Consumers are demanding poultry meat from birds that have never received antibiotics. We can argue whether or not this is a good thing but the bottom line is if you want to sell chicken today you are probably going to have to forgo antibiotics in some fashion. What does this mean for growers? What role do they play in ensuring birds thrive under this consumer mandate?
The greatest challenge for birds raised antibiotic-free (ABF) is coccidiosis leading to necrotic enteritis. Necrotic enteritis is caused by the spore-forming bacteria Clostridium perfringens and can cause high mortality (200-400 birds per day or more) around 16-20 days of age. The role of the poultry grower is to make the house inhospitable to cocci and clostridial growth while at the same time providing a brooding environment that encourages early feed consumption and high levels of bird activity. The three most important components for a grower to manage are:
- relative humidity
- floor temperature
- litter pH
Role of Relative Humidity
Controlling relative humidity (RH%) throughout the brooding period is essential to prevent a bloom of Clostridium and coccidia when ventilation needs are low. Houses should be ventilated for RH% (the best time to measure RH% is in the morning during brooding) and directional air flow maintained to keep the litter dry. Allowing the floor to get damp and tacky will cause increases in cocci and clostridium that will infect chicks.
Use ventilation to manage relative humidity levels.
Keeping RH% in a house within the desired range of 50-65% will depend on the:
- preparation of a house for brooding
- amount of space each chick actually utilizes once placed
- style and accuracy of ventilation within a house
Relative humidity that is too low results in dehydrated chicks and too little cocci protection when using cocci vaccines. Relative humidity that is too high will result in caked litter, too many cocci oocysts and too much Clostridium.
Floor Temperature at Placement
Chicks and poults are unable to regulate their body temperature for the first four days of life. The temperature of the litter at placement should ideally be 92-95°F at the time the chicks are placed. A lower temperature is stressful for the chicks and degrades gut health.
Temperature measured at the litter surface vs core will vary drastically.
In houses that are left open during the downtime, litter core temperature can be as much as 20-50 degrees lower than houses kept closed.
Litter core temperatures (one-two inches below the litter surface) need to be at least 90°F at the time of placement. In houses that are left open during the downtime, litter core temperature can be as much as 20-50 degrees lower than houses kept closed. Proper house preparation begins at catch and houses should be shut tightly immediately after catch in order to keep them warm for the next flock. Pre-heating to the final set temperature should begin at least 48 hours prior to chick and poult placement to ensure proper litter temperature and litter curing. Use a meat thermometer to monitor litter core temperatures.
Chicks and poults should be active when placed, well spread out and eating out of the feed pans and feeder lids. Birds that huddle, congregate under the brooders, avoid brooders completely or only sit in the feed without eating are not comfortable. Sometimes it only takes an additional degree of floor heat to drop the relative humidity below the breakpoint for litter caking and clostridial growth, and to make birds comfortable so that they eat more.
Benefits of Litter Acidification
Litter ecology is the dominant factor in the development of gut health, especially in ABF operations. Because built-up litter has a litter ecology dominated by normal, healthy poultry microflora, newly hatched birds are able to populate their gut more quickly and establish a more stable gut flora when placed on re-used litter, reducing the likelihood necrotic enteritis.
Acidifying the litter with a stable acid shifts microbial litter ecology to one that is more favorable to normal gut flora in the litter. Applying a litter acidifier to the dirt pad at cleanout and on top of the litter prior to chick placement will keep the litter pH in a low range that prevents pathogen growth and toxin production.
As a poultry grower, your responsibility in making ABF programs work is to ensure chicks are as comfortable and active as possible, and to keep cocci and clostridium from overgrowing. Starting birds off on a warm floor at the proper floor/core temperature and relative humidity with litter at a low pH will help you to do just that.
As consumer scrutiny forces producers to be more vigilant in the growing process, Jones-Hamilton field staff can offer support in the development of a comprehensive litter management program that meets ABF requirements and animal welfare demands.