RESUMEN
Meat quality of beef-cross-dairy cattle born in the dairy industry and finished on hill-country pastures is not well characterised. This experiment aimed to objectively evaluate meat quality traits of 15 Angus and 18 Hereford sires via progeny testing of their 326 beef-cross-dairy offspring, and to compare the intramuscular fat (IMF) percentage with the AUS-MEAT marble scores. Beef-breed sires had similar and overall good objective meat quality characteristics. Ultimate pH was not affected by sire (P > 0.05). The differences among sires in meat quality (fat yellowness b*, meat redness a*, yellowness b* and chroma C*, cook loss and shear force, P < 0.05) were small and all values were within the normal range for beef. Marble scores could capture the variation of IMF at marbling score 1-3, but was not effective to distinguish between 0 and 1. In conclusion, the effect of sire on the meat quality of the beef-cross-dairy progeny in this study was of minor importance.
Asunto(s)
Cruzamiento , Carne , Animales , Carbonato de Calcio , Bovinos , Industria Lechera , Carne/análisis , Nueva ZelandaRESUMEN
Carotenoids, powerful anti-oxidants, play a significant role in protecting the skin from oxidation and help in balancing the redox status of skin. This study was aimed at investigating cattle skin to identify carotenoids in the lower epidermis (grain) and dermis (corium) layers for classification using Raman spectroscopy which is a powerful technique for the detection of carotenoids in cattle skin due to the strong resonance enhancement with 532 nm laser excitation. The spectral differences identified between these two layers were quantified by the univariate analysis of Raman peak heights and partial least squares (PLS) analysis. We compared the performance of the Raman spectroscopy method with the standard method, high performance liquid chromatography. The univariate analysis results demonstrated that the lower epidermis of the skin has a higher concentration of carotenoid than dermis using the carotenoid Raman peaks at 1151 cm-1 and 1518 cm-1. The carotenoid Raman intensity was linearly correlated with the total carotenoid concentration determined by standard HPLC methods. Partial Least Squares Regression analysis gives excellent results with R 2 = 0.99. Our results indicate that Raman spectroscopy is a potential tool to determine carotenoids in cattle skin with high precision.
RESUMEN
Steers from Angus, Angus×Holstein Friesian, Angus×Holstein Friesian-Jersey and Angus×Jersey cows and a Hereford sire were measured for their carcass and meat quality characteristics. Steers from the Angus×Holstein Friesian cows had a greater final body weight and carcass weight (P<0.05). Steers from Angus×Jersey cows had the lowest carcass weight and dressing-out percentage (P<0.05). There was a greater fat depth over the rump at 12 and 18months of age for the steers from Angus cows (P<0.05) but, not at 24months of age. The steers had similar meat quality characteristics across the breed groups. Steers from Angus×Holstein Friesian and Angus×Jersey cows had a higher ratio of n6 to n3 fatty acids. Using beef-cross-dairy cows to produce steers for meat production does not impact on meat quality. Using Jersey in the breed cross reduced the carcass tissues in the live weight and the potential meat yield.