Abstract:
Animal Production in Australia Vol. 15 EFFECTS OF SUPPLEMENTS ON INTAKE, GROWTH AND BACTERIAL PROTEIN SYNTHESIS IN SHEEP EATING NaOH-TREATED STRAW K. AMANING-KWARTENG*, R.C. KELLAWAY* and JANE LEIBHOLZ* Studies in this laboratory have shown that sheep are able to maintain live weight on NaOH-treated straw as the sole diet (unpublished). This paper summarizes main effects of feeding supplements of cotton-seed meal (C) or whole barley grain (B) to hoggets fed NaOH-treated wheat straw. Straw was hammer milled through a 30 mm screen and sprayed with NaOH solution (45.6 g NaOH in 113 g HzO/kg) followed by a mineral solution supplying (g/kg) 79 H20, 14.2 N, 1.0 S, 0.9 P and (mg/kg) 1.8 Cu and 0.11 Co and sprinkled with limestone supplying (g/kg) 1 Ca. The treated straw was fed ad lib. to hoggets receiving no supplement (0) or supplemented with 150 g/d of B or C. These diets were fed in Experiment 1 to 21 crossbred hoggets (35 kg live weight) and in Experiment 2 to six crossbred hoggets (35 kg live weight) fitted with rumen and abomasal cannulas. TABLE 1 Dry matter intake (DMI) of treated straw, liveweight gain (LWG), wool growth (W), nitrogen leaving the stomach (N flow) and bacterial N synthesized/kg organic matter apparently digested in stomach (BactN/ OMAD) in hoggets fed supplements with a basal diet of NaOH-treated wheat straw Values with different superscripts differ significantly (P < 0.05). No significant differences in straw intake were recorded in either experiment when supplements were 11% of total intake. Increases in liveweight gain due to supplements were similar with the two supplements; the increase in wool production was substantially greater with C than with B. Larger growth responses to C than to B with cattle (Spragg et al. 1984) than with sheep in Experiment 1 may be attributed to higher total DM1 with cattle (127 and 83 g/kgo*75 for cattle and sheep respectively) which in turn may be attributed partly to stage of maturity (cattle and sheep were about 40 and 60% of mature size in the respective experiments. SPRAGG, J.C., KELLAWAY, RX, and LEIBHOLZ, JANE Prod. 15: . (1984). Proc. Aust. Soc. Anim. *Dept of Animal Husbandry, University of Sydney, Camden, N.S.W. 2570. 649
