Assalamualaikum w.b.t. What is the ruling of the slaughter by a woman? Is it true that if a woman slaughter an animal, the slaughter is invalid? Hope for an explanation.
Alhamdulillah, praise and gratitude to Allah SWT for His countless blessings for us all. Praise and salutations to our beloved Prophet Muhammad PBUH, his family, companions and all those who follow his footsteps until the Last Day.
Islam emphasized on the halal and haram of our food and drinks. Hence, Allah SWT explained this matter in His statement:
حُرِّمَتْ عَلَيْكُمُ الْمَيْتَةُ وَالدَّمُ وَلَحْمُ الْخِنزِيرِ وَمَا أُهِلَّ لِغَيْرِ اللَّـهِ بِهِ وَالْمُنْخَنِقَةُ وَالْمَوْقُوذَةُ وَالْمُتَرَدِّيَةُ وَالنَّطِيحَةُ وَمَا أَكَلَ السَّبُعُ إِلَّا مَا ذَكَّيْتُمْ وَمَا ذُبِحَ عَلَى النُّصُبِ
“Prohibited to you are dead animals, blood, the flesh of swine, and that which has been dedicated to other than Allah, and [those animals] killed by strangling or by a violent blow or by a head-long fall or by the goring of horns, and those from which a wild animal has eaten, except what you [are able to] slaughter [before its death], and those which are sacrificed on stone altars,” 
Syeikh Tahur Ibnu ‘Asyur stated in his commentary that this verse described farm animals that are permissible to be eaten. The prohibition in this verse means the prohibition in terms of eating the animal. For it is the meaning meant in the verse. It also explained the situations when farm animals are prohibited to be eaten. 
Sheikh Zakariyya al-Ansari stated there are four requisites for slaughter and they are:
- The person performing the slaughter (slaughterer)
- The animal going to be slaughtered
- The tools or knives used for slaughter
The ijmak of scholars stated that slaughtered animals are halal and permissible to be eaten. 
Conditions for slaughter
In order for an animal to be permissible and halal to be eaten, Allah SWT has commanded it to be slaughtered. Scholars have set guidelines for the slaughtering of animals and its conditions which are:
- The slaughterer regardless of whether it is a man or woman, he/she must be an adult (has reached puberty) or mumayyiz and this is the opinion of the jumhur of scholars.
- The slaughterer must be a Muslim or the People of the Book. Likewise, the slaughter of a person who has denounced Islam (apostate) is invalid. The reason is his slaughter is not for Allah SWT. This is in accordance with the above statement of Allah SWT in surah al-Maidah verse 3. And scholars have set conditions for the People of the Book and among them is that they must be from the believers and mention Allah SWT’s name during the slaughter.
- The animal must be from halal animals to be hunted and not wild and ferocious animals as stated by Allah SWT:
أُحِل لَكُمْ صَيْدُ الْبَحْرِ وَطَعَامُهُ مَتَاعًا لَكُمْ وَلِلسَّيَّارَةِ وَحُرِّمَ عَلَيْكُمْ صَيْدُ الْبَرِّ مَا دُمْتُمْ حُرُمًا
“Lawful to you is game from the sea and its food as provision for you and the travellers, but forbidden to you is game from the land as long as you are in the state of ihram.” 
- It is conditioned to mention the name of Allah SWT during slaughter whether the slaughterer is a Muslim or from the People of the Book. If one forgets or is mute then it is permissible to eat it. This is based on the statement of Allah SWT:
وَلَا تَأْكُلُوا مِمَّا لَمْ يُذْكَرِ اسْمُ اللَّـهِ عَلَيْهِ وَإِنَّهُ لَفِسْقٌ
“And do not eat of that upon which the name of Allah has not been mentioned, for indeed, it is grave disobedience.” 
- Do not include or mix between the praise of Allah SWT and others. Whether it is stated or not.
- Both the windpipe and oesophagus must be cut to hasten the death of the animal.
- Moreover, the condition for the tool used for slaughter is that they must be sharp and not made of bone, nails and teeth. 
Thus, it can be understood that slaughter is one of the approaches to making an animal’s meat or flesh halal or permissible to be eaten. It is prohibited to eat the flesh or meat of animals that aren’t first slaughtered, for then the animal would be considered carcass. This is based on the statement of Allah SWT as follows:
حُرِّمَتْ عَلَيْكُمُ ٱلْمَيْتَةُ وَٱلدَّمُ وَلَحْمُ ٱلْخِنزِيرِ وَمَآ أُهِلَّ لِغَيْرِ ٱللَّـهِ بِه
“Prohibited to you are dead animals, blood, the flesh of swine, and that which has been dedicated to other than Allah,” 
What is considered to be a valid slaughter is when both the windpipe (trachea/halqum) and mari’ (food-tract/oesophagus) of the animal are cut. Syeikh Zakariyya al-Ansari said: “Slaughter includes al-Nahr and killing an animal that cannot be killed normally is by severing the halqum which is the respiratory tract and mari’ that is the food tract.” 
Scholars have set the condition for a slaughter to be performed by a Muslim. This is based on the statement of Allah SWT:
إِلَّا مَا ذَكَّيْتُمْ
“…except what you [are able to] slaughter [before its death],” 
Imam al-Qurtubi stated that all the matters mentioned in the verse are prohibited from being eaten except those that are slaughtered. 
This verse is basically dedicated to Muslims. Imam al-Nawawi said: “The first condition for a slaughter is that the slaughterer is from among the Muslims or the People of the Book.” 
Syeikh Zakariyya al-Ansari stated: “The first requisite for any animal slaughtered or hunted is a slaughterer and the condition is for him to be a Muslim or People of the Book who are halal for us to marry.” 
Syeikh Taqiyuddin al-Husaini al-Hisni said: “It is conditioned for a slaughterer so that his slaughter is halal to be eaten is that for him to be a Muslim or from the People of the Book.” 
The Issue of a Slaughter by a Woman
Coming back to the question presented, if the animal is slaughtered by a woman, it is valid and halal to be eaten. The reason is, that the gender of the slaughterer regardless of whether it is a man or a woman is not the main condition for a slaughterer. The main condition is the slaughterer must be a Muslim. In a hadith narrated by Ka’ab bin Malik, he narrated:
أَنَّ امْرَأَةً ذَبَحَتْ شَاةً بِحَجَرٍ فَسُئِلَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عَنْ ذَلِكَ فَأَمَرَ بِأَكْلِهَا
“A woman slaughtered a sheep with a stone, so the Prophet (ﷺ) was asked about that and he ordered it to be eaten.” 
Al-Hafiz Ibn Hajar said: ““Sa’id bin Mansur with the sanad from Ibrahim al-Nakhaie. Ibrahim said that the slaughter by a woman and child is fine if the person is capable to slaughter and mentions the name of Allah. This is the opinion of the jumhur of scholars.” 
Maulana Zakariyya al-Kandahlawi stated that Imam al-Bukhari placed this hadith under the chapter animal slaughter by women and female slaves. It is as though he is signalling that the slaughter is valid and rejecting the opinion which states that slaughter by women is invalid.
He further states that among the wisdoms of the hadith is that it is permissible to eat animals slaughtered by a woman regardless of whether she is a slave or free woman, adult or a child, Muslim or People of the Book. The reason is the Prophet PBUH instructed them to eat the slaughter by the woman without asking any questions. 
Imam al-Nawawi agreed and said that the slaughter by a woman is valid and it is halal to be eaten. He said: “Undoubtedly, the slaughter of an animal by a woman is halal. This is based on the hadith of Ka’ab as stated by the author (al-Syirazi) of the book. The slaughter by a man is prioritized over a woman’s as stated by the author himself. Whether the woman is free, a slave, menstruating or experiencing nifas (bleeding due to childbirth), Muslimah or from the People of the Book, all of their slaughter is valid and halal to be eaten. This is stated clearly by al-Syafie and agreed by scholars.” 
Slaughter by a woman is valid and halal to be eaten. Yes, some scholars said that the slaughter made by a man is prioritized over a woman. This is when one considers the angle of his strength and ability to slaughter an animal.
 Surah al-Maidah: 3
 See al-Tahrir wa al-Tanwir, 4/124
 See Minhaj al-Tullab, 1/281
 See Mughni al-Muhtaj ila Ma’rifah Alfaz al-Minhaj, 4/265
 Surah al-Maidah: 96
 Surah al-An’am: 121
 See al-Mausu’ah al-Fiqhiyah al-Kuwaitiyah, 21/184
 Surah al-Maidah : 3
 See Fath al-Wahhab, 2/333
 Surah al-Maidah : 3
 See al-Jami’ Li Ahkam al-Quran, 6/50
 See Raudhah Al-Talibin, 2/505
 See Asna al-Matalib Syarh Raudh al-Talib, 7/65
 See Kifayah al-Akhyar fi Halli Ghayah al-Ikhtisar, pg. 684
 Narrated by al-Bukhari (5504)
 See Fath al-Bari, 9/632
 See al-Abwab wa al-Tarajim li Sahih al-Bukhari, 6/58
 See al-Majmu’ Syarh al-Muhazzab, 9/86