[Multifactorial effect of intrinsic animal factors, season and herd effect on the parameter of metabolic profile in dairy cows: energy and protein metabolism].
In this study, we investigated in a multivariate approach the multifactorial relationships between intrinsic factors, season, time of sampling during the year, and herd effect on one side, and selected biochemical markers of the energy and protein metabolism on the other side. A total of 370 cows (158 in summer and 212 in winter) were investigated within 0-160 days post partum. The following metabolites were chosen: glucose, nonesterified fatty acids, b-hydroxybutyrate, cholesterol and urea. Multiple linear regression models with only intrinsic factors had generally low coefficients of determination (r2). Season had a significant effect on all metabolites excepted glucose, but introduction of this factor in the models did not increase r2 markedly. Herd effect was highly significant for all blood parameters. Despite the reduction of the number of cases, models within season showed higher r2 than the overall models. This leads to the conclusion that, according to the season, some factors have different effects which neutralize themselves during the whole year. Many interactions herd x factors were significant for each metabolite. This means that the effect of the factors is different among herds. These interactions were especially strong for glucose, b-hydroxybutyrate and urea nitrogen, which usually show short-term responses to feeding changes. The regression models showed generally high coefficients of determination. It is concluded that these factors and interactions have to be introduced as covariates in models designed to investigate the relationships between biochemical markers and clinical findings.
Klinik für Nutztiere und Pferde, Universität Bern, Schweiz.
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D020155:3-Hydroxybutyric Acid; D000818:Animals; D015415:Biomarkers; D002417:Cattle; D002784:Cholesterol / Q000378:metabolism; D004044:Dietary Proteins / Q000378:metabolism; D004734:Energy Metabolism; D005163:Factor Analysis, Statistical; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000378:metabolism; D006885:Hydroxybutyrates / Q000378:metabolism; D008954:Models, Biological; D015999:Multivariate Analysis; D049590:Postpartum Period / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D012621:Seasons; D013997:Time Factors; D014508:Urea / Q000378:metabolism
D015415:Biomarkers; D004044:Dietary Proteins; D005230:Fatty Acids, Nonesterified; D006885:Hydroxybutyrates; D011506:Proteins; D014508:Urea; D002784:Cholesterol; D005947:Glucose; D020155:3-Hydroxybutyric Acid