Koala milk composition changes significantly as the joey ages. Koala Milk Replacer Early Lactation is specially formulated for young that are completely pouch-bound and dependent on milk. At this stage the young are relatively inactive, with fine fur growth starting to occur. Joeys at this age are prone to disease and mortality and should only be attempted by experienced carers.
There is considerable geographical and sexual variation in koala size, but most small joeys can be aged reasonably accurately based on head length. Refer to the Wombaroo Koala Growth Chart for age estimation guidelines. Body weight is not a good indicator of age because this can vary with regional variation, body condition and level of dehydration.
Success in hand-rearing pouch-bound koalas greatly improves if they receive Impact Colostrum Supplement within a week of coming into care. This can be repeated later as necessary for joeys with a compromised immune system, especially prior to first pouch emergence. Refer to 'Directions for Marsupials' under the Impact feeding guidelines.
Making up Milk
To make 100mL of milk: Mix 22g of powder (3 scoops) with 85ml of warm water.
To make 800mL of milk: Mix 180g of powder with 700ml of warm water.
Add about half of the water to the powder first and mix to a paste. Then make up with remaining water and mix thoroughly. Water is preboiled to ensure that it is sterilised. If the water is too hot it can cause the milk to curdle. If it is too cold then it will be difficult to disperse the powder. An electric whisk can be used for mixing larger quantities. Milk can be stored in the fridge for a day or can be frozen for up to 2 weeks. It may be useful to store frozen milk in small portions (eg ice cube trays), so that the required daily feed volumes can be easily thawed out. Once thawed out, discard any unused milk, and wash feeding utensils thoroughly.
Warm milk to about 30°C and feed using a bottle and teat. A Wombaroo LD teat is recommended for small in-pouch koalas. Feed around 6-8 times a day for furless joeys, reducing this to 4 times a day by the time they are fully-furred. If the joey is showing signs of dehydration (eg during hot weather), give extra drinks of water between feeds. Young joeys dehydrate rapidly if not maintained under optimum husbandry conditions. Consult your veterinarian or experienced carer for further information about husbandry and feeding of koala joeys.
Regional differences present considerable variation in koala growth rate. Refer to the Wombaroo Koala Growth Chart for typical growth rates of smaller northern animals compared to larger southern animals. Weigh joeys regularly to verify weight gains and determine the volume of milk to feed. Overfeeding milk can cause diarrhoea so feed the suggested volumes in our tables.
Transition from Early to Late Lactation
Milk transition refers to when a joey is changed from one Wombaroo milk stage to the next. It is important to transition joeys at the correct age to ensure they are getting the proper nutrition for their stage of development. Gradually transition milk at 160 days of age by mixing decreasing amounts of Early Lactation with increasing amounts of Late Lactation formula over 15-20 days. This transition occurs once the eyes are open, the upper incisors start erupting and fine fur appears on the head. Body weight may be anywhere from 200-350g at this age, depending on geographical location or sex of the joey. This is outlined in the Wombaroo Koala Growth Chart. Note that at about 180-210 days of age young koalas should ideally be provided with 'pap' from an adult animal to assist the transition onto eucalypt leaves.