26 May 2022 – Sodium bicarbonate is commonly added to dairy cow rations to help regulate rumen pH and mitigate the development of acidosis, which can have a significant impact on a cow’s performance and her well-being.
But it can also form part of an effective heat stress management strategy. According to Solvay, the European leader in the production of feed-grade sodium bicarbonate, its Bicar®Z solution can help maintain rumen pH at an optimal level as well as improve dry matter intake and milk production during periods of heat stress.
In this Industry Perspectives, the company’s Strategic Marketing Manager, Stefania Tornelli, and its Soda Ash and Derivatives Technical Marketing Manager, Patrik Neuhaus, talk to Feedinfo about Bicar®Z’s effectiveness in managing acidosis and heat stress, its influence on rumen integrity, and the impact it can have on milk production during periods of increased heat. We also touch on the recent disruptions to sodium bicarbonate supply and find out what Solvay is doing to mitigate impacts on its customers.
[Feedinfo] Looking at heat stress in dairy cattle, how common is the condition today? How can it affect milk production and farm profitability?
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[Stefania Tornelli] Heat stress affects dairy cattle almost everywhere, even in temperate climates. Climate change will exacerbate this, with summers getting warmer and warmer. As a result, heat stress has become one of the major climate change impacts affecting domesticated livestock raised in both intensive and extensive production systems. All animals have a “thermal neutral zone”. This is the temperature range where they are most comfortable and productive, as they do not use additional energy to maintain their body temperature. In the case of dairy cattle, the comfort zone lies between 5°C and 20°C. When the temperature rises above 20°C or the Temperature Humidity Index (THI) exceeds 68°C, dairy cattle become stressed and have difficulty keeping the balance between body heat loss and body heat production. |
This can lead to their feed intake declining and milk yield falling by as much as 20%. There can also be a decrease in milk quality (drop in fat and protein percentages), a reduction in fertility, including an increase in embryonic loss. There is also evidence of an increase in the risk of clinical mastitis.
[Patrik Neuhaus] As Stefania mentioned, heat stress reduces feed intake and feed conversion efficiency, which can decrease a farm’s sustainability score. Plus, there are also the impacts it can have on animal welfare and health to consider.
In terms of the economics, estimates from a decade ago (2010) put the impact of heat stress on the US dairy industry at around $1.09 billion to $1.82 billion annually due to decreased milk production (a drop of around $39,000 in the value of annual milk production for the average dairy farm in the US), compromised reproductive performance and increased culling rates. Equally eye-opening results were also noted in a 2018 study of German farms, where average losses in milk revenues amounted to around €10,000 per year. This shows how significant heat stress’s impact can be on the already tight bottom lines of individual farms. In fact, a conservative global forecast for the year 2045 put direct production losses at $14.7 billion per year (which represents 3.6% of the total global value of meat and milk production from cattle in 2005), with Sub-Saharan Africa being hit the hardest.
[Feedinfo] Why is it so important to have the ideal rumen pH during heat stress? And what impacts can acidosis have here?
[Patrik Neuhaus] The rumen is home to a delicate environment of micro-organisms that ferment plant material into nutrients, primarily volatile fatty acids (VFA) and protein. The excess production of VFAs, or lactic acid, leads to acidification of the rumen and a drop in rumen pH. This is described as rumen acidosis and it affects the balance of the rumen microbiota.
The main risk factor for acidosis is the rapid or increased ingestion of highly fermentable feeds, which is an important feature of modern dairy cow diets that supports high milk yields. These concentrates are quickly fermented into VFAs, thus decreasing the ruminal pH. They also require less rumination, therefore limiting the amount of saliva – which contains bicarbonate, a key natural buffer – that is released into the rumen. This will decrease rumen pH even further and may destabilise ruminal fermentation.
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Heat stress impacts ruminal fermentation in various ways. First, it affects the behaviour of animals, changing their feed intake patterns. Cows tend to eat less frequently (overall dry matter intake reduces, but separate meals are bigger) and will ruminate less. This puts pressure on the ruminal fermentation, as more concentrates are taken up in a short time and less buffer is provided via saliva. Secondly, heat stress also impairs natural buffering capacity. The condition can lead to increased respiration in cows to help them regulate their body temperature, which can reduce carbonic acid and bicarbonate in the bloodstream, resulting in a blood pH increase. To cope with this effect, bicarbonate is released through urine. As a result, less buffering bicarbonate is excreted into the rumen via saliva, increasing the risk of ruminal acidosis. |
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In addition, the increased perspiration and water intake associated with heat stress can result in a loss of potassium and sodium, leading to an imbalance in these key minerals. Also feed itself may be affected by heat, potentially altering feed quality and impacting ruminal fermentation, further increasing the risk for acidosis.
[Feedinfo] So, considering all of this, how beneficial can sodium bicarbonate, like your Bicar®Z solution, be in managing these challenges in dairy cattle?
[Patrik Neuhaus] The use of Bicar®Z can be considered a safety mechanism for ruminal fermentation. It creates a balance between the production and absorption of VFAs in the rumen and enhances the cow’s own natural buffering system to maintain a healthy rumen pH of around 6.2-6.5. In addition to this, Bicar®Z also delivers sodium to the animal, which is involved in maintaining osmotic pressure, controlling water balance and regulating the acid-base balance of the blood.
Both these effects are very beneficial and of particular importance during heat stress, because this is the time when the rumen is at highest risk for acidosis. The addition of Bicar®Z to the ration is an effective way to properly buffer and stabilise the rumen, so that productivity remains high and risk of (sub-acute) ruminal acidosis is minimised. It can also help tackle the loss of sodium through increased urination by increasing the mineral load and, more specifically, the sodium level to restore a healthy balance.
Of course, in order to effectively manage heat stress dairy producers also need to consider housing equipment and farm management, as well as feeding regime changes.
[Feedinfo] There are a number of sodium bicarbonate solutions available to dairy producers. What sets Bicar®Z apart? Why should it be their first choice when looking to address heat stress in their dairy cattle?
[Patrik Neuhaus] We believe we are already a popular choice for livestock farmers in most of Europe and the world, and that is thanks to our tight supply network of nine manufacturing plants (all our European plants are GMP+ and ISO 9001 certified* and our US plants are ‘Safe Feed/Safe Food’ and ISO 9001 certified and FSMA compliant). We have also been producing Bicar® for more than 150 years and, thanks to regular on-site laboratory analysis, we can guarantee a high-quality product.
Solvay is proud of our long 40-year history of supplying the feed market, as well as being the first to offer a specific sodium bicarbonate solution for feed in Europe. This is why, we believe Bicar®Z continues to be a trusted solution for livestock farmers, zootechnical nutritionists and vets around the world.
Bicar®Z is also a buffer that is compatible with organic farming as it is permitted as an organic feed material of mineral origin.
[Stefania Tornelli] To add to what Patrik mentioned, Bicar®Z is also transported according to GMP+ rules (for example, GMP+ B4 certified hauliers where applicable) and related IDTF (International Database Transport (for) Feed) requirements. Plus, it is directly delivered to customers without further manipulation/handling, making it free from related cross-contamination risks.
Our recommendation for feed manufacturers and distributors is to be properly aware and informed about the origin of each feed material and to know how the entire supply chain is managed. A full control of the supply chain is crucial for feed products.
[Feedinfo] What research findings can you share with us in terms of how Bicar®Z supports milk production during heat stress?
[Patrik Neuhaus] Throughout the years, we have benefitted from many collaborative projects with specialised research centres in animal nutrition (such as Spain’s Institute of Agrifood Research and Technology (IRTA), the Training and Research Centre of the Chamber of Agriculture (Schleswig-Holstein), and more) and vet support, as well as universities and customers.
One of these was a 2013 study conducted during the summer months in Spain with the University of Barcelona and the University of Lisbon in which 197 lactating cows were divided into three groups, one of which was a control group. Days in milk were the same for all groups. The main findings were that the addition of 250g of Bicar®Z to the total mixed ration reduced several heat stress indicators (rectal temperature, urinary bicarbonate and pH). It also improved milk production in comparison with the control animals, which increased by 4.3kg of milk per day per cow and remained stable during the whole analysis period, preventing the “summer dip”. Dry matter intake was improved, while feed efficiency was increased by supplementation of Bicar®Z.
[Feedinfo] You are also recommending Bicar®Z for use in poultry to help birds manage heat stress. How effective is it at supporting them during these periods?
[Patrik Neuhaus] Indeed, heat stress is also becoming a growing problem for the poultry sector. The electrolyte balance is an important variable to maintain the productivity and well-being of poultry birds under heat stress, with monovalent electrolytes, like sodium and potassium, being especially key to maintaining the acid-base balance of bodily fluids.
Research has shown that broilers receiving sodium bicarbonate showed higher weight gain and better feed conversion ratios during both starter and finisher phases compared to using other mineral electrolytes. Sodium bicarbonate administered during heat stress also significantly increased water intake, which helps with regulating internal body temperature, and reduced bird mortality. Furthermore, slaughter data indicates that birds consuming diets supplemented with sodium bicarbonate during heat stress have a higher carcass weight and dressing percentage with lower abdominal fat (compared to the use of other sodium electrolytes).
In layers, the effects of heat stress often result in reductions in egg production, feed consumption, and overall egg quality, particularly shell quality, as well as an increase in mortality. Once again, the addition of sodium bicarbonate as a mineral electrolyte source is beneficial in this case. In conjunction with increased water consumption, it helps mitigate the negative effects of heat stress, resulting in improved eggshell quality and egg production in layer hens without the laxative effect worries.
[Feedinfo] Considering how beneficial sodium bicarbonate can be in times of heat stress, there have been some upsets in the supply chain recently, with the Russia-Ukraine conflict adding to these concerns. How is Solvay ensuring a steady and cost-effective supply for its customers?
[Stefania Tornelli] Yes, we are facing heavy consequences linked to military operations unfolding in Ukraine and because of the sanctions currently in place against Russia.
Russia is an important source of energy, such as solid fuels and gas, for our operations and the current events have strongly interfered with the production of soda ash and sodium bicarbonate.
In order to operate our factories and serve our customers in a secure and reliable manner, we have implemented a dedicated “Ukrainian-Russia crisis cell” to monitor the situation and to ensure, where possible, energy and raw materials sourcing.
The global economy is also facing an unprecedented increase in the price of fuel combustibles, utilities and logistics due to the war in Ukraine. As a sodium carbonate, sodium bicarbonate and calcium chloride producer, we are strongly exposed to these costs. We are, therefore, doing everything possible to ensure steady and cost-effective supply for our customers. In fact, with our new production facility in Devnya, Bulgaria, we are continuing our investment in Bicar® and strengthening our commitment to continue satisfying our customers’ sodium bicarbonate needs.
* The company’s Devnya plant in Bulgaria is expected to be certified in the summer
Published in association with Solvay
