Effect of Artificial Light, Temperature, and Humidity on Physiological Response of Dairy Bulls

Abstract

Reproductive and physiological responses of 12 mature dairy bulls were measured under varying artificial incandescent illumination, temperature, and humidity conditions. Bulls in Group I were housed in one-half of a large barn (control), and Group II in the remaining half of the barn, with the addition of incandescent light. Bulls in Group III were housed in an environmental control chamber maintained at 64 F, 15 mm Hg vapor pressure (humidity) and controlled incandescent light. Significant differences (P < 0.01) in favor of the bulls exposed to artificial light were attained for initial progressive motility of spermatozoa, morphologically abnormal spermatozoa, livability (72 hr) of spermatozoa, methylene blue reduction time (modified), and percentage of shippable ejaculates. However, no significant differences were attained for concentration of spermatozoa and volume of semen. The serum protein-bound iodine level declined slightly during the period with 15 hr of light and was essentially equal during the periods with 14 and 16 hr of light. Bulls exposed to artificial light exhibited a significant (P < 0.01) decrease in respiration rate as compared with the control. However, there were no significant differences among groups in body temperatures. © 1963, American Dairy Science Association. All rights reserved.