Abstract:
Animal Production in Australia Vol. 15 SUPPLEMENTATION TO IMPROVE THE UTILIZATION OF PERENNIAL RYE-GRASS STRAW BY YOUNG CATTLE G.H. SMITH* The straw of grasses and cereal crops frequently does not support maintenance of cattle. There are many commercial grass-seed growers in the Mansfield-Alexandra area of Victoria who produce Perennial rye-grass, Phalaris, Demeter fescue and Cocksfoot grass-seed. Following harvest each year, the straw must be removed to enable the crops to grow satisfactorily in the next season. Most of the growers also run beef cattle and so methods of utilising this material as cattle feed are required. An experiment was conducted at Rutherglen Research Institute to examine the influence of various supplements on the consumption of Perennial rye-grass straw by yearling steers. Twelve, Hereford steers, about 240 kg liveweight, and housed individually in metabolism stalls were allocated evenly by liveweight between four treatments. Perennial rye-grass straw (OJ/%N, 57.7% digestible dry matter) was available ad lib to all steers and various supplements were given daily. These were 1. nil (straw only) 2. 1000 g/hd oats 3. 850 g/hd lupins 4. 250 g/hd Golden Pro (Bayer Australia Ltd.). The respective levels were chosen as representing equivalent costs of supplement with the intention of determining which of the three was the most cost-effective. The feeding treatments continued for 40 days and over the final 10 days the digestibilities of the four diets were measured in vivo. All steers were weighed weekly and feed intakes were recorded daily. TABLE 1 Straw DM intake, total DM intake, diet digestibility and liveweight change for steers fed straw and various supplements ?Means within columns with different superscripts differ significantly (P=O.O5) The lupins and Golden Pro supplements produced significantly better straw DM intake, total DM intake and liveweight change compared to the oats and nil supplement (Table I). The digestibility of the diet consumed by steers fed the Golden Pro supplement was significantly less than that of the oat and lupin-supplemented diets. The digestibility of those diets was enhanced by the relatively high digestibilities of oats and lupins. Golden Pro contains maize, urea and bentonite. Its effectiveness in this experiment was presumably due to its capacity to slowly release urea (Meggison et al. lg'j'g). It is concluded that both lupins and Golden Pro were more effective supplements than oats for maintaining the weight of cattle fed on Perennial rye-grass straw. MEGGISON, P.A., McMENIMAN, N.P. and ARMSTRONG, D.G. (1979). Proc. Nutr. SOC. 2:14'7A. *Rutherglen Research Institute, Department of Agriculture, Rutherglen, Vic. 3685. 748