Schwalbach, L. M. J.Greyling, J. P. C.Pretorius, Christa2016-01-082016-01-082008-11-302011-09-202008-11-30http://hdl.handle.net/11660/2069English: The main aim of this study was to evaluate the effectiveness of repeated inoculations of a Corynebacterium cutis lysate (Ultra-Corn®) - a non-specific immune-stimulant, to reduce the milk SCC in commercial dairy cows. An additional aim was to evaluate if these inoculations had any detrimental effects on milk quality. This study was performed in two separate trials, using Holstein cows with SCC’s over 250 000 cells/ml of milk at different stages of lactation from two commercial dairy farms in the Free State Province. On each farm, cows were paired according days in milk and SCC, in order to obtain two homogeneous groups of experimental animals. The two groups of cows in each farm were randomly allocated to a treatment or a control group. Both groups in the same farm were managed under the same conditions for the entire trial periods. The only difference was that cows from the treatment group received 3 weekly inoculations of Corynebacterium cutis lysate(Ultra-Corn® ), while those from the control group received distilled water for injection (the same volume as the cows in the treatment group). Two similar trials were conducted, using the same basic experimental design. Differences were only in the dose of the Corynebacterium cutis lysate inoculated per cow treated, number of experimental animals and duration of the observation periods. In Trial 1, cows from the treated group received 3 weekly vaccinations of Ultra-Corn® (4 ml per cow, thus 80mg of Corynebacterium cutis lysate per cow) injected subcutaneously (sc), while those from the control group received 3 weekly sc injections of 4 ml distilled water. This was followed by 8 weeks of observation of the effect of treatment on milk SCC and composition. In Trial 2, the three doses of Corynebacterium cutis lysate administered weekly per cow for the treated group was 2ml/100kg, thus 40mg Corynebacterium cutis lysate/100 kg per cow. This was followed by 8 weeks of observation of the effect of treatment on milk SCC and composition. Individual quarter milk samples were collected weekly from all cows and analysed for SCC and a combined milk sample (from the measuring bottle in the milk parlour) from each cow was also taken for butterfat, protein, lactose and urea content. The results were compared between the two groups per farm, using ANOVA procedures for repeated measures analysis, using the 95% confidence level (SAS, 2004). The two farms were evaluated separately, due to the possible differences between general management conditions, which could introduce serious confounding factors if the results from the two farms were combined. However, it can be considered that both dairy farms used an acceptable level of commercial dairy management practices and produced an acceptable yield per cow under South African commercial conditions. In general no significant differences were recorded between the treated and control groups of cows in both farms in both trials in terms of milk SCC, butterfat, protein, lactose and urea content of the milk. In this study, the immuno-stimulant effect of Ultra-Corn®, a Corynebacterium cutis lysate could not be confirmed in lactating cows. Although this inoculant does not seem to have any detrimental effects on the main solids of the milk, its use cannot be justified as it did not significantly reduce somatic cell counts in lactating cows. Further research is warranted to develop and evaluate the effectiveness of vaccines against mastitis causing organisms, in order to control SCC and mastitis in dairy cows. However, when such studies are conducted it is advisable to use very high number of experimental units and proper control trials should be conducted. All efforts should be done to ensure minimum environmental changes during these trials, which can introduce serious confounding effects in the experimental design.Afrikaans: Die doel van die studie was om die effektiwiteit van herhaalde inentings van Coryne bacterium cutis lysaat (Ultra Corn®) te evalueer, ‘n nie- spesifieke immuno stimulant, om die melk SST te verander in kommersiële melkbeeste. ‘n Addisionele doelwit was om te evalueer of hierdie inentings enige nadelig effek op melkkwaliteit het. Hierdie studie is uitgevoer in twee aparte proewe deur gebruik te maak van SST’s van meer as 250 000 selle/ml melk in verskeie stadia van laktasie, op twee kommersiële melkplase in die Vrystaatprovinsie. Op elke plaas was koeie geallokeer volgens dae in melk en SST om ‘n homogene groep eksperimentele diere te kry. Die twee groepe diere op elke plaas is ewekansig toegewys aan ‘n behandeling en kontrole groep. Groepe op dieselfde plaas is bestuur onder dieselfde toestande vir die proeftydperk. Al verskil was dat die koeie van die behandelingsgroep 3 weeklikse inentings van Coryne bacterium cutis lysaat (Ultra Corn®) ontvang het, terwyl die kontrole groep gedistilleerde water as inenting ontvang het (dieselfde volume per koei). Twee soortgelyke proewe is uitgevoer deur dieselfde eksperimentele ontwerp te gebruik. Verskille was slegs die dosis Coryne bacterium cutis lysaat per dier, die aantal eksperimentele diere en die tydsduur van die observasieperiode. In die eerste proef het die koeie in die behandelde groep 3 weeklikse inentings van Ultra Corn® (4ml/ koei; dus 80mg van die Coryne bacterium cutis lysaat per koei) onderhuids ontvang. Die kontrole groep het 3 weeklikse inspuitngs van 4 ml gedistilleerde water ontvang. Dit is gevolg deur ‘n 8 weke observasie periode om die effek van die behandeling op melk SST en samestelling te monitor. In die tweede proef is 3 behandelings van Coryne bacterium cutis lysaat weekliks toegedien per koei, die dosis was 2 ml/100 kg, dus 40mg/100kg Coryne bacterium cutis lysaat/100kg per koei. Dit is gevolg deur 12 weke van waarneming van die effek van behandeling op SST en melksamestelling. Individuele uierkwart melkmonsters is weekliks geneem van alle koeie en geanaliseer vir SST en gesamentlike monsters ( van al die kwarte in die maatbottel in die melkstal), van elke koei is ook geneem vir bottervet, proteien, laktose en urea inhoud. Die resultate is vergelyk tussen groepe per plaas deur gebruik te maak van die ANOVA prosedure vir herhaalde meetings by die 95% sekerheidsvlak (SAS, 2004). Die twee plase is apart geëvalueer a.g.v. verskille in algemene bestuurs praktyke wat moontlike verstrengelde effekte kan veroorsaak as die twee plase se resultate saamgegooi is. Dit moet egter beklemtoon word dat beide melkplase ‘n aanvaarbare vlak van bestuur en produksie gehandhaaf het. Oor die algemeen was geen betekenisvolle verskille waargeneem tussen die behandelde en kontrole groepe op beide plase in terme van SST, bottervet, proteien, laktose en urea inhoud. In hierdie studie kon die immuno-stimulant effek van die Coryne bacterium cutis lysaat nie bevestig nie word vir lakterende koeie. Alhoewel die inokulant geen nadelige effek op die bestandele van melk blyk te hê nie, kan die gebruik daarvan nie regverdig word nie, aangesien dit nie die somatiese seltellings in lakterende koeie verlaag nie. Verder navorsing is geregverdig om die effektiwiteit van entstowwe teen mastisis- vormende organismes te ontwikkel om SST en mastitis in melkkoeie te beheer. As sulke studies uitgevoer word is dit wesenlik om ‘n hoë aantal eksperimentele diere te gebruik en gekontroleerde proewe uit te voer. Alle pogings moet aangewend word om die minimum ongewensde verandering tydens die proewe te hê, wat kan lei tot verstrengelde effekte in die eksperimentele ontwerp.enDissertation (M.Sc.Agric. (Animal, Wildlife and Grassland Sciences))--University of the Free State, 2008Udder -- DiseasesMastitis -- TreatmentImmunological adjuvantsImmuno-stimulantUltra-Corn®Corynebacterium cutis lysateHolsteinUreaLactoseButterfatProteinMilk QualityDairySomatic cell countsCowsDissertationUniversity of the Free State