Chen et al. BMC Genomics 2014, 15:100

The above reference have the procedure below, just in case, If you don't have access to the article, I have copied and pasted it for you,

Preparation of exosomes from milk

Porcine milk samples were centrifuged first at 2,000 × g for

30 min at 4°C to remove MFGs as well as mammary glandderived

cells. Defatted samples were then subjected to

centrifugations at 4°C for 30 min at 12,000 × g to remove

residual MFGs, casein and other debris. Subsequently, from

the final supernatant (so-called whey or milk serum), the

membrane fraction was prepared by ultracentrifugation at

110,000 × g for 2 h in an SW41T rotor (Beckman Coulter

Instruments, Fullerton, CA) .

I hope this works for you.

Hie my friend..found this article may help you its free on net.

Comparison of Methods for Isolating Exosomes from Bovine Milk

Tetsuya YAMADA1), Yasuo INOSHIMA1)*, Tsukasa MATSUDA2) and Naotaka ISHIGURO1)

1)Laboratory of Food and Environmental Hygiene, Department of Veterinary Medicine, Gifu University, 1–1 Yanagido, Gifu 501–1193,

Japan

2)Graduate School of Bio-Agricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464–8601, Japan

(Received 27 January 2012/Accepted 12 June 2012/Published online in J-STAGE 26 June 2012)

Hello

And see these attachment and link

Good Luck  

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3369768/

Thank you guys, the articles are a great help

Total exosome isolation (from other samples) reagent - there is a protocol for milk

Thanks Alex

Preprint Charge Detection Mass Spectrometry Measurements of Exosomes ...