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Early Management Sets Flock Performance

by 5m Editor
26 February 2007, at 12:00am

Edgar O. Oviedo-Rondón. DVM, PhD., Dipl. ACPV., Extension Broiler Specialist. Mike J. Wineland, PhD., Extension Broiler Breeder and Hatchery Specialist. North Carolina State University

The brooding phase is the most important stage in the life of chickens and turkeys. During this early period the ability to self regulate body temperature is not completely functional. The immune system, digestive system, muscles and bones are developing at rapid rates. Any reduced development or damage incurred during these first days may not show in performance until later in life. Typical results of improper brooding practices are poor livability and flock uniformity, ascites, flip overs, heart attacks, leg problems, depressed body weights, poor feed conversion and increased processing plant condemnations. If any of the previous problems are reducing your final payment, please place more attention to your brooding practices. One can achieve significant improvements with slight adjustments to ones brooding practices.

The poultry business is getting more competitive and profits in live production are found in paying attention to the small details. Several factors are necessary for good brooding. Three important ones are providing adequate brooding temperature, air quality and easy access to water and feed for the entire flock. This is not as easy as it sounds, since broiler and turkey flocks are a variable population of birds. Variations in hatchlings’ body weights of more than 5 grams indicate that you have different birds with different environmental needs for optimum growth. Optimal conditions for a flock vary according to the breed, and age of the breeder flocks, season of the year, hatchery temperatures, transportation conditions from the hatchery to the farm, and the type of brooding equipment to name a few. Recently, it has been suggested that recommended temperatures are needed to avoid poor performance. But to obtain the best performance of every flock requires some art and science that each grower must develop and apply to individual houses.

It is essential to provide the optimum temperature for the chick’s comfort. Chick body temperature help gauge proper temperatures. Rectal temperatures of 104 to 105oF are normal physiological temperatures that we need to maintain during the first week. Rectal chick temperature will rise to 105 or 106oF after 5 days of age. Higher body temperatures during the first week are detrimental and should be avoided. Rectal temperatures are indicators of effective temperature which is dependent upon environmental temperature (dry bulb), relative humidity and air speed.

Litter temperature is different than the air temperature which is measured at chick height. Litter temperature creates the comfort zone for the chicks, not the air temperature. You can obtain optimal body temperatures with good house preheating and litter temperatures of 90 to 92oF for the first day. Growers with low early mortality and excellent results normally keep litter temperature, measured one inch into the litter, higher than 82oF during the first week. Properly calibrated infrared thermometers can help you to determine those litter temperatures.

Adjusting temperatures to obtain proper air and litter temperatures change according to the type of brooders that you have. Forced air furnaces require higher temperature settings because they heat the air which in turn heats the floor. A conventional pancake brooder directs approximately 40% of its heat to the floor and 60% to the air. Radiant brooders project approximately 90% of their heat to the floor and 10% to the air. Since pancake and radiant brooders direct heat to the floor, the air temperature required to get the desired floor temperature is lower than that required for forced air furnaces. Proper placement of sensors/thermostats are important. They should not be too close to a brooder or too low to the ground where birds can crowd around the sensors and give a false high temperature. They should also not be too close to the side wall, brood curtain or where air is entering the house. Remember that used litter produces some heat due to the bacterial activity. Dry conditions (less than 35% relative humidity) allow for a lower effective temperature. However, for optimum flock performance, keeping the relative humidity in the brooding zone between 60 and 70% is desired. Higher temperatures can give you lower firstweek mortality, because it favors the survival of small chicks, but it can also reduce your final flock performance and profitability due to heat stress of the larger baby-chicks as well as increase gas usage. These differences will be magnified when you are growing heavy birds (> 6 lbs).

Try to keep house temperatures constant, daily variations of ± 5oF are normal. Sometimes, growers trying to maintain temperature and also be more efficient in gas usage, reduce ventilation and consequently the air quality. High ammonia (> 20 ppm) and carbon dioxide (> 3000 ppm – 0.3%) are as bad as low temperatures for chicks and poults. Use litter amendments to reduce ammonia production of used litter. Brooders that are too near to the ground can reduce the oxygen concentration to 16 or 17%, normally it is 20.9%. Make sure your minimum ventilation system works at least one minute out of every five. The inlet system should react to the fan capacity and maintain the same static pressure in the house regardless of the number of fans in operation. Insufficient inlet area leads to reduced air volume while excessive inlet area leads to air falling quickly and onto the birds. Inlets should direct air into the peak of the house, allowing time for mixing and warming before the fresh air reaches the birds.

Water quality is very important, and attention to proper water sanitation during the first week can reduce early mortality of chicks and poults. Water line cleaning and sanitation including full flushing should be performed after every flock. Additionally, you should conduct regular maintenance on the water lines. Dirty triggers can either stick open or closed, worn out triggers will fail to seal and create problems of wet litter. Proper water filtration and sanitation is critical during the first week. Day old chicks can not trigger the nipples at the pressure used for 6-week broilers (60 ml – 2 oz/minute). It is important that you adjust the water pressure from the previous flock every time. The rule of thumb is that nipple drinker lines should have a flow rate of 20 ml (0.70 oz)/minute during the first week. It is important to offer supplemental water in babychick drinkers even with excellent drinker lines. The nipple or drinker height during the first two days should be at eye level. Nipple types with poor side activation need to be slightly higher. Later at 3-5 days of age, chicks should stretch their necks to drink. Water temperature in cups or nipple is important to maintain body temperature. One should try to maintain water temperature around 78oF the first three days. Water temperatures lower than 70oF during the first week can increase early mortality.

It is important to stimulate feed intake during the first week and especially during the first hours. You want a minimum of 95% of your birds to have feed in their crops four hours after arrival. Walk birds to keep them moving and moving to the feed. Place fresh feed first thing in the morning and two or three times per day, even if feed is still on the paper, lids or pans. Use sufficient feeder lids and/or feeder space. If the feeders are constantly full of chicks, it indicates that there is insufficient feed space available. It is important to keep track of the amount of feed consumed during the first week or the time it takes to consume the starter feed. Flocks that eat 1.5 lbs of starter feed in less than 16 days have the best feed conversions, uniformities and body weights. One should use minimum light intensities of 2.5 foot-candles (25 lux) in the brooding area measured at chick level during the first week to stimulate feed intake.

You can improve your chances to obtain the best results possible for each flock by paying attention to details to improve flock uniformity and reduced mortality during the first week. The target body weight at the end of the first week is four times the initial average body weight. However, obtaining average body weights of more than five times the initial chick-weight is correlated with elevated late mortality and increased culling of broilers due to leg problems.

February 2007

Reproduced Courtesy