Khalid bin Ma'dan (may Allah have mercy on him) says: The Messenger of Allah (peace and blessings be upon him) "assigned shares: two shares for Arab horses and one share for the hybrid."
It is munqati' (broken chain); no proof is established by it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الفيء والغنيمة / 12884