Is it acceptable to offer one sheep as `aqiqah for a male child?
Question

Is slaughtering one sheep for a boy acceptable as `aqiqah, or must it be two sheep?
Praise be to Allah.We have previously discussed the ruling on the `aqiqah on our website, and explained that it is Sunnah for the one who is able to do it, as stated in the answer to question no. 20018.
The Sunnah is to offer `aqiqah for the newborn, two sheep for a male and one sheep for a female, because of the report narrated by at-Tirmidhi, 1516 and an-Nasa’i, 4217, from Umm Karaz  (may Allah be pleased with her), according to which she asked the Messenger of Allah (blessings and peace of Allah be upon him) about the `aqiqah, and he (blessings and peace of Allah be upon him) said: “On behalf of a boy two sheep and on behalf of a girl one sheep, and it does not matter if they [the sheep] are male or female.” Classed as authentic by al-Albani in Irwa’ al-Ghalil, 4/391.
It was narrated from `A’ishah (may Allah be pleased with her) that the Messenger of Allah (blessings and peace of Allah be upon him) instructed them to offer two sheep of similar type for a boy and one sheep for a girl. Narrated by at-Tirmidhi, 1513; classed as authentic by al-Albani in Sahih at-Tirmidhi.
Ibn Hajar (may Allah have mercy on him) said in Fat-h al-Bari: These hadiths are quoted as evidence by the majority of scholars for differentiating between a boy and a girl. It was narrated from Malik that they are the same, so one sheep may be offered on behalf of either of them, and he quoted as evidence for that the report which says that the Prophet (blessings and peace of Allah be upon him) offered `aqiqah on behalf of al-Hasan and al-Husayn, one ram for each. Narrated by Abu Dawud. But this does not constitute evidence. Abu’sh-Shaykh narrated this report via a different isnad from `Ikrimah from Ibn `Abbas with the words “two rams for each.” And a similar report was also narrated from `Amr ibn Shu`ayb, from his father, from his grandfather. Assuming that the report of Abu Dawud is proven to be sound, there is nothing in the hadith to refute the many hadiths which state that two sheep should be offered on behalf of a boy. Rather the most that can be said is that it indicates that it is permissible to reduce the number, and that is indeed the case, because the number mentioned is not a stipulated condition; rather it is what is recommended. End quote.
Ash-Shirazi (may Allah have mercy on him) said in al-Madhhab, 8/433: The Sunnah is to sacrifice two sheep on behalf of a boy and one sheep on behalf of a girl, but if a person slaughters one sheep on behalf of each of them, that is permissible. End quote.
Shaykh Ibn `Uthaymin (may Allah have mercy on him) said: If a person can only afford one sheep, that is acceptable and it achieves the purpose, but if he has the means, then sacrificing two sheep is better.
(End quote from ash-Sharh al-Mumti`, 7/492)
Based on that, it is permissible for a person to sacrifice one sheep on behalf of his male child, and that is acceptable, although it is better to sacrifice two sheep if he can afford that.
For more information, please see the answer to question no. 60252.
And Allah knows best.