354 Measurement of core body temperature via implanted data loggers and development of an equation to predict core body temperature from facial surface temperature in market-weight broiler chickens

Our objective was to estimate core body temperature (T(b) ) from facial skin temperature (T(fs) ) in mixed-sex broilers. Chickens were obtained at hatch (d0) and grown in floor pens. At d34, temperature loggers were surgically placed into the abdominal cavity of anesthetized broilers. On d42, 43, 44, 45, and 49, all chickens (n=6/sex) were exposed to ambient temperatures (T(a) ) of 21, 26, 30, and 35°C each day, with d46 through 48 as a 21°C de-acclimation period. Core body temperature was measured using implanted data loggers and T(fs) was measured using an infrared camera. A multiple linear regression prediction equation was developed via Proc Reg using d42 through 45 data, and T(b), T(fs), and the T(b)/T(fs) ratio data from d42 through d45 were analyzed with Proc Glimmix in SAS 9.4 with day as a repeated measure. For the T(b) prediction all parameters were significant yielding the equation T(b)=16.435 + 0.622 ± 0.02(T(fs))+0.346 ± 0.05(sex)-0.086 ± 0.02(day) with R(2)= 0.87, sex = 0 for males and 1 for females, and day = 1 to 4 for T(a) exposure time. Calculated T(b) from d49 were similar to measured T(b) values from d49, averaging 100.03 ± 0.10% of measured d49 T(b) values. Females had greater T(b) (P=0.005; 0.32°C) and T(b)/T(fs) ratio (P