Cattle production practices and the incidence of dark cutting beef

Supplementation of complex natural feed additive containing (C. militaris, probiotics and red ginseng by-product) on rumen-fermentation, growth performance and carcass characteristics in Korean native steers

This study evaluated the effects of a complex natural feed additive on rumen fermentation, carcass characteristics and growth performance in Korean-native steers. In this study, in vitro and in vivo experiment were conducted. Seven different levels of complex natural feed additive (CA) were added to the buffered rumen fluid using AnkomRF gas production system for 12, 24 and 48 h. All experimental data were analyzed by mixed procedure of SAS. Total gas production increased in the CA groups, with the highest response observed in the 0.06% group at 48 h of incubation (linear, p = 0.02; quadratic, p < 0.01). Regarding rumen fermentation parameters, the total volatile fatty acid (TVFA) tended to increase in all the CA groups (p = 0.07). The concentrations of butyrate, iso-butyrate, and iso-valerate significantly increased in all treatment groups (p < 0.05). In the in vivo experiment, 23 Korean-native steers were allocated to two groups: (1) Control and (2) Treatment; control +0.07% CA (DM basis), in a randomized complete-block design and blocked by body weight (ave. body weight = 641.96 kg ± 62.51 kg, p = 0.80) and feed intake (ave. feed intake = 13.96 kg ± 0.74 kg, p = 0.08) lasted for 252 days. Average daily gain decreased in the treatment group (p < 0.01). Backfat thickness significantly decreased in the CA group (p = 0.03), whereas meat color tended to increase (p = 0.07). In conclusion, in the in vitro experiment, the inclusion of complex natural feed additive decreased methane proportion and tended to increase TVFA production, but supplementation to Korean native steers decreased average daily gain and backfat thickness.

Muscle of dark and normal beef differs metabolically

Reduction in muscle glycogen triggered by adverse antemortem handling events alters postmortem energy metabolism and results in a high ultimate pH and dark, firm and dry beef, often referred to as 'dark-cutting'. However, the relationship between atypical dark (AT) beef, postmortem energy metabolism and underlying tissue characteristics remains somewhat unclear. Cattle harvested in the US and Canada representing normal (pH < 5.6), AT dark (pH 5.6-5.8) and dark cutting (DC; pH > 5.8) beef were analyzed for tissue characteristics related to energy metabolism. Results show AT dark beef is more oxidative but similar to normal beef in glycolytic potential and nucleotide abundance. Mitochondria DNA content (P < 0.05, Canada; P < 0.005, US) and oxidative enzymes for DC and AT dark beef were greater (P < 0.01; Canada and US) compared to normal beef. Myoglobin tracked (P < 0.01) with color classification. These findings show both DC and AT beef are inherently more oxidative and raise the possibility that more oxidative muscle may be more prone to develop dark beef.

Integrative surveillance of cattle welfare at the abattoir level: Risk factors associated with liver condemnation, severe hoof disorders, carcase bruising and high muscle pH

Given the multi-dimensionality of animal welfare, any monitoring system for slaughter animals should comprise an integrative vision that facilitates animal welfare and food safety assessment. Thus, the aim of this study was to investigate risk factors as possible causes for liver condemnations, hoof disorders, bruise prevalence, and the quality of beef carcases under commercial operating conditions in Mexico. Data were recorded for 143 journeys encompassing 1,040 commercial cattle, originating from feedlots, free-range, and dairy production systems. Details on journey distance, vehicle type, cattle type, and animals' origin were gathered from abattoir reports. We found that carcase bruising (41%) and hoof disorders (43.9%) had the highest prevalence, regardless of the production system. Variables such as cattle type and production system influenced liver condemnations; old bulls extensively raised were more prone to present parasitosis such as Fasciola hepatica. Transportation conditions (journey distance, vehicle type) and cattle type might have influenced the development of hoof disorders in the evaluated animals. Multivariable logistic regression showed that animals' origin was a potential risk factor for severe bruising and high muscle pH, with cull dairy cows getting the most serious damage. In general, cattle transport conditions were factors that showed interactions with three of the evaluated indicators (severe hoof injuries, carcase bruising, meat pH24h). Our study shows the need to implement integrative surveillance to identify risk factors according to the production system from which the animals originate. With this information it is possible to develop strategies to mitigate specific cattle welfare problems.

Cattle welfare assessment at the slaughterhouse level: Integrated risk profiles based on the animal's origin, pre-slaughter logistics, and iceberg indicators

Detection of on farm and transport animal welfare problems at slaughterhouse level is a key issue for the meat industry; however, usually, the assessments do not include basic aspects of animal health. For that reason, it is necessary to develop an assessment method that has an integrative scope and identifies the risk profiles in animals. Therefore, the aim of the present study was to detect cattle welfare indicators that can be implemented at the slaughterhouse level and to develop integrated risk profiles based on the animal's origin, pre-slaughter logistics, and animal-based indicators. We recorded the origin, commercial category, transportation details, and horn size of 1040 cattle upon arrival at the slaughterhouse. Cattle welfare was measured based on individual scores for vocalizations, stunning shots, carcass bruises, meat pH, severe hoof injuries, and organ condemnations. To characterize operational and logistic practices from the farm to the slaughterhouse, a two-step cluster analysis was applied to the aforementioned variables (production system, cattle type, horn size, journey distance, vehicle type), which identified four clusters: small feedlot and free-range profile (C1, n = 216, 20.8 %), feedlot profile (C2, n = 193, 18.6 %), culled dairy cows profile (C3, n = 262, 25.2 %), and free-range profile (C4, n = 369, 35.5 %). The animal's diet and environmental conditions might have influenced the development of hoof disorders in C1 animals (P = 0.023), the proportion of animals that were re-shot was highest in C2 animals (P = 0.033), and C3 and C4 animals were most likely to suffer injuries such as severe bruising (P = 0.001). In addition, the number of stunning shots, meat pH, carcass bruises, severe hoof injuries, and liver condemnations, explained a significant variation in the incidence of various health and welfare consequences based on an animal's origin, which confirmed their importance as 'welfare iceberg' indicators. The study provided detailed data that can be included into assessment methods for the welfare of slaughter cattle, which can be tailored to specific production systems.