Many nursing moms are told that they must introduce cow's milk at a year. Your nursing toddler is already getting the best milk he can get - mother's milk! Breastmilk has a higher fat content than whole cow's milk (needed for baby's brain growth), and all the nutrients of human milk are significantly more bioavailable than those of cow's milk because it is species specific (not to mention all the components of mother's milk that are not present in cow's milk).
There is no need for additional milk or (or the equivalent nutrients from other foods) as long as your baby is nursing 3-4 times per day. Cow's milk is really just a convenient source of calcium, protein, fats, vitamin D, etc. - it's not required. There are many people in many parts of the world who do not drink milk and still manage to get all the calcium, protein, fats, vitamin D, etc. that they need.
Good non-dairy sources of protein include meats, fish, peas & beans (chick peas, lentils, baked beans, etc.), tofu and other soy products, boiled eggs, peanut and other nut butters (if your child is not allergic).
Good non-dairy sources of fats include soy and safflower oils, flax seed and flax seed oil, walnuts, fish and fish oils, avocado. Adding fats to cooking and baking can work well, for example, stir fry in safflower oil or make mini-muffins with soy or rice milk, oil or butter, and eggs.
Calcium may be derived from many nondairy sources.
Vitamin D can be supplied by sunlight exposure and food sources.
If your child is not nursing regularly and is not allergic to cow's milk products, but simply doesn't like cow's milk, you can incorporate milk into your child's diet in other ways. Many children like cheese, whole-fat yogurt or ice cream. You can also put milk into various food products: pancakes, waffles, muffins, French toast, scrambled eggs, mashed potatoes, and baked goods.
Some moms wish to offer cow's milk to their toddler, but baby doesn't like it. Over the age of 12 months, milk becomes a more minor part of a child's diet. It is sometimes helpful to mix increasing amounts of cow's milk with your expressed milk to help baby get used to the taste. Many dietitians see nothing wrong with adding some flavor (such as strawberry or chocolate) to cow's milk.
Pediatricians now recommend that any cow's milk be whole milk from a cup after the first year and until the child is at least 2 years of age. This ensures that your child receives enough fat, which is essential to proper brain development. After the age of two, if growth is good, you can switch to low-fat or nonfat milk. Note: If your child is nursing, then remember that mom's milk is "whole" milk - the more breastmilk your child gets, the less need to worry about your child getting additional fat from whole milk or other sources.
It's best to limit the amount of cow's milk that your child receives to 2-3 cups (16-24 ounces) per day, since too much cow's milk in a child's diet can put him at risk for iron-deficiency anemia (because milk can interfere with the absorption of iron) and may decrease the child's desire for other foods.