OPTIMIZATION OF WATER USE FOR COOLING DAIRY ANIMALS DURING SUMMER

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Dept. of Livestock Management, University of Veterinary and Animal Sciences, Lahore

Musa Bah:
Dairy animals play a vital role in the provision of milk as one of the cheapest forms of protein for the masses. With increase population growth, urbanization, and income, the demand for livestock products such as milk will continue to increase. The tropics and subtropical parts of the world experience yearly hot and humid summer that leads to heat stress in livestock particularly dairy animals including buffaloes and cows. The dairy cows especially Holsteins Frisian are more susceptible to heat stress because of their high milk yield and of temperate origin.

Heat stress occurs when the animal cannot dissipate heat load and becomes a sink and
this leads to low milk yield, reduced fertility, increased susceptibility to diseases, leading to
annual losses. Different methods are used to reduce the negative impacts of heat stress including the provision of shade, wallowing ponds, water application using handheld hose pipes, and sprinklers. A combination of shade and sprinklers, and water application using handheld hose pipes are the most frequent ways to cool dairy animals. The intensification of buffalo farming systems and reduction in potholes and ponds in villages has led to limited or no access to water for wallowing. In Pakistan, the farmers cool buffaloes by applying water using handheld hose pipes for few minutes during the morning and afternoon hours. About 350 litres of water is used per day to cool a single buffalo in that way. This is more than the amount of water used in cleaning and drinking. In the corporate dairy sector where exotic cows are kept, about 800 litres of water is used daily to cool a single Holstein cow. These methods use a large quantity of groundwater.

The groundwater level is replenished by precipitation and rainfall. The climate change due to rising temperatures has reduced the rainfall and precipitation thereby less groundwater replenishes. Pakistan is projected to become water scarce in 2035. Hence judicious use of this paramount resource is vital under scenarios of decreasing groundwater levels due to climate change. To address the issue, a PhD study was conducted at the University of Veterinary and Animal Sciences, Ravi Campus, Pattoki. The objective of the research was to assess the performance of dairy animals in response to different showering strategies. In first phase, the effect of different sprinkler flow rates on milk yield, body temperature, respiration rate, and behavior was evaluated. The results of these experiments revealed that sprinkler flow rate 1.25 litre/min was more efficient as it yielded similar production, physiological and behavioral responses to that of 2.0 litre/min despite using 37.5% less water. The 2.0 litre/min was the traditional sprinkler flow rate and the 1.25 was used as a water reduction strategy. In second phase of the study, the traditional cooling method of buffalo was compared with that of the modified ones. Three cooling strategies were tested including a traditional method of cooling buffalo with 3-5 minutes water application using a hosepipe twice daily, two showering sessions with one hour each, and three showering sessions each lasting one hour. In the showering sessions, the sprinkler flow rate was 1.2 litre/min whiles direct water application had a flow rate of about 40 litre/min. The results revealed that the strategy of three coiling sessions with sprinklers was more efficient than the traditional one because it yielded more milk, lower body temperature, and respiratory rate, and better animal welfare for the buffaloes, despite using 81.2% less groundwater. Similarly, the different cooling sessions were evaluated 2 for Holstein cows as well. Compared to continuous showering of cows for 10 hours, the four cooling sessions of one hour each had better response to udder health, milk yield, behavior and welfare despite using 93.7% less water. The findings of current research can help the dairy farmers to devise their cooling strategies for cows and buffaloes using less water during summer. The author completed his PhD study in Livestock Management under the supervision of Dr Muhammad Qamer shahid, Associate Professor, at the University of Veterinary and Animal Sciences Lahore.