Figure 1.
Figure 1.

Histograms illustrating distributions of records based on temperature–humidity index (THI) for purebred Duroc animals in North Carolina and Texas.

 


Figure 2.
Figure 2.

Histograms illustrating distributions of records collected based on temperature–humidity index (THI) for crossbred Duroc × F1 (Landrace × Large White) animals in North Carolina and Missouri.

 


Figure 3.
Figure 3.

Daily heat load, defined as the 30-d average units of temperature-humidity index greater than 70, for purebred animals in North Carolina and Texas and for crossbred animals in North Carolina and Missouri.

 


Figure 4.
Figure 4.

Daily heat loads for the North Carolina state weather station with heat load definitions differing by length (30, 50, and 70 d) and temperature–humidity index (THI) threshold (60, 65, 70, and 75).

 


Figure 5.
Figure 5.

Coefficient of determination for different heat load functions, depending on the threshold for temperature–humidity index and the number of days before the weigh date, for purebred Duroc animals in North Carolina and Texas.

 


Figure 6.
Figure 6.

Coefficient of determination for different heat load functions, depending on the threshold for temperature–humidity index and the number of days prior to the weigh date, for crossbred Duroc × F1 (Landrace × Large White) pigs in North Carolina and Missouri.

 


Figure 7.
Figure 7.

Daily observed (gray) and predicted (black) BW by regression of phenotype on heat load (HL) nested in year for purebred Duroc animals in Texas and North Carolina. Heat load was calculated with different threshold (HL = 60, 65, 70, or 74) and averaged for 30 d.

 


Figure 8.
Figure 8.

Daily observed (gray) and predicted (black) HCW by regression of phenotype on heat load (HL) nested in year, across time for crossbred Duroc × F1 (Landrace × Large White) animals in Missouri and North Carolina. Heat load was calculated with different threshold (HL = 60, 65, 70, or 75) and averaged for 30 d.

 


Figure 9.
Figure 9.

Observed and predicted BW by regression of weight on heat load for purebred Duroc animals in Texas and North Carolina. Heat load in the x-axis was calculated with temperature–humidity index above 70 averaged for 30 d.

 


Figure 10.
Figure 10.

Observed and predicted HCW by regression of phenotype on heat load for Duroc × F1 (Landrace × Large White) animals in Missouri and North Carolina. Heat load in the x-axis was calculated with temperature–humidity index above 70 averaged for 30 d.