http://www.poets.org/poetsorg/poem/morning-song. A biography of Ms. Path and references may be found here: http://eretzsongs.blogspot.com/2014/09/the-songs-of-eretz-poet-of-month-for.html.
"Morning Song" is comprised of six three-line stanzas that are not formal tercets. The final two stanzas are enjambed. The rhythm is irregular.
The poem begins with the birth of a baby. The speaker, the mother of the baby, is presumably Plath, as she was known for her ambivalence toward motherhood and toward being a mother. The speaker feels no maternal attachment to her child as is evident in the third stanza. In the fifth stanza, the mother compares herself to something bovine and her baby to something parasitic and feline. The poem ends with the approach of dawn and the baby howling--its "morning song."