Summer stress management in livestock
Dr. Sahil Thakur
MVSc. (Animal Nutrition)
Dairy farm incharge (Field Veterinarian)
sahilthakur4182@gmail.com —– 9418289089
Abstract: Livestock plays an important role in the global economy. Climate change effects are not only limited to crop production, but also affect livestock production, Furthermore, multiple stressors are a common phenomenon in many environments, and are likely to increase due to climate change. Among these stresses, summer stress appears to be the major factor which negatively influences livestock production. An imbalance between metabolic heat production inside the animal body and its dissipation to the surroundings results to heat stress (HS) under high air temperature and humid climates (summer season). The foremost reaction of animals under thermal weather is increases in respiration rate, rectal temperature and heart rate. It directly affects feed intake thereby, reduces growth rate, milk yield, reproductive performance, and even death in extreme cases. Summer stress suppresses the immune and endocrine system thereby enhances susceptibility of an animal to various diseases. Hence, sustainable dairy farming remains a vast challenge in these changing climatic conditions globally.
https://www.pashudhanpraharee.com/summer-stress-management-in-livestock-3/
Introduction: Heat stress happen when the combination of environmental temperature, relative humidity, solar radiation and air movement cause the temperature of the animals to exceed its zone of thermo neutrality. Heat stress is primarily by high air temperature, but intensified by high humidity, thermal radiation and low air movement.
Impact of summer stress and its signs:
Armstrong (1994) reported following responses:
- Decreases feed intake
- Increase water intake
- Change in metabolic rate
- Increased evaporative loss
- Changes in blood hormones concentrations
- Increased body temperature
- Increased respiration rate or Panting is first sign of heat stress (>70/min). It damages the acid base balance as well as calcium homeostasis, this leads to increased incidence of hypocalcaemia and milk fever.
- Dry matter intake reduces, depending on the severity of heat stress may be reduced by 8-12% or more, because reduces blood flow to the rumen and intestines, to avoid increased heat production from feed digestion, increased water intakes that fill the stomach (Saini and Chandrahas, 2013).
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Management of heat stress:
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- Wallowing tanks: It is theeconomical and least laborious device to beat the heat in summer. Buffaloes are made to wallow in clusters in ponds, rivers, tanks or other water bodies for hours together. Wallowing is an main route of heat loss in view of the labile body temperature which permit the animal to store body temperature. Wallowing in animals is a comfortable behaviour during which an animal rolls its body about in sludge, water.
- Foggers: Foggers disperse very fine fine droplets of water which rapidly evaporate and cool the surrounding air, while raising the relative humidity. A fogger system is effective in areas with low humidity and is not recommended in humid climates.
- Misters: These are rings made of ¾” pipe which has misting nozzles. This misting ring has to be fix to an oscillating fan and join to the direct motor water pipeline. This creates good cooling effect inside the shed and is economical than fogging system. This does not work well in humid environments because the mist droplets are too big to evaporate before they arrive the floor and the bed or feed becomes wet.
- Sprinklers: Sprinkler cooling is a process whereby water droplets are applied to wet the animals hair coat to the skin, and fans are used to force dry the animal. In combination with forced air, sprinkling increases the loss of body heat over that possible by sweating alone (Nagpal etal., 2005).
- Fans: High velocity blast fans are to be mounted on sidewalls or top of the wall can help in lowering thermal stress on animals and body temperature. Cows reared under electric fan produced 1.2 kg/ d more milk during the early lactation (Suriyasathaporn etal., 2006)
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- Nutritional management: This is also a most important management to reduce the summer stress with the help of feed and water intake.
- Water intake: It is the most important nutrient for buffalo during summer. It is closely linked to dry matter intake. Primary cation in bovine sweat is potassium, sharp increases in the secretion of potassium through sweat happen during hot climatic conditions alteration in mineral metabolism also affect the electrolyte status of buffalo during hot weather, so supplementation of minerals during hot climate is also important.
- Night grazing: Buffaloes kept in a shed continue rapid heart beat during the night. However, when the animals are permit out into a pasture at night, these physiological responses reduces immediately.
- Feed high energy diet: Low fibre, high fermentable carbohydrate diets lower dietary heat increment as compared to high fibre diets. Although the metabolic energy of dairy buffaloes increases in a hot environment, heat stress depress feed intake. We will also used fatty feeds, calcium salts of fatty acids, as the means of energy supply for buffaloes in summer.
- Feeding by pass protein: dietary protein degradability is also critical under heat stress conditions. It is well known that excessive protein intake increases heat production and decreases reproductive performance. However, the protein requirement of buffalo increases and dry matter intake reduces in a hot environment, consequently, the protein supplied to lactating buffaloes during summer is not always sufficient. By using by-pass protein, the milk yield and protein content of buffalo milk increases but the ruminal ammonia production reduces.
- Increase potassium in feed: It is the main mineral in sweat and as temperature rise, animal lose more potassium through sweating, panting and urination. Ensure your herd receives a high quality potassium source that is protected from overheating to elevate potassium levels to 1.7% of ration dry matter and ration DCAD to +35 to +45 meq/100g ration dry matter and maintain dry matter intake, while meeting increasing nutrient demands. So supplementation of minerals throughout hot climate is also important.
Conclusion
In hot-humid climates, although dairy animal try to acclimatize through physiological changes including cutting down on feed intake and heat production, this does not come without sacrificing part of its productivity. In order to prevent this economic loss to the farmer, there is need to understand and effectively combat heat stress by minimizing its impact on the animal body and its productivity. We can’t control the weather in case of heat related stress, but we can do everything reasonably possible to reduce various kinds of the stress effects on animals. In tropical region, production of the animals can be maintained through nutritional management during heat stress. These strategies include supplementation of monensin, propylene glycol, niacin, yeast, by pass fat as well as sodium bicarbonate.
References:
Armstrong, D. V. (1994). Heat stress interaction with shade and cooling J. Dairy Sci. 77 : 2044-2050.
Buffalo under Heat Stress, AK Balhara, Jerome A and Inderjeet Singh. Central Institute for Research on Buffaloes, Indian Council of Agricultural Research.
Nagpal, S.K., Pankaj, P. K., Ray, B. And Talaware, M. K. (2005). Shelter Management for dairy (are view). Indian J. of Anim. Sci,75(10): 1199-1214.
Suriyasathoporn, W., Boonyaytra, S., Kreausukon, K., Pinyopummintr, T. and Heuer, C. (2006). Modification of Microclimate to improve milk production in tropical rain forest of Thailand. Asian- Aust. J. Anim. Sci. 19:811-815.
Saini, A. L. and Chandrahas (2013). Shelter Management in Modern Dairying.In. Agrotech Publishing Academy, India. 196-207.
