Humayd bin Malik asked Sa'd (may Allah be pleased with him): Our hunting dogs eat some of the game while hunting and leave some. He said: Even if they leave only half, eat it.
This one is mawsul (with a connected chain).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيد والذبائح / 18881