Effects of Calving Body Condition Score on Blood Acid-Base Balance of Primiparous Holstein-Friesian Dairy Cows in a Commercial Dairy Farm: A Case Study

Comparison of blood gas parameters, ions, and glucose concentration in polish Holstein-Friesian Dairy cows at different milk production levels

Genetic selection for increased milk yield has been a key driver of dairy intensification. The modern dairy cow produces much higher amounts of milk than the cattle of several years ago, and this may have an influence on hematologic values at different stages of lactation and on cows with different levels of milk production. The purpose of the study was to investigate the variations in blood parameters such as Ht, tHb, sO₂, FO₂Hb, FCOHb, FMetHb, FHHb, pH, pCO₂, pO₂, standard HCO₃-, actual HCO₃-, BE, BE ecf, ctCO₂, BO₂, p50, and ctO₂ in cows at different milk production levels. In addition, ions such as Na+, K+ , Ca++, Ca++ (7.4), and Cl-, and AnGap and glucose were examined. Our findings indicated that differences in the examined blood parameters between low and high-production dairy cattle do exist. The most apparent differences were connected with blood pH (p < 0.01), oxygen metabolism (Ht, tHb, sO2, FO2Hb; p < 0.01), and glucose utilization (p < 0.01) The results confirm that the parameters connected with blood oxygen metabolism and glucose metabolism increase significantly in high-production animals. In conclusion, reference values should be considered in light of the lactation stage and level of milk production, because these might influence how changes should be interpreted. The main limitation of the study is the delay to analysis. However, the blood was properly stored (4C), thus changes were delayed. Anyway, it is very hard in the field practice to perform it within 5 min after the blood collection and according to studies it has low impact on clinical outcomes.

Effects of higher plasma growth hormone levels on subclinical ketosis in postpartum Holstein cows

Ketosis is a major metabolic disorder that can lead to huge economic losses in postpartum dairy cows by influencing milk production and reproduction performance. Therefore, it is very important to understand the characteristics and significance of plasma GH levels and dynamic changes in postpartum dairy cows for finding pathogenesis of subclinical ketosis (SK). The present study aimed to determine the role of growth hormone (GH) from the onset of SK to the fifth week postpartum and to explain the variations in GH, and metabolic markers namely, β-hydroxybutyric acid (BHBA), non-esterified fatty acid (NEFA) and glucose (GLU) at early and later SK stages in postpartum Holstein cows. A 5-wk test and an intraday 12-h test were conducted in postpartum Holstein cows. Both tests were carried out every three hours from 10:00–22:00 for 7–14 days postpartum (12-h test: n = 16) to determine plasma concentrations of GH, BHBA, NEFA and GLU. The 5-wk test results showed that GH, BHBA and NEFA concentrations were significantly higher in the SK group during the five-weeks postpartum (p < 0.01); GLU concentration was significantly lower in the SK group (p < 0.01). Intraday 12-h test results revealed that the feeding time affected the plasma concentrations of GH, BHBA, NEFA and GLU. After 1-h of feeding time, GH concentrations decreased, while BHBA, NEFA and GLU concentrations increased. After 4-h of feeding time GH, BHBA and NEFA had the highest plasma concentrations, and GLU the lowest. In both experiments, GH was positively correlated with BHBA, NEFA, and negatively correlated with GLU. It can be suggested that GH has a potential role in development and aetiology of subclinical ketosis.