How Stress Impacts Wagyu

Humanity is catching up to something cattle farmers have known for a long time – stress significantly impacts the body. What feeding builds in cattle over weeks, stress can deplete over hours or even minutes. King River, as a conception to consumption Wagyu producer, sees this clearly in the feedback we receive from the abattoir and customers. However, this is not our discovery. Studies conducted by regulatory bodies such as Meat and Livestock Australia (MLA) have concluded that animal care and handling speak volumes even after slaughter – the evidence is in the meat. King River has a host of deliberate practices that give us consistent results at the abattoir. 

Understanding how stress impacts Wagyu and how we take deliberate steps to avoid stressed cattle, it makes sense that King River herds produce high-quality meat for a delicious experience. 

How stress impacts Wagyu meat

Stress impacts Wagyu in two distinct ways:  

  • visually seen in the meat through marbling and colour
  • experienced in the taste when eaten. 

Stress experienced during a Wagyu beast’s life is likely to produce lower marbling and dark cutters.  

Stress causes low marbling in Wagyu

Wagyu is known for premium marbling of fat throughout the meat. The development of this premium fat doesn’t happen overnight. From birth, our King River producers are working to ensure low-stress environments for cattle right through to the final days before slaughter. Fat is essentially energy reserves stored in muscles. As a Wagyu grows, its body uses energy for internal processes such as growing bones and organs and handling external stress from threats and harsh conditions. Only when the body has excess energy, after dealing with stress, does it begin to form intramuscular fat (marbling fat). Unfortunately, these energy reserves are also the first to be used by the Wagyu’s body when they come into stressful situations. So even if intramuscular fat has been developed, it can be quickly depleted by stress.

Stress causes Wagyu dark cutters

A ‘dark cutter’ is when an animal produces cuts of meat that have a dark, sometimes purple, hue. Dark cutters will often have a reduced eating experience, including coarse texture, cooking challenges and less visual appeal. From a farming perspective, cuts higher than the acceptable pH limit won’t be approved by the MLA and have severely reduced sale opportunities and price. The science behind what causes a dark cutter lies in the beast’s glycogen and pH levels. 

Glycogen is essentially energy. Living Wagyu have varying levels of glycogen and a rough pH of 7.1. Once processed, the Wagyu’s glycogen converts to lactic acid, bringing down the pH level of the meat. If a Wagyu does not have enough glycogen in its body, the pH of the meat will remain too high after slaughter and result in a dark cutter. The challenge to farmers and abattoirs is that, unlike marbling which is developed and lost over a longer period of time, the glycogen levels that impact pH can be lost any time in the last 14 days of the Wagyu’s life. 

So even if raised in a stress-free environment, without care and attention to how the Wagyu is prepared for and transported to the abattoir, the cattle may still be dark cutters. It’s important to note that even if a farmer does everything right to care for an animal, if they are highly strung or too docile (which makes transporting a very stressful process for them), a dark cutter may still be the result. However, usually the care of animals has the largest impact on their glycogen. This is why, along with extensive efforts to keep cattle happy in every phase of life, King River gives special care and attention to the final month before slaughter.  

How King River reduces stress in the final 14 days

King River has used the MLA Guidelines for reducing cattle stress to inform each part of the process in preparing our cattle for slaughter. We have found several key ways regarding social factors, the environment and transport to keep Wagyu relaxed throughout the harvesting process. 

Social and environmental conditions

Like any cattle breed, Wagyu naturally create a pecking order once placed in a new group or environment. This process can become very stressful for the herd as they jostle to find their place amongst their peers. To reduce stress in the final two weeks before slaughter, King River ensures that cattle are placed in their harvesting group and final pen at least three weeks before. This gives them ample time to reassert themselves and figure out the new pecking order, returning to peaceful cohabitation for the final weeks. We also ensure that harvesting groups don’t mix at the abattoir or get too close in proximity to each other. 

Leading up to harvest, King River works to keep the Wagyu’s environment as stress-free as possible. This includes regular and consistent feeding and a pen with ample shade and water. Knowing that fully grown Wagyu won’t always eat large portions, we feed them a nutrient and energy-dense diet. This ensures they have enough energy stores for the trip to slaughter without force-feeding, which could create stress. 

Transport to the Abattoir

Preparation for their transport to the abattoir is a deliberate process for King River. Our team works to systematically familiarise and prepare the Wagyu for each stage of the process that could create stress. Cattle kept inside the same pen for too long can find exiting the pen a daunting task. King River regularly lets our Wagyu out of the pen to ‘play’ so that exiting the pen is not only normal but a positive experience. We also take the cattle out for a regular run. This helps to ensure the cattle are strong and fit enough to take on the 12-hour truck ride to the abattoir without becoming tired and anxious. While not wanting to burn too much energy, these runs develop important fitness and strengthen in preparation for transport. Along with runs, King River makes sure to be on the ground with cattle regularly so that they get used to the presence of humans. 

The actual transporting process is highly critical to reducing dark cutters, as this is the final few hours before the Wagyu are slaughtered. Research has shown that traditional mustering can be highly stressful. We circumvent this by keeping our Wagyu in a pen close to where they are loaded onto the trucks. This gives our team less ground to cover as they gently guide the Wagyu towards the loading dock. We make sure to keep the weather in mind and avoid loading in stressful circumstances such as extreme heat, heavy rain, sleet or other unpleasant environmental conditions. Once loaded, King River trucks are all padded with sawdust to give the Wagyu extra support while travelling. This keep the Wagyu comfortable and has proven to help them standing happliy for longer. 

How King River reduces stress over a lifetime

At King River we regularly get the same feedback from the abattoir and customers. What we hear time and time again is that our products are consistent. King River products are consistent because we leave little of the Wagyu’s development to chance. From breeding, to rearing, feeding and slaughter, our team is working to keep our cattle healthy, happy, relaxed, and growing. For a small insight into life on the land at King River, read our blog about the Wagyu Royal treatment.

Our team is proud of our track record with low dark cutters and high marbling. With decades of experience and a deep love of cattle farming, we take every part of the process seriously and get great satisfaction from producing consistent results for our customers. 


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