caa a22 4500 388060549 CHVBK 20180307125119.0 cr unu---uuuuu 161130e199804 xx s 000 0 eng 10.1017/S1357729800009589 doi S1357729800009589 pii (NATIONALLICENCE)cambridge-10.1017/S1357729800009589 Effect of short-term exposure to high ambient temperatures on gas exchange and heat production in boars of different breeds [Elektronische Daten] The effects of short-term exposure to high ambient temperatures on gas exchange, heat production (HE), respiration rate (RR) and rectal temperature were evaluated individually with boars of approximately 100 kg live weight. The boars were of different breeds with four of Yorkshire (YS), eight of Danish Landrace (DL), out of which three were found stress susceptible by the halothane test (DLH+), eight of Duroc (DR) and eight of Hampshire (HS) breeds. After 1 h rest in the respiration chamber at 17·0°C the gas exchange measurements started with al-h basal period at 17 °C, followed by 2h of heating during which temperature increased to 35·0 °C (period I) and then further to 39·7X1 (period II). Then cooling of the chamber started, and after 1 h (period III) temperature had decreased to 21·8°C, and after the 2nd h of cooling (period IV) temperature was 18·2 °C. The gas exchange was measured for each hour from 09.00 h (basal period) until 14.00 h (period IV). RR was recorded every 15 min. Rectal temperatures were measured when the animals were removed from the chamber. The gas exchange and HE increased slowly during period I but rapidly in period II, followed by decreasing values in the cooling periods. HS and DLH+ had considerably higher gas exchange and HE than other breeds in these two periods and the values remained high during period III. In period IV all breeds had gas exchange rates and HE below those of the basal period. RR increased slightly in period I and then a sharp increase followed during period II. Maximum RR was recorded in period III with an average of 183 breaths per min for all breeds. RR increased earlier and more steeply in HS and reached the highest mean value of 236 breaths per min. Four HS boars salivated heavily during heat stress and rectal temperatures of these animals were 39·7 °C when removed from the chamber compared with close to 39·0 °C for all other breeds. It was concluded that there were considerable breed differences in response to heat stress and that DLH+ and HS were more severely stressed than boars ofYS, DL and DR. Copyright © British Society of Animal Science 1998 boars nationallicence breed nationallicence gas exchange nationallicence heat exchange nationallicence temperature nationallicence Tauson A.-H Department of Animal Science and Animal Health, The Royal Veterinary and Agricultural University, Bülowsvej 13, DK-1870 Frederiksberg C, Denmark Chwalibog A. Department of Animal Science and Animal Health, The Royal Veterinary and Agricultural University, Bülowsvej 13, DK-1870 Frederiksberg C, Denmark Ludvigsen J. National Institute of Animal Science, Rolighedsvej 25, DK-1958 Copenhagen V, Denmark Jakobsen K. Department of Animal Nutrition, Danish Institute of Animal Science, Research Centre Foulum, Box 39, DK-8830 Tjele, Denmark Thorbek G. National Institute of Animal Science, Rolighedsvej 25, DK-1958 Copenhagen V, Denmark Animal Science Cambridge University Press 66/2(1998-04), 431-440 1357-7298 66:2<431 1998 66 ASC https://doi.org/10.1017/S1357729800009589 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S1357729800009589 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Tauson A.-H Department of Animal Science and Animal Health, The Royal Veterinary and Agricultural University, Bülowsvej 13, DK-1870 Frederiksberg C, Denmark NATIONALLICENCE 700 1- Chwalibog A. Department of Animal Science and Animal Health, The Royal Veterinary and Agricultural University, Bülowsvej 13, DK-1870 Frederiksberg C, Denmark NATIONALLICENCE 700 1- Ludvigsen J. National Institute of Animal Science, Rolighedsvej 25, DK-1958 Copenhagen V, Denmark NATIONALLICENCE 700 1- Jakobsen K. Department of Animal Nutrition, Danish Institute of Animal Science, Research Centre Foulum, Box 39, DK-8830 Tjele, Denmark NATIONALLICENCE 700 1- Thorbek G. National Institute of Animal Science, Rolighedsvej 25, DK-1958 Copenhagen V, Denmark NATIONALLICENCE 773 0- Animal Science Cambridge University Press 66/2(1998-04), 431-440 1357-7298 66:2<431 1998 66 ASC CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge