Harassment of dairy farmers in the name of cow protection must end and those violating the law will be dealt with sternly, Punjab Chief Minister Parkash Singh Badal said on Tuesday.Badal's warning comes after reports that some self-styled 'Gau Rakshaks' (cow protectors) have been stopping trucks and tractor-trolleys carrying cattle and harassing dairy farmers.The association of dairy farmers had recently highlighted their problems due to the actions of the 'Gau Rakshaks'.Badal, who was in Hoshiarpur on Tuesday, 140 km from here, said dairy farming was an activity allied to agriculture, which substantially supplements the income of farmers."This allied farming activity which involves cattle rearing and trading should not be discouraged at any cost. All of us should exercise restraint and permit the trade of cattle with valid documentation," Badal said.The Punjab Police, in the past week, registered cases against some self-styled 'Gau Rakshaks' at various places in the state.