The doctors in canada said that i can start giving homogenisedmilk to my child at 9 months, but its after 1 year in the states.which is right and why do they have different opinions?

No one...: ...Sits around with a stopwatch and a glass of milk, waiting for the right moment to introduce milk. 9 mo is a reasonable time to start, but some prefer later, some (like me) prefer "sour-milk products" (youghurt, cottage cheese) to whole milk, and most will consider the child's individual factors in the recommendation - such as, not starting milk too early in a child who does not like solids.

Babies need iron: Cows milk contains no iron, and it decreases absorption of iron in food. Rapidly growing children need more iron than toddlers or adults, so can get anemic if they drink lots of milk in the first year. Formula is supplemented with iron. 9 months is ok, if you feed plenty of iron containing foods and no more than 16 oz milk per day; 1 yr is added insurance if he drinks more or eats less.

Neither is 'right': These are just guidelines usually promoted by a national organization. The idea is to give the infant intestine time to mature. Some physicians do not advise cow's milk ever be given.