Abstract:
Proc, Aust. Soc, Anim. Prod, Vol. 18 COWPEAS AND NAVY BEANS AS SUPPLEMENT S FOR ROUGHAGE DIETS FOR SHEEP D.C. PADUANO*, R.F. SLOCOMBE**, J.H.G. HOLMES* and R.M. DIXON* Tropical grain legumes such as navy beans (Phaseolus vulgaris) and cowpeas (Vigna sinensis) have potential as feeds of high nitrogen content and digestibility, but anti-nutritional factors (e.g. lectins, protease inhibitors) limit their use (Liener and Kakade 1980; Williams et al. 1983/84). An experiment examined their value as supplements for sheep fed roughage. Thirty-nine Merino ewes (16-31 kg LW) were held in single pens for two periods each of 49 days. Diets consisted of roughage (50% oaten chaff and 50% barley straw) and minerals ad libitum fed alone or supplemented with 5 g, 10 g, 20 g, or 20 g plus antibiotics of airdry lupin grain per kg LW, or the same amounts of.airdry cowpea (var. Caloona) grain, or the same amounts of airdry navy bean (var. Actolac). The antibiotic consisted of 15 mg terramycin plus 22 mg flavomycin per sheep per day mixed with the supplement. Intake of roughage and supplements were m&asured daily, and LW gain was calculated from weekly measurements of the LW of sheep. Table 1 Dry matter (DM) intake and Iiveweight (LW) gain of sheep fed roughage and several grain legume supplements (n = 6) The highest level of each grain legume (20 g/kg LW), fed with or without antibiotics, was associated with decreases in roughage intake, but increases in total DM intake (Table 1). LW gain of the sheep fed roughage alone was 16 g/d, and this was increased (P<O.OS) by the 10 and 20 g/kg LW levels of lupins or cowpea supplements (75-136 g/d). LW gain was increased to a lesser extent by the same levels of navy bean supplements (32-87 g/d). The antibiotics tended to increase LW gain when given with lupins, but not when given with navy beans. The results suggest that cowpea grain was approximately equal to lupins in nutritive value, but navy beans were lower in nutritive value. LIENER, I.E. and KAKADE, M.L. (1980). In 'Toxic Constituents of Plant Foodstuffs', 2nd Ed. p. 7, editor I.E. Liener. (Academic Press: New York) WILLIAMS, P.E.V., PUSZTAI, A-J., MACDEARMID, A. and INNES, G.M. (1983/84): Anim. Feed Sci. Tech. 12:l. * Agriculture and Forestry, The University of Melbourne, Parkville, Vic. 3052. ** Vet Clinical Centre, The University of Melbourne, Werribee, Vic, 3030. 536