Lora Isabella, Gottardo Flaviana, Contiero Barbara, Dall Ava Brunella, Bonfanti Lebana, Stefani Annalisa, Barberio Antonio
PhD Course in Animal and Food Science, University of Padova, Viale dell'Università 16, 35020, Legnaro, PD, Italy; Department of Animal Medicine, Production and Health, University of Padova, Viale dell'Università 16, 35020, Legnaro, PD, Italy.
Department of Animal Medicine, Production and Health, University of Padova, Viale dell'Università 16, 35020, Legnaro, PD, Italy.
Prev Vet Med. 2018 Apr 1;152:12-15. doi: 10.1016/j.prevetmed.2018.01.009. Epub 2018 Feb 3.
Calves are highly susceptible to disease and mortality occurrence within the first month of life. Even if failed transfer of passive immunity (FTPI) is commonly recognized as a main factor affecting calf health and survival, conflicting results are reported in literature about the association between passive immunity (PI) and calf health, especially regarding enteric diseases. Therefore, a prospective cohort study was conducted on 78 calves of three Italian dairy farms during winters of years 2014-2016, with the specific aim of evaluating the association between PI and health status of calves within 30 days of age under field conditions. Blood samples were collected between 1 and 5 days of age from each calf included in the study, and disease and mortality occurrence was monitored throughout the first month of life. Additionally, fecal samples were collected from calves with scours before treatment. Blood serum samples were tested by an electrophoretic method for the assessment of immunoglobulin (Ig) concentration, whereas fecal samples were submitted to ELISA test for positivity to Escherichia coli K99, rotavirus, coronavirus, and Cryptosporidium spp. Only enteric diseases occurred in calves of this study. Calves that suffered from diarrhea or died within the first month of life had lower serum Ig concentrations than those that remained healthy or survived (P < .05). Even if not significantly (P = .127), lower serum Ig concentrations were observed in sick calves that had been treated with antibiotics compared to those that had not been treated. The odds of disease and mortality occurrence were 24 (95% CI = 3-231) and 11 (95% CI = 1-111) times higher, respectively, for calves with FTPI (serum Ig concentration <10.0 g/L) than for those with an adequate PI transfer (P < .05). Calves with adequate PI transfer had also a 6-day delay in the age at first disease onset compared to those with FTPI (P < .01). Even if estimated on a small number of calves, those with FTPI had higher risks of enteric infections by rotavirus (odds ratio = 12; 95% CI = 1-137) and Cryptosporidium spp. (odds ratio = 9; 95% CI = 1-72) (P < .05). In this study, the PI level influenced the occurrence of enteric diseases and mortality in calves under one month of age, confirming the importance of a proper colostrum provision to calf health and, consequently, to the reduction of antimicrobial use in dairy farming. However, further investigations are needed, particularly focusing on the relationship between PI and specific enteropathogen infections in calves.
犊牛在出生后的第一个月内极易患病和死亡。尽管被动免疫失败（FTPI）通常被认为是影响犊牛健康和存活的主要因素，但文献中关于被动免疫（PI）与犊牛健康之间的关联，尤其是关于肠道疾病的关联，报道结果相互矛盾。因此，在2014 - 2016年冬季，对意大利三个奶牛场的78头犊牛进行了一项前瞻性队列研究，其具体目的是在田间条件下评估30日龄内犊牛的PI与健康状况之间的关联。在研究纳入的每头犊牛1至5日龄时采集血样，并在其出生后的第一个月内监测疾病和死亡情况。此外，在治疗前从患腹泻的犊牛采集粪便样本。通过电泳法检测血清样本以评估免疫球蛋白（Ig）浓度，而粪便样本则进行ELISA检测以确定对大肠杆菌K99、轮状病毒、冠状病毒和隐孢子虫属的阳性反应。本研究中犊牛仅发生肠道疾病。在出生后第一个月内患腹泻或死亡的犊牛血清Ig浓度低于保持健康或存活下来的犊牛（P < 0.05）。即使差异不显著（P = 0.127），与未接受抗生素治疗的患病犊牛相比，接受抗生素治疗的患病犊牛血清Ig浓度较低。FTPI（血清Ig浓度<10.0 g/L）的犊牛发生疾病和死亡的几率分别比被动免疫转移充足的犊牛高24倍（95% CI = 3 - 231）和11倍（95% CI = 1 - 111）（P < 0.05）。与FTPI的犊牛相比，被动免疫转移充足 的犊牛首次发病年龄延迟6天（P < 0.01）。即使是基于少数犊牛进行估计，FTPI的犊牛感染轮状病毒（优势比 = 12；95% CI = 1 - 137）和隐孢子虫属（优势比 = 9；95% CI = 1 - 72）的肠道感染风险更高（P < 0.05）。在本研究中，PI水平影响了1月龄内犊牛肠道疾病的发生和死亡率，证实了为犊牛提供适量初乳对其健康的重要性，从而也对减少奶牛养殖中抗菌药物的使用具有重要意义。然而，还需要进一步研究，特别是关注PI与犊牛特定肠道病原体感染之间的关系。
