Hi Kavitha, this link may be help you

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1865830/

Dear Kavitha,

you can use bovine serum for this purpose, the link beloow may help for you

http://www.ivis.org/proceedings/navc/2005/LA/001.pdf?LA=1

As I know only the rabbit serum is used for this purpose but it is possible to try otherwise you may discover something new.

some media you can use 

 Fletcher (Difco) semisolid medium

 Fletcher’s Medium with 5-FU 

 Stuart (Difco) liquid medium 

HI

All researches are used rabbit serum as ingredient in Leptospira media, but the percentage used ranges from 3% to 10% as I know.

Preliminary data from my lab has shown that serovar Ictero has been responding well to 10% FBS.

If you're looking to spur on growth in general, the paper below talks about some of the metrics affecting Leptospira growth.

Article Rapid Isolation and Susceptibility Testing of Leptospira spp...

Dear , look in

Current advances in urban leptospirosis diagnosis

Article · Apr 2017 · Reviews in Medical Microbiology📷 Mir Naser Sayyed Mousavi 📷 Javid Sadeghi 📷 Mohammad Aghazadeh +1 more author...📷 Hossein Samadi Kafil

We are able to propagate Leptospires without serum in HAN medium at 37C, 3% CO2. https://www.nature.com/articles/s41598-020-66526-4