Animal care statement
The experiment was done at a commercial sow farm that fulfilled animal housing standards and management by farm animal caretakers, trained to abide by authoritative animal welfare standards established by the Law on Animal Welfare 2/2008 published by Diari Oficial de la Generalitat Catalunya [31].
Animals and Housing
The study was conducted at a commercial farm in Spain with 2000 sows. Maternity rooms were mechanically ventilated with high-flow fans and individual room temperature control. There were 27 maternity rooms, each with 16 crates. Each crate had individual sow feeders equipped with feed drop tubes and drinkers and supplemental heat pads for the piglets. There were 452 Naïma Choice Genetics sows (average parity 2.63 ± 0.08; parity 1 to 8) used for the study that had their initial parturition from November 2018 through March 2019 and the average age of pigs at weaning was 24.3 ± 0.23 d. Sows were managed using a continuous flow through maternity rooms, thus requiring a rolling random allotment of sows to peripartum diets with an attempt to balance diet allotment as evenly as possible across sow parity as they entered maternity.
Standard production parameters, including litter size of total pigs born, pigs born alive, stillborn pigs, mummified pigs, pigs after cross-fostering, and pigs weaned were recorded for the initial parturition. According to the study protocol, cross-fostering of litters during the initial parturition was only to be done within 48 h postpartum and only within room and within dietary treatment. However, cross-fostering was not successfully accomplished as requested due to the difficulty to manage piglet welfare yet maintain litter integrity within treatment groups throughout the lactation period at this highly prolific sow farm. Therefore, progeny data after cross-fostering to weaning was excluded from the final data analyses due to these uncontrollable, but confounding factors that make it difficult to manage sow studies, especially when having more than two dietary treatments.
Other parameters evaluated included sow mortality and culls prior to movement to breeding, percentage of sows moved to breeding, the intervals for wean to first estrus and wean to final service, percentage of sows completing their next parturition, and litter size at birth of the next parturition. In addition the change in total and live born litter size from the initial to next parturition was calculated, considering total born litter size of the initial parturition was established before peripartum diets were fed. Post-weaning sow reproductive performance and litter size information at birth for the next parturition was recorded to determine if prior feeding of the peripartum feed in the initial parturition impacted subsequent litter size in the next parturition.
Experimental peripartum sow diets
Three peripartum sow diets containing either 0, 0.5 or 2.5% SDPP were formulated to provide similar levels of net energy and amino acids with SDPP replacing soybean meal (Table 1). Sows were provided 3 kg/d of their assigned peripartum feed pellets from the day of entry in maternity to the day of parturition, and 4.5 kg/d from day 1 to 5 of lactation. Peripartum feed output and refusals were recorded during the peripartum period. Average days of the peripartum period and average daily feed intake per sow corrected for feed refusals are presented in Table 2. Sows were provided a common lactation feed for the remainder of the lactation period to weaning and common breeding-gestation feed to the next parturition, however feed consumption per sow was not recorded during these production periods.
Table 1
Ingredient and nutrient composition of peripartum sow diets.
Ingredient, % | 0% SDPP | 0.5% SDPP | 2.5% SDPP |
Barley | 31.61 | 30.77 | 30.35 |
Corn | 15.00 | 15.00 | 15.00 |
Wheat | 10.00 | 10.00 | 14.00 |
Wheat bran | 20.00 | 20.00 | 20.00 |
Soybean meal (47% CP) | 10.30 | 10.70 | 5.70 |
Spray-dried porcine plasma1 | 0.00 | 0.50 | 2.50 |
Ligno-cellulose product2 | 2.50 | 2.50 | 2.50 |
Beet pulp | 7.50 | 7.50 | 7.50 |
Soy oil | 0.60 | 0.63 | 0.20 |
Calcium carbonate | 1.65 | 1.70 | 1.70 |
Monocalcium phosphate | 0.04 | 0.00 | 0.00 |
Salt | 0.44 | 0.40 | 0.25 |
L-lysine HCL | 0.05 | 0.00 | 0.00 |
L-threonine | 0.015 | 0.00 | 0.00 |
VTM premix2 | 0.03 | 0.30 | 0.30 |
Analyzed nutrients | | | |
Dry matter, % | 87.2 | 87.3 | 87.9 |
Crude protein, % | 14.4 | 15.2 | 14.6 |
Calculated net energy, kcal/kg | 2101 | 2100 | 2100 |
Calcium, % | 0.90 | 1.04 | 1.03 |
Phosphorus, % | 0.43 | 0.45 | 0.46 |
Calculated digestible phosphorus, % | 0.25 | 0.25 | 0.25 |
Lysine, % | 0.65 | 0.67 | 0.69 |
Methionine, % | 0.23 | 0.22 | 0.22 |
Methionine + Cysteine, % | 0.44 | 0.44 | 0.47 |
Threonine, % | 0.56 | 0.53 | 0.57 |
Tryptophan, % | 0.19 | 0.20 | 0.19 |
Isoleucine | 0.59 | 0.61 | 0.57 |
Valine | 0.64 | 0.68 | 0.68 |
1 APPETEIN GS, APC Europe S.L., Granollers, Spain. |
2 FibreCell 5, Agromed Austria GmbH, Kremsmünster, Austria. Ligno-cellulose product made from wood. |
3 ASN GESTATING SOWS 3 FIT; a commercial vitamin-trace mineral premix plus phytase. Provided the following per kg: vitamin A, 8500 UI; vitamin D3, 1500 UI; vitamin E, 30 total; vitamin E, 15 UI; moliphenol, 3 g, vitamin K3, 2 g; vitamin B1, 1.5 g; vitamin B2, 3 g; vitamin B6, 2 g; vitamin B12, 20 mg; pantothenic acid, 10 g; niacin, 15 g; folic acid, 2 g; biotin, 200 mg; choline, 300 g; Fe, 80 g; Cu, 10 g; Zn, 90 g; Mn, 60 g; selenium total, 0.25 g; organic selenium, 0.1; iodine, 2 g; phytase 750. |
Table 2
Peripartum feed intake and litter size during initial parturition by peripartum diet and sow class.
| | Peripartum diet, % SDPP2 | | Statistics (F-test, P =)3 |
Variable | Sow Class1 | 0 | 0.5 | 2.5 | SEM | P | D | L | Q | P x D |
Sows, n | A | 147 | 167 | 138 | --- | --- | --- | --- | --- | --- |
| Y | 94 | 111 | 90 | --- | --- | --- | --- | --- | --- |
| M | 53 | 56 | 48 | --- | --- | --- | --- | --- | --- |
Peripartum days | A | 10.95 | 11.42 | 11.11 | 0.19 | 0.03 | 0.17 | 0.97 | 0.06 | 0.03 |
| Y | 10.46 | 11.02 | 11.29 | 0.23 | 0.31 | 0.05 | 0.04 | 0.19 | 0.24 |
| M | 11.43 | 11.89 | 10.93 | 0.30 | 0.39 | 0.03 | 0.06 | 0.10 | 0.18 |
Feed intake, kg/d | A | 3.72 | 3.67 | 3.69 | 0.02 | 0.03 | 0.07 | 0.41 | 0.03 | 0.02 |
| Y | 3.77 | 3.70 | 3.68 | 0.02 | 0.41 | < 0.01 | 0.01 | 0.05 | 0.04 |
| M | 3.68 | 3.64 | 3.70 | 0.02 | 0.45 | 0.02 | 0.09 | 0.06 | 0.14 |
Total born pigs | A | 14.68 | 14.69 | 13.82 | 0.30 | < 0.01 | 0.06 | 0.02 | 0.62 | 0.42 |
| Y | 14.23 | 14.10 | 12.83 | 0.35 | 0.11 | < 0.01 | < 0.01 | 0.73 | 0.32 |
| M | 15.10 | 15.29 | 15.00 | 0.64 | 0.59 | 0.93 | 0.82 | 0.78 | 0.42 |
Live born pigs | A | 12.65 | 13.12 | 12.28 | 0.29 | 0.07 | 0.10 | 0.14 | 0.12 | 0.16 |
| Y | 12.68 | 12.93 | 11.56 | 0.34 | 0.02 | < 0.01 | < 0.01 | 0.26 | 0.21 |
| M | 12.76 | 13.37 | 13.13 | 0.58 | 0.41 | 0.72 | 0.80 | 0.43 | 0.55 |
Stillborn pigs | A | 1.84 | 1.40 | 1.34 | 0.17 | < 0.01 | 0.06 | 0.08 | 0.09 | 0.71 |
| Y | 1.45 | 1.06 | 1.13 | 0.16 | 0.23 | 0.18 | 0.35 | 0.10 | 0.27 |
| M | 2.07 | 1.61 | 1.59 | 0.43 | 0.84 | 0.65 | 0.50 | 0.46 | 0.71 |
Stillborn, % | A | 11.78 | 8.77 | 9.29 | 1.01 | 0.03 | 0.06 | 0.23 | 0.04 | 0.46 |
| Y | 9.98 | 7.04 | 9.04 | 1.14 | 0.20 | 0.14 | 0.98 | 0.05 | 0.12 |
| M | 12.83 | 9.98 | 9.78 | 1.94 | 0.73 | 0.53 | 0.41 | 0.38 | 0.82 |
Mummified pigs | A | 0.19 | 0.17 | 0.21 | 0.05 | 0.02 | 0.87 | 0.75 | 0.67 | 0.92 |
| Y | 0.11 | 0.11 | 0.14 | 0.05 | 0.66 | 0.84 | 0.56 | 0.92 | 0.57 |
| M | 0.26 | 0.31 | 0.28 | 0.14 | 0.29 | 0.96 | 0.99 | 0.77 | 0.54 |
Mummified, % | A | 1.22 | 1.11 | 1.46 | 0.39 | 0.07 | 0.80 | 0.56 | 0.74 | 0.94 |
| Y | 0.75 | 0.68 | 1.18 | 0.44 | 0.44 | 0.66 | 0.40 | 0.76 | 0.30 |
| M | 1.58 | 2.13 | 1.82 | 0.87 | 0.28 | 0.88 | 0.96 | 0.61 | 0.36 |
Sows to breeding, % | A | 94.4 | 92.8 | 97.8 | 2.05 | 0.23 | 0.20 | 0.12 | 0.37 | 0.69 |
| Y | 92.6 | 92.8 | 95.6 | 2.60 | 0.76 | 0.65 | 0.36 | 0.90 | 0.34 |
| M | 97.3 | 93.8 | 100.0 | 3.55 | 0.88 | 0.32 | 0.34 | 0.32 | 0.87 |
1 Results for class A included data of all sows with parity categorized as Y for young (parity 1 and 2) sows and M for mature (parity 3 to 8) sows. Results for class Y included only data of young sows and class M included only data for mature sows. |
2 Values are least squares peripartum diet means by sow class. |
3 Each sow class was analyzed for the effects of P (A class, parity category Y or M; Y class, parity 1 and 2; M class, parity 3 to 8), D (peripartum diet), L (linear contrast of % SDPP in diet), Q (quadratic contrast of % SDPP in diet) and P x D (interaction of parity category per sow class by diet). |
Blood sampling and analytical procedures
Blood samples were collected on day 2 before the expected parturition date and on day 4 after parturition from the tail vein of 57 randomly selected sows using vacutainer tubes without anticoagulant for a total of 78 samples collected. Samples were collected from 21 of the 57 selected sows at both sampling periods. Blood samples were kept at ambient temperature for 30 to 45 min until clot formation, then subjected to centrifugation at 2000 g for 10 min. The serum was pipetted into new tubes, labeled by date and sow number, then stored at -80 °C until analysis for cytokine and oxidation status parameters. Due to hemolysis some samples were discarded. The final number of sows used, and samples statistically analyzed per diet and sampling period are presented in Table 4.
Table 4
Serum cytokine and oxidation status of prepartum and postpartum sows fed peripartum diets with SDPP.
| | Peripartum diet, % SDPP1 | | Statistics (F-test, P =)2 |
Variable | Period | 0 | 0.5 | 2.5 | SEM | P | D | L | Q | P x D |
Sows, n3 | -2 d | 11 | 13 | 11 | --- | --- | --- | --- | --- | --- |
| + 4 d | 14 | 9 | 14 | --- | --- | --- | --- | --- | --- |
IFN-α, pg/mL | -2 d | 0.97 (10) | 0.49 (9) | 0.58 (9) | 0.38 | 0.80 | 0.17 | 0.30 | 0.14 | 0.88 |
| + 4 d | 1.27 (13) | 0.45 (6) | 0.55 (11) | 0.47 | | | | | |
IFN-γ, pg/mL | -2 d | 1.67 (10) | 1.60 (9) | 1.69 (9) | 0.06 | 0.73 | 0.72 | 0.86 | 0.44 | 0.63 |
| + 4 d | 1.71 (13) | 1.67 (6) | 1.63 (12) | 0.08 | | | | | |
IL-10, pg/mL | -2 d | 3.16 (10) | 3.43 (9) | 3.45 (9) | 1.79 | 0.25 | 0.70 | 0.52 | 0.63 | 0.81 |
| + 4 d | 3.61 (13) | 5.51 (6) | 5.95 (12) | 2.20 | | | | | |
IL-1β, pg/mL | -2 d | 82.7 (10) | 24.5 (9) | 8.98 (9) | 45.2 | 0.88 | 0.23 | 0.18 | 0.35 | 0.99 |
| + 4 d | 82.1 (13) | 31.6 (6) | 18.9 (12) | 55.4 | | | | | |
IL-4, pg/mL | -2 d | 1.68 (10) | 1.30 (9) | 1.25 (9) | 0.29 | 0.81 | 0.19 | 0.18 | 0.27 | 0.99 |
| + 4 d | 1.77 (13) | 1.36 (6) | 1.28 (12) | 0.35 | | | | | |
IL-6, pg/mL | -2 d | 32.5 (10) | 15.6 (9) | 8.46 (9) | 14.1 | 0.81 | 0.24 | 0.25 | 0.26 | 0.91 |
| + 4 d | 28.5 (13) | 7.36 (6) | 12.6 (12) | 17.2 | | | | | |
IL-8, pg/mL | -2 d | 26.0 (10) | 27.9 (9) | 13.5 (9) | 15.0 | < 0.01 | 0.35 | 0.21 | 0.38 | 0.84 |
| + 4 d | 60.6 (13) | 78.7 (6) | 48.5 (12) | 18.4 | | | | | |
TNF-α, pg/mL | -2 d | 31.0 (10) | 44.6 (9) | 19.9 (9) | 18.4 | 0.50 | 0.83 | 0.55 | 0.86 | 0.72 |
| + 4 d | 47.9 (13) | 36.8 (6) | 41.3 (12) | 22.5 | | | | | |
IL-12, pg/mL | -2 d | 146.2 (10) | 89.9 (9) | 63.9 (9) | 33.5 | 0.91 | 0.15 | 0.22 | 0.17 | 0.59 |
| + 4 d | 122.6 (13) | 69.4 (6) | 98.9 (12) | 41.1 | | | | | |
MDA, µM | -2 d | 13.4 (11) | 11.2 (13) | 12.2 (11) | 2.48 | < 0.01 | 0.61 | 0.49 | 0.46 | 0.66 |
| + 4 d | 17.7 (12) | 16.8 (8) | 20.8 (13) | 2.91 | | | | | |
SOD, U/mL | -2 d | 0.97 (11) | 0.62 (13) | 0.75 (11) | 0.15 | 0.07 | 0.12 | 0.20 | 0.11 | 0.75 |
| + 4 d | 1.17 (14) | 0.97 (8) | 0.87 (12) | 0.18 | | | | | |
TAS, mmole/L | -2 d | 0.47 (10) | 0.61 (13) | 0.65 (11) | 0.07 | 0.57 | 0.15 | 0.13 | 0.23 | 0.66 |
| + 4 d | 0.56 (11) | 0.63 (6) | 0.63 (13) | 0.09 | | | | | |
GPx, U/L | -2 d | 7382 (11) | 8188 (13) | 9055 (11) | 496 | 0.92 | 0.01 | < 0.01 | 0.28 | 0.87 |
| + 4 d | 7599 (14) | 8340 (9) | 8806 (14) | 548 | | | | | |
1 Values are least squares diet means and number (n) of serum samples analyzed by sampling period, 2 d before expected parturition (-2 d) and 4 d after parturition (+ 4 d). |
2 Probability values for P (period), D (diet), L (linear contrast of % SDPP in diet), Q (quadratic contrast of % SDPP in diet), and P x D (interaction of period and diet). |
3 Number of sows sampled by period and diet; number of samples analyzed per cytokine or oxidation status marker varied due to discarded samples affected by hemolysis. |
Cytokine serum levels were determined using a cytokine and chemokine panel (ProcartaPlex Pig, Luminex B.V, Hertogenbosch, The Netherlands) as specified by the manufacturer: interferon alpha (IFN-α), interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin (IL), IL-1β, IL-4, IL-6, IL-8, IL-10 and IL-12. Readings were performed on the Luminex MAGPIX system (Luminex B.V, Hertogenbosch, The Netherlands).
Total antioxidant status (TAS), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were determined using a kit from RANDOX laboratories (Crumlin, UK) and readings were performed using an AU400 analyzer (Beckman Coulter, Germany). Malonaldehyde (MDA) levels were determined using a TBARS Assay Kit (Cayman Chemical, Michigan, USA) following the manufacturer protocol and readings were performed using the Multiskan Sky (ThermoFisher Scientific, Waltham, MA, USA).
Statistical analysis
All production data with sow as the experimental unit were statistically analyzed by ANOVA using the GLM procedure of SAS (version 9.4, SAS Inst. Inc., Cary, NC) for the effects of parity class, peripartum diet, and interaction of parity class x peripartum diet. Linear and quadratic contrasts were included in the model to test the significance of SDPP level in the peripartum diet. Parity of sows ranged from 1 to 8; however, parity distribution across dietary treatments was not evenly distributed, especially for sows within parity 3 to 8. Unequal parity distribution across treatments can significantly skew calculated least squares means when using parity in the model, so sows were designated into a parity class where Y = young sows (combined parity 1 and 2 sows) and M = mature sows (parity 3 to 8 sows). The designated parity class was used in the statistical model to test parity effects and the interaction of parity class and diet for all sows. The production data results from all sows using this model are designated as class A in Table 2 (initial parturition data) and Table 3 (postweaning to next parturition data).
Table 3
Subsequent postweaning performance and litter size of sows by previous peripartum feed and sow classification.
| | Peripartum diet, % SDPP2 | | Statistics (F-test, P =)3 |
Variable | Sow class1 | 0 | 0.5 | 2.5 | SEM | P | D | L | Q | P x D |
Wean to first estrus, d | A | 8.63 | 8.65 | 8.96 | 0.64 | 0.92 | 0.92 | 0.68 | 0.96 | 0.36 |
| Y | 8.47 | 8.04 | 9.59 | 0.84 | 0.15 | 0.38 | 0.22 | 0.53 | 0.26 |
| M | 9.83 | 8.96 | 8.51 | 0.98 | 0.23 | 0.59 | 0.34 | 0.59 | 0.03 |
Wean to final service, d | A | 11.43 | 10.97 | 10.69 | 1.00 | 0.88 | 0.87 | 0.64 | 0.80 | 0.76 |
| Y | 10.77 | 10.84 | 11.14 | 1.27 | 0.23 | 0.98 | 0.82 | 0.99 | 0.03 |
| M | 12.63 | 10.86 | 10.02 | 1.73 | 0.53 | 0.51 | 0.30 | 0.53 | 0.52 |
Sows farrowed, %4 | A | 94.4 | 92.8 | 97.2 | 2.08 | 0.18 | 0.29 | 0.19 | 0.40 | 0.61 |
| Y | 92.6 | 92.8 | 94.4 | 2.67 | 0.58 | 0.86 | 0.58 | 0.96 | 0.35 |
| M | 96.2 | 92.9 | 100.0 | 3.37 | 0.88 | 0.32 | 0.34 | 0.32 | 0.87 |
Total born pigs | A | 14.20 | 14.53 | 14.53 | 0.29 | < 0.01 | 0.64 | 0.54 | 0.47 | 0.04 |
| Y | 14.14 | 15.09 | 15.49 | 0.36 | 0.11 | 0.02 | 0.02 | 0.12 | 0.82 |
| M | 14.46 | 13.50 | 13.32 | 0.56 | < 0.01 | 0.26 | 0.19 | 0.25 | 0.50 |
Live born pigs | A | 12.85 | 12.92 | 13.08 | 0.30 | < 0.01 | 0.86 | 0.58 | 0.94 | 0.21 |
| Y | 13.02 | 13.55 | 13.97 | 0.36 | 0.36 | 0.18 | 0.09 | 0.44 | 0.72 |
| M | 13.05 | 11.99 | 11.83 | 0.55 | < 0.01 | 0.20 | 0.16 | 0.20 | 0.79 |
Stillborn pigs | A | 0.91 | 1.21 | 0.97 | 0.10 | 0.25 | 0.08 | 0.75 | 0.03 | 0.55 |
| Y | 0.76 | 1.14 | 0.98 | 0.12 | 0.17 | 0.07 | 0.55 | 0.03 | 0.85 |
| M | 0.96 | 1.14 | 1.01 | 0.22 | 0.20 | 0.78 | 0.97 | 0.48 | 0.13 |
Stillborn, % | A | 6.81 | 8.05 | 6.93 | 0.74 | 0.16 | 0.40 | 0.75 | 0.19 | 0.87 |
| Y | 5.93 | 7.47 | 6.60 | 0.88 | 0.40 | 0.42 | 0.88 | 0.19 | 0.55 |
| M | 6.76 | 7.94 | 7.79 | 1.53 | 0.09 | 0.82 | 0.71 | 0.58 | 0.32 |
Mummified pigs | A | 0.44 | 0.40 | 0.49 | 0.05 | 0.66 | 0.44 | 0.33 | 0.41 | 0.14 |
| Y | 0.36 | 0.40 | 0.54 | 0.06 | 0.26 | 0.08 | 0.02 | 0.99 | 0.43 |
| M | 0.45 | 0.37 | 0.48 | 0.10 | 0.40 | 0.60 | 0.60 | 0.43 | 0.43 |
Mummified, % | A | 3.01 | 2.73 | 3.61 | 0.36 | 0.21 | 0.20 | 0.12 | 0.37 | 0.37 |
| Y | 2.38 | 2.69 | 3.53 | 0.41 | 0.27 | 0.12 | 0.04 | 0.86 | 0.35 |
| M | 3.10 | 2.64 | 4.24 | 0.80 | 0.54 | 0.22 | 0.15 | 0.45 | 0.31 |
Total born change5 | A | -0.53 | -0.30 | 0.61 | 0.42 | < 0.01 | 0.13 | 0.04 | 1.00 | 0.05 |
| Y | -0.13 | 1.01 | 2.45 | 0.51 | 0.76 | < 0.01 | < 0.01 | 0.32 | 0.93 |
| M | -0.70 | -2.03 | -1.68 | 0.86 | 0.05 | 0.48 | 0.57 | 0.25 | 0.83 |
Live born change5 | A | 0.16 | -0.31 | 0.68 | 0.41 | < 0.01 | 0.22 | 0.18 | 0.26 | 0.06 |
| Y | 0.26 | 0.66 | 2.17 | 0.50 | 0.26 | 0.02 | < 0.01 | 0.96 | 0.79 |
| M | 0.27 | -1.58 | -1.31 | 0.82 | 0.045 | 0.19 | 0.30 | 0.11 | 0.95 |
1 Results for class A included data of all sows with parity categorized as Y for young (parity 1 and 2) sows and M for mature (parity 3 to 8) sows. Results for class Y included only data of young sows and class M included only data for mature sows. |
2 Values are least squares peripartum diet means by sow class. |
3 Each sow class was analyzed for the effects of P (A class, parity category Y or M; Y class, parity 1 and 2; M class, parity 3 to 8), D (peripartum diet), L (linear contrast of % SDPP in diet), Q (quadratic contrast of % SDPP in diet) and P x D (interaction of parity category per sow class by diet). |
4 Percentage of sows having next parturition per sows having initial parturition. |
5 Total born change is total born litter size of subsequent parturition minus total born litter size of previous parturition. Live born change is live born litter size of subsequent parturition minus live born litter size of previous parturition. |
Subsets of data using only young sows (class Y) or only mature sows (class M) were analyzed separately for the effects of actual parity (within data subset), diet, interaction of parity and diet, and with the linear and quadratic contrasts included to test significance of SDPP level in the peripartum feed. The least squares peripartum diet means ± SEM using this model to analyze the subsets of data for designated class Y and class M sows are also presented in Tables 2 and 3.
Serology results were analyzed by ANOVA using the GLM procedure of SAS for the effects of sampling period (2 days before and 4 days after parturition), peripartum diet, and interaction of sampling period x peripartum diet. Least squares peripartum diet means ± SEM by sampling period for cytokine and oxidation status markers are presented in Table 4.
For all performance and serology results significance was designated at P < 0.05, with significant trends at P > 0.05, P < 0.10.