EFFECT OF MISTING ON THE MILK PRODUCTION OF FRIESIAN CROSSBRED DAIRY CATTLE

This work was carried out in the animal production research station in Gemmayzeh, Tanta, Al- Gharbia Governorate. The experimental part was during the summer, July and August season of 2015. Twenty-four dairy cattle were selected to the treatment, they were divided to two groups, twelve cows per group. Two cooling systems (Micro Sprinkler System (MSS), Fogger Sprinkler System (FSS)) were used in this work. The main objectives of this work were studying the effect of providing adequate shade on heat stress and milk production of dairy cattle to meet the demands of a small and medium-sized primitive farms for the production of milk, studying some engineering factors affecting the performance of the designed cooling system and to determine the effect of spraying by the designed cooling system and providing adequate shade for dairy cattle at pre- milking automated stage on the production of milk. The obtained results indicated that using the runtime periods of 1.5, 3, and 4.5min. per 15 min., without using a shelter reducing rate of ambient temperatures by 5, 5.9, and 6.4°C compared with 1.9, 3.6, and 5.7°C for MSS, and FSS, respectively. While, by using a shelter, the reducing rate of ambient temperatures by 5.2, 6.1, and 9.4°C compared with 1.9, 3.7, and 3.8°C for MSS, and FSS, respectively. From these pervious results the runtime period of 4.5/15min. was chosen for cooling the cattle. by applying this run time period on animals twice, four, and six times before milking, the milk producing was increased by 1.4% (0.6kg), 1.96% (0.9kg), and 11.57% (5.6kg) compared with the morning production, respectively. Therefore, the runtime period of 4.5/15 min. must be used for cooling the animals six time before milking.