VERSE: 2-54-17, Sanskrit VerseTasya tat vacanam shrutvaa
raaja putrasya dhiimataha
upaanayata dharma aatmaa
gaam arghyam udakam tataha.
When Rama, Lakshmana and Sita, visited Bharadwaja Ashram, Sage Bharadwaja received them well and gave them a cow and water.
Hearing those their words of the brave Princes, the pious sage (Bharadwaja) offered them a cow and water.
Rama, Lakshmana and Sita, on advice from Bharadwaja left to Chitrakoot Mountain crossing the river Yamuna in a self-made bamboo basket-boat. There is no mention of their transporting the cow. There is no mention of the cow accompanying them, when the three (Rama, Lakshmana and Sita) walked.
What happened for the cow later, the Ramayana is silent. Some translators have translated "gaam" as "Madhuparka" a sweet preparation. Literal translation (cow) is better, because the word Madhuparka has gained several meanings over centuries.
*According to Uttara Ramacharita of Bhavabhuti, Madhuparka consists of milk, curd, clarified butter, honey boiled together with a calf's beef. It is given to important guests. In Uttara Rama Charitra, it was given to sage Vasishta by sage Valmiki.
Some others believe that Madhuparka does not include beef.
Nowadays, in South India, many priests performing marriage ceremonies believe that "madhuparka" are clothes. They ask the bride's father to present new clothes to the groom and to Gods.