At first glance, a broiler farm may appear to run smoothly, but what happens when antibiotics are reduced or removed from production practices? Drops in flock performance are often a sign that antimicrobials have been covering up farm management issues. 

Tactical farm management practices can help to address the issues arising during four key broiler production stages, supporting consistent performance and defending against the challenges of producing without antimicrobials.

Preparing for chicks’ arrival

Hygiene and biosecurity are essential across all phases of a bird’s life but are critical for vulnerable new chicks. Chicks do not achieve full immunity until about 14 days of age, arriving on the farm with immature immune systems.

All-in-all-out (AIAO) production is mandatory and the first line of defense against pathogens. Fencing, maintaining a visitor log and requiring clothing/boot changes between houses are other fundamental biosecurity measures.

Chicks’ first point of farm contact is the poultry house floor, so begin with a clean, smooth surface. Clean the poultry house floor with detergent and water between each flock. Next, fill any floor cracks with a hygiene aid containing select organic acids to prevent Salmonella and other harmful bacteria from taking hold and growing into the litter. A solution of detergent and hot water will also remove debris adhering to barn walls, drinkers, nipples and feeding lines.

As part of the house cleaning process, air inlets and mesh filters should be inspected to ensure they are clean and free of dust and an air exchange just before chicks arrive will further support ventilation.

Biofilm in waterlines can be dislodged by adding hydrogen peroxide or a 30% chlorine solution for 24 hours before flushing. Pathogen risk and biofilm in feed lines can be reduced by combining specific blends of organic acids with coarse raw materials, such as oat hulls, and leaving the mixture in lines for a day.

Drinking water should be 77◦F or cooler and its quality assessed with regular sample quality analysis in a laboratory. Adding blends of buffered acids can deliver the added benefit of supporting birds’ gut health and digestive processes.

Make sure the floor is warm for incoming chicks. Preheat the floor to 82◦F - 86◦F prior to applying 1-1.5 kg litter per square meter.

Finally, consider optimal indoor climate conditions for new chicks. A temperature of about 95◦F is ideal.

Add 15 grams of fresh feed per broiler to one line of feed paper running to each water line. With these steps taken, conditions are right for the chicks’ arrival.

Brooding: Assure chick quality

During the first 14 days of life chicks grow rapidly but growth is heavily influenced by chick quality.

Inspect chicks’ condition upon arrival to assess body temperature and weight. Their body temperature should be about 104◦F but may have dropped during transport from hatchery to farm. Continue to check chicks’ temperatures every few hours and incrementally raise the house temperature if birds are cold.

Birds’ behavior will also indicate temperature issues. Huddling together may suggest birds are cold, while moving away from each other may indicate they are too hot. Persistent cries also suggest an issue.

Regarding body weight, a general guideline is that a chick should achieve 4-4.5 times its hatching weight by the end of its first week of life. A good measure for a bird weighing 40 grams at hatching is 180 grams by one week of age. 



Monitoring chick behavior can reveal if environmental conditions need to be adjusted.  Oliver Foerstner  |

To support ventilation throughout the poultry house, air inlets in the house should be adjusted to allow sufficient airspeed and mass. Generally, a 1”-1.5” or 3-4 cm inlet opening will allow incoming air to move upward into the high, upper parts of the house where it can be warmed before slowly descending onto flocks.

Proper ventilation requires delicate adjustments to inlet openings to achieve proper airspeed and mass. During the first few days, this process should be conducted manually and not entrusted to a computerized system. Later, it is possible to use a system to input the minimum number of cubic meters per minute to ventilate and birds’ weight to inform ventilation settings.

Grow-out: Manage growth rate

Referencing growth charts helps assure birds are growing at the proper rate. Genetic enhancements can result in birds growing too quickly, resulting in undue stress on the skeleton. Dimming the lights to 5-10 LUX can help to slow the growth rate; however, dark periods should be limited to four hours as an empty gut stresses a bird’s system.

Inspect droppings twice daily during the grow-out phase to assess gut health. Look for well-digested droppings that are dark brown to black in color and free from particles. Foamy, yellow droppings suggest that protein is not being fully digested. While many factors can affect dropping quality, water is usually a chief suspect as it provides an easy medium for bacteria to grow.

Adding vitamins to drinking water should be avoided. While specific instances may occasionally support the use of vitamins in water (see below), in general, vitamins provide a food source for pathogens to grow in water. Adding a blend of free organic acids can reduce the pH of water, making it harder for bacteria to grow and helping to support feed digestion through a stable microbiota.   

Broilers’ high metabolism makes them susceptible to heat stress and added mortality risk during hot weather. Evaporative cooling can help to address this. Inspect ventilators to make sure they are operating properly and dragging sufficient air across the house to help cool birds.

Thinning out: Protect your investment

As slaughter time approaches, a customary practice is to begin thinning poultry house flocks by about 25-30%. This practice, however, can present biosecurity risks as new visitors enter the house to remove birds and cold air enters through open doors.

Hanging thick plastic sheets in door openings can decrease air infiltration. Enforcing biosecurity measures on all those entering the poultry house also reduces pathogen risk. Finally, producers may consider adding vitamins to drinking water during this phase, but never for more than two or three hours.

Typically, opportunities to adapt basic farm infrastructure – for example, house design - are limited, but when building new poultry housing, consider how the roof design may affect ventilation and relate to the climate. 

In cooler climates, design a house with a cathedral-style roof at a 35 or 45-degree angle, as opposed to a flat roof. In contrast, poultry houses in hot climates are better served by a flat, low ceiling which allows air that has already reached brooding temperature to move quickly through the house.

Implementing tactical farm management practices can help producers achieve high-performing flocks, cycle after production cycle. The results are visible through performance and health metrics, but also expressed in the words of poultry farmers. Says one farmer: “If you pay attention to farm management practices, you will be amazed at what these birds can do, all without antimicrobials.”


Particular care to biosecurity needs to be taken when thinning out. C.Lotongkum |