Is the age of the sacrificial animal a divinely ordained matter, especially with the developments in fattening livestock, which significantly alter their weights?

The sacrificial animal must have reached the legal age, based on the Prophet's (peace and blessings be upon him) saying: "Do not slaughter except a musinnah (an animal of mature age), unless it becomes difficult for you, then slaughter a jadha'ah (a young sheep) of sheep." A musinnah is a thiniyyah (a specific age-group) among camels, cattle, and goats. It is also required that the animal be free from the defects mentioned in his (peace and blessings be upon him) saying: "Four defects disqualify an animal for sacrifice: a one-eyed animal whose defect is obvious, a sick animal whose sickness is obvious, a lame animal whose lameness is obvious, and an emaciated animal that has no marrow." So, if the sacrificial animal has not reached the stipulated age, it is not permissible, even if it is fat.