The an’aam animals are camels, cattle and sheep. No zakaah is due on any other animals unless they are for trade. 

1 – The nisaab of camels is five, according to scholarly consensus, on which a sheep is to be given (as zakaah). For ten camels, two sheep must be given; for fifteen, three sheep; for twenty, four sheep; for twenty-five, a bint makhaad (a she-camel in its second year), and so on, as narrated in the hadeeth, as we shall see below. 

Based on this, whoever owns four camels or less does not have to pay zakaah, unless he wants to. 

The basic principle concerning that is the hadeeth narrated by al-Bukhaari (1454) from Anas, according to which Abu Bakr (may Allaah be pleased with him) wrote this letter to him when he sent him to Bahrain:

In the name of Allaah, the most Gracious, the Most Merciful. This is the obligation of zakaah which the Messenger of Allaah (peace and blessings of Allaah be upon him) enjoined upon the Muslims and which Allaah enjoined upon His Messenger. Whoever among the Muslims is asked for it in the proper manner, let him give it, and whoever is asked for more than that, let him not give. For twenty-four camels or less, for each five, one sheep. If the number reaches twenty-five up to thirty-five, then a female bint makhaad (a she-camel in its second year) is due. If the number reaches thirty-six up to forty-five, then a female bint laboon (a she-camel in its third year) is due. If the number reaches forty-six up to sixty, then a hiqqah (a she-camel in its fourth year) is due. If the number reaches sixty-one up to seventy-five, then a jadha’ah (a she-camel in its fifth year) is due. If the number reaches seventy-six up to ninety then two bint laboon are due (she-camels in their third year). If the number reaches ninety-one up to one hundred and twenty, then two hiqqah are due (she-camels in their fourth year…). If there are more than one hundred and twenty, then for every forty a bint laboon is due and for every fifty a hiqqah. Whoever has no more than four camels does not have to pay zakaah on them unless their owner wants to give. If the number reaches five camels, then one sheep is due…” 

A bint makhaad is a camel that has completed one year.

A bint laboon is one that has completed two years.

A hiqqah is one that has completed three years.

A jadha’ah is one that has completed four years.  

2 – The nisaab for cattle is thirty, according to the majority of scholars, because the Prophet (peace and blessings of Allaah be upon him) said: “For thirty cattle a tabee’ or tabee’ah is due, and for every forty a musinnah.” Narrated by al-Tirmidhi, 622; Ibn Maajah, 1804; classed as saheeh by al-Albaani in Saheeh al-Tirmidhi. 

The tabee’ (male) or tabee’ah (female) is a bovine that is one year old and has entered its second year. It is so called because it follows (yatba’) its mother. 

The musinnah is that which is two years old. 

3 – The nisaab for sheep is forty, according to scholarly consensus, for which one sheep is due, because of the hadeeth narrated by Anas which is quoted above: “The zakaah for sheep in the pasture: if the number is forty up to one hundred and twenty, one sheep is due. If there are more than one hundred and twenty, up to two hundred, then two sheep are due. If there are more than two hundred, up to three hundred, then three sheep are due. If there are more than three hundred, then for every hundred, one sheep is due. And if the flock of a man is less than forty sheep, then no zakaah is due unless their owner wants to give.” 

The majority of fuqaha’ stipulated that in order for zakaah on an’aam animals to be obligatory, they must be in the pasture, i.e., they graze in the pasture for most of the year. As for those which are given feed, no zakaah is due on them unless they are for trade. The evidence that their being pastured is a condition of zakaah is to be found in the words of the Prophet (peace and blessings of Allaah be upon him): “The zakaah on sheep in the pasture…” 

See al-Mughni, 2/230-243

It says in Fataawa al-Lajnah al-Daa’imah (9/202): The scholars are unanimously agreed that zakaah is obligatory in the case of grazing camels, cattle and sheep, if their number reaches the nisaab. The minimum number in the case of camels is five, in the case of cattle is thirty and in the case of sheep is forty. Grazing animals are those that eat grass etc in the pasture, unlike those that are given feed and working animals that are used for carrying loads. 

The scholars differed as to whether zakaah is due on animals that are given feed and working animals. The majority of scholars are of the view that no zakaah is due on them because of the report narrated by Ahmad, al-Nasaa’i and Abu Dawood from Bahz ibn Hakeem, from his father, from his grandfather, who said: I heard the Messenger of Allaah (peace and blessings of Allaah be upon him) say: “For grazing camels, for every forty a bint laboon…” So the obligation to pay zakaah is limited to camels that are grazing, and it is not required in the case of those that are given feed. As for working camels, there is the hadeeth of ‘Ali (may Allaah be pleased with him): “There is no zakaah on working animals.” Maalik and a number of other scholars were of the view that zakaah is obligatory on animals that are given feed and working animals too. End quote. 

See also question no. 49041 

And Allaah knows best.