The experiences from recent years from the organic poultry production indicate, however that poultry to a certain extent is capable of absorbing the contents of nutrients in roughage and that it is a really good idea to complement the feed-compound with roughage.

Improved animal welfare

In trials as well as in practice it has been proven that addition of roughage makes the hens calmer and less aggressive, feather pecking is reduced and the mortality rate decreases.  

Table 1: Mortality rate and score for plumage with and without roughage

Source: FØJO-report no 11- 2001, Research and development of organic egg production

It is unclear, whether the positive impact on the welfare is caused by the fact that:

• The roughage keeps the hens busy
• The roughage gives a larger feeling of satiety and therefore less aggressiveness
• The roughage contributes a nutritional value

The impact may be caused by a combination of all three reasons.

Physiological effects

As a matter of fact roughage is course structured and fills up much of the animals’ intestinal tracts. By ad libitum feeding with maize- or barley/pea whole crop silage we can determine that the gizzard grows from app. 16 g to 30-35 g, when compared with feeding with feed-mix alone. The rate of passage through the gizzard decreases, which is why more acid is added to the feed. It can be seen that the pH decreases from 4.8 (basic feed alone) to 3.9 in the gizzard of hens that are fed with silage. The low pH value slows down the development of bacteria that are sensitive to acid (salmonella and coli). Roughage improves in this way the intestine health.  

Nutritional value

Almost all types of roughage contain far less nutrients per unit of weight than a normal feed compound. The main difference is, however, due to the high water content of roughage. If the contents of nutrients are measured in the dry matter, the difference is much reduced.  

Table 2: Nutrients in roughage and barley / pea whole crop silage

Source: Knowledge Centre for Agriculture, Poultry

In terms of energy app. 7 kg barley / pea – whole crop silage must be used to replace 1 kg basic feed.

If the price of whole crop silage is set at DKK 0.50 per kg, and the price of organic basic feed is set at DKK 3.25, it can be calculated that the price will be increased by DKK 0.25 to replace 1 kg basic feed with whole crop- silage.

Trials and practice indicate that the extra feeding costs of roughage are more than paid back, as a result of increased productivity, when roughage is added to the feed mix.

What roughage is suitable for poultry?

Poultry’s digestive system is not fit to metabolise straw fodder, so all straw fodder inclusive whole crop silage, hay and green grass should be finely chopped to a straw length of maximum 5 cm

Straw is not considered as roughage, whereas hay is approved as roughage by the Danish Plant Directorate. Hay is, however, poor roughage and if given as whole straws, the animals may risk constipation. If you chop the straws, the hens do not want to eat them.

On the contrary hens love green grass, both as whole straws and chopped. The risk is that the hens eat their fills in grass and as a consequence absorb too little feed mix. Fresh grass should therefore only be given to a limited extent – e.g. 20 g / hen / day.

It seems as if silage to a lesser extent has nutritional risks, on condition that it is finely chopped. Whole crop silage of grains, lupines, peas and beans is preferable to silage of green cover crops. The fowl prefers the whole crop silage, probably because of the contents of grains. The grains are easy to digest for the fowl and gives good activity (welfare) to look for the grains.

Caption: Stripper harvested and finely chopped barley / pea whole crop silage. Good roughage for organic hens. Source: From the project: Early harvested protein crops for pigs and poultry, Knowledge Centre for Agriculture, 2008

Based on our experiences silage can be used as feed for poultry ad libitum without any problems. A hen will typically eat 50 – 60 g / day.  

Challenge

Hens and poultry are distinct creatures of habit also, when it is a question of eating. If you change the type of feed, time of feeding or – places you risk that the animals get malnourished for a period, until the animals become accustomed to the new situation. 

The principle for feeding with roughage should therefore be:

Same amount, same type, same time and same place – each day!

Until now this principle has not been followed in particularly many flocks, partly because egg producers have not been aware of the importance of this principle and partly because it has to be admitted that the traditional poultry stables have not been built for feeding with roughage. It has been absolutely impossible to spread considerable amounts of roughage every day in these stables.  

Many attempts to mechanise the work of feeding with roughage have been made – e.g. transportation with mini wagons, conveyor belts, mounting of feed racks, suspension conveyors and feeding in the free range. Long time has passed while trying to find the most optimal solution. For a long time primarily the cheap solution has been pursued. There has been a psychological barrier to invest large amounts in technical skills to handling of roughage.

A solution in the shape of a cable railway plant now exists (but it costs between DKK 300,000 and DKK 500,000). The plant consists of:

• Rail system
• A scatter machine, embedded with load measuring devices
• One or more build-ups that fill roughage, straw litter, grains and oyster shells in the scatter machine
• A computer to control amounts and time for feeding in the different stables

Caption: Roughage in build-up ready to dose in the feeding robot

Caption: The feeding robot collects silage, straw bedding, whole grains, and oyster shells in the storage room.

In principle the farmer only has to load feed in the build-ups, programme the computer and maintain the technique – the rest will take place automatically.

Caption: “The feeding robot, or in popular terms the scatter machine, is able to spread grains, chopped straw and oyster shells by means of distributing plates. Unfortunately the plates cannot handle silage, for which reason the roughage is placed in a long row of 50 cm in width and in the full length of the stable. In return the roughage is fed more times a day to make it possible for all hens to eat”.

Until today such plants have been installed at eight organic egg producers in Denmark. It is a matter of considerable investments, but the estimation is that the invested money will be earned again within 2-3 years, if you have a flock of e.g. 12,000 organic hens.