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.
(A cow's gestation period is about 280 days.) Some cows that do not re-breed can be milked continuously for 2-3 years, but production declines sufficiently over time that this is not usually economically feasible. Consequently, cows with fertility problems get culled from the herd.