From feed to fuel: how propionate helps dairy cows after calving.

By Msc, Msc.M Jolan Lemmens.

SUMMARY

Around calving, dairy cows lack energy as their appetite decreases but milk production starts. Not enough energy coming in and too much energy being used leads to a negative energy balance. While the liver can’t keep up with glucose production, the risk for ketosis and other secondary diseases increases. Propionate helps stabilizing blood sugar as it’s the livers main source of glucose production. Supplementing propionates (like Enertop) has been a proven way of reducing the risk of a negative energy balance.

From feed to faeces.

What is one thing dairy cows and me on a holiday have in common? We eat and chill all day, except I’m not ruminating! But what happens to all the feed that the cows devour all day? How does it metabolize into energy? And how is it even possible that she eats all day and still lacks energy around transition? Let’s take a look at the energy metabolism of a dairy cow, the definition of a negative energy balance, and the role of supplementing propionate.

Feed goes in and faeces come out, but what happens in between? Well, to start feed mainly delivers gross energy through proteins, fats, and carbohydrates. But the cows can’t use all this gross energy for their body’s maintenance or milk production as lots of energy is lost. Firstly, the faeces are basically wasted energy that come out again. But energy is also lost through urine and methane (yup, cows burp their energy away). What’s left is what’s called metabolizable energy: the energy that can be used by the cow for its maintenance (muscle movement, digestion, brain activity, etc.) and production of milk and fat. And this energy consists of amino acids, fatty acids, and carbohydrates. This energy is largely what is used for milk production, to maintain the body, grow the fetus, or as reserves. Finally, during these processes, energy is lost as warmth as well [1]. The bigger picture is shown in the figure below:

Figure 1: energy metabolism by ruminants [1]

Changes during transition period.

Around calving the energy household changes as the cow’s body balance gets disrupted: fetal growth and producing the first milk requires a lot of effort. The cow’s higher demand of energy means that the liver suddenly has to produce massive amounts of energy in the form of glucose. And it just can’t keep up with the higher demand. Lower appetite around calving also means less propionate is produced from the feed, which in turn leads to less glucose produced by the liver [2]. During this period cows are thus likely to enter into a negative energy balance (NEB).

This is a big problem when you know that propionate supplies up to 73% of glucose demands, and the subsequent negative energy balance results in postpartal health disorders, lower milk production, and early culling [3]. A NEB will raise the chances of getting disorders such as milk fever, metritis, ketosis, displaced abomasum and retained placenta [4] and will likely lose body condition between 50 to 100 days after calving [5].

What is a negative energy balance in dairy cows exactly?

The energy balance is defined as “the difference between energy intake from feed and energy required for body maintenance, production, and gestation.” In a negative energy balance the cow needs more energy than she gets from her feed and from addressing her energy reserves [5]. After calving the dairy cow is in a NEB as her appetite is low, but the start of lactation needs a lot of energy. The difference between energy needed and energy intake (calculated as glucose) is estimated at 500 gram of glucose per day in the first days of lactation [2]. But how severe the NEB is depends on genetics, feed intake, the diet itself (energy content), milk yield, and the body condition before calving [6].

In a NEB the cow’s udder keeps on absorbing glucose without limit as the energy source for milk production. During peak lactation the liver synthesizes up to four kilograms of glucose per day in a process called gluconeogenesis. This process provides up to 90 % of blood glucose. But how does the liver produce this energy?

Propionic acid and lactate from the feed serve as the main building blocks of glucose in the liver. As we already mentioned, the feed intake around calving is insufficient to provide enough of those building blocks. Not enough propionate and lactate from the feed means that the liver will look for other building blocks to serve for gluconeogenesis. And this is where trouble starts. As the liver looks for muscle protein to produce energy, the cow’s body condition score decreases and the risk for ketosis increases [7].

Why do you have to supplement propionate to dairy cows?

Propionic comes from the Greek words protos and pion, meaning ‘first’ and ‘fat’ and was first discovered in 1844. Propionic acid is fermented by bacteria with big names such as Propionibacterium freudenreichii, but can also arise as a by-product of the biological production of vitamin B12 [8]. Propionic acid comes in many forms and is used in many different fields from the plastic industry to agriculture. When we look at feed, calcium and sodium propionate are often used [8].

Figure 3: calcium propionate

Preventing or reducing the NEB, and thus the risk for ketosis and other secondary disorders, begins with maintaining correct glucose levels. Glucose production averages 1000 to 1100 g per day during the last three weeks before calving and then sharply rises to 2500 g per day on day 21 after calving [9]. Keeping the blood sugar levels stable reduces the breakdown of body fat and ketone production. Given that glucose is mainly produced from propionates during transition, it is logical that supplementing propionate reduces the risk of a NEB and ketosis [10]. Propionate is deemed a “well-researched option for treatment of hyperketonemia” [10 ]and “the oral administration of glucose precursors is, and remains, the treatment of choice in cases of ketonaemia” [9].

A study on 24 Holstein cows in China showed that supplementing sodium propionate increased the concentrations of glucose and insulin in the plasma of cows, thus providing energy to these Holsteins. Feeding propionate also indirectly leads to extra energy as it can increase feed intake and even improve milk production [11].

So how come feeding propionic acid leads to extra energy? Well, it doesn’t only serve as a raw material for glucose, but it also turns on the right genes to help the liver increase its glucose production itself. For the technical people amongst us: the activated genes are responsible for making the enzymes cytoplasmic phosphoenolpyruvate carboxykinase, mitochondrial phosphoenolpyruvate carboxykinase, and pyruvate carboxylase (these might win you your next game of Scrabble). And these enzymes help change non-sugars into sugars [11].

Enertop

One way of supplementing propionates is through a bolus. Enertop is a fast-acting bolus by Resco with rapidly available energy in the form of soium propionate. Administer 2 boluses at calving or whenever the cow is in need of energy and administer 2 boluses 2 hours later. A dosage provides 98 grams of sodium propionate. Read more on the product page or send us an email (info@resco.be).

I want to buy Enertop

Source list

[1] Van Der Honing, Y. (1978). Verwerking van energie door de herkauwer. ., 90(8), 216–221. http://edepot.wur.nl/384667

[2] DeFrain, J., Hippen, A., Kalscheur, K., & Patton, R. (2005). Effects of Feeding Propionate and Calcium Salts of Long-Chain Fatty Acids on Transition Dairy Cow Performance. Journal Of Dairy Science, 88(3), 983–993. https://doi.org/10.3168/jds.s0022-0302(05)72766-1

[3] Seal, C. J., & Reynolds, C. K. (1993). Nutritional Implications of Gastrointestinal and Liver Metabolism in Ruminants. Nutrition Research Reviews, 6(1), 185–208. https://doi.org/10.1079/nrr19930012

[4] Esposito G, Irons PC, Webb EC, Chapwanya A. Interactions between negative energy balance, metabolic diseases, uterine health and immune response in transition dairy cows. Anim Reprod Sci. 2014 Jan 30;144(3-4):60-71. doi: 10.1016/j.anireprosci.2013.11.007. Epub 2013 Dec 5. PMID: 24378117.

[5] Bekuma, A. (2019). Combating Negative Effect of Negative Energy Balance in Dairy Cows: Comprehensive Review. Approaches in Poultry Dairy & Veterinary Sciences, 6(2). https://doi.org/10.31031/apdv.2019.06.000633

[6] Wathes DC, Fenwick M, Cheng Z, Bourne N, Llewellyn S, Morris DG, Kenny D, Murphy J, Fitzpatrick R. Influence of negative energy balance on cyclicity and fertility in the high producing dairy cow. Theriogenology. 2007 Sep 1;68 Suppl 1:S232-41. doi: 10.1016/j.theriogenology.2007.04.006. Epub 2007 May 2. PMID: 17475319.

[7] Bossaert, P., Leroy, J., Cools, S., Van Loo, H., De Kruif, A., & Opsomer, G. (2008). De metabole adaptatiemechanismen bij hoogproductieve melkkoeien. Vlaams Diergeneeskundig Tijdschrift, 77(4). https://doi.org/10.21825/vdt.87211

[8] Ranaei, V., Pilevar, Z., Khaneghah, A. M., & Hosseini, H. (2020). Propionic Acid: Method of Production, Current State and Perspectives. DOAJ (DOAJ: Directory Of Open Access Journals). https://doaj.org/article/adf7010ed0f9417a89012cdba959e30a

[9] Hostens, M., Bossaert, P., Cools, S., De Kruif, A., & Opsomer, G. (2010). Het gebruik van glucogene precursoren in de voeding van hoogproductief melkvee. Vlaams Diergeneeskundig Tijdschrift, 79(4). https://doi.org/10.21825/vdt.87453

[10] Wukadinovich, M., & Rossow, H. A. (2023). Production Responses of Holstein Dairy Cows to a Sodium Propionate Supplement Fed Postpartum to Prevent Hyperketonemia. Dairy, 4(4), 527–540. https://doi.org/10.3390/dairy4040036

[11] Jiang, M., Meng, Z., Tan, D., Cheng, Z., Wei, Z., Lin, M., Zhao, G., & Zhan, K. (2025). Sodium propionate supplementation improves the negative energy balance in postpartum dairy cattle through regulation of glycolipid metabolism. Journal Of Integrative Agriculture, 25(7), 2950–2958. https://doi.org/10.1016/j.jia.2025.07.019