ISBN-13: 9783659337499 / Angielski / Miękka / 2013 / 196 str.
ISBN-13: 9783659337499 / Angielski / Miękka / 2013 / 196 str.
The four HCS comprised of desert cooling through wet bricks, surface wetting of layers by water sprinkling, time limit feeding during cool hours and ascorbic acid (AA) supplementation in feed, while the 5th system representing usual conditions served as control. The results for the overall experimental period of 24 weeks showed that layers under the desert cooling system, in general, had significantly higher body weight, egg production, egg weight and egg mass output as compared to those under the control and all other systems. Feed intake was significantly higher in the control group as compared to other systems. Whereas, it was significantly lower under time limit feeding than other systems except AA supplementation. The results further showed a significant increase in the abdominal fat percentage, relative weight of reproductive tract, adrenal, pancreas and ovary but a significant decrease in the relative weight of thyroid at peak stress stage as compared the pre-stress stage. SGPT remained highest at peak stress stage but SGOT increased at post-stress stage. The best results were obtained by desert cooling system operated through wet bricks.