Hay conservation for cattle on winter-grazed green panic (Panicum maximum var. trichoglume) pasture in south-eastern Queensland

Abstract

The effects of stocking rate and hay conservation on liveweight gains of weanling Hereford cattle grazing a green panic (Panicum maximum var. trichoglume cv. Petrie) pasture in winter and spring only were measured over seven years. A 2 x2 factorial experiment included stocking rates of 1 .5 and 2 . 5 animals/ha, with and without hay conservation. Protein supplementation using a mixture of cottonseed meal and urea was an additional treatment in two winters. Stocking rate had little effect on pasture yields at the start of grazing or on hay yields. The mean liveweight gains per animal at stocking rates of 1 . 5 and 2.5 animals/ha were 69 and 50 kg, respectively, on non-conserved pasture, and 86 and 54 kg on conserved pasture. Liveweight gain response to conservation was greater at the lighter stocking rate and appeared due to greater accessibility of higher quality pasture in situ rather than to feeding of hay per se. At the light stocking rate, little or no hay was required. Feeding protein produced 6 kg more liveweight gain per animal during the supplementation period in the two winters but this advantage disappeared by the end of grazing. Liveweight gain per hectare decreased with increased stocking rate in both hay and no-hay groups in the first and third year, decreased in the hay group only in the second year and increased in both groups in the last four years of the experiment. The benefit from making and feeding hay was small and the economics of the practice would depend on alternative uses for excess hay.