Relation of dairy productivity of feed supply in the Gympie district of south-eastern Queensland

Abstract

Data were collected for six years from 82 dairy farms in the Wide Bay district of south-eastern Queensland to measure the effect of feed and fertilizer practices on fat production per cow and per hectare. A stabilized regression technique was used in which the effect of each input was estimated separately by grouping farms to give six levels of the test input while all other inputs were held near the mean level. The responses in fat production per cow and per hectare to the inputs measured were: sown tropical pastures with superphosphate, 1.5 ¦ 0.8 kg per 0.1 ha of pasture per cow and 33 ¦ 28 kg per ha ; summer forage, 2.1 ¦ 2.2 kg per 0.1 ha per cow and 9 ¦ 45 kg per ha ; superphosphate on areas other than sown tropical pastures, 10.3 ¦ 1.6 kg per 100 kg per cow and 23 ¦ 3 kg per 100 kg per ha ; irrigation, 5.9 ¦ 1.5 kg per 0.1 ha per cow and 203 ¦ 27 kg per ha; fertilizer nitrogen 0.7 ¦ 0.2 kg per kg nitrogen per cow; temperate pastures, 4.1 ¦ 0.9 kg per 0.1 ha per cow and 90 ¦ 20 kg per ha; supplementary feed, 3.8 ¦ 0.6 kg per 100 kg supplement per cow and 8.1 ¦ 1.5 kg fat per 100 kg supplement per hectare. Restricting the area of night grazing reduced fat production per cow. Sowing tropical pastures and summer forage led to only small increases in production per hectare since stocking rate was not increased, while superphosphate on areas not sown to tropical pastures, irrigation, temperate pastures, and supplementary feed not only increased production per cow but also increased the carrying capacity of the farm.