A Wisconsin man, who was convicted of beating and breaking more than 20 bones of his 2-month-old daughter and causing head trauma to her, has been sentenced to jail for six months.

Twenty-one-year-old Richard A. Root of Oshkosh will also serve seven years of probation, the Oshkosh Northwestern newspaper reported.

The two-month-old baby was admitted to the Aurora Medical Centre emergency room in March with at least 20 broken bones of which nine were of her ribs. The baby also reportedly suffered a broken leg and arm in the attack.

Officials say the act caused other injuries, including bleeding in the baby's brain.

Root reportedly confessed to police after his arrest saying that the baby's constant crying triggered him and he committed the crime.

According to court documents, Root shook the baby because she was crying and had told the police that he even knelt on top of one of her legs while changing her diaper on 10 March, Fox News reported.

Root told police he "snapped" because of stress and lack of sleep, the report added.

The baby was flown to a Children's Hospital of Wisconsin in Milwaukee, where she was treated and later released to a family member.

Winnebago County Circuit Judge Thomas Gritton has ordered Root to avoid alcohol and drugs. He has been asked to keep a steady job or attend school full time and undergo counselling.