Effects of Drinking Water Temperature on Laying Hens Subjected to Warm Cyclic Environmental Conditions
Different drinking water temperatures (Tw) were provided to 24 individually caged, initially 29 wk- (Expt 1) and 30 wk-old (Expt 2) laying hens subjected to warm diurnal cyclic air temperature (Ta) in two separate experiments. Two levels of Tw (27 and 18 oC) in Expt 1 and four (15, 19, 23 or 27 oC) in Expt 2 were tested. Each experiment consisted of a 1-wk acclimation period under thermoneutral conditions (Ta = Tw = 21 oC), a 4-wk exposure to the treatment conditions (Ta = 27 – 35 oC and 27 – 38 oC for Expt 1 and 2, respectively), and a 2-wk recovery period with conditions same as the acclimation period. Cooler Tw tended to be more conducive to feed and water intake of laying hens during the early stage of heat exposure. An optimal range of Tw seems to exist for hens subjected to heat stress. However, large variations among the individual hens may have tempered statistical significance of the treatment effects. Further investigation using more experimental hens is warranted to evaluate Tw effects on the hen production performance.
This proceeding is from Pp. 235-243 in Livestock Environment VI: Proceedings of the 6th International Symposium (21-23 May 2001, Louisville, Kentucky, USA) ed. Richard R. Stowell, Ray Bucklin, and Robert W. Bottcher. Paper No. 701P0201.