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Animal Healthcare
COMBATING HEAT STRESS PROBLEMS IN COWS WITH ENERGY SUPPLEMENTATION
A dairy cow’s environment is defined by air temperature, relative humidity, thermal radiation and air velocity which influence its body temperature. T he changes brought about by the animal’s physiology are attributed to the above-mentioned factors, which are linked to a thermal environment.
Hence, the three fundamentals of dairy farming – health, production and reproduction – can be impacted by heat stress.
Longer exposure to an ‘altered’ thermal environment decreases a cow’s ability to disperse heat. Heat generated during milk production, coupled with heat produced during metabolism, escalates the risk of heat stress, inducing behavioural and metabolic changes to counteract harmful effects.
These changes include panting, reduced dry matter intake (DMI), selective consumption, reduced activity and reduced metabolic rate.
Consequentially, minerals like potassium and sodium are lost through urine and sweat, hindering the energy production cycle. There will be a high demand for water, the requirement of which could spike to an additional 30% to compensate for changes during heat stress.
The cow’s productivity will be impacted more significantly. Studies show that heat stress affects milk quality by altering composition and increasing somatic cell counts and the likelihood of mastitis.
These changes are caused by multiple factors associated with milk production and routine physiology. DMI, ruminal activity and the rate of passage of feed are also affected. The liver is impacted as well due to a response to key hormones, growth hormone and insulin, leading to the curtailing of volatile fatty acids (VFA) production that determines milk production.
Impact on health and production induces cows to enter into a negative energy condition. Negative energy balance (NEB), due to decreased feed intake, can alter metabolism and put the animal at further risk of complications like ketosis and fatty liver syndrome. Recent studies by a university in Minnesota, US, reveal that heat stress can severely affect a cow’s reproductive performance.
Failures in insemination and ovulation, and higher death rate of calves were observed during heat stress.
Thus, pre-determining the impact of heat stress and crafting appropriate measures are critical as heat stress can cause lasting damages. The temperature humidity index (THI) is another factor in managing heat stress. THI is a measure which concerns the combined effects of environmental temperature and relative humidity.
Thus, pre-determining the impact of heat stress and crafting appropriate measures are critical as heat stress can cause lasting damages. The temperature humidity index (THI) is another factor in managing heat stress. THI is a measure which concerns the combined effects of environmental temperature and relative humidity.
Still, there are several factors which must be considered within the THI’s context, like milk yield which can vary to a range of 2-5°C, solar radiation and air movement, which influences heat gain and loss between the animal and environment.
The dairy heat load index (DHLI) is another index to quantify heat stress in grazing cows, and which considers air movement and solar radiation. Counteracting heat stress Appropriate measures should be implemented including managing the environment, balancing feed and providing energy supplementation. Primary measures to control heat stress start with basic infrastructure features, specifically, proper shelter and ventilation.
Foggers and cooling systems can be installed to mitigate animal heat loss. Ration formulas would also help in planning diets and managing heat stress in animals. Instant energy supplementation is yet another measure; notably, supplementation of energy with glucose precursors has shown promising results in managing negative energy balance caused by heat stress.
In addition, products containing gluconeogenic precursors like propylene glycol is recommended for meeting critical energy needs since propylene glycol enters the normal gluconeogenic pathway to produce glucose.
Studies show that supplementation of rumen inert fat (Wan et al, 2010) and key elements like phosphorous, potassium and sodium increased milk production by 0.5% in stressed animals (Schneider et al, 1984). To support ruminal microbes, supplementation of yeast culture is recommended. Nicotinamide is also being supplemented to facilitate energy production.
Furthermore, the positive impact of reducing ketone bodies and increasing blood glucose was reported.
Essential oils
Essential oils are said to increase energy availability and production. Eugenoland carvacolhas was found to increase the amount of volatile fatty acids, thereby mitigating energy deficiency (Bravo, 2009). Aside from using essential oils to boost productivity, those containing eugenol and carvacrol reduce methane production which is known to produce greenhouse gases. Controlling greenhouse gases curtails heat dissipation and exchange between the animal and environment. In light of such a development, Glucaboost by M/s. Natural Remedies Private Limited contains propylene glycol, nicotinamide and phytochemical gluconeogenic additive to manage energy deficiency due to heat stress.
Conclusion
Timely decisions and actions together with right measures help in ensuring farm animals’ health. Indeed, these are supported by proper infrastructures, balanced nutrient rations and, most importantly, energy supplementation to help animals overcome heat stress.
Dr. Anandha Narayanan. S,
International Business Manager-Ruminants
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