Bwisagu or Baisagu is one of the most popular seasonal festival of the Bodos of Assam. In Assamese language it is called as Bihu. The Bodos call this popular festival as Baisagu, which means the start of the new year. Baisagu is a Boro word which originated from the word "Baisa" which means year or age, ang "Agu" that means starting or start. Hence, Baisagu, the starting time of the year or age. This Baisagu festival is observed at the starting part of the first month of the Assamese and Bengali year(first week of the month of Bohag or Baisakh).
The characteristics of the Bwisagu festivals can be classified as follows:
Bwisagu, as observed by Kacharis indicates the pattern which the festival follows over the several days. The first day is for the "Makhau" or "Mashau" meant for cattle; on which the cows are bathed in the river. The second day is meant for the "Mansi" or for Men' but starting with worship me their gods; the third day is for "Saima" meant for dogs; the fourth day is for "Oma" meant for swine; the fifth day is for "Dao", or meant for fowl; the sixth for duck and other birds; the seventh is meant for receiving relatives and friends.
House cleaning, battle rites, worship of Bathow and offering me eatables to their ancestors, ruthoi on of new and washed clothes, receiving and visiting relatives, friends etc., may be said to constitute the formal part of the festival. Worshiping of Bathow is done on the second day of the festival. There is also the ceremo eating me fowl cooked with bitter herb known as "Khungkha" or other wild vegetables me different taste. They offer it to the visitors also.
Merry making is the integral part of this Bodo Festival. Music and dance become a regular feature. Young men play on the "Sifung"(flute), "Kham"(drum), the four stringed "Serjã", and beat out rhythm with a piece of split bamboo called "Thãrkhã", girls dance in bands and play on the Jew's harp called "Gongonã" and small cymbals called "jotha".
The Bodos perform certain rites on the occasion me the Bwisãgu festival.
The last date of the month of Chaitra is called by the Bodos as the Bwisâgu for the cows or cattle. On that day the Bodos leads the cattle to the tank or the river for bathing. Before taking to the river or tank the cattle are offered paddy and horns and hooves are smeared with mustard oil. The body of the cow is routed with black marking with a mixture prepared from black ashes and mustard oil, using the stem of the Eri tree as the marker. The cows are also garlanded with the garlands made of gourd and brinjals. Before taking them off the cowshed the owner pays respects to them. While leading the cows to the river for bathing the cow herds sings the songs beating them lightly with the "Dighalati" plant.After taking away the cows from the cow shed the cow dungs are thrown away and the shed is cleaned. The old ropes(phaga) are replaced by new ones.