DAILY THERMOREGULATORY RESPONSE OF FOUR BREEDS OF NON-PREGNANT COWS IN IBADAN, NIGERIA

Abstract

The thermoregulatory responses of 4 non-pregnant cow breeds (Jersey, N'Dama, White Fulani and Sokoto Gudali) totaling 20 with corresponding replicates n = 4, 4, 4, 8 respectively were determined in an experiment. They were housed under similar conditions, fed same diet, fairly evenly aged (2-21⁄2 years) with weights ranging from 270 to 315kg. Pulse rate, heart rate, respiratory rate and rectal temperature of the animals were measured twice daily-before (7:30a.m.) and after grazing (3:00 p.m.). Ambient temperature and relative humidity were also recorded. The pulse rate (beats/minute) in Jersey cows (57.27) was significantly (P<0.05) higher than that in N'Dama cows (55.84) which had the least value. Heart rate (beats/minute) was significantly (P<0.05) higher in Jersey cows (57.94) than N'Dama cows (56.21). Respiratory rate (beats/minute) in Jersey cows (48.25) was significantly (P<0.05) higher than that of N'Dama cows (40.50), White Fulani cows (41.25) and Sokoto Gudali cows (41.88). There was no significant difference in rectal temperature across the breeds. All parameters evaluated were within the normal hysiological range for cows. The high respiratory rate in Jersey cows indicated that they reflected heat bette than other cow breeds (N'Dama, White Fulani and Sokoto Gudali) examined. Key words: Thermoregulatory response, pre-gestating cows, humid tropical environment.