It is at least doubtful whether at the time when the stigma of impurity was first attached to the Sudras the Hindus themselves did not sacrifice cows and eat beef.

[79] The castes noted below are usually regarded as impure in the Central Provinces.
The Dhobi (washerman) and Kumhar (potter) are sometimes included among the impure castes, but, as already noted, their status is higher than that of the castes in this list.
Audhelia: Labouring caste of mixed descent who keep pigs.
Balahi: Weavers and village messengers and watchmen.
Basor: Bamboo basket-makers and village musicians.
Chamar: Tanners and labourers.
Ganda: Weavers and village musicians.
Ghasia: Grass-cutters, labourers and sweepers.
Kaikari: Vagrant basket-makers.
Kanjar, Beria, Sansia: Gipsies and thieves.
Katia: Cotton-spinners.
Kori: Weavers and labourers.
Madgi: Telugu tanners and hide-curriers.
Mahar: Weavers and labourers.
Mala: Telugu weavers and labourers.
Mang: Broom- and mat-makers and village musicians.

They also castrate cattle.
Mehtar: Sweepers and scavengers.
Certain occupations, those of skinning cattle and curing hides, weaving the coarse country cloth worn by the villagers, making baskets from the rind of the bamboo, playing on drums and tom-toms, and scavenging generally are relegated to the lowest and impure castes.

The hides of domestic animals are exceedingly impure; a Hindu is defiled even by touching their dead bodies and far more so by removing the skins.

Drums and tom-toms made from the hides of animals are also impure.