Die verbetering van die benutting van laegraadse ruvoer vir wol- en vleisproduksie deur aanvulling van beskermde proteienbronne en/of aminosure

[摘要] ENGLISH ABSTRACT:Low quality roughage is often used in the Western Cape as the only source of roughagefor the young growing ruminant. Production levels of these animals is unsatisfactory andtherefore supplementation is required. It is necessary when small grains are fed to alsoinclude protein sources in the diets. For high production, these protein sources must alsobe protected against rumen degradation. Good results are reported with the treatment ofsunflower oilcakemeal (SFOCM) with formaldehyde (0.86 g formaldehyde per 100 gprotein). Protecting methionine with 2-methyl maleic anhydride results in an increase inwool production. This study looked at the effect on dry matter intake (DM-intake), woolproduction and live weight change with supplementing a low quality diet with urea,SFOCM and formaldehyde protected SFOCM (FSFOCM). These diets where alsosupplemented with no methionine, methionine and 2-methyl maleyl methionine (MMM).The DM-intake of total diet are increased (P<0.05) with the supplementing of oats strawand barley (1.1% of live weight) diet with SFOCM and FSFOCM (949 & 935 vs 848gis/d). Supplementing MMM decreased (P<0.05) the DM-intake with 9 %.Supplementing FSFOCM increased (P<0.05) live weight change from 19 to 44 gis/d. Wool production are increased (P<0.05) with 38 % with supplementation of MMM. Theapparent digestibility of crude protein (CP) of the urea diet are increased (P<0.05) bysupplementing methionine when compared with no methionine supplementation (67.28vs. 71.23 %). The apparent digestibility of crude protein (CP) of the SFOCM diet (63.71and 64.96 vs. 70.15 %) and FSFOCM diet (66.39 and 66.26 vs. 70.89 %) are increased(P<0.05) by supplementing MMM when compared with no methionine and methioninesupplementation. The apparent digestibility of fat of the SFOCM diet (61.01 and 65.65vs. 48.33 %) and FSFOCM diet (60.93 and 63.83 vs. 38.14 %) are decreased (P<0.05) bysupplementing MMM when compared with no methionine and methioninesupplementation. The apparent nitrogen balance of the SFOCM diet (-0.15 and 5.41 vs.4.62 gis/d) and FSFOCM diet (2.93 and 5.60 vs. 6.02 gis/d) are increased (P<0.05) bysupplementing MMM when compared with no methionine and methioninesupplementation. The DM- and CP-degradability of barley and DM-degradability of oatsstraw did not differ (P<0.05) between different protein treatments. The higher productionwith the supplementation of amino acids and proteins can be associated with more aminoacids available in the lower digestibility tract and not as a result of better rumen function.

[发布机构] Stellenbosch University