Kahe alternatiivmeetodi täpsus ketoosis piimalehmade tuvastamisel
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Kuupäev
2025
Kättesaadav alates
04.09.2025
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Piimalehmadele iseloomulik ainevahetushaigus ketoos mõjutab loomakasvatusettevõtete majanduslikku edukust. Subkliinilise ketoosi suur levimus karjas, eriti esimesel laktatsiooninädalal, põhjustab loomade produktiivsuse langust ja suurendab loomade raviga seotud kulusid. Subkliinilise ketoosi diagnoosimiseks määratakse ketokehade sisaldust erinevatest kehavedelikest (piim, veri, uriin). Subkliinilisse ketoosi haigestunud lehmade uurimiseks saab määrata erinevaid metaboliite (atsetoon, atsetoatsetaat, β-hüdroksübutüraat – BHB). Kõige stabiilsem ja tundlikum ketokeha on BHB. Seega subkliinilise ketoosi hindamiseks annab selle kontsentratsiooni määramine kõige täpsema tulemuse. Töö peamine eesmärk oli võrrelda kesk-infrapuna-spektromeetriga (MIR) määratud piima BHB ja vereplasmast kiirtestiga „Optium Beta-Ketone Test“ määratud BHB kokkulangevust laboratoorse meetodiga ning seejärel anda ülevaade nende kasutamise võimalusest piimakarja subkliinilise ketoosi levimuse jälgimisel. Valimisse võeti kolme katse raames kolmest Eesti farmist kogutud eesti holsteini tõugu lehmade piima- ja vereproovid. Katsed viidi läbi erinevatel perioodidel ajavahemikus 2016–2023. Piimast määratud ja vereplasma BHB võrdluseks saadi andmetabel, mis sisaldas 1514 proovi, mis koguti 345 lehmalt. Kiirtesti meetodi võrdluseks võeti 140 loomalt kogutud 140 vereproovi, millest määrati BHB nii referentsmeetodil kui kiirtestiga. Piimast määrati BHB Eesti Põllumajandusloomade Jõudluskontrolli AS piimalaboris kasutades infrapuna-spektromeetrit. Leiti, et piima BHB määramisel on optimaalne piirväärtus subkliinilise ketoosi tuvastamiseks 0,13 mmol/l. Antud töö tulemusena selgus, et isegi optimaalse piirväärtuse juures ei ole ainult piima BHB ennustamisel saadud tulemused haigete loomade tuvastamiseks piisavad. See ühtib varasemalt läbiviidud uuringute leidudega, mille kohaselt leiti, et MIR määratud piima BHB sobib kasutamiseks koos mõne teise analüüsimeetodiga. Kiirtesti tulemused ühtisid üldjuhul referentsmeetodiga ehk see on sobiv subkliinilise ketoosi tuvastamiseks poegimisjärgselt. Võrreldes laboratoorse meetodiga on see analüüsimeetod odavam ja kiirem, kuna see ei nõua vereproovide saatmist laborisse. Sarnaselt humaanmeditsiinis kasutatavatele glükomeetritele, on kiirtesti testribade jaoks vajalik vere kogus minimaalne, mis jällegi vähendab selle analüüsi jaoks vajalike vereproovide kogumise invasiivsust.
Ketosis is a metabolic disease that affects mostly dairy cows and it affects the economic success of dairy farms. The high prevalence of subclinical ketosis in the herd, especially in the first week of lactation, leads to a decrease in animal productivity and an increase of the costs associated with treatment. The diagnosis of subclinical ketosis is made by determining the content of ketone bodies in various bodily fluids (milk, blood, urine). Various metabolites (acetone, acetoacetate, β-hydroxybutyrate – BHB) can be measured to identify cows with subclinical ketosis. The most stable and sensitive ketone body is BHB, so measuring its concentration in the blood gives the most accurate results to assess the prevalence of subclinical ketosis. The main aim of this Bachelor’s thesis was to assess the accuracy of mid-infrared spectrometry predicted milk BHB and blood plasma BHB measured with a handheld blood ketone meter (Optium Beta-Ketone Test) compared to the reference method. Based on the results, the author’s aim was to provide an overview of the possibility of using the aforementioned tests for monitoring subclinical ketosis prevalence in dairy herds. Milk and blood samples collected from three Estonian farms during three experiments were analysed. The experiments were conducted at different periods between 2016–2023. A data set containing 1514 samples collected from 345 cows was obtained to compare BHB concentration predicted from milk and measured from blood plasma. A data set containing 140 blood tests from 140 animals was used to assess the accuracy of the handheld blood ketone meter. The samples were selected for analysis only if plasma BHB from the same sample was tested with the ketone meter and the clinical method. BHB in milk was predicted in the milk laboratory of Eesti Põllumajandusloomade Jõudluskontrolli AS using mid-infrared spectrometer (MIR) technology. It was found that the optimal milk BHB cut-off value for detecting subclinical ketosis using infrared spectrometry was 0.13 mmol/L. The results showed that even at the optimal cut-off value, the results obtained from predicting milk BHB alone are not sufficient to identify animals with subclinical ketosis. This finding is consistent with previous studies that found that milk BHB predicted with MIR is suitable for use in combination with other methods. The results of the handheld ketone meters however were found to generally coincide with the reference method, making it suitable for the early detection of subclinical ketosis post-calving. Compared to the clinical method, the handheld blood ketone meter is cheaper and faster, since it does not require sending blood samples to a laboratory. Similarly, to the handheld meters used in human medicine, the required amount of blood for the blood strip is minimal, which reduces the invasiveness of the blood collection procedure.
Ketosis is a metabolic disease that affects mostly dairy cows and it affects the economic success of dairy farms. The high prevalence of subclinical ketosis in the herd, especially in the first week of lactation, leads to a decrease in animal productivity and an increase of the costs associated with treatment. The diagnosis of subclinical ketosis is made by determining the content of ketone bodies in various bodily fluids (milk, blood, urine). Various metabolites (acetone, acetoacetate, β-hydroxybutyrate – BHB) can be measured to identify cows with subclinical ketosis. The most stable and sensitive ketone body is BHB, so measuring its concentration in the blood gives the most accurate results to assess the prevalence of subclinical ketosis. The main aim of this Bachelor’s thesis was to assess the accuracy of mid-infrared spectrometry predicted milk BHB and blood plasma BHB measured with a handheld blood ketone meter (Optium Beta-Ketone Test) compared to the reference method. Based on the results, the author’s aim was to provide an overview of the possibility of using the aforementioned tests for monitoring subclinical ketosis prevalence in dairy herds. Milk and blood samples collected from three Estonian farms during three experiments were analysed. The experiments were conducted at different periods between 2016–2023. A data set containing 1514 samples collected from 345 cows was obtained to compare BHB concentration predicted from milk and measured from blood plasma. A data set containing 140 blood tests from 140 animals was used to assess the accuracy of the handheld blood ketone meter. The samples were selected for analysis only if plasma BHB from the same sample was tested with the ketone meter and the clinical method. BHB in milk was predicted in the milk laboratory of Eesti Põllumajandusloomade Jõudluskontrolli AS using mid-infrared spectrometer (MIR) technology. It was found that the optimal milk BHB cut-off value for detecting subclinical ketosis using infrared spectrometry was 0.13 mmol/L. The results showed that even at the optimal cut-off value, the results obtained from predicting milk BHB alone are not sufficient to identify animals with subclinical ketosis. This finding is consistent with previous studies that found that milk BHB predicted with MIR is suitable for use in combination with other methods. The results of the handheld ketone meters however were found to generally coincide with the reference method, making it suitable for the early detection of subclinical ketosis post-calving. Compared to the clinical method, the handheld blood ketone meter is cheaper and faster, since it does not require sending blood samples to a laboratory. Similarly, to the handheld meters used in human medicine, the required amount of blood for the blood strip is minimal, which reduces the invasiveness of the blood collection procedure.
Kirjeldus
Bakalaureusetöö
Loomakasvatuse õppekaval
Märksõnad
bakalaureusetööd, piimaveis, kiirtest, üleminekuperiood, ketokehad