Department of Clinical Science, Faculty of Veterinary Medicine, University of Tabriz, 5166616471 Tabriz, Iran.
Institute of Animal Science, Physiology and Hygiene Unit, University of Bonn, 53111 Bonn, Germany.
J Dairy Sci. 2020 Jul;103(7):6684-6691. doi: 10.3168/jds.2020-18218. Epub 2020 Apr 22.
Haptoglobin (Hp), one of the major positive acute phase proteins in cattle, is released in response to proinflammatory cytokines. Colostrum intake might influence the response of the innate immune system, including Hp gene expression. Thus, we hypothesized that plasma concentrations and tissue mRNA expression of Hp in neonatal calves might be influenced by early nutrition in the neonatal calf and would thus be greater if receiving colostrum compared with milk-based formula. Two trials were performed. In trial 1, German Holstein calves were fed either colostrum (COL; n = 7) or milk-based formula (FOR; n = 7) up to 4 d of life. Blood was sampled from d 1 to 4 before morning feeding and before and 2 h after feeding on d 4. Tissue samples from liver, kidney fat, duodenum, and ileum were collected after slaughter on d 4 at 2 h after feeding. In trial 2, calves born preterm (n = 7) or at term (n = 7) received colostrum only at 24 h post natum. Blood was sampled at birth, and before and 2 h after feeding. Tissue samples from liver and kidney fat were collected after slaughter at 26 h after birth. Blood plasma, colostrum, and formula Hp concentrations were determined using a competitive ELISA. Tissue expression of Hp mRNA was quantified by real-time quantitative PCR. The formula contained much less Hp (≤0.5 µg/mL) than colostrum (69.3, 93.9, and 20.4 µg/mL from d 1 to d 3, respectively). In trial 1, before colostrum or formula feeding, plasma concentrations of Hp were comparable in both groups. Plasma Hp increased in FOR after feeding, resulting in greater or a trend for greater plasma Hp concentrations in FOR than in COL calves. The mRNA abundance of Hp in liver and kidney fat was 3- and 2.2-fold greater in FOR than in COL calves, respectively, whereas duodenal and ileal abundance of Hp mRNA did not differ between groups. In trial 2, plasma Hp concentrations decreased slightly over time in term calves, but they did not differ in both groups before and 2 h after feeding on d 2. The abundance of Hp mRNA in liver was 5.3-fold greater in term than in preterm calves, whereas its abundance in kidney fat did not differ between groups. Contrasting our hypothesis, formula, but not colostrum feeding was associated with greater Hp mRNA abundance in liver and adipose tissue, indicating that the response of innate immune system seems to be modulated by formula feeding because of the lack of immunoglobulin intake. The lower hepatic abundance of Hp mRNA in preterm calves than in term calves may indicate lower synthetic capacity of the liver for Hp in preterm calves shortly after birth.
结合蛋白（Hp）是牛主要的急性期蛋白之一，它是在受到促炎细胞因子刺激时释放的。初乳的摄入可能会影响先天免疫系统的反应，包括 Hp 基因的表达。因此，我们假设新生小牛的血浆 Hp 浓度和组织 mRNA 表达可能受到新生小牛早期营养的影响，如果接受初乳，其浓度将高于接受基于牛奶的配方奶。进行了两项试验。在试验 1 中，德国荷斯坦小牛在生命的头 4 天内分别喂食初乳（COL；n = 7）或基于牛奶的配方奶（FOR；n = 7）。在第 4 天的早晨喂食前和喂食前以及喂食后 2 小时采集血液样本。在第 4 天喂食后 2 小时屠宰后，采集肝脏、肾脂肪、十二指肠和回肠的组织样本。在试验 2 中，早产（n = 7）或足月（n = 7）的小牛仅在出生后 24 小时接受初乳。出生时、喂食前和喂食后 2 小时采集血液样本。出生后 26 小时屠宰时采集肝脏和肾脂肪组织样本。使用竞争性 ELISA 测定血浆、初乳和配方奶 Hp 浓度。通过实时定量 PCR 定量组织 Hp mRNA 的表达。配方奶中的 Hp 含量要低得多（≤0.5μg/ml），而初乳中（第 1 天至第 3 天分别为 69.3、93.9 和 20.4μg/ml）。在试验 1 中，在喂食初乳或配方奶之前，两组小牛的血浆 Hp 浓度相当。在 FOR 中，喂食后 Hp 增加，导致 FOR 中的 Hp 浓度大于或趋于大于 COL 小牛。FOR 中小牛的肝脏和肾脂肪中的 Hp mRNA 丰度分别比 COL 小牛高 3 倍和 2.2 倍，而十二指肠和回肠中的 Hp mRNA 丰度在两组间没有差异。在试验 2 中，足月小牛的血浆 Hp 浓度随时间略有下降，但在第 2 天喂食前和喂食后 2 小时，两组之间没有差异。足月小牛肝脏中 Hp mRNA 的丰度是早产小牛的 5.3 倍，而两组肾脂肪中的 Hp mRNA 的丰度没有差异。与我们的假设相反，配方奶而不是初乳的喂养与肝脏和脂肪组织中 Hp mRNA 丰度的增加有关，这表明由于缺乏免疫球蛋白的摄入，配方奶喂养可能会调节先天免疫系统的反应。与足月小牛相比，出生后不久的早产小牛肝脏中 Hp mRNA 的丰度较低，这可能表明早产小牛肝脏合成 Hp 的能力较低。
