Table 7.
Effects of a second iron injection administered on days 6 to 8 on pork quality1
| Item | Treatment | SEM | P-value | |
|---|---|---|---|---|
| CON | +Fe | |||
| Muscle pH | ||||
| 45-min pH | 6.09 | 6.04 | 0.09 | 0.73 |
| 24-h pHS | 6.01 | 6.02 | 0.06 | 0.93 |
| Δ pH | 0.07 | 0.02 | 0.13 | 0.77 |
| Drip loss, % | 9.59 | 11.15 | 0.96 | 0.26 |
| Purge loss, % | ||||
| Day 7 | 3.00 | 2.96 | 0.37 | 0.95 |
| Day 14 | 5.57 | 5.48 | 0.61 | 0.92 |
| Day 30 | 8.44 | 8.79 | 0.56 | 0.67 |
| Meat color | ||||
| L* | 60.12 | 60.20 | 1.13 | 0.96 |
| a*S | 8.28 | 8.13 | 0.27 | 0.69 |
| b* | 18.88 | 15.56 | 2.48 | 0.36 |
| Subjective meat quality2 | ||||
| Color | 3.04 | 3.04 | 0.17 | 1.00 |
| Marbling | 1.71 | 1.58 | 0.20 | 0.66 |
| Firmness | 2.50 | 2.38 | 0.24 | 0.72 |
1Treatment means are reported as least squares means from 12 pigs per treatment; data is based on the left side of the carcass. All pigs received an initial iron injection (200 mg Fe) at birth; the +Fe group received a second iron injection (200 mg Fe) at enrollment.
2Color: National Pork Producers Council (NPPC) color scale (1 to 5): 1 = pale pinkish to white; 5 = dark purplish red. Marbling: NPPC marbling scale (1 to 5): percentage fat in the loin muscle. Firmness: NPPC firmness scale (1 to 5): 1 = very soft; 5 = very firm.
SSignificant sex effect present where gilts had a greater pH compared to barrows, P ≤ 0.05.