Abstract Continued increases in pork carcass weights have raised questions regarding their impact on both fresh meat quality and downstream processing performance. Because much pork is further processed, understanding how carcass weight influences the biological and compositional properties of raw materials is critical for maintaining product quality and processing efficiency. The objective was to evaluate the effects of increasing carcass weight on postmortem chilling, fresh meat quality, and the processing characteristics of pork hams and bellies. Across two complementary studies, carcasses were categorized as Average (99–109 kg), Heavy (116–126 kg), and Very Heavy (134–144 kg). Increasing carcass weight slowed postmortem temperature decline, with the greatest effects observed during late chilling and within specific primals (ham > shoulder > loin). Despite these differences, minimal impacts on fresh pork quality traits, including pH, color, water-holding capacity, and tenderness, were observed. Processing outcomes further demonstrated that heavier carcass weights did not impair functional performance. Ham pump retention and cooked yield were not affected by carcass weight, although minor decreases in cured color were observed. In bellies, increased carcass weight resulted in larger dimensions, greater fat content, and reduced iodine value, contributing to improved cooked yield despite slightly reduced pump uptake. However, bacon slices from heavier carcasses were larger and exhibited reduced lean percentage, highlighting potential implications for slicing efficiency, packaging, and consumer perception. Collectively, these results indicate that increasing pork carcass weight up to 144 kg alters postmortem temperature decline and carcass composition without compromising fresh or processed yield outcomes. From an applied perspective, processors may benefit from improved belly yield and fat characteristics but should anticipate changes in product size and composition. These findings emphasize the importance of integrating raw material characteristics with processing considerations to support science-based decision making across the pork value chain.

Broilers are commonly exposed to coccidiosis infections, and the use of dietary strategies to reduce losses in growth performance has practical implications for the poultry industry. Methionine (Met) is typically the first limiting amino acid for broilers and is involved in metabolic and immunological pathways; however, literature is conflicting on how dietary Met requirements are affected by environmental stressors. Our objective was to assess how the Met requirement changes during coccidiosis based on results of growth performance, carcass traits, and health outcomes. Two trials were conducted using 780 male Ross 308 broiler chicks in floor pens randomly assigned to 1 of 12 experimental treatments. All birds received common starter (d 0-10) and finisher (d 24-35, Trial 2 only) diets, and only differed based on their assigned experimental grower diet (d 10-24). Trial 1 experimental grower diets ranged from 2.61 to 6.21 g/kg digestible Met. Trial 2 experimental grower diets were formulated to contain 15% below, at, or 15% above the Met requirement determined in Trial 1. Birds were exposed to a coccidiosis challenge on d 11, with blood and tissue collection (1 bird/pen) on d 18 and carcass processing on d 35 (2 birds/pen) in Trial 2. Data were analyzed using a 1- or 2-way ANOVA. A non-linear regression analysis was conducted in Trial 1 to determine the Met requirement of 4.32 g of digestible Met/kg of diet using BW gain. Coccidiosis infection reduced (P < 0.05) growth performance during the experimental grower and overall study periods in Trial 2. Increasing dietary Met from below requirement to meeting requirement during the grower period improved (P < 0.001) BW gain and feed conversion ratio (FCR), but this effect was only significant between treatments below and above the requirement for the overall study period. There was an interactive effect (P = 0.038) on FCR for the overall study period. These findings provide evidence that the Met requirement is likely increased during coccidiosis based on growth performance outcomes.

Supplementation of vitamin E improves beef colour stability by minimizing lipid oxidation-induced myoglobin oxidation. Mitochondria affect myoglobin redox stability, and dietary vitamin E influences mitochondrial functionality in skeletal muscles. Nonetheless, the influence of vitamin E on the mitochondrial proteome of beef skeletal muscles has yet to be investigated. Therefore, the objective of this study was to examine the effect of dietary vitamin E on mitochondrial proteome of post-mortem beef longissimus lumborum (LL) muscle. Beef LL muscle samples (24 hours post-mortem) were obtained from the carcasses of nine (n = 9) vitamin E-fed (VITE) (1000 IU vitamin E for 89 days) and nine (n = 9) control (CONT) (diet without supplemental vitamin E) heifers. The mitochondrial proteome was analysed using two-dimensional gel electrophoresis and mass spectrometry, and nine differentially abundant spots were identified. All the differentially abundant spots were over-abundant in CONT, and the proteins were electron transport chain enzymes (NADH dehydrogenase iron-sulphur protein 8, NADH dehydrogenase flavoprotein 2, and cytochrome c oxidase subunit 5B), metabolic enzymes (succinate-CoA ligase (ADP-forming) subunit beta; dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex; pyruvate dehydrogenase protein X component), and enzymes involved in ATP regeneration (creatine kinase S-type). The low abundance of these proteins in VITE may decrease mitochondrial activity, resulting in low oxidative activity. These findings suggest that the strong antioxidant activity of vitamin E leads to less expression of mitochondrial oxidative enzymes in beef skeletal muscles.

The objective was to control intrinsic and extrinsic factors associated with the production and slaughter of pigs to determine effects of sire line (Pietrain vs. Duroc ancestry) on growth performance, carcass and belly characteristics, and commercial bacon yields of growing-finishing pigs. There were no differences in growth performance (P ≥ 0.08) or belly processing characteristics (P ≥ 0.09). Pietrain sired pigs had a greater lean yield (P ≤ 0.01). Duroc sired pigs had darker, more highly marbled loins (P ≤ 0.04) and thicker bellies (P < 0.001). Bacon from Pietrain sired pigs had a greater (P = 0.04) lean to fat ratio with 1.58% increase (P = 0.04) in average bacon slice lean. Barrows had more highly marbled loins (P ≤ 0.01) and thicker bellies (P < 0.001) than gilts. Bacon from barrows had a greater slice area (P < 0.001) while bacon from gilts had a greater lean to fat ratio (P = 0.04).

ObjectivesVitamin E is a lipid-soluble antioxidant that can inhibit lipid oxidation and improve beef color stability. The effect of vitamin E on fresh beef color, from the standpoint of lipid oxidation-induced myoglobin oxidation, have been extensively studied. However, the influence of vitamin E on sarcoplasmic proteome profile of beef skeletal muscles is yet to be investigated. Therefore, the objective of this study was to examine the effect of dietary vitamin E on sarcoplasmic proteome of postmortem beef longissimus lumborum (LL) muscle.Materials and MethodsCrossbred heifers, managed with a GrowSafe feeding system, were fed ad libitum corn-based diet containing either no supplemental (CONT) or 1000 IU vitamin E/heifer per day (VITE) for 89 d. The animals were harvested, and carcasses were chilled. The LL muscle samples were obtained from the carcasses of nine (n = 9) VITE and nine (n = 9) CONT heifers 24 h postmortem. The muscle samples were individually vacuum-packaged and frozen at –80°C for proteome analysis. Sarcoplasmic proteome was analyzed using two-dimensional electrophoresis, employing immobilized pH gradient strips (pH 3–10; 17 cm) in the first dimension and 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis in the second dimension. The gels were scanned, and the digital gel images were analyzed. The protein spots exhibiting more than 1.5-fold intensity differences (P < 0.10) between VITE and CONT were subjected to in-gel tryptic digestion and were identified by tandem mass spectrometry.ResultsFive differentially abundant spots were identified using mass spectrometry, and all the spots were over-abundant in CONT. The proteins in the differentially abundant spots were antioxidant proteins (thioredoxin-dependent peroxide reductase, peroxiredoxin-6, and serum albumin) and glycolytic enzymes (β-enolase and triosephosphate isomerase). The antioxidant proteins minimize oxidation of lipids and proteins in muscle matrix, whereas the glycolytic enzymes generate NADPH, which helps maintain the antioxidant proteins in their reduced forms.ConclusionThe strong antioxidant protection offered by vitamin E could have possibly led to less expression of antioxidant proteins as well as glycolytic enzymes that generate antioxidant metabolites in the VITE group, whereas the lack of such protection in CONT group may have led to increased expression of these proteins in the skeletal muscles.

ObjectivesDry aging treatments impart unique flavors desirable by a segment of the population. Ground beef offers flexibility of use at a lower price point. There is potential to add value to lower priced beef cuts by dry aging them and incorporating them into premium grinds. However, the long dry aging period could allow growth of key pathogens. To determine the risk, the prevalence and potential for growth must be assessed. The effect of a dry aging treatment on the population of Salmonella and Listeria monocytogenes was studied.Materials and MethodsAn in-plant assessment of E. coli O157:H7, Salmonella, and Listeria monocytogenes was conducted by swabbing both the fat and lean sides of 25 ribeye rolls or striploins before direct plating and finally enriching samples. Beef shoulder clods were purchased and used to simulate dry aging. The product was cut into 10 cm × 10 cm blocks before inoculating both fat and lean surfaces with a cocktail mixture containing two strains of Listeria monocytogenes and five strains of Salmonella at a rate of 103 CFU/cm2. Blocks were allowed to dry for 15 min between inoculation of sides and before suspension in a refrigerator (4°C) with a circulating fan and 70–80% humidity. Surfaces were removed at a depth < 5mm for collection and plating on selective media at 0, 1, 7, 14, 21, and 28 d post inoculation. Two sides of six blocks were used at each time point; the experiment was replicated a second time. Data were analyzed to test the effect of time, side, and their interaction for each pathogen; replication was a random variable.ResultsSamples collected in a commercial facility showed no occurrence of E. coli O157:H7 or Salmonella, but three presumptive Listeria monocytogenes colonies were found in the quantitative analysis. The plant does not process ready-to-eat products, the main concern with Listeria monocytogenes. Since all product will be trimmed and cooked prior to consumption, and with the low amount of Listeria monocytogenes, the risk associated with Listeria monocytogenes is relatively low. To validate use of the dry aging treatment on sub-primals to be used for ground beef, the microbial population of the key pathogens used during inoculation must not increase over the treatment period. Salmonella levels on d 1 and 14 were similar (P = 0.53), but numerically less than d 0, and lower (P = 0.0028) on d 1, 21, and 28. There was an effect of side of inoculation; the fat side had significantly higher (P = 0.046) Salmonella levels over the duration of the study. This suggests that Salmonella may have had slightly better attachment to fat at inoculation, but it had no bearing on growth dynamics thereafter. There was no day by side interaction detected (P = 0.51). Listeria monocytogenes showed a similar overall trend; counts were similar on d 7, 14, and 21 (P = 0.079), and numerically less than d 0, whereas counts were lower (P = 0.014) on d 1 and 28. No effect of side (P = 0.21) or a day by side interaction (P = 0.66) were observed.ConclusionOverall, Salmonella and Listeria monocytogenes did not increase during the 28d aging period, indicating that dry-aged beef trim is not higher risk than fresh beef trim. Thus, additional risk mitigation steps may not be necessary during processing of dry aged versus fresh ground beef.

The objective was to compare growth performance, belly characteristics, and bacon slicing yields of growing-finishing pigs fed a subtherapeutic dose of an antibiotic, a natural antimicrobial, or a diet containing no antibiotics or antimicrobials. Barrows and gilts (96 each, initial BW: 27.52±3.98kg) were housed in 48 pens (8 replications per treatment) in a 2×3 factorial randomized complete block design. Pens were assigned 1 of 3 diets: antibiotic free, oregano or tylosin phosphate. Pigs were slaughtered at an average BW of 127.31±10.18kg. There were no differences among dietary treatments for growth performance (P≥0.06), carcass cutability (P≥0.42), loin quality (P≥0.28), fresh belly dimensional characteristics (P≥0.11), IV (P≥0.87) or bacon processing characteristics (P≥0.07). Given the lack of differences in meat quality from pigs fed diets without antibiotics, the implementation of VFD in the United States should not result in changes in pork quality.

ObjectivesThe objectives were to: 1) evaluate changes in pork quality parameters during postmortem aging, 2) correlate early postmortem loin quality parameters with aged loin quality parameters, and 3) determine the predictive ability of early postmortem loin quality parameters on aged color and marbling as well as sensory tenderness, juiciness, and flavor using meta- and holo-analysis techniques.Materials and MethodsEleven independent experiments were selected for inclusion in the analysis. Inclusion criteria included studies where pigs were slaughtered at a commercial facility, loins were evaluated on the ventral surface of the loins on d 1 postmortem, and then again after an aging period that ranged from 12 to 28 d. Data sets encompassed approximately 3957 loins. The effects of aging on ventral loin surface quality was determined using a paired-t test. Pearson correlation coefficients within original data sets were calculated and then sample-weighted mean correlations (r) and variances [Var(r)] were calculated across data sets. Stepwise regression, using a holo-analysis approach, was used to determine the predictive ability of early postmortem ventral color, marbling, firmness, and pH on sensory ratings.ResultsVentral loin surfaces became 8% lighter (P < 0.0001), 44.5% redder (P < 0.0001), and 46% more yellow (P < 0.0001) during the aging period. Therefore, it was apparent that loin quality changes during postmortem aging. Because of this, it was necessary to determine the correlation between early and aged pork quality parameters. Early postmortem ventral instrumental lightness (L*) was moderately correlated with aged ventral L* (r = 0.50), aged ventral visual color (r = –0.38), aged chop face (freshly cut) L* (r = 0.44), and aged chop face visual color (r = –0.38). Early postmortem ventral instrumental redness (a*) was moderately correlated with aged ventral a* (r = 0.49) and aged chop face a* (r = 0.46). Early postmortem ventral visual color was moderately correlated with aged ventral L* (r = –0.51), aged ventral color (r = 0.50), aged chop face L* (r = –0.43), and aged chop face visual color (r = 0.43). However, no instrumental or visual color parameters were moderately or strongly correlated to instrumental tenderness or sensory panel ratings of tenderness or juiciness (|r| ≤ 0.36). Early postmortem ventral visual marbling was moderately correlated with aged ventral marbling (r = 0.63) and aged chop face visual marbling (r = 0.56). Visual marbling was not (|r| ≤ 0.12) correlated to instrumental tenderness or sensory panel ratings of tenderness and juiciness. The combination of color, marbling, firmness, and pH were poor predictors (R2 ≤ 0.13) of sensory tenderness (R2 = 0.13) and juiciness (R2 = 0.09), but were moderately predictive of sensory flavor (R2 = 0.28).ConclusionEarly postmortem color and marbling are important pork quality traits in consumers purchasing decisions, but are poorly related to traits associated with eating experience.

The objective of this study was to determine the relative effects of the porcine IGF2 mutation (IGF2-G3072A) and a novel, gene-editing derived myostatin loss-of-function (LOF) mutation on carcass traits and meat quality in pigs. The hypothesis was that both the IGF2 paternal A allele (Apat) and myostatin LOF mutation would increase muscle growth in pigs, but may potentially reduce loin and belly quality. Pigs were either IGF2 paternal G allele (Gpat) and wild-type (WT) for myostatin (n=13), Gpat and heterozygous (HET) for myostatin (n=10), Apat WT (n=11) or Apat HET (n=10). Pigs were raised in mixed sex pens of 10-15 pigs per pen, given free access to a diet that met or exceeded NRC nutrient requirements, and slaughtered at 175 d (±5 d) of age. Loin eye area and back fat depth was measured. Loin and belly quality was measured on the left side of the carcass. Warner-Bratzler shear force (WBSF) was used to determine tenderness of loin chops d14 postmortem. Data were analyzed using the MIXED procedure of SAS with a model including the effects of sex, IGF2, myostatin, and all interactions; means were separated using the pdiff option and considered different when P≤0.05. Ending live weight and hot carcass weight were similar among all genotypes (P≥0.05). Loin eye area was greater (P≤0.05) in HET pigs regardless of IGF2 genotype compared with WT pigs, and tended (P=0.10) to be greater in IGF2 Apat WT pigs compared with Gpat WT pigs. Back fat depth was similar (P≥0.05) among all genotypes. Longissimus dorsi (LD) muscle weighed less (P≤0.05) in WT Gpat pigs in comparison with all other genotypes, and was larger (P≤0.05) in Apat HET pigs compared with Apat WT pigs. Loins from myostatin HET pigs were paler than those from WT pigs, regardless of IGF2 genotype, as evidenced by an increased L* value of approximately 5 units (P< 0.01). However, L* of IGF2 Apat (52.1) and Gpat (53.9) pigs were similar (P≥0.05). Tenderness (WBSF) was similar (P≥0.05) among all genotypes. Bellies from IGF2 Gpat pigs were firmer as indicated by an increased (P<0.05) flop distance compared with all other genotypes. These data suggest that the partial loss of myostatin (HET) increased lean muscle deposition in pigs but resulted in poorer loin color. The IGF2 Apat mutation also tended to increase lean muscle deposition but did not negatively impact loin color. However, both mutations resulted in poorer belly firmness. The objective of this study was to determine the relative effects of the porcine IGF2 mutation (IGF2-G3072A) and a novel, gene-editing derived myostatin loss-of-function (LOF) mutation on carcass traits and meat quality in pigs. The hypothesis was that both the IGF2 paternal A allele (Apat) and myostatin LOF mutation would increase muscle growth in pigs, but may potentially reduce loin and belly quality. Pigs were either IGF2 paternal G allele (Gpat) and wild-type (WT) for myostatin (n=13), Gpat and heterozygous (HET) for myostatin (n=10), Apat WT (n=11) or Apat HET (n=10). Pigs were raised in mixed sex pens of 10-15 pigs per pen, given free access to a diet that met or exceeded NRC nutrient requirements, and slaughtered at 175 d (±5 d) of age. Loin eye area and back fat depth was measured. Loin and belly quality was measured on the left side of the carcass. Warner-Bratzler shear force (WBSF) was used to determine tenderness of loin chops d14 postmortem. Data were analyzed using the MIXED procedure of SAS with a model including the effects of sex, IGF2, myostatin, and all interactions; means were separated using the pdiff option and considered different when P≤0.05. Ending live weight and hot carcass weight were similar among all genotypes (P≥0.05). Loin eye area was greater (P≤0.05) in HET pigs regardless of IGF2 genotype compared with WT pigs, and tended (P=0.10) to be greater in IGF2 Apat WT pigs compared with Gpat WT pigs. Back fat depth was similar (P≥0.05) among all genotypes. Longissimus dorsi (LD) muscle weighed less (P≤0.05) in WT Gpat pigs in comparison with all other genotypes, and was larger (P≤0.05) in Apat HET pigs compared with Apat WT pigs. Loins from myostatin HET pigs were paler than those from WT pigs, regardless of IGF2 genotype, as evidenced by an increased L* value of approximately 5 units (P< 0.01). However, L* of IGF2 Apat (52.1) and Gpat (53.9) pigs were similar (P≥0.05). Tenderness (WBSF) was similar (P≥0.05) among all genotypes. Bellies from IGF2 Gpat pigs were firmer as indicated by an increased (P<0.05) flop distance compared with all other genotypes. These data suggest that the partial loss of myostatin (HET) increased lean muscle deposition in pigs but resulted in poorer loin color. The IGF2 Apat mutation also tended to increase lean muscle deposition but did not negatively impact loin color. However, both mutations resulted in poorer belly firmness.

Improving the sustainability of livestock production has come under increasing producer, consumer, and regulatory scrutiny. Sustainability of livestock production is difficult to define with environmental, economic, and societal aspects. Although life cycle assessments and environmental emission testing are direct measures of environmental sustainability, production efficiencies such as feed efficiency and lean meat yield are also important measures of the sustainability of meat production. The public has also become increasingly wary of technology use in livestock and meat production. Therefore, it is important to assess and report the sustainability impacts of current and emergent technologies. Multiple projects in our laboratory have focused on this area of research. Immunological castration (Improvest; Zoetis, Kalamazoo, MI) provides an alternative to physical castration (PC) for the reduction of boar odor while improving feed efficiency and ADG. Less is known however about the effects of Improvest on lean meat yield and value given the wide range of production factors in the finisher known to affect carcass attributes. The objectives of this study were to determine average effects of immunological castration (IC) on primal yield through a meta-analysis of the literature. Carcasses of IC barrows demonstrated a 1.24 unit improvement (P < 0.001) in carcass cutting yield compared with carcasses from PC barrows. From a sustainability perspective, increased carcass cutting yield results in more edible meat produced from an animal suggesting overall improvements in sustainability of pork production with this technology. Metabolic modifiers such as ractopamine hydrochloride (RAC) have historically been used to increase feed efficiency and lean meat yield of cattle, pigs, and turkeys. While increasing efficiency and lean meat yield will improve sustainability, the direct effects of RAC usage in cattle on environmental emissions have been less well established. Therefore, our objective was to evaluate the effects of ractopamine hydrochloride on N excretion of finishing steers. Two blocks of 6 Angus × Simmental steers (N = 12) were fed a control or RAC diet and housed in metabolism stalls for total collection of feed, orts, feces and urine. Nitrogen balance analyses demonstrated feeding RAC resulted in a 13% reduction (P = 0.02) in total N excretion over the 35 d feeding period. Reductions in N excretion were observed with numerical improvements in LM area suggesting greater N incorporation in the form of increased protein accretion. Therefore, RAC usage in cattle can directly result in reduced environmental nitrogen emissions.

The objective was to assess requirements for RDP in growing beef cattle based on the 2016 Beef Cattle Nutrient Requirements Model. Six Simmental x Angus steers (BW = 324 ± 22 kg) with ruminal and duodenal cannulas were used in a replicated 3 × 3 Latin square design. Periods were 18 d with 13 d for adaptation and 5 d for total collection of feed, fecal, and urine samples. Blood urea N (BUN), ruminal pH, and ruminal NH3 samples were collected on d 18. Steers were limit fed (2.3% of BW) diets with varying inclusions of urea formulated to be deficient in RDP (Low-RDP; CP = 13.2%; RDP = 5.5%), meet RDP requirements (Req-RDP; CP = 15.2%; RDP = 7.7%), or exceed RDP requirements (Hi-RDP; CP = 17.5%; RDP = 10.0%). While DMI was not affected (P = 0.20) by treatment, N intake increased (P < 0.01) with greater dietary RDP. Fecal N was not different (P = 0.69) across treatments, but steers fed the Hi-RDP diet had greater (P < 0.01) urine N compared with steers fed Req-RDP and Low-RDP diets. Steers fed Hi-RDP had greater (P = 0.01) apparent N digestibility than steers fed Low-RDP diets, with steers fed Req-RDP being intermediate and not different (P ≥ 0.10) from other treatments. Absorbed N was affected by treatment (P > 0.01) and increased with greater RDP. Retained N as a percentage of N absorbed was least (P ≤ 0.03) in Hi-RDP steers and did not differ (P = 0.99) between Req-RDP and Low-RDP steers. Retained N (P = 0.36), apparent dry matter digestibility (P = 0.4) and organic matter digestibility (P = 0.36) did not differ between treatments. A treatment × hour effect (P < 0.01) was observed for ruminal NH3 as steers fed Hi-RDP diets had the greatest (P < 0.05) NH3 1, 2, 4, 8, and 12 h after feeding with steers fed Req-RDP being intermediate (P ≤ 0.05) at h 1 and 2. There was a treatment × hour effect (P < 0.01) for BUN as the greatest (P < 0.05) concentrations were observed in steers fed Hi-RDP at h 0 and h 4 with steers fed Req-RDP being intermediate (P ≤ 0.05) at h 4. Feeding steers Low-RDP resulted in decreased ruminal ammonia and BUN. Dietary RDP provided above requirements resulted in greater excretion of urine N that did not contribute to additional N retention.

ObjectivesIncreased intake of dietary sodium has been linked to hypertension and increased risk of heart disease. However, reduction of salt, specifically sodium chloride, in processed meat products can adversely affect production yield, flavor, and food safety. Because salt inclusion in bacon has both positive and negative effects on yield and quality, the objective was to determine the effects of salt level on processing yield, lipid oxidation, and sensory characteristics of bacon. Materials and MethodsBellies (N = 144) were selected within a specified weight range (5.8 to 6.6 kg) from 2 different sources (72 each). Within source, 24 bellies were randomly assigned to 1 of 3 targeted salt levels (food grade salt) in the final product: 1.2, 1.5, or 1.8%. Individual sliced weight of each bacon slab was recorded to calculate commercial slicing yield [(bacon sliced weight / bacon cooked weight) × 100]. Bacon samples, used for TBARS analysis, were stored at –29°C for approximately 0, 30, 60, or 90 d. Thirty-six samples (108 total) were randomly selected from each of the 3 salt treatment groups for sensory determination of saltiness, oxidized flavor, and oxidized odor, using a trained sensory panel. Initial sensory analyses were conducted at approximately 0 d and final sensory analyses were conducted at approximately 90 d after initial sensory analyses. Data were analyzed as a one-way ANOVA randomized complete block design. The model included fixed effect of salt inclusion level and random effect of source. Data for TBARS and sensory analysis were analyzed using repeated measures on the same experimental unit (cured belly) over time. The model included fixed effects of salt inclusion, storage time, and their interaction. Source was included as a random variable. A Tukey’s adjustment was used to adjust for multiple comparisons. ResultsPump uptake (%) was approximately 1 unit greater (P ≤ 0.01) in 1.2% bellies compared with 1.5% and 1.8% bellies, which were similar to each other. Cooked slicing yield (%) was 2.9 units greater (P < 0.01) in the 1.8% bellies compared with the 1.2% bellies, but neither were different from 1.5% bellies. As salt inclusion increased, sensory saltiness scores increased (P ≤ 0.05) during both initial and final sensory analyses. Conversely, oxidized flavor and oxidized odor did not differ among treatments for either time point. Furthermore, lipid oxidation (TBARS) was not different among salt treatment levels within any storage period. ConclusionIncreasing salt inclusion from 1.2 to 1.8% increased bacon slicing yield, slice count, and perceived saltiness of bacon, but did not affect oxidized odor, oxidized flavor, or TBARS regardless of salt inclusion level. Overall, reduction of salt content can adversely affect slicing yield, but does not affect cooked yield nor reduce the rate of lipid oxidation of bacon.

The emergence of branded beef programmes has had tremendous impact on the beef industry worldwide. As a means to ensure consumer satisfaction and as a tool for differentiation, branding strategies have changed over the years, yet the basic principles of a successful beef brand have not. This chapter will discuss the factors that define successful brands, history and growth of branded beef programmes, the effects of brands on consumer perception, changing consumer demands, including natural and organic beef, international beef branding trends and the role of technology in improving the position of branded beef programmes.

Rapid assessment of pork quality by packers necessitates using early postmortem (∼1 d) traits as an indication of aged pork quality (∼14 d). Efforts have been made to develop a grading system based on color and marbling of the ventral side of boneless loins. In order for this system to be successful, there must be a correlation between early postmortem quality traits observed by packers and the same traits observed by consumers after aging. However, the strength and direction of those correlations are unclear. It is also unknown if the correlations between early and aged postmortem quality differ between barrows (B) and gilts (G). Therefore, the objectives were to determine correlations between early postmortem loin quality characteristics and aged loin quality characteristics, and determine if those correlations differed between barrows and gilts. Early postmortem (∼1 d) quality traits included: instrumental and subjective color, marbling and firmness, and loin pH on the ventral surface of the loin. Loins were aged until 14 d postmortem in vacuum packages. Aged quality traits included traits evaluated early as well as shear force and cook loss. Correlations were compared between barrows and gilts using a Fisher's z test. Overall, early subjective firmness scores of barrows were greater (P < 0.001) than those of gilts. No other early quality traits differed between sexes. Early pH was correlated with aged pH (r = 0.80 B; 0.75 G), ventral lightness (r = -0.57 B; -0.54 G), ventral yellowness (r = -0.55 B; -0.55 G), subjective ventral color (r = 0.55, B; 0.41 G), and subjective chop color (r = 0.42 B; 0.44 G). Correlations of early pH and aged quality did not differ between sexes. Early lightness was correlated with aged ventral pH (r = -0.56) and subjective color (r = -0.39) in barrows but not gilts (P ≤ 0.04). Early lightness was correlated with aged lightness (r = 0.60 B; 0.51 G) and yellowness (r = 0.49 B; 0.55 G), but was not correlated with to any aged chop quality traits. Early marbling was correlated with ventral color (r = 0.42) in barrows and ventral marbling (r = 0.67 B; 0.66 G) and chop marbling (r = 0.57 B; 0.59 G) in barrows and gilts. In summary, early pH and lightness were correlated with aged quality characteristics and correlations rarely differed between barrows and gilts. Sex does not need to be accounted for when relating early and aged quality characteristics.

ObjectivesA key challenge facing the pork industry is the lack of insight on the relationship of pork primal quality. It is uncertain whether pigs that produce high quality loins will also produce high quality hams and bellies. Thus, the objective of this study was to correlate fresh loin quality with fresh belly quality and fresh and processed ham quality.Materials and MethodsData were collected on 7,684 pigs (94.50 ± 9.39 kg hot carcass weight) that were housed in 8 different barns. Four barns of pigs (n = 4,290) were raised and slaughtered during the cold season and four barns of pigs (n = 3,394) were raised and slaughtered during the hot season. Within season, 2 barns of pigs were raised on farms focused on lean growth (n = 1,491 in the hot season, n = 2,136 in the cold season) and 2 barns of pigs were raised on farms focused on meat quality (n = 1,903 in the hot season, n = 2,154 in the cold season). A target of 100% of the pigs were evaluated for carcass composition, ham instrumental color, and subjective loin quality. Other loin and belly quality characteristics were evaluated on a target of 50% of the population, and 10% of pigs were targeted for slice shear force (SSF), ham weight, and processed ham characteristics. Temperature decline curves for the longissimus dorsi and semimembranosus were evaluated on 10% of the population. Pearson correlation coefficients between loin quality and other carcass quality and composition traits were computed using the CORR procedure of SAS (SAS Inst. Inc., Cary, NC).ResultsEquilibration of ambient temperature to longissimus dorsi temperature occurred at 15 h postmortem (P = 1.00), yet the semimembranosus had not equilibrated with ambient temperature (P < 0.0001) at 22 h postmortem. Boneless loin weight was correlated (P < 0.0001) with increased HCW (r = 0.723), belly weight (r = 0.476), 1 d ham weight (r = 0.706), and cooked ham weight (r = 0.648), but was not correlated with cooked ham yield (P = 0.68). Loin ultimate pH (24 h) correlated (P < 0.0001) with semimembranosus pH (r = 0.333), and percent moisture of the ham (r = 0.153). Loin L* correlated (P ≤ 0.01) with L* of the gluteus profundis (r = 0.154), gluteus medius (r = 0.329), semimembranosus (r = 0.312), and cured ham (r = 0.111). Loin SSF was correlated with belly flop score (r = -0.348; P < 0.0001), but not with ham bind strength (P = 0.94).ConclusionPrimal weights were correlated with other primal weights. However, correlations between loin quality and belly and fresh and processed ham quality were weak. Differences in chilling rates between the loin and ham may have contributed to weak relationships. Using loin quality to draw conclusions about fresh belly and fresh and processed ham quality may be misleading. This project was funded, in part, by The Pork Checkoff.

ObjectivesThe tenderness of meat is instrumentally determined via Warner-Bratzler shear force (WBSF) and slice shear force (SSF) tests. These instrumental tenderness tools are frequently used as a means to predict sensory tenderness. Therefore, the objective was to determine the strength of relationships between WBSF, SSF and sensory evaluation.Materials and MethodsDietary treatments and different endpoint cooking temperatures were used a means of increasing variation in tenderness. Strip steaks were collected from 12 Angus × Simmental cross steers where half received a control diet (CON) and half were fed a diet including 400 mg·animal-1·d-1 RAC ractopamine hydrochloride (RAC, Actogain) for 35 d prior to slaughter. Carcasses were aged 14 d prior to removal of strip steaks posterior to the 12th and 13th rib interface. Two 2.5-cm thick steaks per degree of doneness (DoD) treatment (63°C, medium-rare and 71°C, medium) were cut and assigned to SSF, WBSF, and trained sensory panel analyses. Steaks were weighed and cooked to an internal temperature of 63°C or 71°C. After cooking, steaks were allowed to equilibrate to 22°C before shear force tests were performed. Cook loss was calculated as [(weight of raw steak, g- weight of cooked steak, g)/weight of raw steak, g] ×100. Trained panelists were asked to evaluate tenderness and juiciness of steak samples using a 15-cm anchored scale (0 = not tender or juicy and 15 = extremely tender or juicy). Data were analyzed as a 2 × 2 factorial, in split-plot design, using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC) with diet as the whole-plot factor and DoD as the split-plot factor. Pearson correlation coefficients between SSF, WBSF, and sensory attributes were computed using the CORR procedure. Treatment differences were considered significant and correlations were considered different from 0 at P ≤ 0.05.ResultsThe association between sensory tenderness and instrumental tenderness was substantiated by the correlation between panel tenderness and SSF (r = –0.66) and WBSF (r = –0.46). Sensory juiciness was also related to SSF (r = –0.42), however sensory juiciness was not related to WBSF (P ≥ 0.31). Despite differences between the correlations of SSF and WBSF with sensory analyses, the 2 instrumental tenderness measures were correlated (r = 0.47). Cook loss and panel juiciness were also correlated (r = –0.46). Steaks from RAC fed steers had greater SSF values (P = 0.05, 22.42 vs. 18.28 kg) than from CON fed steers, however RAC had no effect on WBSF (P = 0.97, 2.97 vs. 2.96 kg). Similar to WBSF, RAC usage had no effect (P = 0.13) on panel tenderness ratings. Steaks cooked to 63°C were more juicy (P ≤ 0.01, 7.24 vs. 8.38) than those cooked to 71°C. Similar to panel ratings for juiciness, steaks cooked to 63°C had less cook loss (P ≤ 0.01, 18.64 vs. 23.66) than steaks cooked to 71°C. However, DoD had no effect (P = 0.15) on panel tenderness ratings.ConclusionIn a group of cattle that would generally be considered tender, decreasing cooking DoD did not further improve sensory tenderness. However, cooking steaks to a lower DoD did improve in sensory juiciness. In this study, SSF values were more closely related to panel tenderness and juiciness ratings than WBSF. Therefore, given the throughput advantages of SSF over WBSF, SSF is the favorable choice for instrumental tenderness evaluation under these experimental conditions.

ObjectivesPork loins are often sorted during fabrication of carcasses based on visual appraisals of color, marbling and firmness, but it is unclear whether these early postmortem traits are related to quality traits observed by consumers. Furthermore, it is also unknown whether the relationships between early and aged postmortem quality differ between barrows and gilts.The objectives were to 1) determine correlations between early postmortem loin quality characteristics and aged loin quality characteristics, and 2) determine if those relationships differed between barrows and gilts.Materials and MethodsEarly and aged loin quality evaluations were collected on 133 barrows and 195 gilts killed on 3 different days. Pigs were transported approximately 195 km to a commercial slaughter facility and held in lairage for a minimum of 3 h. Pigs were immobilized via carbon dioxide gas, and carcasses were blast chilled for 90 min. Loin pH and back fat thickness were measured at the midline of the 10th rib. Early quality measures (1 d postmortem) included 1 d postmortem pH, instrumental color (L*, a*, b*), and subjective color, marbling, and firmness from the ventral surface of boneless loins. Loins were vacuum-packaged and aged 14 d at 4°C. Then, loins were removed from packaging, exposed to oxygen, and reevaluated on the ventral surface for the same loin quality traits (aged quality). Aged loins were sliced into 25 mm thick chops, allowed to bloom, and color measurements were taken from the chop-face. Chops were cooked to an internal temperature of 68°C for Warner Bratzler shear force (WBSF) and cook loss. Pooled correlations between sexes for early postmortem and aged quality characteristics were calculated using the CORR procedure of SAS (SAS Inst. Inc., Cary, NC). To assess differences in relationships between barrows and gilts, comparison of independent correlation coefficients was conducted. Correlations were considered different from 0 and relationships between barrows and gilts were considered different at P ≤ 0.05.ResultsBarrows were heavier, fatter, and had loins that were lighter as a percentage of HCW compared with gilts (P ≤ 0.01). One d postmortem pH was correlated (P ≤ 0.01) with aged ventral color (r = 0.46), aged chop color (r = 0.42), cook loss (r = –0.33) and WBSF (r = 0.16). However, these relationships did not differ (P ≥ 0.11) between barrows and gilts. Early ventral L* was correlated to aged ventral L* (r = 0.55) and WBSF (r = –0.24), but not with chop L* (r = 0.06) or cook loss (r = 0.05). Early ventral a* was correlated to aged ventral a* (r = 0.17), chop a* (r = 0.28), and cook loss (r = –0.25), but not with WBSF (r = –0.04). None of these relationships differed (P ≥ 0.41) between barrows and gilts.ConclusionOne d postmortem pH was correlated with color, water-holding capacity, and tenderness. Early ventral color measurements were correlated with aged ventral color measurements and tenderness, but not with chop color. Therefore, 1 d postmortem pH, L*, and a* could be used as indicators of aged color and tenderness. Given that there were no differences in early and aged postmortem relationships between barrows and gilts, sex does not need to be accounted for when using these early quality traits to predict aged quality.

ObjectivesImmunological castration (with Improvest, gonadotropin releasing factor analog-diphtheria toxoid conjugate) provides an effective alternative to physical castration. Although meta-analyses have been conducted to evaluate the effects of immunological castration (IC) on live performance, these reviews have not evaluated the effects on carcass cutability and belly quality. Therefore, the objective was to evaluate the value of Improvest through a meta-analysis of carcass attributes.Materials and MethodsPigs in all studies were administered Improvest according to manufacturer’s recommendations. To ensure relevance to U.S. packers, only studies utilizing U.S. cutting standards were included. A total of 7 studies were used to determine the effect of Improvest on carcass cutability and belly quality characteristics. Lean cutting yield (LCY) was defined as: LCY = [carcass cutting yield components- natural fall belly)/chilled side wt] × 100. Carcass cutting yield (CCY) was determined using the following equation: CCY = [(whole ham + trimmed loin + Boston butt + picnic + natural fall belly + spareribs)/chilled side wt] × 100. To evaluate the effects of HCW of IC barrows on carcass cutting yields, IC barrows were grouped by HCW as light (< 90.9 kg), average (90.9 to 97.7 kg), or heavy (> 97.7 kg). The effect of HCW in PC barrows was not estimated. Belly thickness was calculated as the average of eight individual thickness measurements. Commercially processed bacon slicing yield was determined using the equation: No. 1 slice yield = (sliced wt/cooked wt of belly) × 100. A 5 yr average of primal prices was used to calculate total value difference between carcasses of equal weights from IC and PC barrows using carcass cutting yield estimates from this meta-analysis. Data were analyzed using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC) with fixed effects of Improvest treatment or HCW group. Study was included as a random effect.ResultsLean cutting yield of IC barrows was 1.39% units greater (P < 0.0001) than PC barrows (70.89 vs. 69.50%). Similarly, CCY of IC barrows was 1.23% units greater (P < 0.001) compared with physically castrated (PC) barrows (86.80 vs. 85.56%). Therefore, based on CCY, value of IC barrows was increased by $2.44 compared with PC barrows. As HCW of IC barrows increased, both CCY and LCY declined linearly (L; P < 0.01), with lighter IC barrows having a 1.46% unit advantage in CCY compared with heavy IC barrows (P < 0.01). Natural fall bellies of PC barrows comprised a greater (P < 0.05) percentage of side weight than those from IC barrows (15.80 vs. 15.50%). Bellies from IC barrows were thinner (P < 0.0001) than PC barrows, but thicker (P < 0.03) than gilts (3.55 vs. 3.83 and 3.23 cm). Slicing yield of bacon from IC barrows was 3.43% less (P < 0.0001) compared with PC barrows (84.24 vs. 87.66%). However, belly yield and slicing yield differences were minimized when IC barrows were marketed at a heavier weight.ConclusionImprovest increased CCY and LCY compared with PC barrows. However, this cutability advantage decreased as IC barrows were slaughtered at heavier weights. Bellies from IC barrows were thinner and had reduced bacon slicability compared with bellies of PC barrows, however these differences were minimized when IC barrows were slaughtered at heavier weights.