These compositions vary by breed, animal, and point in the lactation period.

More than one litter per year results in lactation periods overlapping pregnancies.

Together with a long lactation period, orangutans also have a long birth interval.

The lactation period lasts 2.0 to 2.5 months, though the kits eat solid food after 20-25 days.

They produce 120-390 kg of milk in a lactation period lasting 280-340 days.

After birth, the young enter the lactation period for seven months, until October or November.

Once the lactation period concludes, the female drives off the pups.

A cow can produce 2,500 kg of milk per lactation period, which lasts for about 305 days.

A breastfeeding woman may not ovulate, or have regular periods, during the entire lactation period.

The lactation period is estimated to be about 45 days (Weir 1974).