Practical Management to Reduce Heat Stress in Farm Animals PDF

The practical management to reduce heat stress effcts By Assistance prof.Dr.Majid Al- saadi Veterinary public health Undergraduate study Second stage  The Effects of heat stress on gastrointestinal tract One of the major organs affected by hea...

The practical management to reduce heat stress effcts By Assistance prof.Dr.Majid Al- saadi Veterinary public health Undergraduate study Second stage  The Effects of heat stress on gastrointestinal tract One of the major organs affected by heat stress is the gastrointestinal tract. In ruminants, the effects on barrier function can be explained by: 1. the reduced feed intake during heat stress, 2. the effect of releasing different proteins ( heat shock proteins) 3. releasing inflammation mediators (cytokines) on the tissue itself. The rumen epithelium is essential for several physiological functions, including nutrient absorption and transportion , short- chain fatty acid metabolism and ((barrier protection)). Any disruption of the rumen and intestine barrier can lead to the translocation of toxins ( endotoxins, mycotoxins) and unwanted metabolites (biogenic amines such as histamine) into the blood circulation. Overview about the rumen as well as intestinal epithelium. The rumen epithelial consist of four different cell layers, while the intestinal epithelium has only one cell layer.  What are the sources of Endotoxins? Endotoxins, are a lipopolysaccharides (LPS), a part of the outer membrane of the cell wall of Gram-negative bacteria. The lipid A part is the toxic part of LPS. Endotoxins are released during lysis of bacteria. ((Since an animal’s microflora contain Gram-negative bacteria, endotoxins are always present in the rumen)). Overview of the structure of LPS: Polysaccharide (O-Antigen and Core oligosaccharide) and the toxic lipid A part. Overview of the location of LPS: Polysaccharide on the cell wall of gram negative bacteria Different temperature ranges can affect cow health.* Equivalent Temperature Index for Cattle Heat stress Temperature Mild 23°C ≤ 26°C Moderate 26°C≤ 31°C Severe 31°C ≤ 37°C Emergency ≥ 37°C  heat stress:cause sub-acute rumen acidosis (SARA), which can lead to a massive increase of the endotoxins concentration. ((In healthy animals)) the barrier prevents endotoxins to enter the circulation. But if this barrier is impaired due to heat stress, endotoxins can reach the blood circulation and cause a strong inflammatory response. This response is due to releasing : 1. Cytokines(histamines ) 2. acute phase proteins ( haptoglobin) heat shock proteins 3. LPS-binding protein.(endotoxins) This acute response consumes a lot of energy, which the animal cannot use anymore for growth or milk production, or to reproductive performance The practical management to reduce heat stresse effects Nutritional system in Hot weather First: the water consumption Water acquire a great importance in case of a rise in temperature, and we must take the following steps: 1. Clean fresh water should be provided to animals in suitable quantities 2. It is preferable to give it as cold water to soothing , stimulating and helps to cool the cows and improve their consumption to feed 3. Stripes must placed in a suitable level for the animals with shaded places, and must be taken in cleaning drams, with suitable numbers for each group of animals. 4. Water tanks are made of insulating materials and putting under umbrellas to avoid exposure to direct sunlight Second: the Feedstuff In hot weather, The amount of energy is the determinant of the amount of feed consumed by animals as a results of heat stress which will lead to reduced in feed consumption, and this leading to malnutrition, so we must take into account the following steps: 1. Diet should be of good feedstuffs, rich in energy, protein, vitamins, mineral elements. 2. Increasing of energy , protein and fibers in the diet can be done only by increasing the concentrated feed. 3. Adding fat to the diet is an excellent way to increase energy content, but should not exceed than 5-6% of the dry matter. Oily seeds such as whole soya cotton seeds are very good sources of oil and protein in diet together. 4. It is necessary to take great importance to the protein that animals needed ,On the other hand we should not give the animal an excessive amount of protein because the axes of it will be metabolized and excreted in urine without benefit. Researcher had found that the protein content in Hot weather must not exceed than 17%. 5. Providing fiber in diets it is necessary for the normal digestive functioning of the rumen. 6. take into account the addition of mineral elements and vitamins , especially sodium, potassium, magnesium and vitamin C, A, Other Practical management for reduce heat stress 1. The first way to help animal is secure the appropriate shade, and shading works to lowers the body temperature and respiratory rate and increases feed consumption. 2. designing the roof of animal houses is high with a gradual slope to stimulate air flow and to reduce the transfer of thermal from the roof to the animals. 3. building must be designing to avoid and to reduce the entry of sunlight into the animal houses. 4. fans with Sprinkle water must be using to moisturize and evaporate the animal’s surfaces, to reducing the heat of their bodies. 5. fans and sprinklers are Usually , installed above the feed tools , to become the coldest place in the animal houses , to helped increase feed consumption. 6. Animal must be provide with sufficient areas for feeding and drinking ,And voiding the crowded of animals around the barns, 7. animals must be provided with sufficient amount of non concentrated feedstuff like hay of barley and sweet clover hay 8. Increasing the numbers of food intake with small quantities for many times. 9. avoiding high feed temperature due to exposure to direct sunlight's or high temperature air 10. avoid spoilage exposure to the proliferation of flies and avoid feed infected with external parasites on in order to prevent disturbed animals as additional factors to heat stress 11. increase in the quantities of food provided in the cold periods of the day especially (early morning, late evening) 12. Must be separation of small animals from large and pregnant females from the rest of the herd, as well as providing feed for each breed separately 13. The necessary to transactions for the grains before serving them, such as crushing or grinding, taking into account the complete mixing of these foodstuffs before serving them to animals  Posters for more details about the practical managements to reducing heat stress in some farm animals