Spraying effects on some physiological and behavioural traits of goats in a subtropical climate

Abstract

Heat stress is one of the major factors adversely affecting animal welfare and thus economic benefits of farms. This study was designed to determine the effects of two different spraying methods on goats exposed to high air temperatures. Thirty goats were divided into three groups for the trial (sprayed once per day, OTS; sprayed twice per day, TTS; and non-sprayed, Controls). Respiration and pulse rates, rectal and surface temperatures (from head and udder skin) were taken three times a day (08.00 - 09.00; 16.00 - 17.00 and 00.00 - 01.00) on hot summer days in July 2005 in a Mediterranean climate. Some behavioural aspects such as eating, ruminating, drinking, walking and resting, and daily feed and water consumption were regularly measured. Rectal temperatures, pulse and respiration rates, udder and head temperatures differed between the three groups. Rectal, head and udder temperatures and respiration and pulse rates increased at 16.00 relative to 08.00, and at 00.00 had returned to the same level as at 08.00. TTS goats showed smaller increases in all physiological measurements at 16.00 than the other groups. TTS goats spent more time than OTS and Control goats eating (P=0.002), ruminating (P=0.032) and walking (P=0.021), but less time drinking (P=0.041) and lying (P=0.001). TTS goats consumed more concentrate feed (P=0.001) and alfalfa hay (P=0.024) than the other two groups, whereas Control goats consumed more water (P=0.003) than the other groups. Ultimately, the spraying had positive effects on yearling goats for alleviating heat stress and improving animal welfare.