there is no substitute for mothers milk.. as far as rule of lactation
goes milk production occurs as long as it as emptied from the breast.. a brief lapse in feeding can lead to gradual decrease in milk production..
any ways a ten month old child can be given simple bland home made porridge made out of roasted sprouts of cereals ,pulses and grams with milk.. or simple soft home made food also can be given.. even now if mother is willing then she can continue feeding at frequent intervals as re lactation can occur.. in case of milk cows milk can be used but without dilution and with sugar to provide sufficient calories and protein..
get the child weighed at regular immunization
visit to pediatrician
and further tuning of the diet can be done if necessary..