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

Burger, Willem Jacobus (2002-04)

Thesis (MScAgric) -- University of Stellenbosch, 2002.

Thesis

ENGLISH ABSTRACT: Low quality roughage is often used in the Western Cape as the only source of roughage for the young growing ruminant. Production levels of these animals is unsatisfactory and therefore supplementation is required. It is necessary when small grains are fed to also include protein sources in the diets. For high production, these protein sources must also be protected against rumen degradation. Good results are reported with the treatment of sunflower oilcakemeal (SFOCM) with formaldehyde (0.86 g formaldehyde per 100 g protein). Protecting methionine with 2-methyl maleic anhydride results in an increase in wool production. This study looked at the effect on dry matter intake (DM-intake), wool production and live weight change with supplementing a low quality diet with urea, SFOCM and formaldehyde protected SFOCM (FSFOCM). These diets where also supplemented 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 straw and barley (1.1% of live weight) diet with SFOCM and FSFOCM (949 & 935 vs 848 gis/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. The apparent digestibility of crude protein (CP) of the urea diet are increased (P<0.05) by supplementing methionine when compared with no methionine supplementation (67.28 vs. 71.23 %). The apparent digestibility of crude protein (CP) of the SFOCM diet (63.71 and 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 methionine supplementation. The apparent digestibility of fat of the SFOCM diet (61.01 and 65.65 vs. 48.33 %) and FSFOCM diet (60.93 and 63.83 vs. 38.14 %) are decreased (P<0.05) by supplementing MMM when compared with no methionine and methionine supplementation. 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) by supplementing MMM when compared with no methionine and methionine supplementation. The DM- and CP-degradability of barley and DM-degradability of oats straw did not differ (P<0.05) between different protein treatments. The higher production with the supplementation of amino acids and proteins can be associated with more amino acids available in the lower digestibility tract and not as a result of better rumen function.

AFRIKAANSE OPSOMMING: Die benutting van strooi as 'n laegraadse ruvoer deur die jong groeiende herkouer is 'n algemene praktyk wat in die Weskaap toegepas word. Produksie is egter laag en aanvulling van beperkende voedingstowwe is dus noodsaaklik. Saam met kleingrane word proteïenbronne meestal as aanvulling gebruik. Vir hoë produksie is dit dikwels nodig om proteïen aan te vul wat teen ruminale afbraak beskerm word. Die formaldehiedbehandeling (0.86 g formaldehied per 100 g proteïen) van sonneblomoliekoekmeel (SBOKM) is alreeds baie suksesvol toegepas vir die beskerming van proteïen teen ruminale afbraak. Deur metionien met dimetielmaleïelsuuranhidried te beskerm, is wolproduksie verhoog. Die studie het die effek van aanvulling van ureum, SBOKM en formaldehiedbehandelde SBOKM (FSBOKM) saam met geen metionien, metionien en 2,3 - dimetielmaleïelmetionien (MMM) op droëmateriaal (DM) -inname, wolproduksie en liggaamsmassaverandering ondersoek. Die DM-inname van jong Merinohamels op 'n hawerstrooi en gars (1.1% van liggaamsmassa) dieet is verhoog (P<0.05) deur die aanvulling van SBOKM en FSBOKM (949 & 935 vs 848 g/s/d). Die DM-inname is egter met 9 % verlaag (P<0.05) deur aanvulling van MMM. Die aanvulling van FSBOKM het die liggaamsmassatoename verhoog (P<0.05) van 19 na 44 gIs/d. Wolproduksie is met 38% (P<0.05) deur MMM-aanvulling verhoog. Die skynbare verteerbaarheid van ruproteïen (RP) by die ureumbehandeling is verhoog (P<0.05) met metionienaanvulling teenoor geen metionienaanvulling (67.28 vs. 71.23%). By SBOKM (63.71 en 64.96 vs. 70.15%) en FSBOKM-behandelings (66.39 en 66.26 vs. 70.89%) is skynbare verteerbaarheid van RP verhoog (P<0.05) met MMM-aanvulling teenoor metionien- of geen-metionienaanvulling. By SBOKM (61.01 en 65.65 vs. 48.33%) en FSBOKM-behandelings (60.93 en 63.83 vs. 38.14%) is skynbare verteerbaarheid van vet verlaag (P<0.05) met MMM-aanvulling teenoor metionien- of geen metionienaanvulling. By SBOKM (-0.15 en 5.41 vs. 4.62 gIs/d) en FSBOKM-bahandelings (2.93 en 5.60 vs. 6.02 gIs/d) is skynbare N-balans verlaag (P<0.05) met MMM-aanvulling teenoor metionien- of geen-metionienaanvulling. Die effektiewe verteerbaarheid van DM en RP van gars en effektiewe verteerbaarheid van DM van strooi is nie beïnvloed (P>0.05) deur die aanvulling van proteïen nie. Die verhoogde produksie kan dus geassosieer word met 'n verhoogde voorsienning van aminosure in die SVK deur aanvulling en nie weens verbetering in die rumenfunksie nie.

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