Abstract：
A dysregulated inflammatory response contributes to the occurrence of disorders in cows during the transition period from pregnancy to lactation. However, a detailed characterization of clinically healthy cows that exhibit an enhanced inflammatory response during this critical period remains incomplete. In this experiment, a total of 99 individual transition dairy cows and 109 observations (18 cows monitored in 2 consecutive lactations), submitted to similar transition management were involved to evaluate the relationship between elevated an inflammatory response and metabolic and oxidative status, as well as transition outcomes. Blood was taken at -7, 3, 6, 9, and 21 DIM, and concentrations of metabolic parameters (glucose, β-hydroxybutyric acid, nonesterified fatty acids [NEFA], insulin, IGF-1, and fructosamine) were analyzed. Additionally, oxidative parameters (proportion of oxidized glutathione to total glutathione in red blood cells, the activity of glutathione peroxidase [GPx] and superoxide dismutase, concentrations of malondialdehyde, and oxygen radical absorbance capacity) and acute phase proteins (APP) including haptoglobin (Hp), serum amyloid A (SAA) and albumin-to-globulin ratio (A:G) were determined in the blood at 21 DIM. The 3 APP parameters were used to group clinically healthy cows into 2 categories through k-medoids clustering (i.e., a group showing an acute phase response, APR; n = 39) and a group not showing such a response (i.e., non-APR; n = 50). Diseased cases (n = 20) were handled in a separate group. Lower SAA and Hp concentrations as well as higher A:G were observed in the non-APR group, although for Hp, differences were observed from the APR group and not from the diseased group. Only 1 of the 5 oxidative parameters differed between the groups, with the non-APR group exhibiting lower GPx activity compared with the diseased group. The non-APR group showed the highest IGF-1 levels among the 3 groups and and lower NEFA concentrations compared with the diseased groups. Cows in the diseased group also showed reduced dry matter intake and milk yield compared with clinically healthy cows, regardless of their inflammatory status. Moreover, the APR group exhibited temporarily lower activity levels compared with the non-APR group. These findings highlight that cows with a lower inflammatory status after 21 DIM exhibited better metabolic health characteristics and productive performance, as well as activity levels. Nevertheless, the detrimental effects of a higher inflammatory status in the absence of clinical symptoms are still relatively limited.
摘要：
在从怀孕到哺乳的过渡期间，失调的炎症反应导致奶牛疾病的发生。然而,在这个关键时期表现出增强的炎症反应的临床健康奶牛的详细表征仍然不完整。在这个实验中,共有99头个体过渡奶牛和109头观察(在2次连续泌乳中监测了18头奶牛)，提交类似的过渡管理，以评估炎症反应升高和代谢之间的关系，氧化状态以及过渡结果。在牛奶中的-7、3、6、9和21d取血（DIM）和代谢参数的浓度（葡萄糖，β-羟基丁酸（BHBA），非酯化脂肪酸（NEFA），胰岛素，分析了胰岛素样生长因子1（IGF-1）和果糖胺）。此外,氧化参数（红细胞中氧化谷胱甘肽与总谷胱甘肽的比例（GSSG（％）），谷胱甘肽过氧化物酶（GPx）和超氧化物歧化酶（SOD）的活性，丙二醛（MDA）和氧自由基吸收能力（ORAC）的浓度和急性期蛋白（APP），包括触珠蛋白（Hp），在21DIM的血液中测定了血清淀粉样蛋白A（SAA）和白蛋白与球蛋白的比率（A：G）。3个APP参数通过k-medoids聚类将临床健康奶牛分为2类，即，显示急性期反应的组(APR，n=39)和一组没有表现出这样的反应，即，非APR(n=50)。在单独的组中处理患病病例（n=20）。在非APR组中观察到较低的SAA和Hp浓度以及较高的A：G，尽管在APR组中观察到Hp差异，不是来自患病的群体。5个氧化参数中只有一个在组间不同,与患病组相比，非APR组表现出更低的GPx活性。非APR组的IGF-1水平在3组中最高，与患病组相比，NEFA浓度较低。与临床健康奶牛相比，患病组还显示出减少的干物质摄入量和产奶量，不管他们的炎症状态。此外，与非APR组相比,APR组表现出暂时较低的活性水平.这些发现强调，在21DIM后炎症状态较低的奶牛表现出更好的代谢健康特征。生产性能以及活动水平。然而，在没有临床症状的情况下，较高的炎症状态的不利影响仍然相对有限。
