Figure 1.
Figure 1.

Experimental design used to treat sows with different temperatures when in breeding/gestation and farrowing rooms. Treatments are denoted as TN-TN-TN, TN-HS-TN, HS-TN-HS, and HS-HS-HS, where the series of abbreviations represent the thermoneutral temperature (TN; 18°C to 20°C) or heat stress (HS; 24°C to 30°C) that the sow experienced in gestation-farrowing-breeding. Sows were in the breeding/gestation room from d 0 to 20 and the farrowing room from d 20 to 44 and were returned to the breeding/gestation room after d 44. Sows moved out of the environmental chambers on d 57.

 


Figure 2.
Figure 2.

Ambient temperature averaged across all study days inside each environmental chamber used in the study [2 heat stress (HS) chambers, 1 for farrowing and 1 for breeding/gestation, and 2 thermoneutral (TN) chambers, 1 for farrowing and 1 for breeding/gestation]. Data were collected by using 2 Hobo Data Loggers (Onset Computer Inc., Pocasset, MA) positioned at sow head level within each room. The chambers were programmed to achieve daily ambient temperature cycles of 18°C to 20°C for TN and 24°C to 30°C for HS.

 


Figure 3.
Figure 3.

Least squares means with SEM (value at lower right of each panel) for rectal temperature during the day (0800, 1200, 1600, and 2000 h) for sows that were in (A) gestation (late pregnant sow), (B) farrowing (lactating sow), and (C) breeding (weaned sow). Treatments are TN-TN-TN, TN-HS-TN, HS-TN-HS, and HS-HS-HS, where the series of abbreviations represent the thermoneutral temperature (TN; 18°C to 20°C) or heat stress (HS; 24°C to 30°C) in gestation-farrowing-breeding. There was a treatment by time interaction (P < 0.01) for gestation and farrowing but not breeding.

 


Figure 4.
Figure 4.

Least squares means with SEM (value at lower right of each panel) for rectal temperature (A and B) during each day of the trial and (C and D) on each day relative to the day of farrowing. Data are for (A and C) 0800 h and (B and D) 2000 h. Treatments are TN-TN-TN, TN-HS-TN, HS-TN-HS, and HS-HS-HS, where the series of abbreviations represent the thermoneutral temperature (TN; 18°C to 20°C) or heat stress (HS; 24°C to 30°C) in gestation-farrowing-breeding. For (A) and (B), sows were in breeding/gestation from d 0 to 20, were farrowing from d 20 to 44, and were weaned and returned to breeding/gestation on d 44. There was an effect of day (P < 0.001) in (A), (B), (C), and (D) and a treatment by day interaction (P < 0.001) in (B). There was an effect of treatment (P < 0.001) in (D).

 


Figure 5.
Figure 5.

Least squares means with SEM (value at lower right of each panel) for respiration rate during the day (0800, 1200, 1600, and 2000 h) for sows that were in (A) gestation (late pregnant sow), (B) farrowing (lactating sow), and (C) breeding (weaned sow). Treatments are TN-TN-TN, TN-HS-TN, HS-TN-HS, and HS-HS-HS, where the series of abbreviations represent the thermoneutral temperature (TN; 18°C to 20°C) or heat stress (HS; 24°C to 30°C) in gestation-farrowing-breeding. There was a treatment by time interaction (P < 0.001) for gestation, farrowing, and breeding.

 


Figure 6.
Figure 6.

Least squares means with SEM (value at lower right of each panel) for respiration rate (A and B) during each day of the 55 d of the trial and (C and D) on each day relative to the day of farrowing. Data are for (A and C) 0800 h and (B and D) 2000 h. Treatments are TN-TN-TN, TN-HS-TN, HS-TN-HS, and HS-HS-HS, where the series of abbreviations represent the thermoneutral temperature (TN; 18°C to 20°C) or heat stress (HS; 24°C to 30°C) in gestation-farrowing-breeding. For (A) and (B), sows were in the breeding/gestation from d 0 to 20, were farrowing from d 20 to 44, and were weaned and returned to the breeding/gestation on d 44. There was a treatment by day interaction (P < 0.001) for (A) and (B). There were effects of both treatment (P < 0.001) and day (P < 0.001) for (C) and (D).

 


Figure 7.
Figure 7.

Least squares means with SEM (value at lower right of each panel) for feed intake (A) during each day of the 55 d of the trial and (B) on each day relative to the day of farrowing. Treatments are TN-TN-TN, TN-HS-TN, HS-TN-HS, and HS-HS-HS, where the series of abbreviations represent the thermoneutral temperatures (TN; 18°C to 20°C) or heat stress (HS; 24°C to 30°C) in gestation-farrowing-breeding. Sows were in the breeding/gestation from d 0 to 20, were farrowing from d 20 to 44, and were weaned and returned to breeding/gestation on d 44. There was a treatment by day interaction (P < 0.001) for (A) and (B).

 


Figure 8.
Figure 8.

Least squares means and SE (bar) for (A) average diameter of ovarian follicles and (B) serum estradiol on day relative to weaning. Treatments are denoted as TN-TN-TN, TN-HS-TN, HS-TN-HS, and HS-HS-HS, where the series of abbreviations represent the thermoneutral temperature (TN; 18°C to 20°C) or heat stress (HS; 24°C to 30°C) that the sow experienced in gestation-farrowing-breeding. There was an effect of day (P < 0.001) for (A) and (B).

 


Figure 9.
Figure 9.

Least squares means for (A) serum glucose, (B) NEFA, (C) IGF-1, and (D) insulin concentrations for sows at d 15 (during gestation), d 29 (after farrowing), d 43 (day before weaning), and d 47 (3 d after weaning). Treatments are TN-TN-TN, TN-HS-TN, HS-TN-HS, and HS-HS-HS, where the series of abbreviations represent the thermoneutral temperature (TN; 18°C to 20°C) or heat stress (HS; 24°C to 30°C) that the sow experienced in gestation-farrowing-breeding. x–zMeans with different superscripts differ across day of trial (P < 0.05). a,bWithin means, different superscripts differ (P < 0.05).