Glanbia’s group managing director Siobhán Talbot is retiring on a high. The announcement this Wednesday morning that she would leave her position of 10 years next January coincided with strong half-year results for the Kilkenny-headquartered nutrition multinational and an upgrade in its profit forecast for the remainder of her tenure. Glanbia expected adjusted earnings per share to increase by five to 10 per cent this year in March, then improved this outlook to seven to 11 per cent in May, and is now guiding 12 to 15 per cent in earnings growth. By the time the year is out, it…