Table 4.
Effects of RFI line and hygiene of housing conditions on antioxidant enzymes and glutathione content in tissues of growing pigs
| Line | Low RFI | High RFI | P values | |||||
|---|---|---|---|---|---|---|---|---|
| Hygiene | Good | Poor | Good | Poor | MSE | Line | Hygiene | LxH |
| Week 6 (n = 36) | ||||||||
| SOD | ||||||||
| PRAT | 81.4 | 109.4 | 99.5 | 104.8 | 26.1 | 0.44 | 0.06 | 0.17 |
| Liver | 2727 | 2289 | 2929 | 2520 | 551 | 0.25 | 0.03 | 0.94 |
| LL | 203 | 201 | 224 | 218 | 29.8 | 0.07 | 0.68 | 0.82 |
| CAT | ||||||||
| PRAT | 1002 | 1299 | 1169 | 1500 | 258 | 0.04 | 0.001 | 0.84 |
| Liver (× 103) | 72.3 | 74.3 | 88.0 | 71.6 | 25.1 | 0.44 | 0.40 | 0.28 |
| LL | 1060 | 1116 | 1048 | 1020 | 193 | 0.41 | 0.83 | 0.52 |
| GSH-Rx | ||||||||
| PRAT | 77.9 | 107.1 | 110.5 | 133.4 | 20 | < 0.001 | < 0.001 | 0.64 |
| Liver | 5518 | 5214 | 5007 | 5098 | 631 | 0.16 | 0.63 | 0.37 |
| LL | 121 | 102 | 116 | 117 | 23.6 | 0.53 | 0.29 | 0.23 |
| GSH - Liver | 5389 | 6202 | 5318 | 5122 | 1433 | 0.68 | 0.91 | 0.34 |
| GSSG - Liver | 275 | 286 | 283 | 257 | 162 | 0.83 | 0.88 | 0.77 |
| Ratio - Liver | 23.7 | 29.2 | 26.4 | 21.9 | 14.8 | 0.66 | 0.93 | 0.35 |
| Week 13–14 (n = 35) | ||||||||
| SOD | ||||||||
| PRAT | 42.4 | 53.9 | 53.4 | 82.5 | 18.9 | 0.004 | 0.004 | 0.18 |
| Liver | 2594b | 2392a | 2507b | 3257c | 661 | 0.09 | 0.24 | 0.05 |
| LL | 221 | 218 | 241 | 240 | 30 | 0.05 | 0.85 | 0.89 |
| CAT | ||||||||
| PRAT | 781 | 810 | 812 | 1107 | 293 | 0.11 | 0.11 | 0.19 |
| Liver (× 103) | 834 | 961 | 1004 | 923 | 180 | 0.29 | 0.72 | 0.10 |
| LL | 1006 | 960 | 852 | 945 | 200 | 0.23 | 0.73 | 0.31 |
| GSH-Rx | ||||||||
| PRAT | 52.2 | 67.9 | 59.8 | 89.3 | 23 | 0.07 | 0.007 | 0.38 |
| Liver | 4334 | 4783 | 5066 | 5391 | 672 | 0.007 | 0.11 | 0.78 |
| LL | 98 | 100 | 103 | 105 | 18 | 0.42 | 0.83 | 0.92 |
Pigs from two genetic lines divergently selected for low (LRFI) or high (HRFI) residual feed intake (RFI) were housed either in good or poor hygiene conditions during the first 6 weeks after their transfer in growing-finishing pens (period 1, challenge). Half of these pigs were killed at week 6, whereas another half were placed in good hygiene conditions until slaughter at weeks 13 or 14 (period 2, recovery). Activities of antioxidant enzymes such as glutathione reductase (GSH-Rx), superoxide dismutase (SOD) and catalase (CAT) were assessed (nM/min/g tissue) in perirenal adipose tissue (PRAT), liver and longissimus lumborum (LL) muscle. Reduced (GSH) and oxidized (GSSG) forms of glutathione (expressed as pmol per well) were also assessed in the liver. The ratio between reduced and oxidized forms (GSH:GSSG) was calculated. Letters (a,b,c) were added in case of interaction (LxH; P < 0.10) between hygiene (H) and RFI line (L), and means sharing a common letter did not differ. MSE: root mean standard error of the statistical model. Bold face highlights significant differences (P ≤ 0.05) between treatments, and when italicized, this denotes a trend (0.05 < P ≤ 0.10)