Reduction of bird heat stress. M. Czarick (University of Georgia)
Published:April 19, 2012
Dr. Mike Czarick, Senior Public Service Associate at University of Georgia, discusses the principles of keeping birds cold during hot weather during the XXII Latin American Poultry Congress, August 2011.
The time of offering the feed to bird is also important. As the heat production from feed digestion and metabolism will reach the maximum level 3.5 to 4 hours after feed consumption, it will be better don't offer the feed to birds 4 hours before environmental maximum temperature. Using darkness during the hotest hours of day also could help.
Dear colleagues
Many thanks for the comments. We have to change the photoperiodic regimn during heat stress. By putting lights off during peak heat stress(10am-4pm), the birds will not consume feed and then their heat production decline dramatically.
Beside all above remedies, practically tested method of reducing body temperature of birds is to give shower with water spray pressure pump. This is similar assistance that bird is seeking to release its body temp, one can observed close to water reservoirs when wild birds taking bath by dipping their head and throwing water on their body hence cooling down body temp. In my observation broiler breeder kept in cages in poultry house temp 30 C and RH 85 %, swearly panting, air speed noted 700 ft per minute, desert cooling system not assisting birds to cool down in middle of the day. Noted surface temp of comb and wattles was 33-34 C after spraying water, first thing noted was closing of beaks, painting gone, comb and wattles temp reduced to 27 C within 40 second and remain low for 10-20 mints in presence of 700 ft per mint air speed. Body feathers remain wet for more than 30 minutes and panting restored after one hour or more. For whole day water bath repeated 5 to 6 times a day when house temp goes > 28 C. It also increases RH 2% which is obvious but not harms the birds due to high air speed in presence of water bath which gives instant cooling to birds body. This observation has done at stage when birds consuming 475 kcal ME energy per day and producing 87% prod kept in cage on 0.72 sft space per bird having 3 birds in a cage. Weekly mort not more than 0.25% during hot wave days. Peak prod remain persistant for > 13 weeks. Overall flock performed better than breed (Habbard) standard. Eggs gathered before each bath to avoid egg wetning. Similar activity done on floor birds with adjustable spray gun to avoid litter dampness.
I reinforce the comment of Dr. Charles Ibe, together with all alternatives used to reduce heat stress effect, we should not forget the water temperature, that usually becomes high at high environmental temperature. When we talk about water temperature, at hot environment cooler the better. How many farms are cooling sistematicaly the water for the broilers?
Dear all,
Thank you for all your contributions. Just like Dr. Ibe said, here in Nigeria, it has been found that the brown and black birds are more susceptible when compared with white birds. During the hot months, around which the shed temperatures usually exceed 30 degree Celsius, the mortality starts going up. In most of the farms I consult for, many of which are using fans and water foggers, still have persistently high mortality during this hot period even after using salt, bicarbonate as well as ammonium chloride. Most of these mortality are due to prolapse and vent pecking, and the mortality drops once the ambient temperature drops and or when the humidity drops.
So for now, I am yet to see any strategy/treatment that can best be adopted to address heat stress in caged layers, especially in humid tropical region like Nigeria.
I am open to suggestions from anyone that has successfully managed heat stress in this type of region with heavy brown or black birds raised in cages.
Thanks
OLAYINKA AYANYEMI
Interestingly, the current problem facing Nigeria poultry industry has prompted me study an alternative ventulation system that is not expensive and more effective in relieving poultry birds of heat stress in the humid climate. I am looking forward to sharing my ideas as soon as the study is completed. One thing is sure and that is, if the system is integrated into poultry houses, there will be significant reduction in the mortality in poultry production.
Cheers
OLAYINKA AYANYEMI thanks for your contributions.
The hot season happens to be a seriously problematic and mortality season in Nigeria.
At my end, we try also to reduce the build up of the DEEP BODY TEMPERATURE (DBT) inside the shed. This is in addition to ventilation control mechanisms already in place inside each shed. Yet, the heat stress is noticed during PM exerrmination.
Thanks.
OLAYINKA AYANYEMI if you notice the birds affected most are the heavier sized ones. This makes it easier for you. At the onset of heat stress which you can read ten days ahead using MSN weather forecast . All you need to have is a decongesting pen. For those in 4 per cell . Reduce them to 2 per cell. those in 5 per cell reduce them to 3 per cell. Have a holden deep litter pen to hold the decongesters which includes the heavier size birds. Allow them to run around in deep litters for throughout the heat stress period in Northern Nigeria which is from Middle February to early May. For those remaining in cages foggers and cold drinking water wil help the a lot including Vitamin C and betaine. Jos area is best area in Nigeria to site open sided poultry farms because of low temperatures throughout the year.
Another strategy is to use white birds that can reflect heat. Rather white light breeds that can start laying at 1.4 Kg instead of heavier breed that can lay at 1.8kg. I am adapting lighter white breed in Kaduna that is close to you in Abuja. I guess you know me. You can put a call to me. Your weather forecast should be one of the key tools that will assist you to readjust your strategy. Other strategies are using oil for energy or reduce your energy diet during the heat period. Dr Charles C Ibe DVM FCVSN(avian medicine) Poultry Health Consultant
The effectiveness of fans at inducing wind-chill comfort for birds depends a lot on the speed that the air is reaching the birds.
The speed of the air is reduced by obstructions and the material of the cages may be reducing the speed of the air reaching the birds.
In cages the birds are in a line and they may be blocking the ones downwind themselves.
Between these two types of obstruction the air speed may be considerably reduced
I am in Grenada where the climate is similar and the layers are not caged and the poultry houses are simple with netting sides with no fans.
As the birds are free to move around they may not be obstructing each other from the natural air flow and there is a minimum of other obstructions.
Freeing your birds from cages for this reason may make life a lot more comfortable for them.
About 20% of the cages could be converted to nesting boxes for egg-laying and the remainder removed.
This may be worth trying.
Generally, the cage rows and air movement are parallel. The air moves freely in the passages. There might be a mistake in positioning the fans or calculating the number of fans and pad area required. The deep litter houses are easy to manage for cooling because the height of the houses also is low and the air volume can be effectively managed. Of course, free moving birds choose the area of their comfort and move around.
if practicing heat acclimation during brooding and pullet period may helping birds encounter the heat stress and to plan to raise bird in the hot period such as low birds density, low market weight, less activity in the house and maintenance the ventilation system
heat stress is a common issue with the tropical climates the following are the effective ways
- use of electrolytes particularly the vit C along with soda bi carb can help
- use of more ventilation along with water spray is more effective even with high humidity the spray of water on birds helps to reduce mortality but often leads to more culls
- the best to reduce mortality by 20-40% is to give midnight drinking that is switch on the lights for more than half an hour during midnight just birds to drink cool water if possible or the fresh water it helps a lot
- nutritional modifications can help use of more fat as energy source use of more enzymes . enzymes can help a lot it can help
- there is no complete solution but better would be more better housing system with proper insulation can help a lot
- in poultry we had to comb the purposeine all the efforts single one would not serve
as already in many of the comments noted, in challenging conditions, especially heat stress, there is no single product able to serve as the optimum solution. Besides nutrition, all other factors need to been considered: biosecurity, cooling systems/ methods, ventilation, bedding materials, water quality and availability, stocking density...etc. From a nutritional point of view, the higher the challenges, the higher the demand is on methyl groups. I completely agree with and with Dr. Fiodor S. Marchenkov, betaine is a proven nutritional aid. As a multi-functional nutrient, betaine is acting as an efficient methyl group donor and as an organic osmolyte, with direct influence on the gastrointestinal tract (GIT) and health. In heat stress conditions, the mineral and water balance might be disturbed and the cell wall integrity potentially damaged and the osmoregulatory responses are highly energy consuming processes. Betaine can improve the litter quality by reducing the litter’s moisture content and can reduce the wet litter related problems. Furthermore is involved in the energy metabolism, can reduce the energy required for the osmoregulation. Additionally, has further potential benefits like lowering carcass fat content and increasing breast meat yield, has a significant role in hepatic protection and it is a source of glycine, relevant in low protein diets. Glycine is one of the amino acids present in the bile salts and one of its functions is to produce uric acid to eliminate the excess of nitrogen from the body via the urine. All positive effects of betaine are dosage responding and in hot climatic conditions, betaine shouldn’t be applied in order to save methionine. It needs to be added “on top” at a level of min. 1000 mg (active betaine)/ kg of complete feed. In such conditions is nothing to be “saved”; all vitamin levels should be increased min. 10%, Vit. C at the level of 200 mg/ kg of finished feed, sodium bicarbonate is beneficial of course and all measures together will help to have less medication costs, less mortality and better production efficiency in heat stress conditions.
Sincerely, Ana Gavrau, Product Manager, AGRANA Stärke GmbH.
Gentlemen, Great valuable comments in this article. We do support Betaine usage as an osmolyte to help regulate body temperature, together with and increased oil content in the diet. The combination of betaine and other osmolytes, associated with liver protector gives excellent results, maintaining feed intake and reducing mortality. Let me know in case anyone needs further details. Thanks to all.
Heat stress effects can be substantially mitigated through the addition of betaine HCl and betaine in the diets or drinking water. This strategy has been broadly adopted and effectively used in markets with significant heat stress issues. Betaines work in a fundamentally different mechanism from VC, increasing cellular water retention capacity and decreasing endogenous heat generation. For more information, please msg me at jstuan@sunwincn.com.
Thanks Ana Gavarau for your highly detailed and informative contribution.
Also appreciating Kapil Manwal for showing interest in our situation. As for the cage type, we have both the "A" and "H" type cages with some of the pen houses having 2-, 3- and 4-rows. We are also using exhaust fans for ventilation.
Many Thanks
I have a good experience with Xtract regarding heat stress. Because of the natural healthy properties of protectors, some naturally occurring ingredients from plants and spices can protect animals from heat stress and help breeders minimize the economic impact of such extreme conditions.
It is excellent presentation for understanding control of heat stress through better management of ventilation. Further we need to properly maintain the functioning of evaporative cooling pads & Fans so that they perform as per capacity designed. Choked pads & dirty fans will reduce efficiency of ventilation.
Vit C, Sodium bicarbonate, Betain etc are additional tools to manage heat stress. Again better ventilation has much greater impact (greater than 80% impact).
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