Introduction to the challenge addressed
The occurrence of dark, firm and dry (DFD) meat causes significant financial losses globally in the fresh meat market. Sometimes, the problem affects the production of Meat Mertolenga PDO from the farm "Currais e Simalhas", located in the south of Portugal (Alentejo), near Évora. In young animals, dark cutting is usually associated with the depletion of glycogen from muscle stores prior to slaughter. Depletion of muscle glycogen has been related to a multitude of factors, including animal temperament and aggressiveness (Ponnampalam et al, 2017).
The existence of more temperamental animals and susceptible to stress is a problem in the Mertolenga autochthonous breed. The mentioned farm, which runs a feedlot operation, receives calves from different suckler farms, where management and handling facilities are different and probably influence on the behaviour of the animals.
To face this issue, a simple system for the identification of problem animals was implemented at the Currais e Simalhas farm. This farm is a bull performance testing center and also operates a feedlot unit. The farm has 23 ha, and test approximately 70 purebred bulls each year, from over 30 consignors representing three breeds (Mertolenga, Aberdeen-Angus and Limousine). Feedlot production is for purebred Mertolenga calves only and is fully marketed by the Promert producer group.
Description of Innovation
The identification of problem animals is conducted during the performance test of young bulls that are candidates for future breeders, with the aim to select animals that are less susceptible to stress and to know the suckler farms of origin where most bull are temperamental.
The individual assessment consists in a measure of the animal gait from the squeeze chute where the it was weighed and identified based on the method described in Vetters et al. (2013). The animal can exit walking, trotting or running, conditioned by their temperament and reaction to handling. Each animal is evaluated every time it is weighed. On average each animal is weighed 4 times during the time it is on the farm.
In the farm are conducted two additional tests, but further results and analysis are needed to recommend both as good practices, considering the time and effort that require. One is to observe for one minute the behaviour of each animal (exploration, fear) on the pen after leaving the scale:
- Period of time that the animal is active or quiet;
- Approximation to the film camera or not;
- If vocalized.
And finally, it is measured the behaviour after the introduction of a novel object (a ball), to perform a neophobia test (fear to a novel object/situation) in the animals. The ball is thrown into the pen and during the next four minutes it is recorded:
- Latency time to touch the ball;
- Period of time of the animal attentive or not to the ball;
- The number of times it touched the ball;
- Whether or not the animal played with the ball;
- Period of time of the animal being active or quite;
- If the animal urinated/defecated;
- If vocalized.
Impact on farm performance
The expected impact is with the selection of future less stressed bulls to eliminate as much as possible the occurrence of DFD meat. At the same time, the existence of less stressed animals, better results in productive performance are expected.
In the two videos below, you can see an example of a less temperamental animal and a much more stressed one.
Calm young bull - Click on the image to see the video.
The effort and work required to implement this good practice (animal gait from the squeeze chute) is small when compared to the very important gains expected to be obtain.
Ponnampalam E.N., Hopkins D.L., Bruce H., Li D., Baldi G., Bekhit A.E. (2017). Causes and Contributing Factors to “Dark cutting” Meat: Current Trends and Future Directions: A Review. Comprehensive Reviews in Food Science and Food Safety 16: 400-430.
Miller M. 2007. Texas Tech University. Beef Facts, Product Enhancement. National Cattlemen’s Breed Association.
MacKay J.R.D., Haskell M.J., Deag J.M., van Reenen K. (2014) Fear responses to novelty in testing environments are related to day-to-day activity in the home environment in dairy cattle.
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Hirata M., Kubo S., Taketomi I., Matsumoto Y. (2016). Responsiveness of beef cattle (Bos taurus) to human approach, novelty, social isolation, restrain and trade-offs between feeding and social companionship. Animal Science Journal, Volume 87, Issue 11: 1443-1452.
King et al., 2006. Influence of animal temperament and stress responsiveness on the carcass quality and beef tenderness of feedlot cattle. Meat Science, Volume 74, Issue 3: 546-556.
Vetters MDD; Engle TE; Ahola JK; Grandin T. 2013. Comparison of flight speed and exit score as measurements of temperament in beef cattle. Journal of Animal Science, 91(1): 374-81.
Assessment of Temperament in Cattle and Its Effect on Weight Gain and Meat Quality and Other Research on Hairwhorls, Coat Color, Bone Thichness, and Fertility.