Raising paw quality with litter management

Footpad dermatitis (FPD) is a condition affecting broilers and turkeys and is also known as pododermatitis and paw burn, all of which refer to a type of contact dermatitis on the footpad and toes.

Before the mid 1980, chicken paws were of little value and were rendered with feathers, blood and other unslable portions. Chicken paws prices have skyrocketed because of an export demand for high quality paws, transforming this product into the third most important economic part, behind breasts and wings.

However, paws are downgradeed or condemned for a variety of reasons that include a condemned carcasses, plant machinery mutilations or FPD lesion. Roughly 99% of condemned paws are a result of FPD lesions. Not only is FPD a revenue loss, it is currently being used as an indicator of bird welfare in animal welfare audits. Improving foot health not only provides opportunity for increased profit from exportable chicken paws, but also ensures that the poultry industry continues to meet animal welfare standards.

Litter moisture

Recent work at the University of Georgia, USA, focuses on environmental factors-the relationship between litter moisture and depth and paw quality. Unfortunately, previous research has contradicting results. Some research has shown that paw quality is better with deeper litter and others have shown it is best with shallow depths. In this study, as litter depth increased, moisture decreased dan paw quality improved.

Wet litter can cause ulceration of broiler foot pads. Lesions have beed found to be more severe as litter moisture increases. Continuosly standing on wet litter causes the footpad to soften and become more prone damage, predisposing the bird to developing FPD. Drying out the litter and moving birds from wer litter to dry litter has been shown to reverse the severity of FPD.

Litter Management

Litter play as important role in moisture management. It acts as a sponge, absorbing moisture and allowing for the dilution of fecal material. Thicker bases of litter allow water retention and dissipation away from the surface where it comes into contact with birds. Litter must not only be able ti absorb lots of moisture, but should also have a reasonable drying time to get rid of that moisture.

Bedding material has become more expensive and, as a result, there are situations where inadequate amounts of shavings are placed in broiler houses. Litter sometimes may be spread unevenly throughout the house, being thicker in the middle than along the sides. Evenly spread out litter is critical to prevent ‘slicking over’ of the litter along the sidewalls. Ultimately the bedding material used depends on cost and availability. Regardless of the source of bedding, when possible use materials with smaller particle sizes, as they have been shown to produce better paws.

Litter management between flocks

If broiler houses are cleaned out between flocs, at least three to four inches of litter is need to handle the moisture. If on a bulit-up litter program, it is important to remove the caked litter to allow the litter base to dry before chicks are placed. Running fans during the day will remove moisture from the litter more rapidly.

Several methods are use to manage litter between flocks, such as tiling, removing cake and top-dressing and windrowing. Six commercial 40x500-foot broiler houses were used to evaluate how litter management in between flocks would influence the incidence of FPD. The three litter methods use were cake removal, complete cleanout and windrowing. Each treatment was applied to two houses. The result indicated tha the windrowed houses produced more Grade A and B paws in the processing plant than did caked and cleaned-out houses.

Drinker Management

Proper drinker line management according to manufacturer’s guidelines can prevent excessive moisture form being added to the litter. Drinkers that are too low or have the water pressure set too high tend to result in wetter floors. Water lines that may have a biofilm or other particulates can serusl in leaky nipples, which will also increase litter moisture. Regular flushing and sanitizing the drinker system will reduce water leakage. This will keep litter dried and improve its quality, subsequently resulting in better paw quality.

Managing the moisture undeneath the water and feed lines is essential because the birds spend the majority of their time in this area. Keeping litter dry in this area can reduce problems not only from FPD but also form hock and breast burns.

Ventilation

If relative humidity (RH) is not currently being monitored in broiler houses, it should be used as a house management tool. A main objective of minimum ventilation is to control house moisture, with the goal being to keep the RH between 50% and 70%.

More incidences of FPD and hock lesions have been observed in clod weather compared to warm weather and have a high correlation with relative humidity in the broiler house. These seasonal effects are related to the increased relative humidity in broiler houses that are because of reduced ventilation during cold weather. Circulation fans and attic inlets have been proven to promote dry floors in cold weather.

Bird density

The sudden onset of wet litter associated with higher bird densities in one area of a house compared to another is considered to have a large influence on the development of FPD. Litter conditions deteriorate as moisture increases with increased stocking density. As stocking density increases, water consumption per bird increases.

As bird drink more water, their feces become watery and contributes to overall litter moisture. One way to combat this is to properly use migration fences, even in cold weather months. Migration fences put in place after birds are released to the entire house from partial house brooding will ensure they are evenly spaced out, allowing for better litter management and temperature regulation.

One simple, cost effective way to monitor bird density is to add additional water meters. Water meters for the fron, middle and back of the house can indicate bird densities by simply looking at daily water consumption. Higher consumption in one end of the house means that there are more birds than in the other sections.

Make sure to have a dry litter base of at least three inches at the start of the flock to provide an adequate ‘sponge’ to handle the moisture. Proper housing and equipment management will allow for decreased RH inside the house and drier litter. Keeping litter drier can go along way to producing a healthier and more profitable flocks*****

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Necrotic enteritis – a silent profit robber

Figure 1

 A brief overview and a case report from india

Necrotic enteris (NE) was first described in chickens in 1961. NE is caused by the gram-positive bacterium, Clostridium perfringens. This article discusses a brief review of NE in the literature and a case report of NE in young commercial pullets in India.

Clostridium perfringens

It is an anaerobic bacterium, i.e. one that grows in the absence of oxygen, and it has the ability to form spores. The spores are small structures highly resistant to environmental stresses. They consist of a tough hard coat that encapsulates the bacterial genetic material and protein necessary for growth. By virtue of forming spores, the bacteria enter a dormant phase when environmental conditions are unfavourable and remain so for as long as necessary. Once present within a chicken house, clostridial spores can remain alive for centuries. Clostridia are capable of producing among the mos potent toxins ever known. It is the toxins that responsible for causing disease. They cause damage to the tissue and destroy red blood cells, thereby reducing the oxygen carrying capacity of the blood. In some cases, they prevent nerves from sending signals to the heart and lungs.

What is necrotic enteritis?

NE is a condition characterised by death or necrosis of the intestinal lining predominantly of the middle and lower small intestine which may be accompanied by necrosis in caeca and liver in some cases. It is transmitted with the ingestion of droppings contaminated soil, water, feed, or litter.

Figure 2

Triggering factors

In healthly chickens, clostridial bacteria normally live harmlessly in the lower gut and are found in the caeca and lower large intestine. The pH and high oxygen content of the healthy small intestine do not support growth of the organisms. For NE to occur, there needs to be a triggering factor that tips the balance in favour of the clostridial bacteria allowing them to proliferate and migrate to the upper small intestine.

Among the known trigger factor are:

• Direct damage to the intestinal lining by coccidial challenge or bacterial overgrowth.
• Feed factors that alter the gut environment like rapeseed, fishmeal, wheat or protein level.
• Immunosuppresion which reduces resistance to gut infections, e.g. CAV, IBD, Marek’s disease, physiological stress.
• Physical factors that damage the gut lining like litter material, a lack of grit or a change in physical feed presentation.

A Case report

In a commercial layer flock of 29 weeks, it was noticed that the peak production standard was no being maintained although morality was within an acceptable range. On investigation, it was foud that the birds were suffering from sub-clinical NE.

Figure 1 shows the changed appearance of the birds comb. Necropsy finding revealed enlarged gas-filled small intestine with the NE observed from the duodenum to the ileum (figure 2). The mucosal surface of the affected area of the intestine was covered with a tan orange pseudo-membrane. This “dirty turkish towel” appeareance is commonly associated with NE. Histopathological examination of the small intestine revealed extensive necrosis of the the villi and infiltration of the lamina proproa with mononuclear cells.

It was also observed that the flock was underweight and each bird was receiving only 207kcal metabolissable energy and 16.8g crude protein daily, compared to the requirements of 290kcal and 18g, respectively. Few birds were showing nasal dishcarge also indicative of mycoplasma infection.

Maize, de-oiled soybean meal, broken rice, sorghum, de-oiled peanut cake, fish and squilla were among the major ingredients of the feed.

The farm records indicated that the farmer had similar problems with previous flocks. For the treatment, it was recommendend that the feed formulation be modified to ensure the birds received adequate levels of energy, protein, lysine, methionine etc. Fishmeal and squilla were removed from the feed, which was supplemented with enzymes and tetramutin (combination of tiamulin and chlortetracycline).

Within 15 days, the flock showed good improvement with regards to the hen-day production, bodyweight etc.

-Dr. Avinash Dhawale,

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