Bukhari

Hadith Commentary:
From this hadith, the purpose of the chapter—namely, the obligation of giving the zakat of cows and oxen—is established, because punishment will be for the abandonment of that which is obligatory.
In the narration of Muslim, these words are also present in this hadith: "and he does not pay its zakat."
According to the conditions of Imam Bukhari, he did not find any hadith regarding the zakat of cows.
Therefore, under this chapter, he mentioned this hadith and used it as evidence for the obligation of zakat on cows.

Hadith Commentary:
(1)
From this hadith, it is understood that those who do not pay the zakat of animals will be punished until the people's reckoning is completed, and among these animals, cattle are also mentioned.

(2)
Imam Bukhari rahimahullah has established from this the obligation of zakat on cattle, but he did not describe the manner of zakat regarding them, because in his view, there was no hadith that met his conditions on this subject. However, Imam Tirmidhi rahimahullah has narrated from Hazrat Mu'adh bin Jabal radi Allahu anhu, who said that the Messenger of Allah sallallahu alayhi wa sallam sent me to Yemen and commanded me to collect, as zakat, a musinnah (two-year-old calf or heifer) from every forty cattle and a tabi’ (one-year-old calf or heifer) from every thirty.
(Jami’ al-Tirmidhi, Zakat, Hadith: 623)
In addition, it is narrated from Hazrat Abdullah bin Mas’ud radi Allahu anhu, who reports from the Messenger of Allah sallallahu alayhi wa sallam that he said:
“In thirty cattle, a one-year-old calf (tabi’), which has entered its second year, and in forty cattle, a two-year-old calf or heifer (musinnah), which has entered its third year, is due as zakat.”
(Jami’ al-Tirmidhi, Zakat, Hadith: 622)
Zakat is also applicable to buffaloes at the same rate. Their zakat schedule is as follows:
1 to 29 cattle: No zakat.
2) 30 to 39: One-year-old calf or heifer (tabi’)
3) 40 to 59: Two-year-old calf or heifer (musinnah)
4) 60 to 69: Two one-year-old calves or heifers
5) 70 to 79: One one-year-old calf or heifer + one two-year-old calf or heifer
6) 80 to 89: Two two-year-old calves or heifers
7) 90 to 99: Three one-year-old calves or heifers
The principle is that for every thirty, a one-year-old calf or heifer is taken, and for every forty, a two-year-old calf or heifer is taken.
In addition, the following conditions also apply:
• For most of the year, they graze on pasture, etc., in the wild.
• They are used for agricultural work, etc.
• If they are maintained entirely at the owner’s expense and kept for personal use, then there is no zakat on them.
If they are kept for trade or as a dairy farm, then zakat will be due on their income.

(3)
Imam Bukhari rahimahullah has referenced the hadith of Bukayr, which Imam Muslim rahimahullah has narrated with his connected chain. In it, camels, cattle, and goats are mentioned, from which zakat was not given.
(Sahih Muslim, Zakat, Hadith: 2295(987))

(4)
Imam Bukhari rahimahullah has mentioned zakat regarding cattle in a deferred manner, because in the Arab region, they are very rare, and perhaps their nisab is only occasionally completed. Most likely, this is the reason Imam Bukhari rahimahullah has only mentioned its obligation and not other details.
(Fath al-Bari: 3/407)