Scarring of the outside flat in beef: determining one origin of this quality defect

Scarring of the Outside Flat’ is the expression used in Switzerland to designate a quality defect appearing on the main muscle used to produce dried meat, the Biceps femoris or gluteobiceps. This problem, already known for decades and now clearly increasing, was still yet not explained. This led the inter-branch organisation for meat to award a research mandate to ALP. Ultrasound was chosen as an investigative tool to allow diagnosis and follow-up of the live animal, especially during the rearing period. This turned out to be a wise approach. The affected zone was pinpointed on the live, standing animal. Lesions were observed and monitored over time. The discovery of a case remained negative up till then, corroborated by abnormal blood values, allowed to exclude most of hypotheses made up to that point. A new hypothesis was that a point trauma due to a fall by slipping and to rotation of the hindquarters on a hard surface generated the lesion observed. The ultrasound scan was positive for 91 % of the animals declared to have fallen and by those that were euthanised the presence of a scar was confirmed. The rise in this phenomenon might therefore result of the increasing freestall housing with hard-surfaced areas, whith an associated increasing risk of falling.