Influence of grazing management and copper supplementation on the growth rate of Hereford cattle in south-eastern Queensland

Abstract

A 4-year study was made to evaluate the influence of grazing management and copper supplementation on the growth rate of Hereford cattle on predominantly Paspalum dilatatum pastures in south-eastern Queensland. Two systems were compared-one of set stocking and the other of rotational grazing through four paddocks, each for a period of seven days. The overall stocking rate was the same for both treatments. As this was a locality in which cattle consistently showed a low copper status in liver, half the animals in each grazing treatment were supplemented at regular intervals with intravenous copper sulphate.
In two of the four' years the yield of pasture in the rotationally grazed paddocks was adequate for conservation in January /February. In 1957, approximately 56 tons of silage was conserved from the four 4-acre rotationally gra1ied paddocks, and fed back to animals in the rotational grazing treatment from June to December in that year. In 1959 approximately twice the amount of pasture was available. No conservation was practised as the object in this year was to con1pare the two grazing systems without the added variables of pasture harvesting and animal supplementation.
The data from this study support the following conclusions:-
(1) At a stocking intensity of one animal per acre in this environment the growth rate of Hereford cattle is not affected by the application of rotational grazing alone.
(2) Management by rotational grazing facilitates pasture conservation in years in which effective rainfall occurs in December/January.
(3) Feeding back of conserved pasture as a supplement in late winter/ early spring increases animal productivity.
(4) In this locality a growth response to copper therapy in cattle can be expected in some seasons.