Table 1.
Chemical composition, fatty acid profile and fat-soluble antioxidants content of TMR and pasture in the different trial periods.
| Item | TMR | Pasture | Grazing Period # | SEM | p-Values | ||||
|---|---|---|---|---|---|---|---|---|---|
| P1 | P2 | P3 | S | P | |||||
| Chemical composition (% of DM): | |||||||||
| DM (dry matter), % | 53.65 | 31.53 | 27.15 c | 32.90 b | 34.55 a | 0.217 | *** | ** | |
| Crude protein (CP) | 17.26 | 14.78 | 15.74 a | 14.40 b | 13.71 b | 0.181 | ** | * | |
| OM (organic matter) | 91.77 | 92.07 | 91.70 | 92.12 | 92.40 | 0.157 | n.s. | n.s. | |
| Ether extract (EE) | 2.69 | 2.89 | 2.82 | 2.93 | 2.92 | 0.031 | n.s. | n.s. | |
| Crude fiber (CF) | 15.85 | 28.10 | 26.71 b | 28.17 a | 29.92 a | 0.176 | *** | ** | |
| Nitrogen free extractive (NFE) 1 | 55.97 | 46.30 | 46.43 | 46.62 | 45.85 | 0.417 | ** | n.s. | |
| Ca 2 | 0.76 | - | - | - | - | - | |||
| P 2 | 0.37 | - | - | - | - | - | |||
| NEL (Mcal/kg DM) 2 | 1.66 | 1.44 | 1.47 | 1.44 | 1.42 | 0.005 | ** | n.s. | |
| Fatty acids profile (% of total FA): | |||||||||
| Total FA (g/kg DM) | 15.84 | 17.81 | 21.74 a | 17.48 b | 14.22 c | 0.236 | * | ** | |
| C16:0 | 14.91 | 13.88 | 12.80 b | 13.75 b | 15.10 a | 0.417 | n.s. | * | |
| C18:0 | 7.32 | 2.20 | 1.78 | 2.06 | 2.75 | 0.194 | *** | n.s. | |
| C18:1 cis-9 | 18.22 | 1.71 | 1.38 | 1.78 | 1.97 | 0.210 | *** | n.s. | |
| C18:2 cis-9, cis-12 | 39.82 | 12.18 | 10.42 c | 12.02 b | 14.10 a | 0.308 | *** | * | |
| C18:3 cis-9, cis-12, cis-15 | 8.65 | 64.47 | 68.10 a | 64.77 b | 60.54 c | 1.172 | *** | *** | |
| C18:2/C18:3 | 4.60 | 0.19 | 0.15 b | 0.19 ab | 0.23 a | 0.000 | *** | ** | |
| Other | 11.08 | 5.56 | 5.52 | 5.62 | 5.54 | 0.343 | *** | n.s. | |
| Fat-soluble antioxidants (mg/kg DM): | |||||||||
| α-tocopherol | 8.64 | 26.91 | 34.41 a | 26.14 b | 20.18 c | 0.447 | *** | *** | |
| All-trans β-carotene | 6.73 | 66.97 | 82.32 a | 67.12 b | 51.47 c | 0.851 | *** | *** | |
TMR: total mixed ration; TMR composition (% of DM): Corn silage—42.0; Alfalfa hay—10.0; Grass hay—7.3; Corn grain—10.0; Triticale—5.0; Soybean meal—9.0; Rape-seed meal—12.0; Sodium bicarbonate—0.3; Salt—0.4; Vitamin and mineral premix—4.0. SEM: standard error of the mean. S—TMR vs. pasture, P—effect of the grazing period. 1 Calculated by difference 100—(%CF + %CP + %EE + %ash). 2 Estimated using values of NRC [17]. # Grazing period (3 weeks): P1—May, P2—June, P3—June/July. a–c Mean values within a row without a common superscript differ significantly (p < 0.05). Statistically significant difference: * p < 0.05; ** p < 0.01; *** p < 0.001; n.s.—not significant.