As hay is not grown in a laboratory setting and is harvested with machinery, rabbit owners may often find random dried plants in their purchases of hay, even with the best quality control. In general, picking out these unrecognized plants and feeding the rest of the hay is okay. The following are some pictures of plants that have been observed to be included in packaged and bales of hay.
Dried dock (Rumex spp.) [source]
Dried mullein (Verbascum thapsus) [source]
Dried mallow (Malva spp.) [source]
Dried pigweed/amaranth (Amaranthus spp.) [source]
Dried horsenettle berries (Solanum carolinense) [source]
Dried barnyard grass (Echinochloa crus-galli) [source]
Dried foxtail (Setaria viridis) [source]
Dried field pennycress (Thlaspi arvense) [source]
Dried common milkweed (Asclepias syriaca) [source]
Dried hoary alyssum (Berteroa incana) [source]
Dried purple thistle (Cirsium horridulum) [source]
Dried sow thistle (Sonchus spp.) [source]
Dried horsetail (Equisetum arvense) [source]Dried weeds found in hay