What is the ruling regarding the Zakat on grazing animals (Sā'imah) versus fed animals (Ma'lūfah) and working animals (Awāmil)?

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Zakat is obligatory on animals designated as 'Sā'imah' (grazing animals). The term 'Sā'imah' is used to exclude animals that are fed (Ma'lūfah) or used for labor (Awāmil), as the majority of scholars hold that there is no Zakat on the latter two categories. The evidence for restricting Zakat to Sā'imah is the Hadith found in the narration of Bahz bin Hakim which explicitly states, "On every fourty grazing camels..." This qualified statement must take precedence over general narrations that omit the qualification. Furthermore, the concept of growth (Namā') is essential in Zakat, and the cost of feeding kept animals often consumes their potential growth, unless they are intended for trade, in which case they are subject to Zakat of trade.