Degradability of protein concentrates available in north Australia

Abstract

Animal Production in Australia 1998 Vol. 22 DEGRADABILITY OF PROTEIN CONCENTRATES AVAILABLE IN NORTH AUSTRALIA R.J. MOSS, I.K. BUCHANAN, N.D. CASEY, A.L. MATSCHOSS AND P.R. MARTIN Australian Tropical Dairy Institute, DPI, Mutdapilly Research Station, MS 825, Peak Crossing, Qld 4306 Forages provide the major source of dietary protein for dairy production, but additional protein can be required in concentrates and there may be nutritional advantages to more slowly degraded protein. Meat and bone meal (MBM) has been widely used, but is no longer permitted to be fed to ruminants. The in sacco technique (Orskov et al. 1980) was used with three rumen fistulated Holstein-Friesian steers fed lucerne hay (20% CP), to describe degradation of dry matter (DM) and protein (P) for concentrates available in northern Australia. Quickly degraded (QD), slowly (SD), effective rumen degradation (ERD) and undegraded P (UDP) (g/kg DM) fractions of DM and P were calculated using the equation P=a+(b*c)/(c+r) assuming a rumen outflow rate r=0.08h-1 for high production (AFRC 1993) (Table 1). Table 1. Degradabilities of dr y matter (DM) and protein (P) in protein rich concentrates Feed CP (%) Dry matter Cottonseed meal (CSM) 21.2 CSM (1% HCHO) Sunflower meal Rumentek� canola meal Whole cotton seed (WCS) Copra meal Palm kernel extract (PKE) Lucerne hay Meat and bone meal (Cattle) Fish meal (Sea Pep�) Feather meal Protein Cottonseed meal (CSM) 44.2 45.6 CSM (1% HCHO) Sunflower meal 38..9 Rumentek� canola meal 42.3 Whole cotton seed (WCS) 23.1 Copra meal 24.8 Palm kernel extract (PKE) 17.4 Lucerne hay 20.0 Meat and bone meal (Cattle) 56.7 Fish meal (Sea Pep�) 54.2 Feather meal 92.4 59.1 24.5 3.8 8.9 45.1 24.2 4.8 25.7 13.4 20.0 2.9 15.7 11.3 16.8 3.5 83.3 10.4 10.8 28.1 9.8 21.4 4.8 0.056 0.004 0.158 0.101 0.016 0.034 0.050 0.065 0.077 0.002 0.035 0.070 0.003 0.181 0.120 0.033 0.013 0.037 0.087 0.092 0.016 0.027 212 245 38 89 451 242 48 257 134 200 29 6 5 6 1 19 2 1 5 5 11 4 9 2 5 5 3 6 9 6 6 6 4 a b c QD SD ERD UDP ERDP (% CP) (g/kg DM) 24 1 39 37 7 22 30 20 16 2 5 3 7 2 6 3 0 2 5 3 2 8 4 2 4 4 5 4 3 4 2 2 5 6 3 6 2 6 5 6 9 2 8 5 2 0 5 4 2 1 2 7 2 7 9 7 4 1 1 4 6 2 8 5 0 2 3 1 1 1 1 3 3 8 0 9 1 6 3 9 0 8 4 9 3 9 9 2 9 1 9 4 7 8 4 6 33.0 59.0 67.5 43.9 73.1 78.1 45.7 33.2 87.3 19.2 78.9 35.3 78.5 94.2 10.4 65.8 92.0 54.6 54.1 35.7 19.3 163 5 212 239 7 49 51 57 164 32 44 21 4 26 25 16 4 6 10 20 12 8 52.6 12.5 71.2 60.1 86.4 19.9 40.0 56.6 38.7 27.3 9.6 Cottonseed meal (> 40% CP), with an effective rumen degradability (ERDP) of 53%, was more rapidly degraded than MBM but provided more UDP than sunflower or canola meal. In contrast, 86% of protein in unprocessed whole cotton seed (WCS) when cracked was degraded in the rumen. Entire WCS was not degraded. Copra meal and palm kernel extract (PKE) have similar ME and P to WCS and lower degradability than WCS or oil seed meals. Fish meal has a similar protein level and degradability to MBM but cost precludes its use in dairy rations. Hydrolysed feather meal (92% CP equivalent) had very low degradability (ERDP < 10%) and would be unsuitable if rumen degradable protein is limiting. Oil seed meals are acceptable alternatives to MBM. Formaldehyde will reduce their degradability. Response to protein concentrates of different degradability may be small (Moss et al. 1996). AFRC (1993). Energy and Protein Requirements of Ruminants. (CAB International: Wallingford, UK). MOSS, R.J., MARTIN, P.R. and ANSELL, J. (1996). Proc. Aust. Soc. Anim. Prod. 21, 95-98. ORSKOV, E.R., HOVELL, F.D. DeB and MOULD, F. (1980). Trop. Anim. Prod. 5, 195-213. 340