Investigating the impact of pre-slaughter management factors on meat quality outcomes in cattle raised for beef: A scoping review

Abstract

IntroductionThe pre-slaughter management period is a critical juncture in the beef supply chain, having implications not only for animal welfare and product quality, but also for profitability. During this period, cattle are exposed to many stressors in a short time, many of which have been shown to impact meat quality. Understanding how cattle management during this terminal step in the production chain affects meat quality and economic outcomes is crucial.MethodsThe objective of this study was to investigate, synthesize, and report on research evaluating the impact of management factors during the pre-slaughter period on beef meat quality. A systematic approach was used to search for peer-reviewed and primary studies published in English in CAB Abstracts, PubMed, and Web of Science. A total of 3,217 non-duplicate records were screened for eligibility; articles were deemed eligible for inclusion if they included beef cattle in the pre-slaughter period and reported at least one meat quality outcome. After three screening rounds, 85 articles met all inclusion criteria. Data pertinent to the scoping review’s aims were extracted, including study location, population characteristics, pre-slaughter factors reported, and outcomes of interest.ResultsEurope (35, 41%) and South America (21, 25%) represented approximately two-thirds of the studies. Bulls (37, 43.5%) and steers (34, 40.0%) were the most reported sex classes, with the most frequent breed types reported as predominantly British or Continental and Bos indicus breeds (24, 28.2%; 24, 28.2%, respectively). Transportation (n=46), lairage (n=36), and handling (n=35) practices were the most reported pre-slaughter factors. Overall, 59 studies reported pH as an outcome of interest – almost double that of the next highest outcome, bruising (n=35). Muscle pH was most assessed with predictors at the abattoir (n=37); conversely, the effects of transportation were most evaluated on bruising (n=23).DiscussionA trend across all the categories was that there were relatively few studies evaluating the impact of pre-transport factors on meat quality. Charting the relevant literature is a critical step towards understanding the relationship between pre-slaughter management and end-product quality; doing so will help industry stakeholders in the beef production chain optimize management practices that improve meat quality and enhance profitability.

Preslaughter factors affecting mobility, blood parameters, bruising, and muscle pH of finished beef cattle in the United States

“…Even still, there is limited information about the effects of preslaughter factors on animal welfare and meat quality outcomes, particularly among finished beef cattle in the US. A recent scoping review investigating the impact of the preslaughter period on beef quality outcomes reported that only 10 of the 85 studies assessed were conducted in North America, with even fewer studies ( n = 5) conducted in the US ( Sullivan et al., 2022 ). The objective of the current study was to track individual animals throughout the slaughter process to identify preslaughter factors associated with key welfare and quality outcomes in finished beef cattle in the US.…”

“…A limited number of studies have assessed the effects of pen density on welfare ( Davis et al., 2022a ) or meat quality outcomes in beef cattle ( Sullivan et al., 2022 ). Also, to the authors’ knowledge, studies have yet to be conducted on the impact of lairage density on beef cattle mobility.…”

“…In addition, although season has repeatedly been identified as a risk factor for carcass bruising ( Huertas et al., 2015 ), the findings are highly variable across the available literature and contribute to the ongoing challenges associated with assessing and managing bruising in the beef supply chain. Comparing risk factors associated with bruising across studies is difficult because numerous variables, including sex class, animal type, quality of animal handling and facilities, and methodologies used to quantify and characterize bruising, may confound the prevalence of bruising ( Sullivan et al., 2022 ). Although animal handling was not assessed in the current study, we can postulate that mobility and bruising were potentially related.…”

“…However, cortisol levels can be highly variable and not always indicative of adverse events, so it is typically analyzed alongside other parameters. Postmortem, meat quality defects can also be measured to assess the extent to which an animal has coped with stress in the preslaughter period ( Sullivan et al., 2022 ). Chronic stress prior to slaughter can initiate the antemortem catabolism of muscle glycogen, which, if significant, can inhibit the normal postmortem pH decline of the muscle, resulting in beef that is too high in pH with a characteristic dark, purplish-red color ( Ponnampalam et al., 2017 ).…”

“…While some preslaughter factors like transportation ( Tarrant, 1990 ; Knowles, 1999 ; Schwartzkopf-Genswein et al., 2012 ), animal handling ( Warriss, 1990 ; Grandin, 2014 ; Gallo et al., 2022 ), and lairage practices ( Gallo et al., 2003 ; Liotta et al., 2007 ; Teke et al., 2014 ) are well-researched and their relationships to animal welfare well understood, other factors such as truck waiting times to unload at the plant, lairage pen density, and the use and efficacy of heat mitigation techniques in lairage are underrepresented in the current body of work ( Davis et al., 2022a ; Sullivan et al., 2022 ). It is also challenging to draw conclusions from studies conducted in varying parts of the world and with diverse cattle populations, as the final marketing phase varies considerably across the globe, for example, in transport type and conditions, lairage duration, and slaughter practices.…”