How can we reconcile the religious texts that refer to the age of the sacrificial animal (musinnah, having completed a year), with the difficulty of finding sheep over six months old in Europe? And is it permissible to exercise ijtihad (independent reasoning) in this matter?

For sacrificial animals (adhaahi), only those that have reached the age specified by Islamic law are acceptable, even if a younger animal is large in size, with abundant and fatty meat. Scholars have agreed on this, except for what has been narrated from some allowing the 'Jadha'' (a specific age category) particularly from sheep, and some allowing it from all species. The majority relied on the hadith: "Do not slaughter except a Musinna (an aged animal), but if it becomes difficult for you, then slaughter a Jadha' from the sheep."

The story of Abu Burdah bin Niyar (may Allah be pleased with him) indicates that the abundance and quantity of meat do not permit sacrificing an animal that has not reached the considered age, and that this is a devotional ruling.

There is no recognized madhhab (school of thought) or statement from a past scholar that permits sacrificing an animal younger than the Jadha'.

There is no room for ijtihad (independent reasoning) to alter the prescribed ages for sacrificial animals, as it is an act of worship restricted by conditions, and if a person is unable to fulfill it, it is waived for them. As for regulating livestock breeding, there is no religious impediment to it.