Abstract:
Proc, Aust. Soc. Anim. Prod. Vol. 18 LUPIN SUPPLEMENTATION IN LATE PREGNANCY: EFFECTS ON EWE LACTATION AND LAMB GROWTH G.N. HINCH* and C.J. THWAITES* In recent years there has been increasing evidence of the positive effects of pre-partum protein supplementation on milk production (Cowan et al. 1981). With this in mind an experiment was designed to examine the effects of lupin grain supplementation during pregnancy on ewe milk production and lamb growth. Fifty two crossbred ewes conceiving to a synchronised oestrus in January 1987 were ultrasound scanned for littersize and subsequently allocated according to littersize to two- groups (Lupin or Sorghum grain). The ewes grazed on dry Phalaris/clover pastures with supplementation (200 g/h/d) commencing 'at 100 days post conception at a rate of 200 g/h/d and continuing until parturition at which time all ewes were given a lupin supplement (250 g/h/d). Milk production levels were recorded (Table 1) using an oxytocin/machine milking technique (McCance 1959) , and lamb weights were recorded at birth and at each milking. The effects of littersize were significant (P<O.Ol) for all parameters measured while the 'supplement' effect interacted with littersize (F*=) i the twins supplemented with lupins being significantly different from the other 'treatments' (Table 1). Table 1 Birthweight, milk production and lamb weight (8-e.) for littersize x feed groups These data suggest that there is likely to be a 'carryover' effect of pregnancy supplementation with lupin grain on milk production and lamb growth and confirms the report of Earl and Male (1988) of a positive effect of lupin supplementation on birthweight and lamb growth in twin lambs. The present data illustrates that this effect is only apparent for twin rearing ewes and that increases in lamb growth are related to milk production effects. Further studies are necessary to determine whether the positive effect of protein supplements will occur in a variety of pasture conditions and for ewes of different body condition. COWAN, R-T., ROBINSON, J-J., MCBATTIE, I. and PENNIE, K. (1981). Anim. Prod. 33:lll. EARL, C-R. and MALE, R.H. (1988). Proc. Aust. Soc. Anim. Prod. 17:392. McCANCE, I. (1959). Aust. J. Agric. Res. 10:839. * Dept Animal Science, University of New Bngland, Armidale, N.S.W. 2351, 489