"Afternoon with Irish Cows" is a poem by Billy Collins, who served as America's poet laureate and is among the most well-known and popular contemporary poets. He wrote this poem when he was in Ireland. It is five stanzas with seven lines in each stanza. Like much contemporary poetry, it does not have a set rhyme scheme and is not written in any particular form (e.g., sonnet or haiku). It is the poet speaking ("I") and observing a simple country scene. The language he uses is simple and direct; the only word that might require looking up is "apologia" (a formal defense of an opinion). As a writer, he would no doubt be aware of the famous Apologia by Cardinal Newman, although this doesn't seem relevant to understanding the poem.
Even though the poem appears informal, even casual, in its tone and language, Collins uses numerous literary devices. In the first stanza, he uses a simile: "as if they had taken wing, flown off to another country" (line 7). You could also see this as a comic moment, as cows, of course, do not fly. Then in stanza three, there is an example of an allusion: "or pierced through the side with a long spear" (21). This refers to Christ, who was stabbed in the side while on the cross. Like Christ, animals are often depicted as innocent and, again like Christ, they are often killed, cows especially.
Finally, Collins often humanizes the cows, giving them qualities more associated with people than with animals. He writes, "How mysterious, how patient and dumbfounded / they appear in the long quiet of the afternoon" (13-14). There are several other examples which the astute reader will be able to find.
Note: You can also find a song version of the poem.