The Prophet ﷺ said: When one of you comes to the cattle, he should seek permission of their master if he is there; if he permits, he should milk (the animals) and drink. If he is not there, he should call three times. If he responds, he should seek his permission; otherwise, he may milk (the animals) and drink, but should not carry (with him).  

أَنَّ نَبِيَّ اللَّهِ ﷺ قَالَ إِذَا أَتَى أَحَدُكُمْ عَلَى مَاشِيَةٍ فَإِنْ كَانَ فِيهَا صَاحِبُهَا فَلْيَسْتَأْذِنْهُ فَإِنْ أَذِنَ لَهُ فَلْيَحْلِبْ وَلْيَشْرَبْ فَإِنْ لَمْ يَكُنْ فِيهَا فَلْيُصَوِّتْ ثَلاَثًا فَإِنْ أَجَابَهُ فَلْيَسْتَأْذِنْهُ وَإِلاَّ فَلْيَحْتَلِبْ وَلْيَشْرَبْ وَلاَ يَحْمِلْ  

That the Prophet ﷺ said: "When one of you comes upon livestock, if its owner is with it then seek his permission. If he permits him then let him milk it and drink. If there is no one with it then call out three times, if someone answers then seek his permission. If no one answers then let him milk it and drink without carrying (any of it away)." [He said:] There are narrations on this topic from Ibn 'Umar and Abu Sa'eed.  

أَنَّ النَّبِيَّ ﷺ قَالَ إِذَا أَتَى أَحَدُكُمْ عَلَى مَاشِيَةٍ فَإِنْ كَانَ فِيهَا صَاحِبُهَا فَلْيَسْتَأْذِنْهُ فَإِنْ أَذِنَ لَهُ فَلْيَحْتَلِبْ وَلْيَشْرَبْ وَلاَ يَحْمِلْ وَإِنْ لَمْ يَكُنْ فِيهَا أَحَدٌ فَلْيُصَوِّتْ ثَلاَثًا فَإِنْ أَجَابَهُ أَحَدٌ فَلْيَسْتَأْذِنْهُ فَإِنْ لَمْ يُجِبْهُ أَحَدٌ فَلْيَحْتَلِبْ وَلْيَشْرَبْ وَلاَ يَحْمِلْ قَالَ وَفِي الْبَابِ عَنْ عُمَرَ وَأَبِي سَعِيدٍ  

[Machine] If one of you comes upon an animal, and it has its owner with it, then let him ask permission from the owner. If he gives him permission, then let him take its milk and drink it. And if it does not have an owner, then let him call out three times. If it responds to him, then let him ask permission from it. And if it does not respond, then let him take its milk and drink it. And do not carry it. Al-Sheikh said: The narrations from Al-Hasan regarding Samurah, some of the huffaz do not consider them reliable. And it is claimed that it is from a book other than the Hadith of Al-Aqiqah, which mentions hearing. And if it is authentic, then it is applied in case of necessity.  

إِذَا أَتَى أَحَدُكُمْ عَلَى مَاشِيَةٍ فَإِنْ كَانَ فِيهَا صَاحِبُهَا فَلْيَسْتَأْذِنْهُ فَإِنْ أَذِنَ لَهُ فَلْيَحْتَلِبْ وَلْيَشْرَبْ وَإِنْ لَمْ يَكُنْ فِيهَا فَلْيُصَوِّتْ ثَلَاثًا فَإِنْ أَجَابَهُ فَلْيَسْتَأْذِنْهُ وَإِلَّا فَلْيَحْتَلِبْ وَلْيَشْرَبْ وَلَا يَحْمِلْ قَالَ الشَّيْخُ أَحَادِيثُ الْحَسَنِ عَنْ سَمُرَةَ لَا يُثْبِتُهَا بَعْضُ الْحُفَّاظِ وَيَزْعُمُ أَنَّهَا مِنْ كِتَابٍ غَيْرَ حَدِيثِ الْعَقِيقَةِ الَّذِي قَدْ ذُكِرَ فِيهِ السَّمَاعُ وَإِنْ صَحَّ فَهُوَ مَحْمُولٌ عَلَى حَالِ الضَّرُورَةِ  

The Prophet ﷺ said: When one of you comes to the cattle, he should seek permission of their master if he is there; if he permits, he should milk (the animals) and drink. If he is not there, he should call three times. If he responds, he should seek his permission; otherwise, he may milk (the animals) and drink, but should not carry (with him). (Using translation from Abū Dāʾūd 2619)   

"إذا أتى أحدُكم على ماشِيةٍ فإن كان فيها صاحبُها فليستأذنه، فإن أذن له فليحتلِبْ وليشربْ، وإن لم يكن فيها فليصوَّتْ ثلاثًا، فإن أجابه أحدٌ فليستأذنه، فإن لم يُجبْه أحدٌ فليحتلب ولْيَشْرَبْ، ولا يَحْمِلْ".