Table 2.
Effect of HS and feeding management on growth performance and feeding behavior of finishing pigs1
| Contrasts P-value | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Items | TN–AL | TN–PF8 | HS–AL | HS–PF8 | RSD2 | Statistics3 | AL vs. PF84 | AL: TN vs. HS5 | PF8: TN vs. HS6 |
| Live BW, kg | |||||||||
| Day −7 | 66.2 | 66.0 | 65.8 | 67.0 | 1.3 | R**, D**, G × D** | 0.65 | 0.81 | 0.52 |
| Day 0 | 74.6 | 73.8 | 73.5 | 74.6 | 0.89 | 0.51 | 0.60 | ||
| Day 20 | 97.7a | 91.7b | 91.6b | 90.9b | <0.01 | <0.01 | 0.61 | ||
| ADFI, g·d−1 | |||||||||
| P1 | 2,605 | 2,527 | 2,655 | 2,649 | 135 | G**, P**, G × P** | 0.45 | 0.54 | 0.15 |
| P2 | 2,929a | 2,415b | 2,388b | 2,343b | <0.01 | <0.01 | 0.40 | ||
| ADFI per BW, g·kg BW–1·d–1 | |||||||||
| P1 | 37.1 | 36.2 | 38.1 | 37.7 | 1.9 | R**, G**, P**, G × P** | 0.29 | 0.30 | 0.13 |
| P2 | 34.1a | 29.2b | 28.9b | 28.6b | <0.01 | <0.01 | 0.54 | ||
| ADG, g·d−1 | |||||||||
| P1 | 1,195 | 1,122 | 1,100 | 1,085 | 134 | G**, P**, G × P* | 0.18 | 0.14 | 0.56 |
| P2 | 1,154a | 903b | 911b | 811b | <0.01 | <0.01 | 0.14 | ||
| FCR | |||||||||
| P1 | 2.19 | 2.29 | 2.45 | 2.49 | 0.29 | R*, G*, P** | 0.43 | 0.06 | 0.14 |
| P2 | 2.55b | 2.70ab | 2.63ab | 2.92a | <0.01 | 0.53 | 0.11 | ||
| Total meal duration/day, min·d–1 | |||||||||
| P1 | 62 | 63 | 69 | 60 | 17 | G × P* | 0.60 | 0.45 | 0.74 |
| P2 | 73 | 72 | 51 | 50 | 0.87 | 0.03 | 0.03 | ||
| No. of meals/day, n·d−1 | |||||||||
| P1 | 12.2 | 10.9 | 11.3 | 13.0 | 1.6 | P**, G × P**, R × G × P* | 0.76 | 0.41 | 0.08 |
| P2 | 11.8b | 15.1a | 11.8b | 14.2ab | <0.01 | 0.95 | 0.44 | ||
| Meal duration, min·meal−1 | |||||||||
| P1 | 5.2 | 6.2 | 6.4 | 4.8 | 1.5 | G × P* | 0.59 | 0.17 | 0.17 |
| P2 | 6.5a | 4.9ab | 4.8ab | 3.9b | 0.04 | 0.05 | 0.33 | ||
1A total of 48 pigs were allocated to four experimental groups in three replicates. All pigs were housed at thermoneutrality (P1: day −7 to −1) before being subjected to either thermoneutral (TN) or heat stress (HS) conditions (P2: day 0 to 19). In each environment, diet was provided either ad libitum (AL) (2 feed provisions/day) or pair fed (PF8) (8 feed provisions/day) with the HS pigs fed AL as the reference group.
2Residual standard deviation.
3The pig was considered as the experimental unit. Data were analyzed using PROC MIXED model with replicate (R), experimental group (G), day (D), or period (P), and their interactions as fixed effects.
4Contrast statement: [TN–AL, HS–AL] vs. [TN–PF8, HS–PF8].
5Contrast statement: [TN–AL] vs. [HS–AL].
6Contrast statement: [TN–PF8] vs. [HS–PF8].
a–cLSmeans within a row with different superscripts letters differ (P < 0.05) according to the experimental group.
*P < 0.05; **P < 0.01.