The Detection of Bovine Estrus by Lactoferrin Monoclonal Antibody.

Jihwan Lee,Suhyun Lee,Kyungwoon Kim,Seungmin Ha,Seokhyun Lee,Manhye Han,Younbae Park,Myunghum Park,Hakjae Chung,Gulwon Jang

doi:10.3390/ani11061582

Abstract

Simple SummaryThis study aimed to develop monoclonal antibodies with high specificity against bovine lactoferrin, which we have previously demonstrated to be overexpressed in bovine cervical mucus during estrus. Using an enzyme-linked immunosorbent assay, we observed that our monoclonal exhibited strong affinity for bovine lactoferrin protein. In addition, upon testing the new heat detection kits based on our antibody on 12 Korean native cows, we demonstrated an accurate detection of estrus during estrous synchronization. This is the first report of a non-invasive method to detect estrous using antibodies that bind to physiological material in cows. The results of this study suggest that the antibodies and a fabricated heat detection kit can be utilized to improve estrous detection in the cattle industry.To improve reproductive performance in cattle, the accurate detection of estrus and optimization of insemination relative to ovulation are necessary. However, poor heat detection by farm staff leads to a decreased conception rate, thus inflicting economic damage to the beef and dairy industries. This study aimed to develop monoclonal antibodies (mAb) that can specifically bind to the bovine lactoferrin (bLF) protein, which we have previously demonstrated to be overexpressed in bovine cervical mucus during estrus. Female rats were intraperitoneally immunized with bLF protein as the antigen. Anti-bLF mAbs were then purified by affinity chromatography, and their binding affinity for the bLF antigen was examined using ELISA. We found a high binding affinity between mAbs and bLF. Finally, we developed a rapid bovine heat detection kit using the anti-bLF mAbs that we generated and tested on cervical mucus from 12 cows (estrous synchronization, n = 2; natural cycling, n = 10). We found that the kits accurately detected estrus. Overall, our fabricated heat detection kit based on rat anti-bLF mAbs could pave the way for the development of potent tools for heat detection devices for dairy cattle, thereby preventing economic loss.

Highlights

In South Korea, the milk production of dairy cows has tremendously increased over the past 30 years
We aimed to develop a heat detection kit based on the anti-bovine lactoferrin (bLF) monoclonal antibodies (mAb) that binds to bLF, present in the cervical mucus
We found seven predicted candidate antigenic peptide regions from bLF amino acid sequences (Table 1)

Summary

Introduction

In South Korea, the milk production of dairy cows has tremendously increased over the past 30 years. The 305-day adjusted milk yield of Holstein-Friesian cows increased by approximately 40% from 6176 kg in 1990 to 10,352 kg in 2019 through the government’s herd improvement program [1]. Esslemont (1997 yr) and Senger (1994 yr) reported that the economic loss caused by poor heat detection in the UK and US was estimated to be £200 million and $300 million per year, respectively [7,8,9]. According to data released by Statistics Korea (2020), misdiagnosis or failure to detect estrus results in approximately $378 per cow during one estrous cycle (21 days) (http://kostat.go.kr/portal/eng/index.action, accessed on 5 January 2021). A recent survey on the reasons for involuntary culling among dairy farmers in South Korea revealed that reproductive failure accounted for the highest proportion (31.4%) [10]

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