Among the organs crucial to a cow’s overall health and productivity, the liver stands out as a powerhouse of metabolic activity and immune function. We often liken it to the engine in a high-performance vehicle – you can have all the bells and whistles, but if you’re not taking care of the engine, you certainly won’t be winning any races. Farmers have an unending to-do list at any given time, so they can be forgiven for only reacting to clinical signs of disease the majority of the time. However, with the liver so crucial to the health and wellbeing of their animals, it’s vital vets and nutritionists are there to educate and support dairy farmers to recognise the subtle of liver distress.
In this article, we’ll explore the importance of a healthy liver in dairy cows, its functions, and the impact of liver health on immunity, reproductive success, and milk production. We’ll also delve into the essential minerals and trace elements necessary for optimal liver function, and how we as experts can support farmers in making the right decisions to ensure their animals’ livers are as healthy as possible.
The liver: an unsung hero of dairy cow health
This multifunctional organ is responsible for myriad essential physiological processes, including:
- Metabolism: The liver metabolises nutrients from the diet, synthesises proteins, and regulates glucose and lipid metabolism.
- Detoxification: It filters toxins and harmful substances from the blood, detoxifying the body.
- Immune function: The liver plays a key role in the body’s immune response, producing proteins and enzymes that defend against pathogens.
- Nutrient storage: It stores essential nutrients such as glycogen, vitamins, and minerals, releasing them as needed.
By supporting the majority of interconnected processes within the body, liver health is often the most overlooked yet most important factor in optimal dairy cow performance. Milk production, immunity, and reproduction rely on a healthy liver.
Common issues affecting liver health
New Zealand’s lush pastures can contribute to various health issues in dairy cows that can impact the liver. Grass tetany, caused by low magnesium levels, can lead to muscle tremors and even death, affecting liver function due to metabolic disturbances. Fatty liver syndrome, prevalent during high energy intake or metabolic stress, involves fat accumulation in the liver, impairing its function. Ketosis, common during early lactation, results from energy imbalances, if ketosis is allowed to run out of control this disease can lead to a rapid buildup of fat in the liver, and result in liver failure. Mineral imbalances of copper, selenium, and zinc in the diet can also effect liver function and harm liver health. Additionally, infectious diseases like leptospirosis and salmonellosis cause liver inflammation. These diseases are a higher risk due to our temperate climate and high rainfall.
Addressing these specific health issues requires a multifaceted approach that includes proper nutrition, mineral supplementation, disease prevention, and veterinary management. By implementing proactive measures to mitigate these risks and promote liver health, we can support our dairy farmers in optimising the performance and wellbeing of their herds.
Common mistakes made by New Zealand dairy farmers
Inadequate mineral supplementation
One of the most common mistakes is insufficient mineral supplementation, leading to imbalances that can compromise liver health. While farmers understand that, logically, a balanced diet is necessary for better cow health, there is often limited understanding around what constitutes a balanced diet. A diet that is adequately formulated to support good liver function needs to be rich in essential macro and micro minerals, as well as containing adequate and good quality protein (amino acids) along with good levels of energy. To achieve this, rumen function needs to be well maintained, in order to ensure a good flow of high energy fatty acids are constantly flowing to the liver. Toxins are a big issue for liver health – a poorly functioning rumen will generate endotoxins that can put a heavy strain on the liver. In order to maximise rumen function and health, it is essential to maintain a stable rumen pH level.
Lastly, feed toxins can have a huge impact on liver health. Mycotoxins in feed can rapidly destroy liver cells, so it is important to identify risks around mouldy feed and often invisible mycotoxins that can be present in concentrate feeds and mitigate these risks through the use of toxin binders.
Overreliance on pasture
While pasture is a staple of New Zealand dairy farming, overreliance on pasture without correcting mineral supplementation can result in nutrient deficiencies, particularly in essential minerals crucial for the health of the liver. Modern grasses have been cultivated for high ME in pursuit of high production and without ample fibre or a good rumen buffer, these grasses are rocket fuel for rumen bacteria, dropping pH quickly during grazing and rumination.
Failure to recognise symptoms
Farmers may overlook or misinterpret symptoms of liver health issues, such as reduced appetite, weight loss, and decreased milk production, attributing them to other factors such as heat stress or infectious diseases. This can delay diagnosis and treatment, exacerbating the condition.
Misdiagnoses
Liver health issues may be misdiagnosed or overlooked altogether, as they can present with vague or nonspecific symptoms. Farmers and veterinarians may focus on more obvious conditions, such as mastitis or lameness, while underlying liver problems go unnoticed.
Symptoms
Signs of an unhealthy liver and medical conditions resulting from it:
Symptoms
- Reduced appetite and feed intake
- Weight loss and poor body condition
- Jaundice (yellowing of the eyes and mucous membranes)
- Decreased milk production
- Behavioural changes (lethargy, aggression)
Medical conditions
- Fatty liver syndrome: Accumulation of fat in the liver, leading to impaired function and health issues.
- Hepatitis: Inflammation of the liver, often caused by infectious agents or toxins.
- Liver abscesses: Pockets of infection within the liver, leading to systemic illness and reduced productivity.
Mineral supplementation as part of the solution
Macro minerals, including calcium, phosphorus, and magnesium, play fundamental roles in supporting liver function and overall metabolic processes.
- Calcium is crucial for the activation of enzymes involved in liver detoxification pathways. It also aids in bile acid synthesis, which is essential for fat digestion and absorption.
- Phosphorus contributes to cellular energy metabolism within liver cells, ensuring proper functioning and detoxification processes. It also supports the synthesis of nucleic acids and membrane structure.
- Magnesium is involved in numerous enzymatic reactions within the liver, including those related to carbohydrate metabolism and protein synthesis. It also supports antioxidant defence mechanisms, protecting liver cells from oxidative damage.
Micro minerals, such as copper, zinc, and selenium, play critical roles in supporting liver health by acting as cofactors for various enzymatic reactions and antioxidant defense mechanisms.
- Copper is essential for the synthesis of ceruloplasmin, a copper-containing protein that plays a role in antioxidant defense and iron metabolism within the liver. It also supports the production of bile acids, which aid in the digestion and absorption of fats.
- Zinc is a cofactor for several liver enzymes involved in detoxification processes, including metallothionein and superoxide dismutase. It also supports protein synthesis and immune function within the liver.
- Selenium acts as an antioxidant, protecting liver cells from oxidative damage and supporting the activity of selenoproteins involved in detoxification and immune function.
Synergistic actions of macro and micro minerals
Macro and micro minerals work synergistically to support liver health by ensuring the proper functioning of enzymatic pathways, antioxidant defence mechanisms, and metabolic processes.
Calcium and phosphorus, for example, collaborate to maintain cellular integrity and energy metabolism within liver cells. Proper calcium and phosphorus balance is essential for efficient liver function and detoxification.
Copper, zinc, and selenium work together to support antioxidant defence mechanisms within the liver, protecting cells from oxidative stress and promoting overall liver health. Copper-dependent enzymes, such as cytochrome c oxidase, require zinc for proper function, highlighting how these minerals depend on each other.
By incorporating a balanced combination of macro and micro minerals into the diet of dairy cows, farmers can support liver health and optimise metabolic processes critical for overall health and productivity. Agvance products offer tailored solutions to address both macro and micro mineral requirements, providing comprehensive support for liver health.
Agvance solutions for liver health
Agvance offers a range of innovative products designed to support liver health and optimise metabolic processes:
Ascocool – Seaweed Concentrated Extract
Prioritising liver health is essential for dairy farmers looking to maximise animal health and performance. The liver is a key component of metabolic activity, immune function, and reproductive success in dairy cows, making its maintenance central to optimal performance. By ensuring adequate intake of essential minerals and trace elements, we can support dairy farmers in safeguarding liver health, enhancing immunity, improving reproductive outcomes, and maximising milk production.