CORRELATION OF NOVEL METABOLIC BIOMARKERS  WITH FAT COW SYNDROME IN DAIRY COWS

Srishti Soni¹, Varun Kumar Sarkar¹, Babul Rudra Paul¹, Jitendra Singh Gandhar¹ and Ujjwal Kumar De²

¹Ph.D Scholar and ² Senior Scientist

Division of Medicine, ICAR- ICAR-Indian Veterinary Research Institute, Uttar Pradesh, India

Corresponding author email :- srishusoni987@gmail.com

Introduction

“Fatty liver disease” or “fat cow syndrome” or Hepatic lipidosis  is a physiologic condition that develops in dairy cows during the period of transition from pregnancy to lactation. (Bobe et al ., 2004, Ametaj, 2005). Within two weeks of calving, 40 percent to 60 percent of high-yielding dairy cows (day milk yield > 35 kg) develop mild to severe  degree of fatty liver disease (Starke et al., 2011). Furthermore, on a dairy farm, the two weeks following parturition are not uncommon to account for 50% of morbidity (Bradford et al., 2015).

A negative energy balance is associated with excessive demand for nutrients due to the increased performance necessary for milk production, as well as reduced dry matter intake around parturition (Mullins et al., 2012). Although adipose tissue is the primary source of fatty acid synthesis in cattle, the liver plays a critical role in coping with significant surges in energy demand. (Kreipe and Deniz, 2011).

The quick mobilization of energy supplies from tissue depots in the form of non-esterified fatty acids is one significant modification (Geelen and Wensing, 2006). When hepatic uptake and storage of these non-esterified fatty acids in the form of triacylglycerols exceeds their removal during early lactation, hepatic lipidosis develops (Bobe et al., 2004). The rate of triacylglycerol production in the liver tissue of ruminants is similar to that found in other species (Ingvartsen, 2006). Triacylglycerols are released from hepatocytes as part of lipoproteins, with very low-density lipoproteins (VLDL) accounting for the majority of it. They are used for energy production through mitochondrial breakdown by oxidation. In ruminants, the secretion of VLDL from the liver is very limited compared with other species such that the resulting storage of excess lipids in hepatocytes leads to liver damage and depressed liver functions (Ingvartsen, 2006 and Geelen and Wensin, 2006).

 

Pathogenesis

 

Predisposing Factors for FCS

1. Overfeeding of dairy cows during the dry period leads to overconditioning (body condition score >3.5, 5-point scale) (Roche et al., 2009).

 

2. Negative nutrient balance during early to late lactation (Wankhade et al., 2017).

 

Two Hit Theory for Fat cow syndrome, Non-Alcoholic Fatty Liver Disease (NAFLD)

1. “First hit” is related to Insulin resistance which leads to lipolysis of surrounding tissues. This further causes increased free fatty acids and increases Triacyl glycerol in the liver and further aggravates hepatocellular toxicity. (Tiniakos et al., 2010) (Day, 2011)
2. “Second hit” is related to imbalance between the coexisting systems of oxidation and anti-oxidation in the liver. The increase in lipid peroxidation results in persistent reactive oxygen species (ROS) production.
3. “Third hit” is related to cell death and irreversible cell repair of hepatocytes. (Erickson, 2009).

 

CLINICAL FINDINGS

• Usually occurs within the first few days following parturition
• Commonly precipitated by condition which interferes with the animal’s appetite temporarily
• Rumen contractions are weak or absent and the feces are usually scant
• A severe ketosis not respond to the usual treatment
• Some cattle exhibit nervous signs consisting of a staring gaze, holding the head high and muscular tremors of the head and neck

 

DIAGNOSIS

• Fatty liver disease lacks effective diagnosis methods
• The only reliably diagnostic method is the liver biopsy
• It is not a practical method at farm level because-
• It cause temporary discomfort to cows
• It needs special training
• High risk of infection
• Can be lethal if a major blood vessel is punctured
• Liver biopsy can damage liver and adversely impact cattle production and health (Bobe et al., 2008; Shen et al., 2018)
• Therefore, a non-invasive technique would be very useful

Serum biochemistry

The so far available biomarkers which are more specific for Negative energy balance (e.g. non esterified fatty acids) and damaged liver function (e.g. aspartate aminotransferase, bilirubin) are not specific for fatty liver disease (Gerspach et al., 2017)

Milk ketones

Several cow side milk ketone tests are available for the detection of subclinical ketosis in postpartum dairy cows. The Pink test liquid and the Ketolac test strip are highly sensitive for subclinical ketosis when used with milk.

B-mode ultrasonograms

The digital analysis of B-mode ultrasonograms has potential to Classify the degree of hepatic triacylglyceride (TAG) infiltration  and thus estimate liver TAG content

Digital analysis of ultrasonograms could provide important  technology for rapid non-invasive, on-farm diagnosis and thereby more effective treatment of fatty liver in dairy cows.                                           (Bobe et al., 2008)

NOVEL BIOMARKERS FOR DIAGNOSIS OF FATTY LIVER DISEASE

Novel markers are more sensitive and specific for fatty liver disease, being less invasive and allowing the diagnosis of fatty liver disease in individual animals as well as at the level of herd management

Phosphatidylcholines

• They are precursors for the synthesis of triacylglycerols indicating that their plasma concentration may decrease in response to an enhanced hepatic triacylglycerol production. (Jacobs et al., 2013)
• On the other hand, phosphatidylcholines are required for the secretion of hepatic triacylglycerols as VLDL particles, indicating that a reduced phosphatidylcholine concentration may directly cause an excessive accumulation of triacylglycerols in the liver. (Gerspach et al., 2017).

Serum paraoxonase-1 (PON1)

• Serum paraoxonase-1 (PON1), an enzyme exclusively synthesized by the liver, as a sensitive non-invasive biomarker for diagnosis of fatty liver in dairy.
• Liver diseases like non alcoholic fatty liver disease, may lead to enhanced catabolism and/or the inactivation of PON1 molecules which results in low PON1 activity (Kotani et al., 2021)

 

• Adding serum PON1 measurement to different batteries of serum diagnostic panels showed a combination of high sensitivity, specificity, and overall diagnostic accuracy in diagnosing fatty liver cows (Farid et al., 2013).

 

Fibroblast growth factor 21 (FGF21)

• The FGF-21 is known as a kind of protein expressed predominantly in the liver, and plays important roles in lipid and glucose metabolism
• Many studies proved that FGF-21 can be a novel biomarker for fatty liver in human beings and showed a significant positive correlation with liver fat
• Similarly, in studies of Shen et al. (2018) observe that greater concentration of FGF-21 in fatty liver cows, and the positive correlation between concentration of FGF-21 and liver TAG.
• These results indicate that the concentration of serum FGF-21 could be potentially developed as biomarkers to detect fatty liver in dairy cows. ( Shen et al., 2018)

 

 

Serum Hbα, Hbβ and total Hb

The studies of Shen et al. (2018) found that the concentration of serum Hbα, Hbβ and total Hb were less in fatty liver cows compared with control cows and negatively correlated with the concentration of liver TAG and had good power to predict liver TAG concentration. indicated that the concentration of serum Hb may be a biomarker for fatty liver in dairy cows (Shen et al., 2018).

 

Neutrophil gelatinase-associated lipocalin (LCN2)

• The damaged liver produced LCN2, affecting the function of the protein especially high density lipoprotein (HDL) and leading to a reduction of apolipoproteins; in turn, reduction of apolipoproteins exacerbates fatty liver disease
• LCN2 was also associated with liver regeneration, and can be used as a sensitive biomarker for fatty liver (Sultan et al., 2013)

 

MicroRNAs (miRNAs)

• MicroRNAs (miRNAs) are a class of small non-coding RNAs with ∼22 nucleotides in length.

• miRNAs play important regulatory roles during life activities and physiological processes, such as developmental timing, cell development, differentiation, apoptosis, cell death, carcinogenesis, and reactions to both biotic and abiotic stresses to environmental stress response, as well as the pathogenesis of non-alcoholic fatty liver disease.
• MiR-122, the most abundant miRNA in the liver, is expressed specifically in hepatocytes and is involved in NAFLD development mainly through regulating lipid metabolism
• These miRNAs could be potential diagnostic biomarkers in cattle fatty liver (Huang et al., 2020).

TREATMENT

The prognosis for severe fatty liver is unfavorable and there is no specific therapy

Several different therapeutic approaches have been tried based on empirical experience

Fluid and electrolyte therapy

The recommended treatment includes continuous IV infusion of 5% glucose and multiple electrolyte solutions, and the intraruminal administration of rumen juice (5-10 L) from normal cows in an attempt to stimulate the appetite of affected cows.

Glucagon

The S/C injection of 15 mg/d of glucagon for 14 days beginning at day 8 post partum decreases liver triglyceride concentrations in cows older than 3.5 years

The effect of glucagon on lipid metabolism is both direct and indirect because it directly increases lipolysis in adipose tissue but indirectly decreases lipolysis by increasing concentrations of plasma glucose and insulin

Glucocorticoids

Prednisolone at 200 mg IM daily for days decreased liver triglyceride concentrations

Propylene glycol

Propylene glycol given orally at 1 L/day promotes gluconeogenesis and is used for the treatment of ketosis

 Insulin

Insulin as zinc protamine at 200-300 SC twice daily promotes the peripheral utilization of glucose

Novel therapeutic targets for fatty liver disease

Findings about the molecular mechanisms how the fatty liver disease develops would help scientists to discover novel therapeutic targets for fatty liver disease.

Studies have shown that peroxisome prolferator-activated receptor (PPARγ) participates or regulates the fat deposition in liver by affecting the biological processes of

• Hepatic lipid metabolism,
• Insulin resistance,
• Gluconeogenesis,
• Oxidative stress,
• Endoplasmic reticulum stress
• Inflammation, which all contribute to fatty liver

Suggesting that PPARγ might be a potential critical therapeutic target for fatty liver disease (Shi et al., 2020).

https://www.pashudhanpraharee.com/application-of-biosensors-technology-for-monitoring-of-animal-health-care-livestock-management-2/

References

Ametaj, B.N., 2005. A new understanding of the causes of fatty liver in dairy cows. Adv Dairy Technol, 17, pp.97-112.

Bobe, G., Young, J.W. and Beitz, D.C., 2004. Invited Review: Pathology, Etiology. Prevention, and Treatment of Fatty Liver in Dairy Cows. Journal of Dairy Science, 87, pp.3105-3124.

Bradford, B.J.; Yuan, K.; Farney, J.K.; Mamedova, L.K.; Carpenter, A.J. Invited review: Inflammation during the transition to lactation: New adventures with an old flame. J. Dairy Sci. 2015, 98, 6631–6650. [Google Scholar] [CrossRef]

Day, C.P., 2011. Non-alcoholic fatty liver disease: a massive problem. Clinical medicine, 11(2), p.176.

Farid, A.S., Honkawa, K., Fath, E.M., Nonaka, N. and Horii, Y., 2013. Serum paraoxonase-1 as biomarker for improved diagnosis of fatty liver in dairy cows. BMC veterinary research, 9(1), pp.1-11.

Geelen, M.J.H. and Wensing, T., 2006. Studies on hepatic lipidosis and coinciding health and fertility problems of high‐producing dairy cows using the “Utrecht fatty liver model of dairy cows”. A review. Veterinary Quarterly, 28(3), pp.90-104.

Huang, Y., Zhang, C., Wang, Y. and Sun, X., 2020. Identification and analysis of mirnas in the normal and fatty liver from the holstein dairy cow. Animal Biotechnology, pp.1-12.

Ingvartsen, K.L., 2006. Feeding-and management-related diseases in the transition cow: Physiological adaptations around calving and strategies to reduce feeding-related diseases. Animal feed science and technology, 126(3-4), pp.175-213.

Jacobs, R.L., van der Veen, J.N. and Vance, D.E., 2013. Finding the balance: The role of S‐adenosylmethionine and phosphatidylcholine metabolism in development of nonalcoholic fatty liver disease. Hepatology, 58(4), pp.1207-1209.

Kotani, K., Watanabe, J., Miura, K. and Gugliucci, A., 2021. Paraoxonase 1 and Non-Alcoholic Fatty Liver Disease: A Meta-Analysis. Molecules, 26(8), p.2323.

Mullins, C.R., Mamedova, L.K., Brouk, M.J., Moore, C.E., Green, H.B., Perfield, K.L., Smith, J.F., Harner, J.P. and Bradford, B.J., 2012. Effects of monensin on metabolic parameters, feeding behavior, and productivity of transition dairy cows. Journal of Dairy Science, 95(3), pp.1323-1336.

Roche, J.R., Friggens, N.C., Kay, J.K., Fisher, M.W., Stafford, K.J. and Berry, D.P., 2009. Invited review: Body condition score and its association with dairy cow productivity, health, and welfare. Journal of dairy science, 92(12), pp.5769-5801.

Shen, Y., Chen, L., Yang, W. and Wang, Z., 2018. Exploration of serum sensitive biomarkers of fatty liver in dairy cows. Scientific Reports, 8(1), pp.1-7.

Shi, K., Li, R., Xu, Z. and Zhang, Q., 2020. Identification of crucial genetic factors, such as PPARγ, that regulate the pathogenesis of fatty liver disease in dairy cows is imperative for the sustainable development of dairy industry. Animals, 10(4), p.639.

Starke, A., Schmidt, S., Haudum, A., Scholbach, T., Wohlsein, P., Beyerbach, M. and Rehage, J., 2011. Evaluation of portal blood flow using transcutaneous and intraoperative Doppler ultrasonography in dairy cows with fatty liver. Journal of dairy science, 94(6), pp.2964-2971.

Sultan, S., Cameron, S., Ahmad, S., Malik, I.A., Schultze, F.C., Hielscher, R., Rave‐Fränk, M., Hess, C.F., Ramadori, G. and Christiansen, H., 2013. Serum Lipocalin2 is a potential biomarker of liver irradiation damage. Liver International, 33(3), pp.459-468.

Tiniakos, D.G., Vos, M.B. and Brunt, E.M., 2010. Nonalcoholic fatty liver disease: pathology and pathogenesis. Annual Review of Pathology: Mechanisms of Disease, 5, pp.145-171.