A ventilation group for a livestock or industrial plant, the plant having a roof (C) provided with at least an upper opening (A) communicating with an external environment; and at least a lateral opening, provided in at least a lateral wall of the plant and communicating with the external environment; the group comprising: at least a collecting and conveying channel , comprising a bottom and lateral walls ; fixing means, for fixing the channel to the roof (C), so that the channel is arranged below the upper opening (A); the channel being conformed and predisposed for collecting atmospheric precipitation which arrives from the external environment through the upper opening (A), and for conveying the atmospheric precipitation towards a ground surface; at least a passage for the air, predisposed to place in communication an inside of the plant with the upper opening (A) of the roof (C), so as to generate an air flow which enters the plant through the lateral opening and which reaches towards the external environment through the passage and the upper opening (A); the channel being fixable to the roof (C) so as to be inclined towards the ground surface, to facilitate conveying of the atmospheric precipitation; the channel having a width that is at least equal to a width of the upper opening (A), preferably greater than the width of the upper opening (A); the ventilation group being characterised in that it comprises, alternatively or in combination: a grid or a net, provided in at least a lateral wall of the channel , for preventing entry into the plant of insects and/or foreign bodies without precluding passage of the air; and/or a grid or a net, positionable at the upper opening (A) of the roof (C), for preventing entry into the plant of insects and/or foreign bodies and for receiving thereon snow precipitation which otherwise would overload the channel . at least a collecting and conveying channel , comprising a bottom and lateral walls ; fixing means, for fixing the channel to the roof (C), so that the channel is arranged below the upper opening (A); the channel being conformed and predisposed for collecting atmospheric precipitation which arrives from the external environment through the upper opening (A), and for conveying the atmospheric precipitation towards a ground surface; at least a passage for the air, predisposed to place in communication an inside of the plant with the upper opening (A) of the roof (C), so as to generate an air flow which enters the plant through the lateral opening and which reaches towards the external environment through the passage and the upper opening (A); the channel being fixable to the roof (C) so as to be inclined towards the ground surface, to facilitate conveying of the atmospheric precipitation; the channel having a width that is at least equal to a width of the upper opening (A), preferably greater than the width of the upper opening (A); the ventilation group being characterised in that it comprises, alternatively or in combination: a grid or a net, provided in at least a lateral wall of the channel , for preventing entry into the plant of insects and/or foreign bodies without precluding passage of the air; and/or a grid or a net, positionable at the upper opening (A) of the roof (C), for preventing entry into the plant of insects and/or foreign bodies and for receiving thereon snow precipitation which otherwise would overload the channel . a grid or a net, provided in at least a lateral wall of the channel , for preventing entry into the plant of insects and/or foreign bodies without precluding passage of the air; and/or a grid or a net, positionable at the upper opening (A) of the roof (C), for preventing entry into the plant of insects and/or foreign bodies and for receiving thereon snow precipitation which otherwise would overload the channel . <EOS>