Felicity Norman took the case to London's High Court after the plans were approved on appeal, highlighting neighbours' anxieties about noise and odours.
She said there was a "proliferation" of poultry farms in Herefordshire and objectors were not having their concerns "taken seriously".
But now a senior judge has rejected her challenge - and ruled that she had no right to bring the case to court in the first place.
Farmer, G.T. Williams, wants to build two new poultry sheds, with a capacity for 82,500 birds, on Rogers Farm, near Bush Bank.
Birds would be turned round for slaughter in cycles lasting about 35 days before the sheds were cleaned out and a new flock brought in.
Herefordshire County Council initially refused planning permission, citing odour objections and the noise of fork lift trucks and ventilation fans.
But that decision was reversed by a planning inspector in December last year and planning consent was granted.
The inspector agreed that odours given off by the sheds could be "quite intense" whilst they were cleaned out between cycles.
But the smells would only be short term and Williams had carried out a "robust" assessment of potential odour impacts.
The council's own independent consultants had concluded that potential odour concentrations would be below the Environment Agency's benchmark.
The Environment Agency had issued Williams with an environmental permit and he would have to comply with its terms.
The inspector said: "I conclude that there will be no significant harm to the living conditions of neighbours arising from the proposal in respect of odour and noise."
Norman, a councillor who is also chair of the North Herefordshire Green Party, challenged the decision on various grounds.
But Judge Justine Thornton QC last week dashed her hopes - and Norman will now have to pay £5,000 in legal costs.
The judge agreed that the inspector was "mistaken" when he said that the doors to the poultry unit would face away from neighbours' homes.
But, ruling that that made no difference to the outcome, she added: "I am satisfied that the error was not material."
Claims that the inspector "misunderstood" technical evidence about odour concentrations were also rejected.
His decision was "adequately reasoned" and he was entitled to take account of the conditions attached to the environmental permit.
Judge Thornton noted that Norman lives 10 miles away from the farm and would not be personally affected by the development.
Although she "may feel aggrieved" at the grant of planning permission, she had no legal standing to challenge it, the judge ruled.
In July, a judge approved plans for an intensive chicken farm near Tasley in Shropshire that would produce over one and a half million birds per year, despite local residents' concerns about smells.
In August last year, plans were approved for a 179,000-bird chicken farm within an area of outstanding natural beauty in Wiltshire.