Slaughter and fabrication/boning processes and procedures

J.A. Scanga , in Improving the Safety of Fresh Meat, 2005

13.2.12 Final washing

Following determination of hot carcass weight, carcasses are generally subjected to a sequence of several 'final intervention' decontamination technologies designed to address the possible presence of visible contamination and pathogens on carcass surfaces ('multiple hurdles' systems). Initially, all carcasses are washed with large volumes of ambient-temperature water. Most plants also incorporate a thermal or steam pasteurization system designed to apply water at temperatures in excess of 82 °C, as well. Technologies for final carcass washing, along with final slaughter decontamination intervention systems, can be found in Chapters 16, 17 and 21.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9781855739550500133

SPECIES OF MEAT ANIMALS | Sheep and Goats

E.L. Walker , M.D. Hudson , in Encyclopedia of Meat Sciences (Second Edition), 2014

Effects of Management on Carcass Composition

Sheep

Across all breeds and weights, carcasses from rams are the leanest and ewes are the fattest. Ram lambs tend to have the largest and the longest carcasses and possess larger loin muscles compared with ewes. Wether lambs are intermediate. Delaying castration or slaughtering ram lambs before puberty can increase the carcass lean to fat ratio.

Goats

Few studies have evaluated the effects of gender on carcass composition in goats. Time of castration affects dressing percentage, and variations in timing may explain why there is limited agreement between the published studies. In most cases, goats are slaughtered either before or soon after puberty (4–8 months); therefore, the effects of the male sex steroids may not have had sufficient time to affect dressing percentage. The proportion of retail carcass cuts is also affected by gender; however, breed and age have greater effects on carcass composition.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780123847317000787

SLAUGHTER-LINE OPERATION | Pigs

H. Channon , in Encyclopedia of Meat Sciences (Second Edition), 2014

Carcass Grading, Weighing, and Stamping

Pork carcass grading is generally based on carcass weight and a measurement of the fat and lean content of the carcass on the slaughter floor before chilling. In Australia, producer payments for pork carcasses are based on hot carcass weight and fat depth at the P2 site, located 65  mm from the midline of the carcass at the last rib. In Canada, the national grading system classifies pork carcasses into indexes based on measurement of fat and muscle depth 7   cm from the midline of the carcass between the third and fourth last thoracic ribs and carcass weight. Within the European Union, carcasses are divided into six classes and assigned a letter (S, E, U, R, O, or P), which indicates estimated lean meat content (S>60%, E=55–60%, U=50–55%, R=45–50%, O=40–45%, and P<40%). In the US, fat depth at the last rib may be measured and the expected yield of four cuts (ham, loin, picnic shoulder, and Boston butt) included in the carcass grading process. Information regarding grade, carcass weight, gambrel identification, and producer's tattoo number may be registered electronically and used in reporting back to producers. In Japan, fat thickness is measured at the narrowest point between the 9th and 13th thoracic vertebrae, carcass weight is obtained, and assessments of carcass appearance, meat, and fat color are then used by the grader to determine the grade of each carcass.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780123847317001586

Valorization of meat by-products

Giulia Baldi , ... Massimiliano Petracci , in Food Waste Recovery (Second Edition), 2021

21.4.1 Blood

Representing up to 7% of carcass weight of most animals, blood is one of the most abundant by-products generated by the abattoirs but also one of the most problematic due to high volumes produced and its high pollutant load (Del Hoyo et al., 2008; Toldrà et al., 2019). Albeit religious restraints along with negative consumer perception make its use limited for direct human consumption, blood from veterinary-approved disease-free animals is often collected from slaughterhouses and separated into usable fractions, in order to exploit their remarkable nutritive value. The addition of anticoagulants such as sodium citrate, heparin, or EDTA is a common technique aimed at avoiding blood coagulation during processing procedures: whole blood with anticoagulants is further separated into its main fractions (e.g., 55%–65% of plasma and 35%–45% of red blood cells) through centrifugation (Toldrà et al., 2019). While coagulated blood is usually dried and used for animal feeding or fertilizing purposes, red blood cells, as well as plasma, are addressed to the extraction of functional compounds designed not only to food but also to pharmaceutical and medical purposes (Bah et al., 2013; Toldrà et al., 2019). In more detail, plasma fraction possesses a valuable protein content, of which globulin represents up to 60% (Hyun and Shin, 2000). Proteins found in the plasma fraction present the most relevant technological properties, and for this reason, they are often employed as a value-added ingredient in the food industry or as nutritional supplements (Ofori and Hsieh, 2011). On the other hand, the red blood cell fraction is mainly composed of hemoglobin, a rich source of high-bioavailable heme iron (Toldrà et al., 2019). Hemoglobin hydrolysates possess valuable nutritional properties and represent a good source for the extraction of bioactive peptides (Bah et al., 2013). However, hemoglobin, although it has good foaming and emulsifying properties, has limited applications in the food industry due to the dark color and undesirable flavor. Within the pharmaceutical and biomedical industry, blood proteins such as thrombin are widely employed in blood coagulation agents and skin-graft procedures, while fibrin is used in surgical repair of internal organs (Marti et al., 2011).

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780128205631000172

SPECIES OF MEAT ANIMALS | Pigs

G. Eikelenboom , ... R.E. Klont , in Encyclopedia of Meat Sciences, 2004

Dressing Percentage

Dressing percentage is the ratio of dressed carcass weight to the weight of the live animal, expressed as a percentage. Carcass weight is usually determined at the time of classification. To compare dressing percentages from various studies, it is important to know how the carcass is defined, for instance whether it includes head and legs. When the individual live weight is determined, this is usually done shortly before or at delivery.

Dressing percentage is variable. The content of the intestines can be a major influencing factor. Producers sometimes feed their pigs until delivery, although there are many reasons not to do so: (1) not feeding reduces the risk of (cross) contamination of the carcasses with enteropathogens during the evisceration process; (2) it reduces the labour at slaughter; (3) stress and death losses during transport are lower; (4) ultimate pH is higher and meat colour and WHC improve (with prolonged fasting); and (5) there is less waste to dispose of after slaughter. However, when the interval between last feeding and slaughter exceeds 24 h, there can be a negative effect on carcass weight. Therefore, a deprivation period between last feeding and slaughter of 12–16 h is usually recommended. In order to promote feed deprivation prior to delivery, pigs are weighed in some slaughterhouses immediately after bleeding. The calculated 'dressing percentage' is communicated to the producers, together with weight and classification data.

Other factors that influence dressing percentage are breed, age, live weight, muscularity, carcass fatness and gender. Older and heavier pigs usually have a higher dressing percentage. In comparison with most other breeds, pigs from very muscular breeds, such as the Belgian Landrace breed and Piétrain breeds have a 2% and 4% higher dressing percentage, respectively. Gilts have a somewhat higher dressing percentage than castrates, and entire males have the lowest. The differences in dressing percentage between young entire males and castrates may easily be 1.5%, in favour of the latter.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B012464970X001094

Methods to measure body composition of domestic animals

Steven M. Lonergan , ... Dennis N. Marple , in The Science of Animal Growth and Meat Technology (Second Edition), 2019

Price Based on the Hot Carcass Weight

When selling cattle on the basis of the hot carcass weight, some cattle buyers will refer to this method as "in the beef" selling. This marketing option removes the risk for estimating dressing percentage by the packer buyer. A practical example for this option would be the elimination of the packer buyer to estimate the "mud-weight" on the hide of the cattle, which often occurs in the Midwest states during the wet seasons. Also in this system, the cattle feeder or producer is responsible for the trim loss that occurs before the hot carcass reaches the scales to obtain the carcass weight. An example may be the trim loss to the carcass during inspection if the USDA inspector removes a portion of the carcass before the carcass weight is obtained. In this method of selling cattle, the cattle feeder also stands the risk of condemnation of the entire carcass by the USDA inspector if disease is detected in the carcass during the inspection process. The packer provides the cattle feeder a price based on the value of the hot carcass weight for the load of cattle marketed.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780128152775000081

SPECIES OF MEAT ANIMALS | Pigs

D.D. Boler , in Encyclopedia of Meat Sciences (Second Edition), 2014

Carcass Classification

In various parts of the world, a pig's value is determined by carcass weight and an estimation of carcass leanness. In the US, pigs generally are marketed from a single barn over potentially several weeks. The majority of pigs are sold on a matrix type basis that offer premiums for carcasses meeting certain specifications and charges discounts to carcasses that do not comply with the desired carcass weight and lean meat percentage specifications. By doing this, producers are able to better manage carcass weight as well as carcass composition. This can be accomplished by marketing the heaviest pigs within a pen first, and then lighter pigs in subsequent weeks. This increases allotted space per pig in a pen, decreases competition for feeder access, and allows slower growing pigs more time to reach a desired compositional end point. This marketing approach allows producers to be rewarded for marketing pigs that have a desired carcass weight (not too heavy or too light) with minimal carcass weight variation and a desired percentage of lean meat. In many pork slaughter facilities, estimation of carcass leanness is carried out at the very end of the harvest process. Carcass leanness estimations can be accomplished using a variety of technologies. The use and application of these technologies vary greatly around the world. Some examples include: the Fat-o-Meater, Hennessy probe, animal ultrasound system, or a simple ruler to measure fat thickness. Some of these technologies are more invasive than others. So, the method used to determine carcass composition will vary among packers and regions of the world. Other technologies, such as dual energy X-ray absorptiometry, are available to determine carcass leanness, but might be prohibitive in a large-scale fast moving production facility. As fat thickness or fat content is the most variable tissue in carcasses, it plays a very influential role in estimating carcasses lean percentage. Therefore, fat thickness is included in nearly every regression equation, regardless of technology used, to estimate carcass lean percentage. Even though the value of carcasses to the live pig producer is determined by carcass weight and estimation of carcass leanness, the value of carcasses to packers is determined by the cutability of carcasses or the amount of meat products derived from those carcasses. In the US, pork carcasses are fabricated into five primal pieces ( Figure 1). Those pieces are the ham (22–25% of the chilled half carcass), loin (20–22% of the chilled half carcass), picnic shoulder (ventral region of the shoulder, which accounts for approximately 9–11% of the chilled half carcass), belly (12–15% of the chilled half carcass), and Boston butt shoulder (dorsal region of the shoulder, which accounts for approximately 8–10% of the chilled half carcass). The Boston butt, picnic, loin, and ham are often referred to as the four lean cuts or lean carcass cutability. When the belly is included, the calculation is referred to as carcass cutability. Lean carcasses generally have a greater cutability than fatter carcasses because there is less fat (also less valuable) to trim away, thereby a greater percentage of carcasses can be sold as lean meat.

Figure 1. A pork carcass fabricated into the five US primal pieces: (a) ham (22–25% of chilled half carcass), (b) loin (20–22% of chilled half carcass), (c) Boston butt (8–10% of chilled half shoulder), (d) belly (12–15% of chilled half carcass), and (e) picnic shoulder (9–11% of chilled half carcass).

In Europe, carcasses are classified based on lean meat percentage using the EUROP classification system that is based on muscle and fat thickness. In that system, E has the greatest lean meat percentage (>55%), U=50–55% lean meat, R=45–50% lean meat, O=40–45% lean meat, and P is the least lean meat percentage (<40%). Similar to the US, European packers also estimate lean meat percentage with objective tools such as a caliper to determine midline fat thickness, Fat-o-Meater and Hennessy optical probes, and various ultrasonic scanners.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780123847317000799

Biochemical changes of postmortem meat during the aging process and strategies to improve the meat quality

R. Ramanathan , ... Naveena Basappa Maheswarappa , in Meat Quality Analysis, 2020

5.2.2.3 Tendercut

Another way of increasing tenderness was introduced in the early 1990s by utilizing the carcass weight to stretch muscles of the loin and round. Tendercut requires two cuts to be made on the carcass through bone, connective tissue, adipose tissue and some minor muscles, and the carcass can be suspended traditionally by the Achilles tendon. These cuts are to be made shortly after slaughter, and prior to the onset of rigor mortis. The first cut is made between the 12th and 13th thoracic vertebra, like when splitting the carcass into fore- and hindquarters; however, it is continued to completely sever the multifidus dorsi and finishes prior to the longissimus. The second cut is made between the sirloin and round and completely severs the ischium of the pelvis and the junction between the fourth and fifth sacral vertebra and connective tissue. Significant gaps should appear between the loin and sirloin–round junction to ensure sufficient stretching of the carcass. Tendercut has shown to improve tenderness by increased sarcomere length and reduced Warner–Bratzler shear force (WBSF) in loin and round muscles including vastuslateralis, rectus femoris, and vastus medialis; in addition to the longissimus and gluteus medius when combined with electrical stimulation. Tendercut requires more hands-on labor, as well as requiring higher railing systems due to lengthier carcasses than traditional beef carcasses. These are most likely the reasons that few commercial systems have adopted this system; however, tendercut has been validated by several studies in the United States, Canada, and Norway.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780128192337000057

Strategies to limit meat wastage: Focus on meat discoloration

Ranjith Ramanathan , ... Gretchen G. Mafi , in Advances in Food and Nutrition Research, 2021

2 Significance of meat waste

With high demands for meat proteins, many countries have conducted research resulting in heavier carcass weights without significant reductions in feed, water and labor efficiencies, with the overall effect being increased value per unit of protein produced. Gerbens-Leenes, Mekonnen, & Hoekstra, (2013) estimate the water footprint of meat production to be almost one-third of the total agriculture water footprint. Water usage goes far beyond providing for live animals and the production of their feed. Using beef as an example, and applying average dressing percentages and carcass weights, the estimated water used in processing one carcass is 11   L per kilogram of boneless beef but can vary depending on the size and capability of plants (Legesse et al., 2018). By applying the estimated meat loss/waste of 22% annually, and the estimated beef demand of 54,957 metric tons by 2027 (OECD-FAO, 2018), the world would be losing 12,090 metric tons of beef, and therefore wasting more than 860 million liters of water just in the processing stages (Fiala, 2008).

Once meat, along with other organic food waste, is discarded and taken to a landfill, it can produce a concoction of greenhouse gases and can greatly contribute to human-based gas production. The Environmental Protection Agency, (2020) reported that in 2018, 15.1% of human methane production originated from municipal waste alone. Greenhouse gases are claimed to have an environmental impact. Unless proactive measures are taken to limit global meat wastage, the environmental effects and availability of natural resources could be irreversible. However, with continued research in inefficiencies of feeding systems and the reduction of the meat water footprint, the continued demand for meat can have a neutral impact on the environment, and its greater availability will add to improved global health and satisfaction of consumers.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/S1043452620300528

Muscle Development and Growth

A. Rowlerson , A. Veggetti , in Fish Physiology, 2001

1. Morphometry

Although somatic growth can be easily measured in the form of body weight (or carcass weight or length and/or condition factor), this gives only an indirect measure of muscle growth. A long-established method, which provides useful quantitative data, is measurement of muscle fiber diameters (or cross-sectional areas) in a representative area of lateral (trunk) muscle in fish of different ages, sizes, or conditions (e.g., Willemse and van den Berg, 1978; Weatherley et al., 1979, 1980a,b, 1988; Stickland 1983; Veggetti et al., 1990; Kiessling et al., 1991; Meyer-Rochow and Ingram, 1993; Rowlerson et al., 1995; Alami-Durante et al., 1997; Fauconneau et al., 1997; Johnston et al., 1998; Galloway et al., 1999a,b; Radaelli et al., 1999; Valente et al., 1999). The diameters of the larger fibers provide an index of hypertrophic growth which continues until they reach the functional maximum value characteristic of the species. Fibers also grow in length, but as measurement of this form of hypertrophy requires a more complex sampling technique, it is less often used (see Kiessling et al., 1991; Alami-Durante et al., 1997).

The distribution of fiber diameters (or areas), and especially the presence of very small diameter fibers, is often used as a measure of the appearance of new fibers and thus of hyperplasia (examples are shown in Fig. 1 and a method for quantitative analysis described by Johnston et al., 1999). Strictly, however, the presence of small fibers does not necessarily indicate fast growth because they are typical of fish size rather than growth rate (Weatherley and Gill, 1982, 1987a; Weatherley et al., 1988), and even some slow-growing fish have muscle containing small diameter fibers (Weatherly and Gill, 1987b). In longitudinal studies it is desirable to count the total fiber number in a transverse section of the trunk at each time point, or if that is not possible, at least to derive an estimate from the whole area occupied by muscle and the mean fiber diameter. Ideally, this estimation should use an appropriately weighted value for diameter if there is a zonal distribution of different diameters within the myotome. Fortunately, zonal differences are largest in the smaller fish (in which total fiber counts can be made relatively easily), and are less marked (although not insignificant, see Kiessling et al., 1991) in larger fish for which total fiber number counts are not practicable.

Fig. 1. Morphometric data illustrating the growth of fast-white fibers in an epaxial quadrant of lateral muscle in the sea bream, Sparus aurata, from hatching to 5 months (a,b) and in the sole, Solea solea, at the ages shown (c). Data refer to one representative large subject at each age, and are from studies by Rowlerson et al., 1995 and Veggetti et al., 1999. (a) Hyperplasia (represented by the number of fibers with diameter less than 5 μm) occurs in two phases: an early stratified phase which peaks in midlarval life followed by a later, mosaic phase which starts in the month following metamorphosis (at the time indicated M) and continues well into juvenile life (beyond the period shown here). (b) As hyperplasia ceased toward the end of larval life, mean diameter increased. As hyperplasia increased again after 60 days the mean diameter remained steady again (and only increased substantially after 150 days when the proportion of very small diameter fibers decreased again). The mosaic phase generates a far larger number of fibers than was formed in the earlier phase, and together with hypertrophic growth brings the fish to commercial size. (c) The histogram illustrates the left-skewed unimodal distribution of fiber diameters during the stratified hyperplastic phase in a 21-day-old sole, the typical bimodal distribution of fiber diameters during active mosaic hyperplasia (2.5 months), and the wide range of fiber diameters (but very few under 10 μm) in a small subject at one year when hyperplastic growth had ceased, but most fibers were still relatively small in diameter.

Some authors use a combination of fiber number and size to estimate "cellularity" (fiber number in relation to fiber area and/or whole muscle cross-sectional area, e.g., Stickland et al., 1988; Nathanailides et al., 1995a; Johnston and McLay, 1997; Matschak et al., 1997, 1998; Johnston, 1999), and counts of nuclear numbers in relation to fiber numbers or areas can also provide useful information (Koumans et al., 1991, 1993a; Johnston, 1993a; Alfei et al., 1994; Nathanailides et al., 1996; Johnston and McLay, 1997; Alami-Durante et al., 1997).

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/S1546509801180064