The objective of this research was to determine the effects of mid-gestational maternal inflammation on performance, carcass characteristics, and meat quality of offspring. Pregnant gilts were administered either lipopolysaccharide (LPS; n = 7) or saline (CON, n = 7) from days 70 to 84 of gestation. Gilts assigned to the LPS treatment were administered an intravenous injection of reconstituted LPS every other day with a beginning dose of 10 mu g LPS/kg body weight and subsequent doses increasing by 12%, while CON gilts received intravenous injections of comparable volumes of saline. Gilts farrowed naturally, and at day 66 of age, a total of 59 pigs, both barrows and gilts began a 3-phase feeding regimen designed to meet or exceed nutrient requirements for growing-finishing pigs. Pigs were weighed on days 0, 35, 70, and 105 of the finishing trial to determine average daily gain, average daily feed intake, and gain-to-feed ratio (G:F). On day 106, pigs were slaughtered under the supervision of the U.S. Department of Agriculture Food Safety Inspection Service. Ending live weight, hot carcass weight, and dressing percentage were determined. The left side of carcasses was weighed and fabricated to determine carcass cutting yields. The semitendinosus was collected for histological samples. Fresh belly characteristics and loin quality were measured. Two chops were collected for Warner-Bratzler shear force and proximate analysis. No differences (P >= 0.13) between LPS and CON pigs were observed for growth performance in phases 1, 2, 3, or overall (days 0 to 105) performance with the exception of overall G:F reduced in CON pigs compared with LPS pigs (P = 0.03). There was a tendency for carcass yield to be reduced (P = 0.06; 0.82% units) in LPS pigs compared with CON pigs. Additionally, longissimus muscle area tended to be reduced (P = 0.10) 2.27 cm2 in LPS compared with CON pigs. Loin chop quality traits including instrumental color, subjective color, marbling, firmness, pH, and drip loss were not different (P >= 0.09) between LPS and CON pigs. Fresh belly characteristics were not different (P >= 0.22) between LPS and CON pigs. There were no differences in primal and subprimal weights, except that LPS pigs tended to have a reduction (P >= 0.07) in tenderloin and Canadian back weights compared with CON pigs. Furthermore, LPS pigs had no differences (P >= 0.25) in muscle fiber composition or size; however, LPS pigs tended (P = 0.10) to have a 13% reduction in estimated muscle fibers number compared with CON pigs. In summary, mid-gestational inflammation did not result in reduced meat quality, growth performance, or carcass yields of offspring. An acute maternal inflammatory challenge during mid-gestation tended to reduce muscle fiber number in the offspring, but did not impact growth performance, carcass characteristics, or overall pork quality. Gestation is a crucial time for communicating the outside environment to the fetus. Any influence on the fetus during gestation may have lifelong effects on the offspring. Most muscle fiber formation occurs in the beginning of the third trimester of gestation. Therefore, maternal inflammation during this period may be detrimental to fetal muscle development, which can ultimately stunt growth potential and influence carcass characteristics and meat quality. A majority of previous research that investigates maternal inflammation as a result of innate immune activation focuses on neuropsychiatric disorders in the offspring, offering little relevance to animal agriculture. The influence of maternal infection on long-term growth performance, carcass characteristics, and meat quality has received little attention. Therefore, the objective of this study was to elucidate the impact of maternal inflammation on offspring growth, efficiency, carcass characteristics, and pork quality. The gestational challenge resulted in pigs that tended to have fewer total muscle fibers. However, gestational inflammation did not have an impact on overall growth performance, carcass characteristics, or pork quality of the offspring.

The objective was to determine the effects of maternal inflammation on offspring muscle development and postnatal innate immune response. Sixteen first-parity gilts were randomly allotted to repeated intravenous injections with lipopolysaccharide (LPS; n = 8, treatment code INFLAM) or comparable volume of phosphate buffered saline (CON, n = 8). Injections took place every other day from gestational day (GD) 70 to GD 84 with an initial dose of 10 mu g LPS/kg body weight (BW) increasing by 12% each time to prevent endotoxin tolerance. On GD 70, 76, and 84, blood was collected at 0 and 4 h postinjection via jugular or ear venipuncture to determine tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-1 beta concentrations. After farrowing, litter mortality was recorded, and the pig closest to litter BW average was used for dissection and muscle fiber characterization. On weaning (postnatal day [PND] 21), pigs were weighed individually and 2 barrows closest to litter BW average were selected for another study. The third barrow closest to litter BW average was selected for the postnatal LPS challenge. On PND 52, pigs were given 5 mu g LPS/kg BW via intraperitoneal injection, and blood was collected at 0, 4, and 8 h postinjection to determine TNF-alpha concentration. INFLAM gilt TNF-alpha concentration increased (P < 0.01) 4 h postinjection compared to 0 h postinjection, while CON gilt TNF-alpha concentration did not differ between time points. INFLAM gilt IL-6 and IL-1 beta concentrations increased (P = 0.03) 4 h postinjection compared to 0 h postinjection on GD 70, but did not differ between time points on GD 76 and 84. There were no differences between INFLAM and CON gilts litter mortality outcomes (P >= 0.13), but INFLAM pigs were smaller (P = 0.04) at birth and tended (P = 0.09) to be smaller at weaning. Muscle and organ weights did not differ (P >= 0.17) between treatments, with the exception of semitendinosus, which was smaller (P < 0.01) in INFLAM pigs. INFLAM pigs tended (P = 0.06) to have larger type I fibers. INFLAM pig TNF-alpha concentration did not differ across time, while CON pig TNF-alpha concentration peaked (P = 0.01) 4 h postinjection. TNF-alpha concentration did not differ between treatments at 0 and 8 h postinjection, but CON pigs had increased (P = 0.01) TNF-alpha compared to INFLAM pigs 4 h postinjection. Overall, maternal immune activation did not alter pig muscle development, but resulted in suppressed innate immune activation.

The objective was to characterize the effects of increasing carcass weight on pork carcass characteristics and yields from traditional and alternative fabrication methods, as well as evaluate the size of novel retail cuts. Pigs (n = 85) were slaughtered and divided into 3 hot carcass weight (HCW) categories: Average (99 to 109 kg), Heavy (116 to 126 kg), and Very Heavy (134 to 144 kg). Loin muscle area (LMA) and back fat depth were measured on all carcasses. Paired right and left sides were fabricated traditionally and alternatively (shoulder separation at the 4th/5th rib), respectively. From the alternative side, the serratus ventralis (SV) was removed from the cellar-trimmed butt, and the triceps brachii (TB) was removed from the picnic shoulder. All individual primals and subprimals were weighed for yield calculations. Data were analyzed using the MIXED procedure in SAS including the main effect of weight class, with sex and sire line as fixed blocking effects. Differences were considered significant at P ≤ 0.05. Regardless of fabrication method, whole primal and subprimal weights increased (P < 0.01) in heavier carcass weight classes compared with lighter classes, but when expressed as a percentage of chilled side weight, these increases did not often translate into meaningful differences in distribution of carcass weight. While the alternative shoulder-loin separation reduced loin and belly length, loins and bellies from heavier carcasses weighed more than those from carcasses typically produced in the U.S. pork industry today. Serratus ventralis weight was increased (P < 0.01) approximately 0.28 kg from Average to Very Heavy, while the TB weight was increased (P < 0.01) approximately 0.24 kg from Average to Very Heavy. At heavier weights, alternative fabrication of carcasses yielded novel cuts from the shoulder including the SV and TB that were of size to warrant further exploration as retail offerings.

The objective of this study was to determine the effect of increasing hot carcass weight (HCW) on pork ham and belly processing characteristics. Pigs (n = 85) were slaughtered and divided into 3 HCW categories: Average (99 to 109 kg), Heavy (116 to 126 kg), and Very Heavy (134 to 144 kg). Fresh hams were fabricated and further processed as 3-piece (inside, outside, and knuckle) boneless cured hams. Fresh belly quality measurements were taken before bacon processing. Data were analyzed using the MIXED procedure in SAS including the main effect of weight class, with sex and sire line as random blocking effects. Means were considered significant at P <= 0.05. There were no differences (P = 0.08) in ham processing characteristics including pump uptake, retention, and cook yield. However, cured hams from heavier car- casses were less red and less yellow (P < 0.01). Heavier carcasses produced longer, thicker, and wider bellies (P < 0.01), but bellies did not differ in firmness (P = 0.16). Despite reduced pump uptake (P < 0.01), bellies from heavier carcasses had greater cooked yield than those from lighter carcasses (P < 0.01). Total area of sliced bacon increased with increasing carcass weight. Bacon slice lean area percentage decreased (P < 0.01) in bacon from Very Heavy carcasses compared to lighter carcasses. Iodine value was decreased (P = 0.04) approximately 2.5 units from 68.6 in fresh bellies from Average carcasses to 66.2 in bellies from Very Heavy carcasses. Overall, processing characteristics of hams and bellies were not impaired at heavier carcass weights, though the consumer acceptability of larger slices of bacon from heavier carcasses should be determined.

The objective of this study was to determine the effect of chronic inflammation during late gestation on offspring muscle development. Starting at gestational day (GD) 70, first-parity gilts were administered either lipopolysaccharide (LPS, n=7) or saline (CON, n=8) via jugular venipuncture every other day until GD 84. LPS was initially given at 10 µg/kg BW and was increased by 12% each instance of administration. Volume of PBS was increased accordingly. Rectal temperatures of gilts were collected at 0, 2, 3, and 4-h post injection. Gilts farrowed naturally at GD 114 (±2). At postnatal day (PND) 3, the pig closest to the average litter weight was euthanized, and the longissimus dorsi, psoas major, semitendinosus, heart, lungs, liver, and kidneys dissected and weighed. The semitendinosus was frozen in liquid N cooled-methylbutane and sectioned for muscle fiber typing analysis. Data were analyzed as a one-way ANOVA with cohort as a random effect and significance considered at (P ≤ 0.05). Gilts exposed to LPS had a 1.3°C increase in rectal temperature at 3 and 4-h post injection (P < 0.05), indicating successful induction of an inflammatory response. LPS exposure reduced (P = 0.04) the weight of piglets born alive and tended to reduce (P =0.09) the weight of piglets weaned, but did not alter the percent of pigs born alive or survival during the suckling period (P ≥ 0.29). Semitendinosus weight was also reduced (P < 0.01) in LPS pigs, and tended to be reduced (P =0.09) as a percentage of whole-body weight. However, there were no differences between treatments in any other tissues. Further, maternal LPS exposure did not alter fiber type proportions, average fiber area, or estimated number of fibers (P ≥ 0.17). Overall, these data indicate that chronic maternal LPS exposure during late gestation did not reduce offspring muscle fiber formation.

The goals of this study were to determine the impact of maternal PRRSV infection on offspring muscle and immune development and the potential of dietary soy isoflavones to mitigate those effects. Thirteen first-parity gilts ("gilts") were randomly allotted into one of three treatments: not infected and fed a diet devoid of isoflavones (CON), infected with porcine reproductive and respiratory syndrome virus (PRRSV) and fed the control diet (POS) or that supplemented with 1,500 mg/kg soy-derived isoflavones (ISF). Gilts were inoculated with PRRSV intranasally on gestational day (GD) 70. After farrowing (GD 114 ± 2), 1-2 offspring ("pigs") closest to the average litter weight were selected either at birth (3 ± 2 d of age) or weaning (21 ± 2 d of age) to determine body, muscle, and organ weights as well as muscle cell number and size. Four weaned pigs of average body weight within each litter were selected for postnatal immune challenge. At PND 52, pigs were injected with 5 µg/kg BW lipopolysaccharide (LPS) intraperitoneally. Serum was collected at 0, 4, and 8 h following LPS administration to analyze tumor necrosis factor alpha (TNF-α). At PND 59, pigs were administered a novel vaccine to elicit an adaptive immune response. At PND 59, 66, and 73, peripheral blood mononuclear cells were isolated and T-cell populations determined by flow cytometry. Both POS and ISF pigs exhibited persistent PRRSV infections throughout the study (PND 1-73). At PND 3, whole body, muscle, and organ weights were not different (P > 0.22) between groups, with the exception of relative liver weight, which was increased (P < 0.05) in POS compared with CON pigs. At PND 21, ISF pigs had reduced (P ≤ 0.05) whole body and muscle weights, but greater (P < 0.05) kidney weight compared with CON, and greater (P < 0.05) relative liver weight compared with CON and POS. Muscle fiber number and size were not different (P > 0.39) between groups at birth or weaning. After LPS administration, TNF-α was greatest in ISF pigs (P < 0.05) at both 0 and 8 h post-challenge. At the peak time-point of 4 h post-challenge, ISF pigs had the greatest concentration of TNF-α and CON pigs had the lowest, with POS pigs being intermediate (P = 0.01). After vaccination, ISF offspring had shifts in T-cell populations indicating an impaired immune response. These data indicate that maternal PRRSV infection may impact offspring organ growth and immune function, particularly when the dam is supplemented with isoflavones.

Gestational health challenges may influence growth performance and immunity of offspring pigs during postnatal life. In particular, porcine reproductive and respiratory syndrome virus (PRRSV) is endemic in the U.S. herd, but its effects on surviving piglets are largely unknown. Further, dietary supplementation with soy isoflavones lessened the severity of PRRSV infections in weaning and growing pigs. Therefore, the goals of this study were to determine the impact of maternal PRRSV infection on offspring muscle and immune development and the potential of isoflavones to mitigate those effects. Thirteen first parity gilts were randomly allotted to 1 of 3 treatments: fed a diet devoid of isoflavones and not infected (CON), fed the control diet and infected with PRRSV (POS), and fed the control diet supplemented with 1,500-ppm soy isoflavones and infected with PRRSV (ISF). Isoflavone supplementation reduced (P = 0.04) viral load in dams 21d after infection, but did not alter (P > 0.05) feed disappearance and rectal temperature. Piglet mortality was increased (P = 0.04) by PRRSV infection in dams, and surviving piglets were infected with PRRSV throughout the study. Interestingly, muscle and organ weights were not different (P > 0.05) among treatments at postnatal d (PND) 3 with the exception of relative liver weight which was increased (P = 0.04) in POS compared with CON, with ISF being intermediate. Infected litters were lighter (P = 0.02) at PND 21, likely due to postnatal infection. Interestingly, at PND 21 relative liver weight was increased (P < 0.01) in ISF compared with CON and POS. Muscle fiber number and size did not differ between treatments (P ≥ 0.39). Piglets born to infected dams had slower responses during innate immune stimulation (P < 0.01) and also had shifts in T cell populations compared with CON pigs (P ≤ 0.02), indicating an inadequate vaccine response. Overall, maternal infection altered offspring immune responses but not muscle fiber development. Isoflavone supplementation did not mitigate these effects.

The objective was to determine endpoint temperature and Warner-Bratzler shear force (WBSF) variability (range, coefficient of variation) differences in both pork and beef cooked using grilling and sous vide. Four 2.54-cm steaks were cut from 10 beef eye-of-round (semitendinosus) Choice-grademuscles (n= 40) and aged for 21 d. Four 2.54-cm chops were cut from 51 pork loins (n = 204) sourced from standard commercial pigs and aged for 7 d. Steaks and chops were randomly allotted within whole muscle to 4 treatments: grilled to 63°C, sous vide to 63°C, grilled to 71°C, and sous vide to 71°C. Four cores measuring 1.25 cm in diameter were excised parallel to the muscle fibers of each chop and steak respectively, and analyzed forWBSF. Temperature accuracy was defined as how close thermometer readings were to the targeted cooked temperature. Temperature precision was defined as how similar 2 thermometer readings within a single cut were to each other. WBSF accuracy was defined as how close individual core values were to the cut average. WBSF precision was defined as how similar individual core values were to each other. In both pork and beef, sous vide was more accurate (P< 0.01) and precise (P< 0.01) in achieving target endpoint temperature at both 63°C and 71°C. At 63°C, chops cooked using sous vide were more tender than grilled (P< 0.01), but at 71°C, chops cooked using sous vide were less tender than grilled (P< 0.01). Steaks cooked to 71°C using sous vide had the lowest core coefficient of variation, whereas other treatments were not different. Cooking method had no effect on averageWBSFwithin target endpoint temperature. Overall, these data indicate that sous vide is more precise and accurate in reaching target temperature but may decrease tenderness when used at 71°C in pork.

The objective was to determine the effect of maternal infection and dietary supplementation of isoflavones during gestation on offspring immune function. First parity gilts (n = 24) at gestational day (GD) 65 were allotted to one of three treatments: uninfected and fed a diet devoid of isoflavones (CON), infected with porcine reproductive and respiratory syndrome virus (PRRSV) and fed the control diet (POS), or infected with PRRSV and fed a diet supplemented with 1,500 ppm soy isoflavones (ISF). Gilts were inoculated intranasally with saline or 2.5×104 TCID50/mL of suspended live PRRSV (NADC20 strain) on GD 70. At farrowing, 4 offspring pigs weighing closest to the litter average were selected for postnatal immune challenges. Innate immunity was determined by serum TNF-α concentrations after lipopolysaccharide (LPS) injection (5 µg/kg BW) on postnatal d (PND) 52. Adaptive immunity was determined in the same pigs by peripheral T cell population shifts following vaccination against porcine circovirus-2 on PND 59. Whole blood was collected on days post-vaccination (DPV) 0, 7, and 14 for T cell phenotyping. In the innate immune challenge, all groups experienced increased TNF-α after LPS injection with peak response at 4 h, with ISF eliciting higher (P = 0.04) TNF-α concentrations than CON, and POS being intermediate. Also, ISF had higher (P < 0.01) TNF-α concentrations at both 0- and 8-h post-challenge compared with CON and POS. Prior to vaccination, ISF had elevated memory T cells and reduced total and naïve T cells (P ≤ 0.02). At DPV 14, the reduced total and naïve T cells persisted in ISF pigs. Overall, these data indicate that maternal PRRSV infection alone does not predispose pigs to an exaggerated immune response. However, maternal isoflavone supplementation during PRRSV infection altered offspring innate and adaptive immune responses.

The objective was to determine the effects of sous-vide cooking and degree of doneness on consumer eating experience of pork chops when cooked color was expected to differ. The hypothesis was consumers would prefer a cooked brown color and would rate grilled chops more acceptable than sous-vide chops. Chops were cooked to 63 °C or 71 °C using either an open-hearth grill or a sous-vide device. Participants evaluated four samples for tenderness, juiciness, flavor, and overall acceptability. Participants rated a greater percentage of chops cooked sous-vide at 63 °C as tender (82.82%), juicy (55.83%) and acceptable (60.34%) compared with all other cooking method and degree of doneness combinations. Participants rated a greater percentage of sous-vide chops as tender and acceptable compared to grilled chops. Participants rated a greater percentage of chops cooked to 63 °C as tender, juicy, flavorful, and acceptable when compared to 71 °C. Even when participants could visualize cooked color, they preferred chops cooked to 63 °C compared with chops cooked to 71 °C. Overall, participants preferred chops cooked to 63 °C compared to 71 °C regardless of the cooking method and preferred chops cooked to 63 °C using the sous-vide cooking method the most among all treatments.

The objective was to evaluate the effects of porcine respiratory and reproductive syndrome virus (PRRSV) infection and dietary soy isoflavone supplementation on carcass cutability and meat quality of commercial pigs. Barrows (21 d of age) were randomly allotted to experimental treatments that were maintained throughout the study: non-infected pigs received an isoflavone-devoid control diet (CON, n = 22), and infected pigs received either the control diet (PRRSV-CON, n = 20) or that supplemented with total ISF in excess of 1,500 mg/kg (PRRSV-ISF, n = 25). Pigs were penned by treatment, with 6 pigs within a pen. Following a 7-day adaptation, weanling pigs were inoculated once intranasally with either a sham-control (PBS) or live PRRSV (1×105 TCID50/mL, strain NADC20). Pigs were maintained on experimental diets for 166 d after inoculation and then slaughtered (192 or 194 d of age; approximately 120 kg BW). At 1 d post-mortem, left sides were separated between the 10th and 11th rib for determination of loin eye area (LEA), backfat thickness (BF), and loin quality (ultimate pH, instrumental color, drip loss, visual color, marbling, and firmness). Loin chops were aged 14 d post-mortem prior to Warner-Bratzler shear force (WBSF) determination. Belly width, length, thickness, and flop distance were determined. Data were analyzed as a one-way ANOVA with pig as the experimental unit. Carcass yield, LEA, BF, and estimated lean percentage did not differ (P > 0.26) among treatments. Loins from CON pigs had increased ultimate pH (P = 0.01), reduced L* scores (P = 0.005) coupled with darker visual color scores (P = 0.004), were firmer (P < 0.0001), and exhibited reduced drip loss (P = 0.01) compared with PRRSV-CON and PRRSV-ISF pigs. However, WBSF did not differ (P = 0.51) among treatments after 14 d of aging. Bellies from CON pigs were more firm compared with bellies from PRRSV-CON and ISF pigs (P < 0.01). These data suggest PRRSV infection did not alter carcass characteristics but may have marginally reduced loin and belly quality. Supplementation with dietary soy isoflavones did nothing to mitigate the detrimental effects of PRRSV infection.

The objective was to evaluate the effects of porcine respiratory and reproductive syndrome virus (PRRSV) infection and dietary soy isoflavone supplementation on carcass cutability and meat quality of commercial pigs. Barrows were randomly allotted to experimental treatments that were maintained throughout the study: non-infected pigs received an isoflavone-devoid control diet (NC, n = 22), and infected pigs received either the control diet (PC, n = 20) or that supplemented with total ISF in excess of 1,600 mg/kg (ISF, n = 25). Following a 7-d adaptation, weanling pigs were inoculated intranasally with either a sham-control (PBS) or live PRRSV (1×105 TCID50/mL, strain NADC20). At 1 d postmortem (192–194 days of age; approximately 120kg BW), left sides were separated between the 10th and 11th rib for determination of loin eye area (LEA), backfat thickness (BF), and loin quality (ultimate pH, instrumental color, drip loss, visual color, marbling, and firmness). Loin chops were aged 14 d postmortem prior to Warner-Bratzler shear force (WBSF) determination. Belly width, length, thickness, and flop distance were determined. Data were analyzed as a one-way ANOVA with a model including effects of PRRSV status and dietary treatment, and also with single-df pre-determined contrasts to compare NC and PC (infection status) and PC and ISF (ISF effect within infected pigs). Carcass yield, LEA, BF, and estimated lean percentage did not differ (P > 0.26) among treatments. Loins from NC pigs had increased ultimate pH (P = 0.01), reduced L* scores (P = 0.005) coupled with darker visual color scores (P = 0.004), were firmer (P < 0.0001), and reduced drip loss (P = 0.01) compared with PC and ISF pigs. However, WBSF did not differ (P = 0.51) among treatments after 14 d of aging. Bellies from NC pigs were more firm compared with bellies from PC and ISF pigs (P < 0.01). These data suggest PRRSV infection and soy isoflavone supplementation do not alter carcass characteristics but may marginally reduce loin and belly quality.

ObjectivesThe objective was to determine the ability to detect differences in cook loss and Warner-Bratzler shear force (WBSF) value between chops aged for differing time periods and cooked to varying degrees of doneness in a sous-vide style cooker.Materials and MethodsLoins (n = 68) from pigs humanely slaughtered at the University of Illinois Meat Science Laboratory were separated between the 10th and 11th rib into anterior and posterior sections. The posterior section was cut into 6 separate 2.54 cm thick chops. The middle 4 chops were randomly designated for aging of 3 d and cooked to 63°C, aged 7 d and cooked to 63°C, aged 14 d and cooked to 63°C, or aged 14 d and cooked to 71°C. Chops (n = 272) were cooked by placing them in a water bath with an immersion circulator set to the desired end-point temperature for 90 min. Cook loss was calculated for each chop by measuring initial and final weight, and accounting for packaging weight. Four cores measuring 1.25 cm in diameter were cut parallel to the muscle fibers from each chop and analyzed for WBSF. Data were analyzed using a 1-way ANOVA. Least squares means were separated using the probability of difference (PDIFF) option in the MIXED procedure of SAS.ResultsCook loss increased as aging period or degree of doneness increased. Among chops cooked to 63°C, chops aged 3 d had 1.14% units less (P < 0.01) cook loss than those aged 7 d, and chops aged 7 d had 1.13% units less (P < 0.01) cook loss than those aged 14 d. Among chops aged for 14 d, chops cooked to 71°C had 10.06% units greater (P < 0.001) cook loss than chops cooked to 63°C. Differences in tenderness were also detected between aging periods. Among chops cooked to 63°C, chops aged 3 d required 0.27 kg more (P = 0.02) force to shear than those aged 7 d, but chops aged 7 d did not differ (P = 0.15) from those aged 14 d. End-point cooking temperature had a greater effect on tenderness, with chops aged 14 d and cooked to 71°C requiring 0.83 (P < 0.001) kg more force than those aged 14 d and cooked to 63°C. Previous studies have reported a decrease in Warner-Bratzler shear force between 7.10–21.29% when comparing early (1–3 d) and mid (7 or 9 d) aging and decreased between 3.53–15.38% when comparing mid and late (14–21 d) aging. In the present study, Warner-Bratzler shear force decreased 9.00% from early-to-mid aging and 5.86% from mid-to-late aging.ConclusionOverall, these data indicate sous-vide is an acceptable cooking method for use in experiments as expected differences in cook loss and WBSF were detected in chops aged to differing time points or cooked to differed degrees of doneness.

Adequate carcass chilling is required to optimize pork quality and food safety. The rate at which carcasses chill is dependent on their mass. Hot carcass weight has increased steadily over the years, certainly affecting the chilling rate of the average carcass in contemporary abattoirs. Therefore, the objective was to model the effect of HCW on temperature decline of a contemporary population of pork carcasses slaughtered at a commercial abattoir that used a blast-chilling method. In addition, carcasses were sorted into HCW classes, and the effect of HCW group was tested on the rate of temperature decline of the longissimus dorsi and semimembranosus. Hot carcass weight, internal temperature of the loin muscle (at the 10th rib) and ham, as well as ambient temperature, were recorded from 40 to 1,320 min postmortem (45 time points) on 754 pork carcasses. An exponential decay model based on Newton's law of cooling,  T(t)=Ta+(T0-Ta)e-kt, was fit to temperature decline of the ham and loin of the whole population using PROC MODEL of SAS. The initial models for the decline of both ham and loin temperature displayed significant autocorrelation of errors based on evaluation of the autocorrelation function plots and Durbin-Watson test (P < 0.0001). Therefore, second- and third-order autocorrelation parameters were tested. Based on Durbin-Watson test, the use of second-order autocorrelation model with lags of 1 and 2 was deemed adequate and was therefore included in all subsequent models. This base model and its respective parameter estimates were all significant (P < 0.01) for the whole population. Carcasses approximating 85, 90, 95, 100, and 105 kg (± 1 kg) were selected and binned into their respective weight classes. Dummy variables were used to compare the effect of HCW class on parameter estimate of ham and loin models. The developed model significantly fit all weight classes (P < 0.01) for both ham and loin temperature decline. For both loin and ham models, estimates of the rate constant (k) generally decreased as HCW increased. For loin temperature, k estimate for 105-kg carcasses was 0.00124 less (P = 0.02) than 85-kg carcasses, with the intermediate HCW classes not differing from the 85-kg class. For ham temperature, estimates of k for 90, 95, 100, and 105 kg HCW were all significantly and successively less than the k estimate for 85 kg class. For perspective, loins of 95-kg carcasses were estimated to reach 2 °C in 17 h, whereas loins from 105-kg carcasses would not reach 2 °C until 27 h. For hams, 95-kg carcasses were projected to reach 2 °C in 21 h, whereas those from 105-kg carcasses would take 28 h. Overall, HCW significantly affects the rate of temperature decline of pork hams, but not loins from pork carcasses weighing between 85 and 100 kg.

Today, the United States exports 2.2 million tons of pork and pork products annually, representing just over 26% of U.S. pork production. In order to meet specific demands of a growing export market, pork quality and carcass characteristics are now integrated into breeding objectives. Color and marbling are 2 loin quality traits that influence consumer acceptability of pork and while correlations between early and aged ventral quality have been established, it is unclear if those correlations differ between production objectives (meat quality vs. lean growth). Therefore, the objective of this experiment was to compare correlations among early postmortem ventral loin quality characteristics and aged ventral loin and chop quality characteristics between pigs sired by either Pietrain (lean growth) or Duroc (meat quality) boars. Early postmortem (~1 d) quality traits included: instrumental and visual 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 Warner-Bratzler shear force (WBSF) and cook loss. Correlations were compared between Pietrain and Duroc-sired pigs using a Fisher's z-test. Early instrumental lightness (L*) was moderately correlated with aged ventral L* (Pietrain r = 0.47; Duroc r = 0.65) and aged ventral visual color (Pietrain r = 0.42; Duroc r = 0.58). Early ventral visual color was moderately correlated with aged chop L* (Pietrain r = 0.46; Duroc r = 0.60) and aged chop visual color (Pietrain r = 0.45; Duroc r = 0.57). Early visual marbling was strongly correlated (Pietrain r = 0.68; Duroc r = 0.84) with aged chop visual marbling. Within the Duroc-sired pigs, early L* was moderately correlated with aged chop L* (r = 0.64) but only weakly correlated (r = 0.35) within the Pietrain-sired pigs and those correlations differed at P ≤0.02. Within the Duroc-sired pigs, early ventral visual color was moderately correlated with aged pH (r = 0.44) and aged ventral L* (r = 0.57) but only weakly correlated (r ≤ 0.29) within the Pietrain-sired pigs and those correlations differed at P ≤0.03. No early postmortem quality traits were correlated (|r| ≤ 0.34) with WBSF or cook loss for either sire line. In summary, correlations between early and aged postmortem quality traits rarely differed between Duroc- and Pietrain-sired pigs. It is not necessary to account for sire line when relating early and aged quality characteristics.

Modifying fabrication specifications of domestic pork carcasses to reflect product specifications in key export markets may increase gross value for U.S. pork. Changes in specifications may also yield value-added cuts that increase demand for U.S. pork in both export and domestic markets. The objective was to evaluate differences in value of carcasses fabricated using either typical U.S. cutting specifications, or alternative specifications. Paired left and right sides (30 sides total; n = 15) were weighed and cut into primal and subprimal pieces according North American Meat Institute (NAMP, DOM) or alternative-style specifications (ALT). Alternative-style carcasses were separated into shoulder (4th/5th rib separation), loin, belly, and ham (sirloin-on) primals. Alternative-style shoulders were fabricated into a cellar-trimmed (CT) butt, triceps brachii (cushion), boneless picnic, and a brisket. Carcass values for all three pricing scenarios were calculated using the USDA Agriculture Marketing Service Carlot Report values from the weeks of April 5, 2013, to April 7, 2017. Value for the pork brisket was estimated based on relative value of the beef brisket compared to the beef shoulder clod (NAMP #114) resulting in a value of $2.485/kg for the pork brisket. Comparisons between fabrication styles and value of each side were made using a paired T-test. Whole bone-in loin yields of ALT carcasses were 6.23 units less (P < 0.0001) than DOM carcasses. Similarly, yields from trimmed and squared bellies of ALT carcasses were 0.83 units less than (P ≤ 0.01) DOM carcasses. In contrast, trimmed shoulders of ALT carcasses were 3.81 units greater (P < 0.0001) and hams were 3.39 units greater (P < 0.0001) than DOM carcasses. Despite reductions in yield of loins and bellies, ALT carcasses were numerically $1.29 (P = 0.17) and $0.66 (P = 0.56) more valuable than DOM carcasses in the 4 yr average and best pricing scenarios, respectively. Alternative-style carcasses were $1.99 (P = 0.03) more valuable than DOM carcass when using the most depressed pricing scenario. Fabricating pork carcasses using alternative-style specifications reduced the yield, and therefore the value, of the loin and belly compared with DOM carcasses. However, added value from the pork brisket and CT butt recuperated this value. Therefore, alternative-style fabrication methods may increase gross carcass value in some pricing scenarios.