Diet starch concentration and starch fermentability affect markers of inflammatory response and oxidant status in dairy cows during the early postpartum period

摘要

Our objective was to evaluate the effects of diet starchconcentration and starch fermentability on inflammatoryresponse markers and oxidant status during theearly postpartum (PP) period and its carryover effects.Fifty-two multiparous Holstein cows were used in acompletely randomized block design experiment with a2 × 2 factorial arrangement of treatments. Treatmentswere starch concentration and starch fermentability ofdiets; diets were formulated to 22% (low starch, LS)or 28% (high starch, HS) starch with dry-ground corn(DGC) or high-moisture corn (HMC) as the primarystarch source. Treatments were fed from 1 to 23 d PPand then switched to a common diet until 72 d PPto measure carryover (CO) effects. Treatment period(TP) diets were formulated to 22% forage neutraldetergent fiber and 17% crude protein. The diet forthe CO period was formulated to 20% forage neutraldetergent fiber, 17% crude protein, and 29% starch.Coccygeal blood was collected once a week during theTP and every second week during the CO period. Liverand adipose tissue biopsies were performed within 2 dPP and at 20 ± 3 d PP. Blood plasma was analyzedfor concentrations of albumin, haptoglobin, reactiveoxygen and nitrogen species (RONS), and antioxidantpotential (AOP), with lipopolysaccharide-binding protein(LBP) and TNFα evaluated during the TP only.Oxidative stress index (Osi) was calculated as RONS/AOP. Abundance of mRNA from genes involved in inflammationand glucose metabolism in liver and genesinvolved in lipogenesis in adipose tissue were determined.Data were analyzed separately for the TP andCO periods. During the TP, treatments interacted toaffect concentrations of TNFα, haptoglobin, and LBP,with HMC increasing their concentrations for HS (9.38vs. 7.45 pg/mL, 0.45 vs. 0.37 mg/mL, and 5.94 vs. 4.48μg/mL, respectively) and decreasing their concentrationsfor LS (4.76 vs. 12.9 pg/mL, 0.27 vs. 0.41 mg/mL, and 4.30 vs. 5.87 μg/mL, respectively) comparedwith DGC. Effects of treatments diminished over timefor LBP and haptoglobin with no differences by theend of the TP and no main CO effects of treatmentfor haptoglobin. The opposite treatment interactionwas observed for albumin, with HMC tending to decreaseits concentration for HS (3.24 vs. 3.34 g/dL) andincrease its concentration for LS (3.35 vs. 3.29 g/dL)compared with DGC, with no carryover effect. FeedingDGC increased the Osi during the first week of the TPcompared with HMC, with this effect diminishing overtime; during the CO period HMC increased Osi forHS and decreased it for LS compared with DGC, withthis effect diminishing toward the end of CO. FeedingHMC increased the abundance of genes associatedwith inflammation and gluconeogenesis in liver for HSand decreased it for LS compared with DGC. FeedingHS increased the mRNA abundance of genes associatedwith adipose tissue lipogenesis compared with LS.Results during the TP suggest that feeding LS-DGCand HS-HMC elicited a more pronounced inflammatoryresponse and induced an upregulation of genes associatedwith inflammation and gluconeogenesis in liver,without effects on Osi, but effects on plasma markersof inflammation diminished during the CO period.