Managing Cattle Stress To Improve Meat Quality
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Overall eating quality of beef can be impacted by many aspects like breed, ranch management, and slaughter practices. Although, we will only be covering the first two in this post, as they are the most applicable.
Beef is one of the most expensive meats that a customer will purchase, and because of this, there is an expectation for consistent quality, which includes an eating experience. The major eating quality factor for consumers purchasing beef is the tenderness of the meat. However, even as it is the most important factor, it has been shown to be inconsistent over the years. Flavor must also be taken into consideration, as it can impact the both the palatability and, due to the halo affect, impact the other metrics of good beef.
Inherent breed differences can cause differences in consumer experiences, for example, Wagyu having a sweeter tasting meat or bos indicus cattle having a tougher meat. These differences come down to the fact that Wagyu have a greater concentration of oleic acid and that bos indicus cattle have greater quantity of calpastatin and fast twitch muscle fibers in their muscle as well as less IMF. It is suggested that cattle should not be any more than 25% bos indicus, unless the animal is raised in an extreme environment.
When it comes to management of the cattle, feed has been shown to impact meat quality. While one study observed that cattle fed corn for at least 100 days are rated as more tender than their grass-fed counterparts, others have observed the opposite. The common factor, is how much backfat the animal has, where the more there is, the more tender the meat tends to be. This is likely due to increases in intramuscular fat, which as discussed above, increasing meat tenderness. This suggests that feedstuff is limited by its ability to provide energy for fat production, and that either feeding system can provide the same tenderness given the same fat cover. However, I would like to see further research on this comparison given similar genetics and finished to equal backfat.
The more impactful aspect of the diet, is the change in meat flavor. This is due to changes in the fatty acids present in the meat. This is where grass-fed beef can develop a different taste, as they have greater omega-3 fatty acids and conjugated linoleic acid, whereas grain-fed cattle develop greater quantities of omega-6 fatty acids. This change in flavor has been shown to impact consumer preference, but use of grain finishing for 2–4 months can improve flavor profiles.
The final aspect that can be managed by the cattle producers is the level of stress the animal experiences, especially the stress just prior to slaughter. Increased stress when loading and transporting cattle has been shown to negatively impact the eating quality of the meat. Factors that are potentially managed by the ranch and that can affect the stress most are loading and offloading procedures, driver care, and space available to each animal once loaded into a trailer. There are also other impacts once the animal reaches the slaughter facility like comingling of animals and unfamiliar environments, however, they are not affected by the producer so these aspects will not be discussed in this R2R.
The impact of stress on the meat quality is through the stress hormones, as they release muscle glycogen (the stored form of glucose). This depletion of energy stores increases the pH of the meat, deepening its red hue and producing a “dark cutter”. The dark-colored beef does not only look less appealing to consumers, but it also has a decreased tenderness and juiciness associated with the increased pH. This is where the acronym “DFD” came from in the meat science realm: Dark, Firm, Dry. Unfortunately, these DFD cuts also grow microorganisms faster and wet and dry age poorly as well. One large factor that can be altered by the producer is animal temperament, as the calmer the animal is, the less of a chance there is for bruising and DFD to occur.
Read more about it here:
Towards an integration of pre- and post-slaughter factors affecting the eating quality of beef
ScienceDirectGrzegorzPogorzelskia
