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.
We have a broiler farm using tunnel ventilation and evaporative cooling system. We operate fans and air speed according to the age and inner climate conditions. We belive that the enthalpy in the house which counts at the end of the day. The birds do not suffer from heat stress if all climate parameters under control.
Our company have around 45 farms through out Pakistan having different climatic condition.
We have three major thing in mind. Temperature, humidity, & density of birds according to the age. 1-Temperature according to age we can maintain through wind speed, Cooling pads thickness, number of pads according to requirement & flute angle of pas 45x45 or 45x15, water flow on cooling pads. 2- High Humidity in coastal areas. Here the temperature is important but most important is exchange of total air volume of house as soon as possible that 0.5 to 0,minutes. As if the out side humidity is 80% inside the humidity will be very high.so, we need to expel this air as soon as possible as early you remove the air birds will be comfortable. Density. In hot & humid areas density of birds play very important roll in these area we have to increase the space per bird at a maximum level it will reduce the temperature as.well as humidity it will reduce the panting & suffocation.It is a very wide subject we can discuss it one by one some other time.Now there are so many types of environmental control devices even you can feed int the whole life of birds environmental requirement it will control according to birds requirement automatically.
It is a nice knowledgeable presentation on control of heat stress. Ref. to Dr. Danny Hooge's article on the same subject, use of 0.4 to 0.5% Sodium Bicarbonate. (NaHCo3) in feed can be helpful to control the Respiratory Alkalosis and reduce the losses during high heat time. I have applied this recommendation in many farms of broilers, particularly naturally ventilated houses and got good results. Kindly let me know your opinion on this issue, in addition to your recommendations on managemental factors.
Best regards, Dr. M. Akram, Consultant Microbiologist, Micro Lab. Karachi Pakistan.
Dr. Mohammad Akram
Hi, your recommendation is Ok.. The research I just concluded two months ago using naturally well ventilated houses gave a very good result. I strongly support your recommendations.
Warmest regards, Nwose Roseline Bwuguru, Animal Nutrition and Forage Science (FUNAI) Ebnyi State, Nigeria.
Dr zeeshan awan what about the osmoprotection with betaine? weight gain -this is the result of methionine sparring; can replace 15-20% dietary Meth. I usually advice betaine as osmoregulator for heat stress period.
Dear Dr.Zeeshan, betaine is natural osmolyte substance. It hold the water inside the cells. Paralelly betaine reduced fat content and increased meat content in broilers. Saudi Arabia poultry farms use betain against heat stress in high doses, till 2 kg/tonn of feed, according to recommendations of Danisco Animal Nutrition/DuPont Biotechnologies. Of course, other methods against heat stress, like sodium bicarbonate and vitamin C is reason to run paralelly, for better results. And effective ventilation/humidity, to reduce temperature, too.
Dr. Fiodor S. Marchenko
Betaine quality matters in Asian Markets as most of the farmers are not educated and prefers cost comparing as cheap China products are on shelves . Difference between Betaine if any should be highlighted
Dear Goh Geng Hua ,
I was refering on natural betaine, from sugar beet molasses.
The main differences, between natural and synthetic betaine are the content on chloride (Cl) and on trimethylamines (TMA). High Cl levels have negative impact on the osmolytic function of betaine, and high TMA levels can confer a "fishy-taint" to the end-products. Furthermore, EFSA recognized high TMA levels as being corrosive to the eye, to the skin, and irritant to the respiratory tract (published in the EFSA Journal 2012). Therefore can lead to discomfort which can affect directly the production efficiency. I can only advise you to check the TMA level in your Betaine HCl product, this shouldn’t exceed 200ppm/ kg.
Thank you for all valuable information, thank you Dr. Mike Czarick for the very interesting and informative video presentation, and for the feedbacks on my contribution.
Thanks my colleagues for your valuable information and I suggest that you can use Vitamin C in water and using cold water also at same time in open houses beside soudium bicarbonate in feed. In broilers, you have to remove the feed during hot hours (almost from 10 am to 4 pm) to reduce bird’s stress due to heat increment (due to digestion and metabolism).
S A Elsafty
Prof. of Poultry Production Ain Shams Univ.
Emad Elgazzar WHY DECREASE OIL CONTENT?
Oils have a lower Heat Increment than both proteins and carbohydrates. They also facilitate production of a denser ration, which can compensate for reduced feed intake.
Heat stress results in respiratory alkalosis leading to excessive loss of Carbon dioxide due to open mouth breathing. CO2 released comes from two sources 1) breakdown of Carbonic acid and 2) Oxidation of simple sugar (glucose). Carbonic acid breakdown can be compensated with addition of Sodi bicarb. Dietary electrolyte balancing will involve optimal addition of salt so that value for Sodium and Chloride correspond the Potassium balance. DEB should be within 170 -250. Protein catabolism will result in more serious effect, therefore, reduce CP % by 0.5-1%. Addition of Vit C with osmoregulator will reduce dehydration provided there is continuous cool drinking water supply.
apart from adittion of Vitamin C, and bicarbonate already mentioned, it is important birds affected by heat stress don't dehydrate and restore the electrolytic balance.
This can be done with the addition in water also of Betaine combined with electrolytes. By this way as betaine is an osmolyte, we can increase water consumption with electrolytes but at the same time retaining water in the animal.
Is is also a good option.
Thank you so much gentlemen for all your comments and contributions to reduce heat stress on broilers especially during summer time. Indeed, i find your recommendations helpful and will definitely, result to better health of the broilers and better percentage of harvest recovery.
Again, my profound thanks.
Heat stress term has been using when the environmental temperature reached up to 28 C. However, some researchers claimed that the environmental temperature lower than 25 C in night and poultry consume enough feed the effects of heat stress may compensate, in contrast to this daytime and night, high temperature may cause heat stress. Some research results also showed that in the hatchery and early life of chicks exposed to a high temperature they may increase the ability to stand to heat stress. Nowadays, broilers growing very fast in a short period about 38 to 42 d. Therefore for broilers, low feed consumption due to heat stress is very important to reach a good BWG for the market. However, laying hens and turkey poults more resistant against to heat stress. Vitamin C in feed and water commonly using for heat stress. However, there are many researches, if no real heat stress, vit C addition to diets is not working and no effectiveness. We should know animals exposure up to 28 C whole day and frequent breathing, low feed consumption and other behaviors.
We should consider heat stress and humidity too. In high humidity together high temperature the animal performance and mortality will increase.
You are right but in some areas of Pakistan, we can only reduce the temperature to 29-30 C with maximum possible ventilation. In this situation, we have to look for the alternatives to combat heat stress.
Under respiratory alkalosis, there is poor calcium metabolism leading to poor shell formation. The best way to tackle heat stress is to apply cooling strategies like cold water during the heat hours and external cooling effect like fans, water foggers etc. Betaine, Bicarbonates and Vitamin C works within thermoneutral zone. ExternalTemperatures above thermoneutral zones leads to deaths. Decongesting the birds help a lot. Broilers in cages and deep litters are worst hit. Commercial layers survive best in deep litters than in cages. The only problem they have is low performance because of low feed consumption. Here I suggest a deep litter decongesting pen during the heat months. In Nigeria, heat period are from late February to middle May. White coloured layers better survive heat stress. Brown and black heavyweight layers are vulnerable. Black ones are worst vulnerable. The best is the light breed of layers especially the white ones.