noun
Refers to hay, grass, or other feed given to livestock, especially horses. The cross-reference 馬草 (まぐさ) is a near-synonym also meaning horse feed.
See also: 馬草
馬に飼い葉をやる。
I give fodder to the horse.
冬の間、牛のために飼い葉を蓄える。
During winter, we store up feed for the cattle.
馬草 specifically means horse feed, while 飼い葉 is a broader term for animal fodder in general.
Compound of 飼い (kai, 'keeping, raising') + 葉 (ha, 'leaf'), referring to leaves or grass used as feed. The reading かいば is a straightforward combination of the kun'yomi readings of the two kanji.