In England and Wales it is called Year 6 and the pupils are usually 10 to 11 years old. Often it is the seventh year of school; the years being called Reception, Year 1, Year 2, Year 3, Year 4, Year 5 and Year 6.
Quick Answer. According to Animals Australia, the natural lifespan of a dairy cow is approximately 20 years. The average lifespan of a beef cow is 15 to 20 months.
After calving, it takes 60 to 90 days for cows to resume cycles. This period is called postpartum anestrous. In first calf heifers, postpartum anestrous lasts longer than mature cows. It normally takes 90 to 120 days for first calf heifers to resume cycles.