Moazeni Mostafa, Rasooli Aria, Nouri Mohammad, Ghorbanpoor Masoud, Mosavari Nader, Zakian Amir
Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Department of Animal Health Management, School of Veterinary Medicine, Shiraz University, Shiraz, Iran.
Vet Med Sci. 2025 Jul;11(4):e70431. doi: 10.1002/vms3.70431.
The purpose of this study was to investigate the effects of heat treatment on bovine colostrum at 60°C for 90 min on the viability of bacterial pathogens and IgG concentration. In the first experiment, eight batches (4.5 L) of bovine colostrum were inoculated with Escherichia coli (10 cfu/mL), Salmonella Enteritidis (10 cfu/mL), Mycobacterium avium subsp. paratuberculosis (MAP;10 cfu/mL) and Mycobacterium avium subsp. avium (MAA;10 cfu/mL). These batches were then heat-treated using a commercial on-farm batch pasteurization system at 60°C for 90 min. Samples were collected before inoculation, after inoculation, and at 30, 60, 75 and 90 min post-heat treatment to assess pathogen viability. In the second experiment, batches of colostrum (10 L) were heated at 60°C for 90 min across seven replicates. Subsamples were collected before treatment and at 30, 60, 75 and 90 min during heat treatment to measure IgG concentration. The findings indicated that heating colostrum at 60°C for 30 min resulted in detectability (viability) of E. coli and S. Enteritidis in 12.5% and 25% of replicates, respectively, and after 60 min in 0% of replicates. In addition, heat treatment at 60°C resulted in the growth of MAP and MAA in 25% and 12.5% of replicates after 60 min, respectively, and 0% of replicates after 90 min. Importantly, the treatment did not significantly affect IgG concentration (5.7 mg/mL reduction after 90 min) (p > 0.05). According to the results, heating colostrum at 60°C for 60 min completely eliminates E. coli and S. Enteritidis and can render mycobacteria undetectable by culture in most situations. In situations where the control and eradication program for Johne's disease is being considered, heat treatment of colostrum at 60°C for 90 min can be beneficial without concern for a significant reduction in IgG levels.
本研究的目的是调查在60°C下对牛初乳进行90分钟热处理对细菌病原体活力和免疫球蛋白G（IgG）浓度的影响。在第一个实验中，向八批（4.5升）牛初乳接种大肠杆菌（10 cfu/mL）、肠炎沙门氏菌（10 cfu/mL）、副结核分枝杆菌（MAP；10 cfu/mL）和鸟分枝杆菌亚种鸟型（MAA；10 cfu/mL）。然后使用商用农场批量巴氏杀菌系统在60°C下对这些批次的牛初乳进行90分钟的热处理。在接种前、接种后以及热处理后30、60、75和90分钟采集样本，以评估病原体活力。在第二个实验中，将多批（10升）初乳在60°C下加热90分钟，共进行七次重复实验。在处理前以及热处理期间的30、60、75和90分钟采集子样本，以测量IgG浓度。研究结果表明，在60°C下加热牛初乳30分钟后，分别有12.5%和25%的重复实验中可检测到（仍有活力）大肠杆菌和肠炎沙门氏菌，60分钟后在所有重复实验中均未检测到。此外，在60°C下热处理60分钟后，分别有25%和12.5%的重复实验中检测到MAP和MAA生长，90分钟后在所有重复实验中均未检测到。重要的是，该处理对IgG浓度没有显著影响（90分钟后降低了5.7 mg/mL）（p>0.05）。根据结果，在60°C下加热牛初乳60分钟可完全消除大肠杆菌和肠炎沙门氏菌，并且在大多数情况下可使分枝杆菌无法通过培养检测到。在考虑约翰氏病的防控计划时，在60°C下对牛初乳进行90分钟的热处理可能是有益的，无需担心IgG水平会显著降低。
