Natural variations of milk somatic cell count in dairy cows
The main objectives of this thesis were to find out which factors affect the day-to-day variations of somatic cell count (SCC) in bovine milk and how the results of on-line measurements of SCC can be applied in automatic milking systems. The effect of milking interval and milk fraction during sampli...
| Autor principal: | |
|---|---|
| Formato: | Otro |
| Lenguaje: | sueco Inglés |
| Publicado: |
2007
|
| Materias: | |
| Acceso en línea: | https://stud.epsilon.slu.se/12008/ |
| _version_ | 1855571981926137856 |
|---|---|
| author | Woloszyn, Marta |
| author_browse | Woloszyn, Marta |
| author_facet | Woloszyn, Marta |
| author_sort | Woloszyn, Marta |
| collection | Epsilon Archive for Student Projects |
| description | The main objectives of this thesis were to find out which factors affect the day-to-day variations of somatic cell count (SCC) in bovine milk and how the results of on-line measurements of SCC can be applied in automatic milking systems. The effect of milking interval and milk fraction during sampling on SCC was investigated.
Mastitis is regarded as one of the most costly diseases in the world in dairy production. Most of the mastitis cases are without visible symptoms (subclinical) and pass unnoticed. Cows having subclinical mastitis contribute the most to the total production loss for the farmer. With the new technology of on-line measuring of milk SCC comes the possibility to measure the SCC at every milking at a very low cost, getting an good overview of the variations in SCC. But it is of great importance to be able to interpret these consecutive SCC values and to know how and why the variations of milk SCC fluctuate.
After investigating what factors that have an impact on an uninfected gland two experiments were performed, the first regarding the effect of milking interval on SCC and the second, the importance of the selected milk fraction. Both factors are assumed having an effect on the SCC.
In the first experiment data from 83 different cows during a four-month period were examined for the influence of milking interval on the SCC. The cows were housed in a barn with the automatic milking system VMS, provided by DeLaval. The VMS was equipped with an on-line cell counter, OCC. The data was analysed using SAS REG procedure. Even though a trend between lower SCC and longer milking interval could be seen on all milking data, the correlation was not significant on total milkings level. However, 82% of the single cows had a negative correlation between SCC and milking interval, of which 34% were significant (P < 0.05). Although the results of this study showed that milking interval affects an uninfected udder, there was no possibility of creating a compensating algorithm applicable on all cows.
The second experiment was performed in Switzerland during 40 days. A special milking machine with four separate milk containers was used enabling the measuring of quarter SCC. In total, 3420 milk samples from 19 cows were tested for SCC. All analyses were made by the Institution of Veterinary Physiology, University of Bern, using the Wilcoxon Signed Rank Test in SigmaStat. The result of this study showed that foremilk SCC did not very well represent the SCC of total milk of single quarters or whole udder milk. Foremilk SCC was significantly higher (P < 0.001). The study also showed that single quarter milk was not representative when estimating whole udder milk SCC. The mean of measured SCC of whole udder milk was significantly higher (P < 0.001) than the volume corrected SCC calculated from total quarter milk. |
| format | Otro |
| id | RepoSLU12008 |
| institution | Swedish University of Agricultural Sciences |
| language | Swedish Inglés |
| publishDate | 2007 |
| publishDateSort | 2007 |
| record_format | eprints |
| spelling | RepoSLU120082017-11-14T08:58:47Z https://stud.epsilon.slu.se/12008/ Natural variations of milk somatic cell count in dairy cows Woloszyn, Marta Animal feeding The main objectives of this thesis were to find out which factors affect the day-to-day variations of somatic cell count (SCC) in bovine milk and how the results of on-line measurements of SCC can be applied in automatic milking systems. The effect of milking interval and milk fraction during sampling on SCC was investigated. Mastitis is regarded as one of the most costly diseases in the world in dairy production. Most of the mastitis cases are without visible symptoms (subclinical) and pass unnoticed. Cows having subclinical mastitis contribute the most to the total production loss for the farmer. With the new technology of on-line measuring of milk SCC comes the possibility to measure the SCC at every milking at a very low cost, getting an good overview of the variations in SCC. But it is of great importance to be able to interpret these consecutive SCC values and to know how and why the variations of milk SCC fluctuate. After investigating what factors that have an impact on an uninfected gland two experiments were performed, the first regarding the effect of milking interval on SCC and the second, the importance of the selected milk fraction. Both factors are assumed having an effect on the SCC. In the first experiment data from 83 different cows during a four-month period were examined for the influence of milking interval on the SCC. The cows were housed in a barn with the automatic milking system VMS, provided by DeLaval. The VMS was equipped with an on-line cell counter, OCC. The data was analysed using SAS REG procedure. Even though a trend between lower SCC and longer milking interval could be seen on all milking data, the correlation was not significant on total milkings level. However, 82% of the single cows had a negative correlation between SCC and milking interval, of which 34% were significant (P < 0.05). Although the results of this study showed that milking interval affects an uninfected udder, there was no possibility of creating a compensating algorithm applicable on all cows. The second experiment was performed in Switzerland during 40 days. A special milking machine with four separate milk containers was used enabling the measuring of quarter SCC. In total, 3420 milk samples from 19 cows were tested for SCC. All analyses were made by the Institution of Veterinary Physiology, University of Bern, using the Wilcoxon Signed Rank Test in SigmaStat. The result of this study showed that foremilk SCC did not very well represent the SCC of total milk of single quarters or whole udder milk. Foremilk SCC was significantly higher (P < 0.001). The study also showed that single quarter milk was not representative when estimating whole udder milk SCC. The mean of measured SCC of whole udder milk was significantly higher (P < 0.001) than the volume corrected SCC calculated from total quarter milk. Huvudsyftena med detta examensarbete var att ta reda på vilka faktorer som påverkar dag-till-dagvariationen av somatiska celler i komjölk och hur resultaten av on-line registrering av celltalet kan appliceras i automatiska mjölkningssystem. Effekten på celltalet av mjölkningsintervall och olika mjölkfraktioner under provtagning undersöktes. Mastit anses vara en av de mest kostsamma sjukdomarna i världen inom mjölkindustrin. De flesta fall av mastit sker utan några synliga symptom, så kallad subklinisk mastit, och passerar obemärkt. Kor med subklinisk mastit är de som orsakar den största delen av lantbrukarens totala produktionsförlust. Med den nya onlineregistreringsteknologin kommer möjligheten att mäta celltalet under varje mjölkning till ett mycket lågt pris. Detta ger en mycket god överblick på celltalsvariationerna för varje enskild ko. Det är av stor vikt att kunna tolka dessa på varandra följande värden och veta hur och varför celltalet varierar. Efter att ha undersökt vilka faktorer som påverkar celltalet i ett friskt juver utfördes två försök; det första med avseende på hur mjölkningsintervallet inverkar på celltalet och det andra betydelsen av vald mjölkfraktion. Båda dessa faktorer antas ha en inverkan på celltalet. I det första experimentet undersöktes data från 83 kor under en fyramånadersperiod med avseende på hur mjölkningsintervallet inverkar på celltalet. Korna inhystes i ett stall med det automatiska mjölkningssystemet VMS från DeLaval. VMS:en var utrustad med en on-linecellräknare, OCC. All data analyserades med ”SAS REG procedure”. Trots att det fanns en trend mellan lägre celltal och längre mjölkningsintervall då all celltalsdata för alla kor analyserades, var korrelationen inte signifikant. Däremot hade 82% av de enskilda korna en negativ korrelation mellan celltal och mjölkningsintervall, varav 34% var signifikant (P < 0.05). Trots att resultatet av detta försök visade att mjölkningsintervallet hade en inverkan på celltalet, var det inte möjligt att skapa en kompenserande algoritm som gick att tillämpa för alla kor. Det andra experimentet utfördes i Schweiz under 40 dagar då en särskild mjölkningsmaskin som tillät fjärdedelsmjölkning användes. Totalt mättes celltalet på 3420 mjölkprover från totalt 19 kor. All statistisk analys utfördes av institutionen för veterinärfysiologi, Berns universitet, med ett ”Wilcoxon Signed Rank Test” i SigmaStat. Resultatet av detta försök visade att celltalet i förmjölken inte representerade celltalet i helmjölken från de enskilda fjärdedelarna och inte heller celltalet i heljuvermjölken. Celltalet i förmjölken var signifikant högre (P < 0,001). Försöket visade också att helmjölken från de enskilda fjärdedelarna inte var representativ vad gäller estimering av celltalet i heljuvermjölk. Medeltalet av det uppmätta celltalet i heljuvermjölken var signifikant högre (P < 0,001) än det volymkorrigerade celltalet uträknat från den totala fjärdedelsmjölken. 2007-10-25 Other NonPeerReviewed application/pdf sv https://stud.epsilon.slu.se/12008/1/woloszyn_m_171114.pdf Woloszyn, Marta, 2007. Natural variations of milk somatic cell count in dairy cows. UNSPECIFIED, Uppsala. Uppsala: (VH) > Dept. of Animal Nutrition and Management (until 231231) <https://stud.epsilon.slu.se/view/divisions/OID-650.html> urn:nbn:se:slu:epsilon-s-8770 eng |
| spellingShingle | Animal feeding Woloszyn, Marta Natural variations of milk somatic cell count in dairy cows |
| title | Natural variations of milk somatic cell count in dairy cows |
| title_full | Natural variations of milk somatic cell count in dairy cows |
| title_fullStr | Natural variations of milk somatic cell count in dairy cows |
| title_full_unstemmed | Natural variations of milk somatic cell count in dairy cows |
| title_short | Natural variations of milk somatic cell count in dairy cows |
| title_sort | natural variations of milk somatic cell count in dairy cows |
| topic | Animal feeding |
| url | https://stud.epsilon.slu.se/12008/ https://stud.epsilon.slu.se/12008/ |