Khalil, Abdeltawab Abdelrazek Yassin http://orcid.org/0000-0002-0247-8986
Article History
Received: 3 July 2019
Accepted: 29 July 2019
First Online: 12 September 2019
Ethics approval and consent to participate
: As this is a retrospective study depended mainly on data analysis, so we did not handle any cows at all.
: Not applicable.
: The author declares that he has no competing interests.