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The blood and urine tests for assessing the animal health and metabolic status in high yielding herds are an integral part of herd management. The objective of this study was the testing of different blood and urine parameters in regard to daily fluctuations.
This investigation is supposed to include factors that influence blood and urine parameters during the course of the day. Blood and urine samples, were collected in a conventional dairy farm from March 2010 to February 2011. Based on the samples daily profiles of metabolites, enzymes and minerals have been created. For this study, eight study groups were set up based on the stage of lactation and age profile. In this study the classification of the subjects were new-born, suckling calves, dry cows, close ups, colostrum, fresh cows, high-and low-yielding group. The groups consisted of 10 to 11 clinically healthy animals. The blood and urine test sampling were carried out in four-hour intervals at 6 am, 10 am, 2pm, 6pm, 10pm, 2am and 6am over a period of 24 hours. Regarding adult animals, the blood sample was taken from the vena caudalis mediana and regarding the calves through the external jugular vein catheterization.
The urine samples were obtained by a manual stimulation of the dorsal udder levels. The serum and urine sample processing was right after the sampling was conducted. In the blood serum parameters total protein, albumin, urea, cholesterol, bilirubin, glucose, NEFA, BHB, creatinine, AST, CK, GGT, GLDH, calcium, inorganic phosphate, chloride, potassium, sodium and magnesium were analysed. The parameters creatinine, pH, bases, acids, ammonium, NSBA, BSQ, calcium, potassium, magnesium, sodium and chloride were determined in the urine.
The blood and urine parameters were examined with the two-factorial variance analysis in regards to the influence of the day time of day and group. Only a few parameters on the basis of the histograms showed a normal distribution. A major part of the lab values showed a left-skewed distribution shape. The application and validity of parametric tests should be assessed critically in the study of laboratory parameters. In terms of glucose, NEFA, BHB, acids (urine), NSBA, BSQ, chloride (urine) and potassium (urine) significant time of day influences were detected. The time of the feeding could be determined as a main influencing factors with an exception of the urinary chloride value. For the urine chloride value the influence of time of day was proven in the analysis of variance, but the cause could not be named here directly. A renal regulation or feed intake is assumed to be influential. Among the investigated parameters the daily curves of TP, Alb, Chol, urea, glutamate dehydrogenase, P, Cl, Na, Ca are particularly consistent. Particularly strong daily fluctuations were recorded at BHB, Crea (urine), bases (urine), acids (urine), NSBA, BSQ, K, Mg (urea), Cl (urine), K (urine), and Na (urine recorded).
The Bili, Glu, and GGT concentrations were subject to greater fluctuations in the groups of calves than in the adult animals. The group effect was significant for all parameters examined. Therefore age, stage of lactation and dry period, milk yield and feed composition have a significant influence on the level height and the course of laboratory parameters. Significant differences were found in glucose, calcium and inorganic phosphate in relation to age. In the groups of calves these parameters were measured in significantly higher concentrations. The calves reported significantly lower levels compared to adults in relation to BHB, AST and magnesium. Great care must be shown when taking blood samples for the determination of creatine kinase, since even small tissue injuries after multiple blood sampling from the tail vein can result in a significant deflection of the CK-value. A blood sample from the large body veins is recommended here. In conclusion the results can be expressed by the following recommendations for sampling and interpretation: A certain time of specimen collection based on the results cannot be recommended. Therefore the time of the sample collection can be adjusted according to the operational processes. However, care shall be taken in a course of study at the time of sampling, otherwise the comparative values of the sampling time points may differ significantly from each other, without a pathological state. Dividing the herd into different control groups is recommended for assessing its all-over health.
The classification should be based on the age (juvenile - adult) and lactation stage and dry period of the subjects. At least 8 to 10 samples within the groups shall be taken to obtain a better overall picture of a study group. This project paper is an instrument to evaluate the highlighted results in order to provide a statement regarding the metabolism and health status in high yielding herds. The results of the studied parameters can thus be compared.