Physical form of maize grain in finishing rations of ram lambs

[摘要] English: The effect of whole (WMG), ground (GMG) and fine (FMG) maize grain in finishingrations for lambs containing 20 and 40% lucerne hay respectively was investigated.Thirty 3-month-old SA Mutton Merino lambs were randomly allocated to 6 treatments of5 animals each. A digestibility and production study was carried out (60 lambs in total).All lambs were kept in individual pens for the duration of the various studies.The dry matter intake (DMI) of the lambs in the digestibility study consuming the rationwith WMG was significantly (P=0.0052) lower than those fed FMG. Processing of maizegrain resulted a significant (P<0.05) reduction in the apparent digestibility of dry matter,crude protein, acid detergent fibre and gross energy as well as digestible crude proteinand metabolisable energy (ME).In contrast with DMI (P>0.05) the apparent digestibility of dry matter, crude protein andgross energy were significantly (P<0.05) decreased with an increase in roughage level to40%. Acid detergent fibre digestibility showed no statistical significant (P>0.05)differences between dietary roughage levels. Lucerne hay level did not influence(P>0.05) the ME-content of the finishing rations within a specific physical form.Physical form of maize grain in finishing rations for lambs did not significantly (P>0.05)influence DMI, feed conversion and carcass characteristics. The inclusion of FMG in afinishing ration with 40% lucerne hay resulted in a significant (P=0.0013) lower MEintake.A significantly (P<0.05) poorer weight gain and energy efficiency were observedfor lambs fed WMG in the ration.The inclusion of 20 and 40% lucerne hay in finishing rations of lambs did notsignificantly (P>0.05) influence DMI, ME-intake and weight gain as well as feed andenergy efficiency. A higher (P<0.05) carcass weight and dressing percentage occurredwhen 20% compared to 40% lucerne hay was included in the lamb-finishing ration.It was concluded that the physical form of maize grain in finishing rations has noinfluence on the performance of lambs. Accordingly no physical form x roughagelevel (20 to 40% lucerne hay) interaction exists in finishing rations for lambs.

[发布机构] University of the Free State