Table 1.
Ration ingredients and proximate and fatty acid (FA) composition of the experimental diets throughout the lactation period.
| Items | Early- and Mid-Lactation Experimental Diets 1 | Late-Lactation Experimental Diets 1 | ||||
|---|---|---|---|---|---|---|
| Control | DOP40 | DOP80 | Control | DOP40 | DOP80 | |
| Ration ingredients, % DM basis | ||||||
| Alfalfa hay | 17.4 | 17.5 | 17.6 | 20.2 | 20.3 | 20.4 |
| Concentrate | ||||||
| Dehydrated orange pulp (pellets) | 0 | 20.0 | 40.0 | 0.00 | 19.4 | 38.6 |
| Grain oats | 22.1 | 13.2 | 4.38 | 21.4 | 12.8 | 4.24 |
| Grain barley | 8.53 | 5.11 | 1.70 | 8.28 | 4.96 | 1.65 |
| Grain corn | 19.3 | 11.6 | 3.89 | 18.8 | 11.3 | 3.77 |
| Soy flour, 44% | 7.31 | 10.2 | 13.0 | 7.09 | 9.92 | 12.6 |
| Sunflower pellets, 28% | 12.8 | 12.5 | 13.8 | 12.5 | 12.1 | 13.5 |
| Grain peas | 10.3 | 8.12 | 4.05 | 10.0 | 7.87 | 3.93 |
| Salt | 0.41 | 0.41 | 0.41 | 0.39 | 0.39 | 0.39 |
| Stabilized lard | 0.41 | 0.00 | 0.00 | 0.39 | 0.00 | 0.00 |
| Vitamins and minerals | 1.31 | 1.31 | 1.32 | 1.01 | 1.01 | 1.02 |
| Proximate composition and nutritive value, % DM | ||||||
| DM, % | 87.2 | 87.6 | 88.1 | 87.1 | 87.1 | 88.1 |
| Crude protein | 17.8 | 16.6 | 18.4 | 20.9 | 18.7 | 18.3 |
| Neutral detergent fiber | 24.3 | 22.6 | 25.4 | 29.8 | 26.6 | 28.3 |
| Acid detergent fiber | 12.3 | 15.9 | 19.0 | 14.7 | 15.2 | 16.8 |
| Acid detergent lignin | 4.14 | 4.19 | 5.45 | 3.09 | 3.13 | 3.43 |
| Ether extract | 3.42 | 2.31 | 1.71 | 2.63 | 1.85 | 1.43 |
| Ash | 4.82 | 6.44 | 7.50 | 6.50 | 7.47 | 8.64 |
| Gross energy, kcal/g DM | 4.56 | 4.44 | 4.42 | 4.37 | 4.31 | 4.25 |
| Forage unit for lactation, UFL/kg | 0.98 | 0.98 | 0.97 | 0.98 | 0.98 | 0.96 |
| Protein digestible in the intestine (PDI) | 10.5 | 10.9 | 11.3 | 10.4 | 10.4 | 11.4 |
| Total phenolic compounds, g gallic acid equivalents/kg DM | 5.29 | 6.74 | 8.57 | 5.68 | 7.07 | 8.67 |
| Total antioxidant capacity, mmol trolox equivalents/kg DM | 14.9 | 20.4 | 26.3 | 11.4 | 19.4 | 31.5 |
| α-tocopherol, mg/kg DM | 3.18 | 26.5 | 70.1 | - | - | - |
| FA composition, % total FA | ||||||
| C8:0–C14:0 | 1.10 | 2.99 | 4.58 | 3.88 | 4.22 | 6.11 |
| C16:0 | 23.7 | 23.6 | 27.7 | 23.3 | 25.1 | 27.6 |
| C16:1 | 0.77 | 0.62 | 0.64 | 0.57 | 0.42 | 0.69 |
| C18:0 | 9.02 | 9.83 | 11.4 | 8.90 | 8.98 | 11.9 |
| C18:1 n-9 cis | 26.0 | 23.6 | 20.6 | 26.9 | 20.7 | 15.5 |
| C18:2 n-6 cis | 37.0 | 35.3 | 30.2 | 34.2 | 36.3 | 31.7 |
| C18:3 n-6 | 0.14 | 0.19 | 0.47 | 0.29 | 0.20 | 0.38 |
| C18:3 n-3 | 2.22 | 3.85 | 4.38 | 1.93 | 4.00 | 6.08 |
| ∑SFA | 33.8 | 36.5 | 43.7 | 36.1 | 38.3 | 45.6 |
| ∑MUFA | 26.8 | 24.2 | 21.2 | 27.5 | 21.1 | 16.2 |
| ∑PUFA | 39.4 | 39.3 | 35.1 | 36.4 | 40.5 | 38.2 |
| ∑n-6 | 37.2 | 35.5 | 30.7 | 34.5 | 36.5 | 32.1 |
| ∑n-3 | 2.22 | 3.85 | 4.38 | 1.93 | 4.00 | 6.08 |
| n6/n3 | 16.7 | 9.22 | 7.01 | 17.8 | 9.13 | 5.28 |
1 The control group’s diet was based on a commercial concentrate, with alfalfa hay as forage; for the DOP40 and DOP80 groups, 40% and 80% of the concentrate’s cereal was replaced with DOP.