Characteristics of Holstein cows predisposed to ketosis during the post-partum transition period

Evaluation of the Use of Different Sensitive Cardiac Biomarkers in Determining Myocardial Damage in Cows With Subclinical and Clinical Ketoses

BACKGROUND

It is unclear whether the increase in BHBA concentration damages the myocardium in ketotic cows. Measurement of troponin is the gold standard in myocardial injury.

OBJECTIVE

The objective of this study was to explore the impact of elevated β-hydroxybutyrate (BHBA) concentrations on myocardial damage in cows diagnosed with subclinical ketosis (SCK) and clinical ketosis (CK). Additionally, the study aimed to elucidate the relationship between heart-type fatty acid-binding protein 3 (H-FABP 3) and high-sensitivity cardiac troponin I (hs-cTnI) concentrations, as well as their correlation with various biochemical parameters that assess myocardial and metabolic health.

METHODS

The animal material used in this study consisted of 30 postpartum Holstein cows, aged between 2 and 5 years. The study group comprised 10 cows with SCK, 10 with CK and 10 cows in the control group (CG).

RESULTS

The concentration of hs-cTnI in cows with CK was significantly higher compared to both the CG (p < 0.005) and the SCK group (p < 0.019). Similarly, the H-FABP 3 concentration in the CK and SCK groups was significantly elevated compared to the CG (p < 0.001). The creatinine kinase myocardial band (CK-MB) levels were significantly higher in cows with CK compared to the CG (p < 0.010). Furthermore, the aspartate aminotransferase (AST) levels in the CK group were significantly elevated compared to the CG (p < 0.011). A significant positive correlation was observed between BHBA concentration and the levels of both hs-cTnI and H-FABP 3 in ketotic cows. Additionally, significant correlations were found between various biochemical parameters (alanine aminotransferase [ALT], AST, CK-MB and phosphorus) and the concentrations of H-FABP 3 and hs-cTnI.

CONCLUSIONS

This study showed that high BHBA concentrations in ketosis cows may indirectly cause myocardial damage. However, future studies need to investigate the relationship between oxidative stress and changes in antioxidant concentrations and troponin.

Changes in haematological and serum biochemical parameter concentrations from the day of calving to ketosis onset in Holstein dairy cows during the postpartum period

BACKGROUND

Dairy cows commonly experience a negative energy balance (NEB) during early lactation as energy demands for maintenance and milk production exceed intake. Although most cows metabolically adapt to NEB and avoid ketosis, those that fail to adapt develop ketosis, which disrupts metabolism and reduces productivity. Haematological and serum biochemical parameters are crucial for understanding these metabolic disruptions. However, limited research has examined how these parameters change from calving to ketosis onset. This study aimed to investigate these changes, identify parameters associated with ketosis classification, and evaluate their implications for dairy cow health. Blood samples were collected from the jugular vein of Holstein cows and β-hydroxybutyrate (BHBA) was tested once every three days during the postpartum period (8 times in 21 days).

RESULTS

Cows were categorised into three groups based on their highest BHBA concentration: non-ketosis (NK; BHBA < 1.2 mmol/L; n = 75), subclinical ketosis (SCK; BHBA ≥ 1.2 mmol/L and < 3.0 mmol/L; n = 46), and clinical ketosis (CK; BHBA ≥ 3.0 mmol/L; n = 35). The NK group had the highest red blood cell and monocyte counts, red cell distribution width, and alanine transaminase (ALT) concentrations. However, this group had the lowest mean corpuscular volume, mean corpuscular haemoglobin, non-esterified fatty acid (NEFA), and total bilirubin concentrations on the day of calving and at ketosis onset, followed by the SCK and CK groups (p < 0.05). In the NK group, counts of neutrophils, monocytes, and eosinophils, along with NEFA and lactate dehydrogenase (LDH) concentrations, decreased from the day of calving to ketosis onset. Conversely, ALT, aspartate transaminase (AST), and magnesium concentrations increased in the SCK and CK groups (p < 0.05). The NK group had the most pronounced changes in glucose, triglyceride, and magnesium and the lowest BHBA, LDH, and AST concentrations, followed by the SCK and CK groups (p < 0.05).

CONCLUSIONS

This study identified key haematological and serum biochemical changes associated with ketosis classification in dairy cows, highlighting metabolic adaptations in the NK group that mitigate ketosis risk and metabolic dysfunctions in the SCK and CK groups that develop ketosis. These findings provide practical markers for early detection and management of ketosis, supporting improved dairy cow health and productivity.

Genetic Background of Blood β-Hydroxybutyrate Acid Concentrations in Early-Lactating Holstein Dairy Cows Based on Genome-Wide Association Analyses

Ketosis is a common metabolic disorder in the early lactation of dairy cows. It is typically diagnosed by measuring the concentration of β-hydroxybutyrate (BHB) in the blood. This study aimed to estimate the genetic parameters of blood BHB and conducted a genome-wide association study (GWAS) based on the estimated breeding value. Phenotypic data were collected from December 2019 to August 2023, comprising blood BHB concentrations in 45,617 Holstein cows during the three weeks post-calving across seven dairy farms. Genotypic data were obtained using the Neogen Geneseek Genomic Profiler (GGP) Bovine 100 K SNP Chip and GGP Bovine SNP50 v3 (Illumina Inc., San Diego, CA, USA) for genotyping. The estimated heritability and repeatability values for blood BHB levels were 0.167 and 0.175, respectively. The GWAS result detected a total of ten genome-wide significant associations with blood BHB. Significant SNPs were distributed in Bos taurus autosomes (BTA) 2, 6, 9, 11, 13, and 23, with 48 annotated candidate genes. These potential genes included those associated with insulin regulation, such as INSIG2, and those linked to fatty acid metabolism, such as HADHB, HADHA, and PANK2. Enrichment analysis of the candidate genes for blood BHB revealed the molecular functions and biological processes involved in fatty acid and lipid metabolism in dairy cattle. The identification of novel genomic regions in this study contributes to the characterization of key genes and pathways that elucidate susceptibility to ketosis in dairy cattle.

Circulating exosome-mediated AMPKα-SIRT1 pathway regulates lipid metabolism disorders in calf hepatocytes

Subclinical ketosis (SCK) in dairy cows is often misdiagnosed because it lacks clinical signs and detection indicators. However, it is highly prevalent and may transform into clinical ketosis if not treated promptly. Due to the negative energy balance, a large amount of fat is mobilized, producing NEFA that exceeds the upper limit of liver processing, which in turn leads to the disturbance of liver lipid metabolism. The silent information regulator 1 (SIRT1) is closely related to hepatic lipid metabolism disorders. Exosomes as signal transmitters, also play a role in the circulatory system. We hypothesize that the circulating exosome-mediated adenosine 5'-monophosphate (AMP)-activated protein kinase alpha (AMPKα)-SIRT1 pathway regulates lipid metabolism disorders in SCK cows. We extracted the exosomes required for the experiment from the peripheral circulating blood of non-ketotic (NK) and SCK cows. We investigated the effect of circulating exosomes on the expression levels of mRNA and protein of the AMPKα-SIRT1 pathway in non-esterified fatty acid (NEFA)-induced dairy cow primary hepatocytes using in vitro cell experiments. The results showed that circulating exosomes increased the expression levels of Lipolysis-related genes and proteins (AMPKα, SIRT1, and PGC-1α) in hepatocytes treated with 1.2 mM NEFA, and inhibited the expression of lipid synthesis-related genes and protein (SREBP-1C). The regulation of exosomes on lipid metabolism disorders caused by 1.2 mM NEFA treatment showed the same trend as for SIRT1-overexpressing adenovirus. The added exosomes could regulate NEFA-induced lipid metabolism in hepatocytes by mediating the AMPKα-SIRT1 pathway, consistent with the effect of transfected SIRT1 adenovirus.

Evaluation of the Metabolic Relationship between Cows and Calves by Monitoring Calf Health and Cow Automatic Milking System and Metabolic Parameters

With this study, we investigated the relationship between a cow's and calf's metabolic state, and its effect on health status. To achieve this, 20 calves of primiparous and 20 calves of multiparous cows were selected. The calves were monitored for 30 days and scored for signs of disease, as described in McQuirk (2008); according to score, they were divided into healthier calves; the Low calf score group (LCS, 5-8), Medium calf score group (MCS, 9-12) and High calf score group (HCS, 14-17); or calves most prone to disease. Their mothers were monitored for the same period with a Lely Astronaut 3 herd management system (Lely, Maassluis, The Netherlands) for rumination time, milk yield, milk fat, protein, lactose concentrations and milk fat to protein ratio. Both cows and calves were sampled for blood, and concentrations of glucose with β-hydroxybutyrate were registered. The results indicate that primiparous cows had a 16% higher blood glucose concentration (3.03 mmol/L SE = 0.093) compared with multiparous cows (2.61 mmol/L, SE = 0.102) (p < 0.01), but no difference in calf glucose was recorded. Β-hydroxybutyrate levels did not differ significantly between cows and calves by parity group. Rumination time was longest in the HCS group at 550.79 min/d. and was 16% longer compared with the LCS group (461.94 min/d.; p < 0.001) and 8% longer compared with the MCS group (505.56 min/d.; p < 0.001). The MCS group rumination time mean was statistically significantly higher compared with the LCS group by 8% (p < 0.001). Milk yield was also highest in the HCS group (44.8 kg/d.): 19% higher compared with the MCS group (36.31 kg/d., p < 0.001) and 13% higher than the LCS group (38.83 kg/d., p < 0.001). There was also a significant difference between the MCS and LCS groups of 6% (p < 0.001). The HCS group had the highest milk fat concentration (4.47%): it was 4% higher compared with the LCS group (4.28%, p < 0.001) and 5% higher than the MCS group (4.25%, p < 0.001). Milk fat to protein ratio was highest in the HCS group (1.21) and was 7% higher than in the MCS group (1.12, p < 0.001) and 8% higher than in the LCS group (1.11, p < 0.001). The LCS group was determined to have the highest concentration of milk lactose (4.66%). It was 1% higher compared with the MCS group (4.62%, p < 0.001) and 1.07% higher than the HCS group (4.61%, p < 0.001). We can conclude that parity did not affect calf health status and that cows of the HCS group showed symptoms of negative energy balance expressed through higher milk yield, higher milk fat concentration and higher milk fat to protein ratio, with lower milk lactose concentration. Further and more thorough research is needed to evaluate the relationship between pregnant cows and calves.