Abstract:
Proc. Aust. Soc. Anim. Prod. 1996 Vol. 21 PRODUCTION OF PRIME LAMBS FROM PULSE STUBBLES D.S. BROOKA, J. HOSKINGBC and J.H.G. HOLMES B * Longerenong College, University of Melbourne, RMB 3000, Horsham, Vic. 3401 * Parkville Campus, University of Melbourne, Parkville, Vic. 3052 'Current address: Better Blend Stockfeeds, Oakey, Qld 4401 The stubble of pulse crops is commonly used as feed for the production of prime lambs. Dry matter digestibility of the vine residues is low (Valizadeh et al. 1993), and rapid growth is dependent on the level of grain in the stubble (Allden and Geytenbeek 1980). In a survey, Williams (1995) found an average of 465 kg/ha of faba beans, and 202 kg/ha of chick peas, on the ground post harvest. A trial was conducted at Longerenong College, Horsham, Vic. between February and May 1994 to evaluate faba bean and chick pea stubbles for the production of prime lambs, and to evaluate the use of barley as a supplement to lambs grazing these stubbles. One hundred and twenty six Poll Dorset x (Border Leicester x Merino) mixed sex lambs were grazed for 8 weeks on faba bean or chick pea stubble at a stocking rate of 6 lambs/ha, and received either no supplement or 300 g/hd.day of whole barley fed every second day in a trough with a feeding space of 300 mm/hd. Each treatment was replicated twice. Lambs were weighed fortnightly after a 3 hour fast. Vine and grain residue was measured at the commencement, and at 3 times during the trial, using sampling methods adapted from Cayley and Bird (199 1). Table 1. Mean growth rate (k SE) of lambs (g/day) grazing faba bean or chick pea stubble with or without barley supplementation, and grain residues (2 SE) in the stubble (kg/ha), at intervals during the grazing period There were no differences (P>O.O5) in growth rate during the trial, but growth rate of the unsupplemented lambs tended to decrease in the final period presumably because grain residues were decreasing. There were significant differences in grain residue available in faba bean stubble grazed by supplemented and unsupplemented lambs in period 3 and 4. Lambs grazing faba bean and chick pea stubbles achieve satisfactory growth rates when there is adequate grain residues. As grain residues decrease, growth rates can be maintained by barley supplementation. ALLDEN, W.G. and GEYTEENBEEK, P.E. (1980). Proc. Amt. Sot. Anim. Prod. 13: 249-52. CAYLEY, J.W.D. and BIRD, P.R. (1991). '` Techniques For Measuring Pasture' Technical Report Series No. 191 (Victorian Dept. of Agriculture). VALIZADEH, R., YATES, N.G. and CARTER, E.D. (1993). Proceedings of 7th Australian Agronomy Conference, Adelaide, ~447. WILLIAMS, B. (1995). In 'The Southern Mallee and Northern Wimmera Crops and Pasture Manual', pp. 107-8 (Birchip Cropping Demonstration Site). 493