RESUMO
This research explores the relationship between generally accepted and alternative cattle age-prediction methods and chronological age. Cattle (n = 386) of documented ages ranging from 370 to 1,115 d of age were used. Dentition (DEN), USDA maturity score (MS), lens weight (LW), and lens total N (LN) content were used as possible predictors of age. Correlations with age were determined: LW (r = 0.77); DEN (r = 0.74); LN (r = 0.71); and MS (r = 0.64). Stepwise backward regression was used to generate an age prediction equation: Age (mo) = -21.79 + 17.23(LW, g) + 0.038(DEN). By this equation, 38% of cattle = 20 mo of age were verified as = 20 mo of age. Independent measures verified the following percentages of cattle as = 20 mo of age: LW (20.2%), MS (11.0%), DEN (9.6%), and LN (8.7%). The DEN verified that 87.6% were verified as <30 mo old, and LW verified 81.6% of cattle as <30 mo old. A separate group of cattle (n = 18) ranging in age from 1 to 12 yr were evaluated for lens properties, for which LW (R(2) = 0.91) and LN (R(2) = 0.92) were highly correlated with age. The LW and DEN were the best predictors of age for cattle 13- to 37-mo-old and yielded the most accurate age prediction when used in combination (R(2) = 0.67).
Assuntos
Bovinos , Dentição , Cristalino/química , Cristalino/fisiologia , Nitrogênio/análise , Tamanho do Órgão/fisiologia , Determinação da Idade pelos Dentes/veterinária , Fatores Etários , Animais , Bovinos/anatomia & histologia , Bovinos/fisiologia , Feminino , Masculino , Valor Preditivo dos Testes , Estados Unidos , United States Department of AgricultureRESUMO
This study determined the effects of potassium lactate (KL), sodium chloride, sodium tripolyphosphate, and sodium acetate on colour, colour stability, and oxidative properties of injection-enhanced beef rib steaks. Enhancement solutions (8.5% pump) contained combinations of KL (0% or 1.5%), sodium chloride (0.3% or 0.6%), sodium tripolyphosphate (0% or 0.3%), and sodium acetate (0% or 0.1%). Steaks were packaged in a high-oxygen modified atmosphere (80% O(2)/20% CO(2)). Steaks with KL or KL and sodium acetate were darker but more colour stable (P<0.05) than control steaks. Steaks had less glossy surfaces when they contained acetate (P<0.05) and KL (P<0.11). Increasing sodium chloride content resulted in darker, less colour-stable steaks (P<0.05). Removing phosphate had little impact on colour (P>0.05). Both KL and sodium acetate improved visual appearance of injection-enhanced beef rib steaks, whereas the greater salt level were detrimental.
RESUMO
The objective was to determine the effects of potassium lactate (0% or 1.5%; KL), sodium chloride (0.3% or 0.6%), and sodium acetate (0% or 0.1%) on injection-enhanced (8.5% pump), beef strip-loin steaks. All treatments contained 0.3% phosphate and 0.058% rosemary. Steaks were packaged in a high-oxygen modified atmosphere (80% O(2)/20% CO(2)) and were evaluated on d 2, 9, and 14 for surface shininess/gloss, shear force, and descriptive sensory attributes. As time in MAP progressed, oxidized, stale, and rancid flavours increased (P<0.05) and surface shininess/gloss decreased (P<0.05). Brown-roasted and beef flavours were most intense (P<0.05) on d 9. Using KL increased (P<0.05) brown-roasted and beef flavours and limited rancid flavour. Sodium acetate decreased (P<0.05) shear force. Adding more salt increased salty and rancid flavours (P<0.05). Sodium acetate and KL both improve sensory attributes of injection-enhanced beef.