Benutting van verrykte gars en 'n koring/garsmengsel as afrondingsrantsoene vir vroegspeenlammers

Abstract

Utilization of enriched barley and a u'heat/barley mixture in feedlot rations for early weaned lambs. Whole barley and a wheat/barley mixture (67:33) were enriched with either a locally composed supplement (containing urea and minerals absorbed into the grain, with calcium hydroxide and an ionophore bound to it with molasses) or a commercially available enrichment formula, and fed to early weaned (ca 8 weeks) SA Mutton Merino lambs under feedlot conditions. Commercial lamb creep pellets were included in the experiment as a control. The voluntary intake (DMi), average daily gain (ADG) and feed conversion ratio (FCR; kg feed/kg gain), as well as the blood mineral levels of the lambs were measured. Samples of the liver, kidneys and rumen wall of all the lambs were taken during slaughter for histological investigations, to determine the occurrence of abscesses. The DMi of the enriched grains was 13,4 - 20,9 % lower (P ≤ 0,01) than that of creep pellets. The ADG of lambs receiving enriched grains was 9,7-16,1% lower (P ≤ 0,05) than that of the lambs on the creep pellets. The FCRs of the lambs on the whole grain rations enriched with the locally composed supplement were 9,3 and 10,1 % better (P ≤ 0,05), respectively, than those of the lambs on the creep pellets. The incidence of abscesses in the rumen, liver and kidneys tended to be higher (P ≤ 0,05) in lambs receiving the commercial enrichment formula. Blood minerals of the lambs on the respective rations were within the accepted range. The finishing of early weaned lambs on enriched whole grain as sole source, thus appears to be feasible, despite slightly lower DMi and ADG figures when compared to lamb creep pellets.

Heel gars en 'n koring/garsmengsel (67:33) is verryk met 'n
plaasliksaamgestelde-verrykingsmengsel (insluitende ureum en minerale, in die pitte geabsorbeer, met kalsiumhidroksied en ionofore met melasse daaraan gebind) of met 'n kommersieelbeskikbare-verrykingsmengsel, en onder voerkraaltoestande aan vroeggespeende (ong. 8 weke) SA Vleismerinolammers gevoer. Kommersiële lamkruippille is as 'n kontrolerantsoen ingesluit. Die vrywillige daaglikse voerinname (DMi), gemiddelde daaglikse massatoename (GDT) en voeromsettingsverhouding (VOV) sowel as die bloedmineralevlakke van die lammers is bepaal. Monsters van die lewer, niere en rumenwand van alle lammers is tydens slagting geneem en histologies ondersoek vir tekens van absesse. Die DMi van die verrykte kleingrane was 13,4 - 20,9% laer (P ≤ 0,05) as dié van lamkruippille. Die gemiddelde GDT van die lammers op verrykte graan was ooreenstemmend 9.7 - 16,1 % laer (P ≤ 0,05) as dié van lammers op lamkruippille. Die VOV van lammers op die gars en die koring/garsmengsel, aangevul met die plaasliksaamgestelde-verrykingsmengsel, was onderskeidelik 9,3 en 10,1 % beter (P ≤ 0,05) as dié van lammers op lamkruippille. Die voorkoms van absesse in die rumen, lewer en niere het hoër geneig (P ≤ 0,05) in lammers wat kommersieelverrykte-heelgraanrantsoene ontvang het. Bloedmineraalvlakke van lammers op die onderskeie rantsoene was binne die aanvaarde grense. Die afronding van vroeggespeende lammers op verrykte grane as enigste bron blyk dus uitvoerbaar te wees, ten spyte van effens laer DMi- en GDT-syfers as dié van lamkruippille.

Keywords: Average daily gain, barley, enrichment, feed conversion,
voluntary intake, wheat.