Can potential for dark cutting be predicted by phenotype? Relationship between sex, carcass characteristics, and the incidence of dark cutting beef

Abstract

Recent research indicated that reduced carcass muscling and weight are associated with beef dark cutting. Existing data from a single farm (44 heifers, 136 steers) from three normal beef quality grades (Canada AAA, AA, A) and the dark cutting grade (Canada B4) (n = 35, 106, 28, and 11, respectively) were used to identify relationships between sex, live animal, and carcass characteristics and the incidence of dark cutting. Categorical modelling showed a trend (P = 0.106) for heifer carcasses to have a greater probability [11.36 ± 4.78% standard error of the mean (SEM)] of dark cutting than carcasses from steers (4.4 ± 1.76% SEM). Mixed model analysis of variance indicated dark cutting heifers weighed less than cattle from normal grades at weaning (P = 0.0229) and slaughter (P = 0.0295). Logistic regression revealed that the probability of each carcass grade occurring was influenced by dry matter intake (DMI) (P = 0.0034), and the probability of dark cutting was lowest (P = 0.0286) in cattle with carcasses greater than 300 kg. Results suggested that cattle at risk of dark cutting may be identified by weight, average daily gain (ADG), and feed intake.Key words: average daily gain, beef, carcass weight, dark cutting, dry matter intake, ultrasound fat depth.Résumé : La recherche récente indique qu'une réduction des muscles de la carcasse et du poids sont associés au boeuf à coupe sombre. Les données existantes d'une seule exploitation (44 génisses, 136 bouvillons) de trois calibres de boeuf habituels (Canada AAA, AA, A) et le calibre coupe sombre (Canada B4) (n = 35, 106, 28 et 11, respectivement) ont été utilisés pour identifier les relations entre le sexe, les caractéristiques de l'animal vif et de la carcasse et l'incidence de coupe sombre. Les modèles par catégories indiquent une tendance (P = 0,106) pour que les carcasses de génisses aient une plus grande probabilité [11,36 ± 4,78 % d'erreur type (SEM, « standard error of the mean »)] de coupes sombres que les carcasses de bouvillons (4,4 ± 1,76 % SEM). L'analyse de variance à modèle mixte indique que les génisses à coupe sombre pèsent moins au sevrage (P = 0,0229) et à l'abattage (P = 0,0295) que les bovins de calibres normaux. L'analyse de régression logistique a révélé que la probabilité que chaque calibre de carcasse survienne était influencée par la prise de matière sèche (DMI, « dry matter intake ») (P = 0,0034), et la probabilité de coupes sombres était la plus faible (P = 0,0286) chez les bovins ayant des poids de carcasses de plus de 300 kg. Les résultats suggèrent que les bovins à risque de coupes sombres peuvent être identifiés par le poids, le gain moyen quotidien (ADG, « average daily gain ») et la prise alimentaire. [Traduit par la Rédaction] Mots-clés : gain moyen quotidien, boeuf, poids de carcasse, coupe sombre, prise de matière sèche, épaisseur de gras par ultrasons.

Causes and Contributing Factors to “Dark Cutting” Meat: Current Trends and Future Directions: A Review

“…Based on the pH threshold of 5.7 and AUS‐MEAT color reference standards (a 1 to 7 scale), McGilchrist and others () found that DC carcasses had reduced eye muscle area, carcass weight, and subcutaneous rib fat depth. The results of this research were supported by those of Holdstock and others () and Mahmood and others (b), which showed that DC carcasses as assessed by subjective color measures, both with atypical (ultimate pH 5.8 to 6.0) and typical (pH greater than 6.0) ultimate pH values, had decreased carcass and muscle weights relative to normal carcasses. That physiological attributes may be indicators of the likelihood of DC suggests that cattle that produce a DC carcass may not be experiencing additional stress prior to slaughter through transport and handling, but that some cattle have less resistance to or recover more slowly from physical stress than others (McGilchrist and others ; Holdstock and others ; Mahmood and others ).…”

“…That physiological attributes may be indicators of the likelihood of DC suggests that cattle that produce a DC carcass may not be experiencing additional stress prior to slaughter through transport and handling, but that some cattle have less resistance to or recover more slowly from physical stress than others (McGilchrist and others ; Holdstock and others ; Mahmood and others ). Specifically, research into the incidence of DC in heifers and steers in Canada (Mahmood and others ,b) substantiated that heifers most likely to cut dark had reduced weaning and slaughter weights, and that cattle regardless of gender most likely to cut dark had decreased carcass weights and longissimus thoracis muscle areas at the 12th to 13th rib interface.…”

Meat and sensory quality of major muscles from Angus, Charolais, and Angus crossbred steers with high and low residual feed intake

“…Pearson's correlation coefficient analysis was performed to determine linear relationships between independent variables including RFI and RFIf values using R with the package Hmisc version 4.0-2, and a Bonferroni correction was used to compensate for the likelihood of type I error. Twenty-nine comparisons were made; thus, correlations were considered significant at P = 0.0017 as calculated by 0.05/29 (Mahmood et al 2016).…”

Evaluación de los componentes del manejo antes, durante y después de la matanza y su asociación con la presencia de carne DFD en bovinos del noreste de México

“…El estrés crónico y la exposición de largos plazos de estrés agudo, justo antes de ser sacrificado, hacen que las reservas de glucógeno muscular se consuman rápidamente (2) , reduciendo la cantidad de ácido láctico que se forma por la glucólisis anaerobia en el músculo luego de la muerte del animal, lo cual provoca la presencia de carne DFD, también llamada Corte Oscuro (16,17) . Existen diferentes factores intrínsecos que aumentan el riesgo de una mayor presencia de carne DFD tales como: el origen racial (más frecuente en Bos indicus) (18,19) , el sexo (mayor en machos enteros) (7,20) , el peso (menos común en ganado de mayor peso vivo) (21,22) , la cantidad de grasa (se presenta más frecuentemente con valores bajos en el espesor de la grasa subcutánea) (4,23) y la edad (es más frecuente en animales viejos) (24,25) . Las condiciones ambientales también influyen en la presencia de carne DFD, las temperaturas extremas provocan estrés por calor o por frío (26,27) .…”