The marmoset is a highly vocal and highly social new world monkey with high reproductive rate. We are interested in the sound processing in the brain of weak marmosets, the vocal development and vocal communications of infant marmosets, as well as the establishment of marmoset models of human mental diseases. The current big challenge is the shortage of marmoset supply, which cannot meet the needs of scientific research, and thus impede the progress of marmoset studies.
Another challenge is the lack of experiments in maintaining a marmoset colony. This hand-rearing method significantly increases the survival rate of marmoset infants, and provides the opportunity to study the development of marmoset infants with similar genetic backgrounds, but raised in different postnatal environments. To begin, clean and sterilize the room by spraying hypochlorous acid or 75%ethyl alcohol on the floor and table.
After leaving for 30 seconds, wipe the table and mop the floor. Set the temperature of the incubator to 35 degrees Celsius and the humidity to 40%Tile a disposable diaper pad to cover the chassis of the incubator. To minimize the stress of the infants, place a couple of blankets and plush toys in the incubator before introducing the infant marmosets.
Wear sterilized personal protective equipment, and warm a couple of blankets to 35 degrees Celsius. Gently hold the infant marmoset with warm blankets, and obtain the weight of the animal as the birth weight. Transfer the animal into the incubator with warm blankets, and record basic information such as the name, birth date, birth weight, parents, and other information of interest.
Dissolve five grams of baby formula in 30 milliliters of boiled water in a 50-milliliter sterile centrifuge tube, and take one milliliter of food with a one-milliliter syringe. Lid the syringe with a custom-made feeding nipple, and use a heating pad to maintain the food temperature at 30 to 35 degrees Celsius. After warming the hands, gently hold the infant with a warm blanket in one hand, and put the feeding nipple into its mouth while softly holding its head with the thumb and index finger of the holding hand.
Slowly push the food out of the syringe at a constant velocity. After the marmoset consumes a proper amount of food, wipe its anus with a swab of warm water to clean the anus and promote defecation. Observe the locomotion of the animal for a few minutes, and record these parameters.
Keep the chassis of the incubator clean by picking up solid feces or changing to a new disposable diaper pad. Starting from P50, mix the ingredients directly in the weighing dishes to prepare the food. Place the food dish in the incubator, and fix the bottom in case it's turned over.
For the first few times, guide the animal to eat voluntarily by luring it to the food dish, and guiding its mouth to touch the food several times. Before returning the infant marmosets to the colony, move them from the animal incubator to small cages, and hang a 50-milliliter water bottle on each small cage. After returning the infants to the colony, feed the infants separately with a plastic weighing dish for one week.
Record the body weight and defecation status once per day. The body weight of each hand-reared infant was obtained, and it increased gradually with age. The comparisons of the body weights between the hand-reared infants and the parent-raised infants at P30 and P60 show no significant differences between these two groups.
