Milk production from a naturalized pasture at Wollongbar and its relation to rainfall

Abstract

The 4 per cent fat corrected milk (FCM) production obtained from cows grazing a 9.7 ha farmlet of naturalized pasture at Wollongbar was measured over the ten-year period to 1968. FCM per cow varied between 1538 kg and 2765 kg and per hectare between 1678 kg and 2847 kg. The factors most likely to have affected production appeared to be climatic effects. It is suggested that soil fertility was unlikely to have affected production markedly and the relation between FCM production per hectare, and several rainfall parameters were established. The most important factor affecting production appeared to be rainfall in early to mid-lactation. Knowledge of rainfall during this period accounted for 93 per cent of the total variation in FCM per hectare between years. The residual standard deviation of the regression was 5 per cent of the mean production per hectare.