Relationship of Radiated Heat Loss Measured by Infrared Thermography to Residual Feed Intake in Beef Heifers

• Author / Creator

  Colyn, Jacob J

• Infrared thermography (IRT) has shown utility in predicting residual feed intake (RFI) differences in mature cows, growing bulls and finishing steers. It was hypothesized that efficient heifers would exhibit decreased radiated heat loss. RFIfat determined on sixty-one crossbred beef heifers over a 113 day post-weaning feed trial ranged from -1.55 to 2.19 kg d-1 (sd= 0.78). Heifers were classified into low, medium, or high RFIfat groups (±0.5 sd of RFIfat µ). Pooled average radiated temperature estimates from multiple IRT images collected on head and ribcage sites over four dates were determined. Low and medium RFIfat heifers had similar cheek-mean temperatures of 19.88ºC and 20.40ºC but were lower than high RFIfat heifers (21.29ºC; P<0.0001). Of the sites examined, cheek-mean temperatures were correlated (r=0.46; P<0.001) to RFIfat while ribcage sites were not. Measurement of radiated heat loss by IRT from the cheek warrants further study to predict growth efficiency in heifers.

• Subjects / Keywords

  • Thermography
  • Infrared
  • Beef
  • RFI

• Graduation date

  Fall 2013

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3BH6D

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.