lbs. sacks, one-ton super-sacks or in bulk. As with other commodities, you can see significant savings if the material is supplied in bulk. If you do not apply or incorporate the alum yourself, you can expect to pay $50 to $100 per house to a custom applicator. In some situations, reduced rates of alum can be used by treating only the brood portion of house, or by applying alum in the key areas, such as under the waterers.

Benefits

Research in Arkansas has demonstrated savings to both the producer and poultry integrator from using alum. Major cost savings are due to reductions in ammonia in the broiler house. This can result in significant cost savings due to reduced energy (heating and ventilation) costs, improved feed conversion, increased weight gains and fewer mortalities. Six-week-old broilers were, on average, 0.15 lb. heavier in treated houses compared to untreated houses. Feed conversion improved from 2.04 to 1.98 lb. feed per lb. of bird.

Other potential savings arise from savings in fertilizer costs from the higher nitrogen contents of the litter, which can equal about 800 lbs. of nitrogen per 100 tons of litter.

A major environmental benefit to treating litter with alum is the reduced risk of soluble phosphorus and heavy metals (zinc and copper) in the runoff. There is also reduced potential to pollute surface waters adjacent to agricultural fields where poultry litter is land-applied (Figure 6). At this time, controlling phosphorus is voluntary and depends on a person’s desire to be a good steward. It is thus difficult to put a dollar value on using alum to limit soluble phosphorus in litter. Restrictions on phosphorus are possible in the future, and alum will be a useful tool for growers to ensure the survival and continued expansion of their industry in watersheds considered to be at risk.

Effect of Alum on Litter Quality

Alum treatment of litter will increase the nitrogen content of the litter, making it a more valuable source of fertilizer material. Alum reduces the amount of soluble phosphorus in the litter, but does not affect the overall quantity of phosphorus in the litter. The phosphorus in the litter will still be available to plants and less will be lost as soluble phosphorus in runoff.

Cattle and other ruminants have a unique digestive system that allows them to use by-products as sources of dietary nutrients. One by-product that can be used as a cattle feed is broiler litter. Litter should not be fed to lactating dairy cows or to cattle within two weeks of slaughter. It is recommended that beef producers avoid feeding alum-treated litter to cattle unless relatively low rates of litter (less than 10 percent by weight) are fed. Research indicates that there were no differences in weight gain associated with feeding alum-treated or untreated litter (at 10 percent of the fresh litter weight) to beef cattle. When higher rates of alum- treated litter (50:50 litter-corn mix) were used, the mixture containing alum was very unpalatable. Consequently, dry matter intake was about 50 percent lower when compared with the mixture containing untreated litter.

Points to Remember

1. Using alum as a litter amendment can dramatically reduce in-house ammonia emissions and improve broiler performance.
2. In most Tennessee broiler houses, between one and two tons of alum per house between grow outs will give excellent ammonia control and soluble phosphorus reduction.
3. Alum does not negatively impact the fertilizer value of broiler litter.
4. Using alum to treat litter is good for the environment by reducing atmospheric ammonia emissions and the quantity of soluble phosphorus in the litter.
5. Workers should wear protective gloves, goggles and dust masks when applying alum.

References:

Moore, P. A. Jr., W. W. Huff, T. C. Daniel, D. R. Edwards, and T. C. Sauer. 1997. Effect of aluminum sulfate on ammonia fluxes from poultry litter in commercial houses. Pages 883 – 891. In: Proceedings of the Fifth International Symposium on Livestock Environment. Vol. II. American Society of Agricultural Engineering.

Moore, P. A. Jr., T. C. Daniel and D. R. Edwards. 1999. Reducing Phosphorus Runoff and Improving Poultry Production with Alum. Poultry Science 78: 692 – 698.

Moore, P. A. Jr., T. C. Daniel, Edwards, D. R. and D. E. Womack. 1998. A Fact Sheet for Treating Poultry Litter with Aluminum Sulfate. University of Arkansas, Fayetteville, AR.

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