In autumn 1740, a meagre harvest commenced and prices in the towns started to fall. Cattle began to recover. But in the dairying districts, cows had been so weak after the Frost that at least a third of them had failed to "take bull," or become impregnated at breeding. This resulted in fewer calves, a shortage of milk, which was widely consumed, and a decline in butter production. To make conditions worse, blizzards swept along the east coast in late October 1740 depositing snow and returned several times in November. A massive rain downpour on 9 December 1740 caused widespread flooding. A day after the floods, the temperature plummeted, snow fell, and rivers and other bodies of water froze. Warm temperatures followed the cold snap, which lasted about ten days. Great chunks of ice careened down the Liffey River through the heart of Dublin, overturning light vessels and causing larger vessels to break anchor. The strange autumn of 1740 pushed food prices back up, e.g., Dublin wheat prices on 20 December were at an all-time high. The widening wars in mid-December 1740 encouraged people with stored food to hold onto it. The populace needed food, and riots erupted again in various cities throughout the country. By December 1740, signs were growing that full-blown famine and epidemic were upon the citizens of Ireland.
Question: A low number of what had resulted in the decline of butter production and the shortage of milk?
Answer: calves