Various factors influence whether a material is suitable as poultry litter. Generally, litter materials should be absorbent, but beyond this they also need to dry out reasonably quickly. Many paper products, for example, absorb moisture, but they do not then dry out well.
Another important criteria is that bedding material should have an additional use. Should this not be the case, poultry producers could end up with large amounts of used bedding materials with no use for them. Historically, once poultry litter has come to the end of its useful life it is spread on fields or fed to cattle, but other options that are receiving increasing focus are its use to generate electricity or to produce gas and/or steam for electricity generation.
For a material to be used as litter, it must be readily available. Some products may be highly suitable for use as litter, but if they are difficult to source, they won’t be used. Additionally, if an alternative material is not cheaper than what is currently used, it won’t be adopted. But if materials have a higher value than those currently used once removed from the poultry shed, or of the current litter materials of choice prove difficult to source, or their quality deteriorates, broiler producers will look to alternatives.
A number of factors need to be kept in mind when evaluating alternative litter materials. Importantly, they should not be toxic to either man or poultry. Their effect on livestock, pets, wildlife and plants also needs to be understood.
It has been shown that bedding material can account for up to 4 percent of a broiler’s diet, therefore, litter must contain no contaminants, such as pesticides or metals, that could make a bird ill or contaminate its meat.
Additionally, in any evaluation of alternative bedding materials, production data need to be taken into account, including growth rate, feed conversion and meat quality. These, together with the cost of the bedding material, will be key in evaluating any new litter option.
Even when all these factors are considered, regional variation still needs to be taken into consideration. What works well for one region or for one producer may not work well in, or for, another, and each producer will need to make his or her own decision when deciding which litter type to use.
Sand is not new as a litter material in poultry production, but its use is generating renewed interest, especially in the south of the US.
Studies have been carried out comparing flocks raised on sand and flocks raised on pine shavings. One study showed that that males kept on sand were 30-40 ponts heavier with no difference noted among females. There was no difference between the sand raised and shavings raised flocks in terms of feed conversion or mortality and, while intitially, the moisture content of the sand litter was higher, as time passed this difference disappeared. Additionally, there was no difference in ammonia levels.
Microbiological testing showed that coliform bacteria, including E. coli and aerobic bacteria were less frequent in sand than in shavings.
Multiple field studies carried out under commercial conditions have shown that broilers raised on sand develop in the same way as those raised on shavings. Moisture and ammonia levels are similar across litters, with bacteria levels significantly lower in sand. Beetle populations also tend to lower using a sand litter. However, sand does not heat up compared with pine shavings, meaning that producers have to pay greater attention to ensuring that floor temperatures are correct before chicks can be placed. A further advantage of sand is that it can be used for extended periods before cleaning becomes necessary. If the litter is removed every one or two years, cleaning can be carried out once every five years. When the litter is kept in the house for longer periods, which can be up to four or five years, as has been noted by some producers, there are no cleaning plans, whether the bedding is sand or not, as long as the birds remain healthy.
As the two commonest litter materials, pine shavings and rice hulls, become ever more expensive, a possible alternative could well be sand.
Studies carried out at the Centro de Investigaciones y Ensenanzas Avicolas de la Escuela Agricola Panamericana, El Zamorano, Tegucigalpa, Honduras have evaluated four different litter approaches: wood shavings, rice hulls, sand, and sand with a top dressing of shavings.
Litter temperature. Differences between approaches were noted, sand having the lowest temperature. This had no negative impact on productivity.
Body weight. Differences between approaches were recorded. Those birds reared on sand and sand with a top layer of shavings showed the greatest weight gain over six weeks, outperforming those birds kept on the more traditional pine shavings and rice hulls. This higher weight gain is thought to be due to the birds consuming sand particles.
Feed conversion index. There was no significant difference between approaches.
Mortality. No significant differences were found across the litter types throughout the production cycle.
Moisture. There were moisture differences across the litter types, with sand having the lowest moisture content over the six week production cycle.
The use of sand as poultry litter can be an excellent substitute for wood shavings and rice hulls, but there are factors that should always be kept in mind:
•The sand should be brought to the right temperature before chicks are placed;
•The size of sand particles should be given consideration so as not cause problems for the machines that remove the gizzard;
•As sand is denser than shavings or hulls, the level of litter will rise more slowly as it is topped up for each flock. It will also last for much longer in the poultry shed;
•Cleaning sand can be much faster and disinfection more efficient, as sand is an inert material. It can be flame disinfected, removing organic material in one go, without the risk of the litter igniting;
•The cost of sand can be much higher than more traditional litters, but the advantages that it offers can outweigh this cost. Additionally, it should be remembered that the prices of shavings and hulls is rising.
The industry will continue looking for alternative litters, but cost and availability will be the ultimate deciding factors in whether they are adopted. Inevitably, some bedding materials will develop locally, but what is important is that, once a material has been identified, suppliers are made fully award of just what exactly the local industry needs.