Pre-slaughter stress and horn status influence physiology and meat quality of young bulls.

The study used 81 young bulls, half of which were disbudded at 7 weeks of age. The effects of horn status during rearing and of acute physical and emotional stress just before slaughter on the physiological status at slaughter and subsequent meat quality were investigated. Bulls were reared in groups containing i) only bulls with horns, ii) only bulls without horns, or iii) mixed (half with, and half without horns). Bulls of each rearing condition were assigned to one of two slaughter conditions: with limited (LS) or with supplementary stress (SS). LS resulted in lower heart rates, stress hormone concentrations and carcass temperature, whereas SS resulted in faster post mortem pH decline and lower juiciness. Horned bulls from unmixed rearing groups had lower early pm temperature, shorter sarcomeres, and lower tenderness compared to disbudded bulls. Correlations and regression analysis revealed relationships between physiological indicators, mainly heart rate before slaughter, and meat quality, including water-holding capacity and indicators of proteolysis.

Meat quality of Angus, Simmental, Charolais and Limousin steers compared at the same intramuscular fat content.

Meat quality and marbling properties of Angus, Simmental, Charolais and Limousin steers (4×16) were compared at an average intramuscular fat content (IMF) of 3.25% in the M. longissimus dorsi. The steers were fattened on a forage-based diet until the desired, ultrasonically estimated IMF content was reached which resulted in considerably different growth and carcass characteristics. The Angus group showed a growth rate similar to Simmental and Charolais while Limousin grew slower, became oldest and provided the heaviest carcasses and best conformation. Angus carcasses showed the lowest weight but the highest fatness score. Marbling was equal for all breeds. Angus and Charolais provided pale meat with low haem iron content. Angus and Limousin beef was more tender on sensory assessment than Simmental beef, corresponding to differences found in shear force (non-significant) and myofibrillar fragmentation index measured at 48 h post mortem. Flavour was similar among breed groups while juiciness was highest for Limousin and lowest for Angus. The juicier beef simultaneously showed the highest drip but the lowest cooking losses. In conclusion, clear differences in meat quality were observed between breeds despite similar IMF contents.

Fatty acid composition, cooking loss and texture of beef patties from meat of bulls fed different fats.

The effect of fatty acid composition on the properties of patties standardised to contain 15% fat was studied. Patties were made of beef from 36 Brown Swiss bulls fed on six different diets with five of them containing additional fats to achieve a high variability in body lipid composition. When the feed contained fullfat oilseeds (rapeseed, sunflower seed, linseed), the proportions of some nutritionally favourable fatty acids were increased in the patties. Patties made from the meat of bulls fed linseed and coconut oil could be distinguished in a sensory triangle test from most other groups. Cooking loss and instrumental texture properties showed no relation to fatty acid composition of patties. Cooking only slightly decreased the proportion of saturated fatty acids in favour of polyunsaturated fatty acids. In conclusion, widely differing dietary fats can be fed to bulls without risking major effects on texture of beef patties.