Panting frequency and score in beef cattle in intensive finishing during summer in the dry tropics

Panting frequency and score are indicative of cattle well-being in intensive finishing feedlots. A six-week-long descriptive observational study was done of intensive finishing beef cattle during summer in the dry tropics in northwest Mexico. Data were collected on pen type, observation time (0800, 1200 and 1600 hours), panting frequency and score, environmental temperature, relative humidity and animal phenotypic predominance (i.e. Bos taurus or Bos indicus). The temperature and humidity index (THI) was calculated. Panting frequency was recorded as the number of animals exhibiting this behavior per pen, and panting scored on a five-point scale. Three categories of phenotype were assigned (no hump, medium hump and large hump), greater hump size being indicative of greater B. indicus influence. Panting frequency was highest at 1200 and 1600 h (P<0.01), when THI values consistently exceeded 84 units. Panting score tended to be higher (P<0.01) in pens with less space for individual animals, at later observation times, and in animals with no hump. Panting frequency and score in beef cattle in intensive feedlots was influenced by time of day, pen design and a predominantly B. taurus phenotype.