Pork muscle profiling: pH and instrumental color of the longissimus thoracis is not representative of pH and instrumental color of shoulder and ham muscles.

From a population of 351 pork carcasses, 3.0-cm thick chops from the 10th rib location of the longissimus thoracis, faced surfaces of the triceps brachii and serratus ventralis muscles from the boneless shoulder, and faced surfaces of the biceps femoris, semitendinosus, semimembranosus, adductor, rectus femoris, and vastus lateralis muscles from the boneless ham were evaluated for pH and instrumental color (Minolta CR-400). Evaluations were conducted for at least three different locations on each of the muscle samples and averaged before data analysis occurred. The longissimus thoracis had the lowest pH and the lightest and least red color compared with the other eight muscles evaluated in this study (mean differences ranged from 0.98 to 8.70 for L*, 3.98 to 12.56 for a*, and 0.026 to 0.409 for pH). Furthermore, regression analysis suggested that pH and color values for the longissimus thoracis were not adequate predictors for pH and color values obtained from other muscles and therefore consideration should be given to the individual muscles that are of interest.

Structural and functional properties of modified cellulose ingredients and their application in reduced-fat meat batters.

The first goal for this experiment was to determine the structural and technological characteristics for methylcellulose (MC), carboxymethyl cellulose (CMC), and microcrystalline cellulose (MCC), while the subsequent goal for this experiment was to determine the application of the modified cellulose ingredients in reduced-fat meat batters. Each ingredient was characterized and then evaluated as a fat replacer using meat batters with targeted fat levels of 20%, 10%, and 5%. It was determined that each modified cellulose ingredient was unique in its structural and technological properties which caused significant effects on the physiochemical properties of the meat batters. Specifically, MC created inconsistences during heating and cooling of meat batters resulting in elevated cooking loss but did not change textural hardness of cooked samples, CMC appeared to interfere with the meat batter matrix resulting in lower textural hardness but maintained levels of cooking loss, and MCC had similar levels of cooking loss and textural hardness when compared with the control samples.

Sous Vide Cook Temperature Alters the Physical Structure and Lipid Bioaccessibility of Beef Longissimus Muscle in TIM-1.

Changes in the physical states, induced with different sous vide cooking temperatures, significantly (P < 0.05) altered lipid bioaccessibility measured in the TNO-simulated gastrointestinal tract model-1 of AAA boneless beef striploin, containing the longissimus lumborum muscle. The denaturation of actin significantly correlates with the total cumulative free fatty acid (FFA) bioaccessibility, whereby the striploin cooked to 60 °C presents the maximum lipid bioaccessibility (15.8 ± 1.0%), rate constant (ka) for FFA hydrolysis (0.087 ± 0.003 min-1), and greatest actin denaturation enthalpy (-0.57 ± 0.06 ΔH). Thus, thermal treatments above 60 °C significantly decrease the kinetics of lipolysis (70 °C = 0.042 ± 0.002 min-1 and 80 °C = 0.047 ± 0.002 min-1) and the resultant total lipid bioaccessibility (70 °C = 8.6 ± 0.7 and 80 °C = 8.3 ± 0.5%). This research highlights the potential to manipulate the physical food structure to alter digestion kinetics, supporting the need to understand supramolecular structures in food and their nutritional outcomes.

A comprehensive perspective of food nanomaterials.

Nanotechnology is a rapidly developing toolbox that provides solutions to numerous challenges in the food industry and meet public demands for healthier and safer food products. The diversity of nanostructures and their vast, tunable functionality drives their inclusion in food products and packaging materials to improve their nutritional quality through bioactive fortification and probiotics encapsulation, enhance their safety due to their antimicrobial and sensing capabilities and confer novel sensorial properties. In this food nanotechnology state-of-the-art communication, matrix materials with particular focus on food-grade components, existing and novel production techniques, and current and potential applications in the fields of food quality, safety and preservation, nutrient bioaccessibility and digestibility will be detailed. Additionally, a thorough analysis of potential strategies to assess the safety of these novel nanostructures is presented.

The effect of bacon pump retention levels following thermal processing on bacon slice composition and sensory characteristics.

The objective was to evaluate the effect of belly pump uptake and cook yield during processing on bacon slice composition and sensory attributes. A total of forty-four bellies were commercially sourced and randomly assigned to two experiments. Each experiment consisted of one smokehouse cooking cycle. Within each experiment, bellies were separated at the medial point and one belly half was assigned to a high pump uptake treatment (HIGH; target of 30% uptake) and the remaining belly half was assigned to a normal pump uptake treatment (NORM; target of 15% uptake). In experiment-1, cook yields were 107.79% for the HIGH bellies and 101.52% for the NORM bellies. In experiment-2, cook yields were 97.41% for the HIGH bellies and 94.74% for the NORM bellies. Overall, bacon slice composition and sensory attributes of bacon from bellies with greater pump retention were largely unaffected, accordingly it was concluded that cook yields ranging in level of pump retention does not affect most attributes of bacon.

Growth performance, carcass quality, fresh belly characteristics, and commercial bacon slicing yields of growing-finishing pigs fed a subtherapeutic dose of an antibiotic, a natural antimicrobial, or not fed an antibiotic or antimicrobial.

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.

A comparison of intact and degraded desmin in cooked and uncooked pork longissimus thoracis and their relationship to pork quality.

The objective was to compare desmin abundance (intact, degraded, and the ratio of intact desmin to degraded desmin) in samples from cooked and uncooked pork and establish its relationship to pork quality traits. Pork chops (2.54-cm thick) from twenty-four pork loins were randomly assigned to treatment (cooked or uncooked). Intact and degraded desmin in cooked and uncooked chops aged 1d were weakly correlated (r<|0.35|) with Warner-Bratzler shear force at 1 and 14d postmortem aging. Intact and degraded desmin in cooked and uncooked chops aged 14d were moderately correlated (|0.35|

Effects of supplementing zinc or chromium to finishing steers fed ractopamine hydrochloride on growth performance, carcass characteristics, and meat quality.

Objectives were to determine the effects of feeding ractopamine hydrochloride (RAC) with zinc (Zn) and chromium (Cr) on feedlot growth performance, carcass characteristics, and meat quality. Steers ( = 179; initial BW = 533 ± 94 kg) were blocked by BW and allotted to 30 pens, and pens were randomly assigned 1 of 5 treatments: (1) control (CONT), (2) RAC only (RO), (3) RAC + Zn (RZ), (4) RAC + Cr (RC), or (5) RAC + Zn + Cr (RZC). Trace minerals were fed from d 0 to 63 to target 1 g of Zn/steer·d (KemTRACE Zn; Kemin Industries, Inc., Des Moines, IA) and 3 mg Cr/steer·d (KemTRACE Chromium; Kemin Industries, Inc.) for Zn and Cr treatments, respectively. Dry-rolled corn, 0.605 kg/steer, was removed from the diet and 400 mg RAC, per 0.605 kg of ground corn carrier, was top dressed per steer immediately following feed delivery to pens fed RAC. There were no effects ( ≥ 0.45) of trace mineral supplementation on DMI, ADG, or G:F before RAC feeding. There were also no treatment effects ( ≥ 0.46) over all 63 d of the trial on DMI, ADG, or G:F. Despite the lack of differences in live performance, steers fed RO and RC averaged 0.10 kg/d greater ( = 0.10) carcass ADG than steers fed RZC and CONT, while steers fed RZ were intermediate and not different. Steers fed RO had the greatest ( = 0.09) carcass G:F, while steers fed CONT had the least carcass G:F, 0.0875 and 0.0774, respectively. Steers fed RO and RC averaged 5.5 kg heavier ( = 0.09) HCW than steers fed RZC and CONT, while steers fed RZ were intermediate and not different. There were no treatment effects ( ≥ 0.32) on LM area, 12th rib fat, marbling score, KPH, carcass yield, or USDA yield grade and distribution. However, carcasses from steers fed RC had the greatest ( = 0.10) percentage grading USDA Select. There were no treatment effects ( ≥ 0.20) on shear force, intramuscular fat, pH, a*, and b*. Steaks from steers fed RO and RC had 11.4% greater ( = 0.08) cook loss than steaks from steers fed CONT and RZC, whereas steaks from steers fed RZ were intermediate and not different. Also, steaks from steers fed RC had 2.11 units greater ( = 0.03) L* values (i.e., were lighter) than steaks from steers fed RZ; steaks from steers fed CONT, RO, and RZC were intermediate. In feedlot steers, the addition of both Cr and Zn supplementation did not improve growth performance or meat quality when fed in combination with 28 d of RAC supplementation; however, RAC, fed alone or in combination with Cr, did increase HCW.

Effects of marketing group on the quality of fresh and cured hams sourced from a commercial processing facility.

The objective was: 1) to characterize the effect of marketing group on fresh and cured ham quality, and 2) to determine which fresh ham traits correlated to cured ham quality traits. Pigs raised in 8 barns representing 2 seasons (hot and cold) and 2 production focuses (lean and quality) were used. Three groups were marketed from each barn. A total of 7,684 carcasses were used for data collection at the abattoir. Every tenth carcass was noted as a select carcass for in-depth ham quality analyses. Leg primal weight and instrumental color were measured on 100% of the population. On the select 10% of the population, hams were fabricated into sub-primal pieces, and 3-piece hams were manufactured to evaluate cured ham quality and processing yield. Data were analyzed as a split-plot design in the MIXED procedure of SAS with production focus as the whole-plot factor, and marketing group as the split-plot factor. Pearson correlation coefficients between fresh and cured ham traits were computed. There were no differences ( ≥ 0.15) in instrumental color or ultimate pH ( ≥ 0.14) among fresh ham muscles from any marketing group. The only exception was the semimembranosus of marketing group 2 was lighter than marketing group 1 ( = 0.03) and the dark portion of the semitendinosus muscle from group 1 was lighter than from group 3 ( = 0.01). There were no differences ( ≥ 0.33) in ultimate pH of fresh ham muscles between production focuses, but several muscles from quality focus pigs were lighter in color than ham muscles from lean focus pigs. The lack of differences in fresh ham quality lead to few differences in cured ham quality. Cured hams from the quality focus pigs had greater lipid content ( < 0.01) than hams from lean focus pigs. Cured lightness values of hams from marketing group 1 and 2 were 1.52 units lighter than hams from marketing group 3 ( 0.01). Overall, marketing group did not impact ham quality. Fresh ham quality was not strongly related to cured ham quality. Some correlations were present between fresh and cured ham traits, but those relationships were likely not strong enough to be used as a sorting tool for fresh hams to generate high quality cured hams.

Pork loin quality is not indicative of fresh belly or fresh and cured ham quality.

The objective was to characterize the relationship between fresh loin quality with fresh belly or fresh and cured ham quality. Pigs raised in 8 barns representing 2 seasons [cold ( = 4,290) and hot ( = 3,394)] and 2 production focuses [lean ( = 3,627) and quality ( = 4,057)] were used. Carcass characteristics and other meat quality data were collected on 7,684 carcasses. All of the carcasses were evaluated for HCW, LM depth, tenth rib fat depth, leg (ham primal) weight, instrumental color on the gluteus medius and gluteus profundus of the ham face, and subjective loin quality. Instrumental loin color and ultimate pH (≥ 22 h postmortem) were collected on the ventral side of loins along with dimensions and firmness scores of fresh bellies from 50% of the carcasses. Ten percent of the boneless loins and fresh hams were evaluated for slice shear force (SSF) or cured ham characteristics. Correlation coefficients between traits were computed using the CORR procedure of SAS and considered significantly different from 0 at ≤ 0.05. Temperature decline, beginning at 31 min postmortem and concluding at 22 h postmortem, for the longissimus dorsi and semimembranosus muscles were evaluated on 10% of the carcasses. Ultimate loin pH was correlated with dimensional belly characteristics ( ≥ |0.07|; < 0.0001) fresh ham instrumental color ( ≥ |0.03|; ≤ 0.05), and semimembranosus ultimate pH ( = 0.33; < 0.0001). Further, ultimate loin pH was correlated ( ≤ 0.01) with pump retention ( = 0.087) and cooked yield ( = 0.156) of cured hams. Instrumental L*on the ventral surface of the loin was related to L* on both muscles of the ham face ( ≤ 0.0001). Even though significant relationships between the loin, belly, and ham were detected, the variability in belly and ham quality explained by variability in loin quality was poor (≤ 22.09%). Compositional differences between the loin and belly may have contributed to those poor relationships. Additionally, differences in temperature declines during chilling between the loin and ham likely contributed to the weak nature of relationships. Equilibration of longissimus dorsi temperature to ambient cooler temperature occurred at 14 h postmortem ( = 0.0005), yet the semimembranosus had not equilibrated with ambient (equilibration bay) temperature ( < 0.0001) at 22 h postmortem. Using loin quality to draw conclusions about fresh belly and fresh and cured ham quality may be misleading.

Effects of time after a second dose of immunization against GnRF (Improvest) independent of age at slaughter on commercial bacon slicing characteristics of immunologically castrated barrows.

The objective was to determine the effects of time after a second dose of anti-GnRF immunization on fresh belly characteristics and slicing yields of immunologically castrated (IC) barrows, physically castrated (PC) barrows and gilts slaughtered at 24 weeks of age. The second dose was staggered so that IC barrows were slaughtered at 4, 6, 8, or 10 weeks after the second dose. Fresh belly characteristics (N=141) were collected at slaughter and bacon was manufactured commercially. The main effects in the model were treatment and the random effects of block and block within replication. Thickness, flop distance, and lipid content increased (L; P<0.04) and iodine value tended to decrease (L; P=0.08) with time after the second dose in IC barrows. Slicing yields increased with time after the second dose (L; P<0.01), but were similar (P=0.11) among sexes. Increasing time of slaughter after second anti-GnRF dose improves fresh belly and bacon slicing characteristics in IC barrows.

Effects of feeding canola meal from high-protein or conventional varieties of canola seeds on growth performance, carcass characteristics, and cutability of pigs.

The objectives of this experiment were to determine growth performance, visceral mass differences, carcass characteristics, fresh meat quality, and carcass cutability of growing-finishing pigs fed diets containing high-protein canola meal (CM-HP) or conventional canola meal (CM-CV). Seven dietary treatments were fed to investigate effects of increasing inclusion rates of CM-HP or CM-CV in a corn-soybean meal diet containing no canola meal (control). Inclusion rates were 33, 66, or 100% replacement of soybean meal with either CM-HP or CM-CV. Pigs (140 barrows and 140 gilts; 2 barrows and 2 gilts per pen) were fed experimental diets in 3 phases with each phase lasting 35, 28, and 28 d, respectively. Within each phase, diets were formulated to be similar in concentrations of standardized ileal digestible indispensable AA and in standardized total tract digestible P, but NE concentrations were not equalized among diets. At the conclusion of the experiment, 1 pig per pen was harvested. Over the 91-d growing-finishing period, no effects of CM-HP on ADG, ADFI, or G:F were observed, but final BW tended ( = 0.06) to be reduced as increasing levels of CM-HP were included in the diets. There was a linear increase ( < 0.05) in ADFI and a linear reduction ( < 0.05) in G:F as CM-CV inclusion level increased. Pigs fed CM-CV also had greater ( < 0.05) ADG and ADFI than pigs fed diets containing CM-HP. There was a linear increase ( < 0.01) in liver weights, as a percentage of live weight, as CM-CV inclusion increased, but that was not the case if CM-HP was included in the diets. There was a linear increase ( < 0.05) in kidney weights, as a percentage of live weight, as CM-HP or CM-CV inclusion increased. There were no differences among treatments for ending live weight, HCW, carcass yield, loin eye area, 10th rib backfat thickness, or estimated carcass lean. Shear force, cook loss, LM moisture, LM extractible lipid, and drip loss were also not different among treatment groups. There were no differences among treatments for any subjective LM quality evaluations (color, marbling, firmness). Pigs fed CM-HP had increased ( < 0.05) boneless lean cutting yields and boneless carcass cutting yields compared with pigs fed CM-CV. In conclusion, CM-HP and CM-CV may fully replace soybean meal as protein supplements in growing-finishing pig diets without substantially impairing pig performance or carcass quality.

Effects of feeding high protein or conventional canola meal on dry cured and conventionally cured bacon.

Objectives were to compare belly, bacon processing, bacon slice, and sensory characteristics from pigs fed high protein canola meal (CM-HP) or conventional canola meal (CM-CV). Soybean meal was replaced with 0 (control), 33, 66, or 100% of both types of canola meal. Left side bellies from 70 carcasses were randomly assigned to conventional or dry cure treatment and matching right side bellies were assigned the opposite treatment. Secondary objectives were to test the existence of bilateral symmetry on fresh belly characteristics and fatty acid profiles of right and left side bellies originating from the same carcass. Bellies from pigs fed CM-HP were slightly lighter and thinner than bellies from pigs fed CM-CV, yet bacon processing, bacon slice, and sensory characteristics were unaffected by dietary treatment and did not differ from the control. Furthermore, testing the existence of bilateral symmetry on fresh belly characteristics revealed that bellies originating from the right side of the carcasses were slightly (P≤0.05) wider, thicker, heavier and firmer than bellies from the left side of the carcass.

Effects of the porcine IGF2 intron 3-G3072A mutation on carcass cutability, meat quality, and bacon processing.

A SNP in a regulatory region of intron 3 within the porcine IGF2 gene (IGF2-G3072A) is associated with increased lean deposition and decreased fat deposition in pigs with paternal A alleles (APat) compared with pigs with paternal G alleles (GPat). However, data regarding fresh and processed meat quality characteristics of pigs with different alleles for this polymorphism are limited. A single heterozygote (AG) boar was bred to homozygous (AA) commercial Yorkshire-cross sows producing F1 barrows and gilts with either GPat or APat. Two farrowing groups of barrows and gilts were group housed, provided ad libitum access to a diet that met or exceeded NRC nutrient recommendations throughout production, and slaughtered at 176 d (±4 d) of age. Fresh LM quality and estimated percent fat-free lean measurements were taken on the left side of carcasses, while carcass cutouts were completed with right sides. Fresh belly and bacon processing traits were characterized for only block 1 pigs. Pig was treated as the experimental unit for all analyses. Ending live weight and HCW were not affected by IGF2 allele; however, 10th rib backfat thickness was 0.41 cm less (P=0.01), loin eye area was 4.0 cm2 greater (P=0.01), and predicted fat-free lean was over 2 percentage units greater (P<0.01) in APat pigs compared with GPat pigs. Furthermore, boneless lean cuts from the shoulder, loin, and ham were heavier (P<0.05) in APat pigs compared with GPat pigs. Minolta L* value was 2.36 units greater (P=0.03) but cooking loss was 1.82 percentage units greater (P<0.01) in APat pigs compared with GPat pigs. Additionally, despite reductions in subcutaneous fat, extractable intramuscular lipid from the LM was 0.64 percentage units greater (P=0.02) in APat pigs compared with GPat pigs. Bellies were 7.17 mm thinner (P=0.01), had 7.27 cm less flop distance (P=0.05), and tended to have 1.34 units greater iodine value (P=0.09) in APat pigs compared with GPat pigs. While not statistically different (P=0.30), the magnitude of difference in slicing yield as a percentage of green weight was 1.57 percentage units between bellies from APat pigs (85.83%) and bellies from GPat pigs (87.40%). Pigs with GPat had superior belly quality that may positively impact commercial bacon production. However, pigs with APat yielded a greater amount of lean product at the expense of producing lighter LM color and increased cooking loss.

A comparison of slice characteristics and sensory characteristics of bacon from immunologically castrated barrows with bacon from physically castrated barrows, boars, and gilts.

The objectives were to compare slice characteristics and sensory attributes of bacon from immunologically castrated (IC) barrows with bacon from other sexes using a trained sensory panel. Bacon was obtained for sensory evaluation from 3 experiments. In Exp. 1, trimmed and squared bellies (n=180) of IC barrows, IC barrows fed ractopamine hydrochloride (IC+RAC), physically castrated (PC) barrows, intact males (IM), and gilts were used. Data were analyzed as a general linear mixed model and pen (n=48) served as the experimental unit. Treatment (sex or diet) was a fixed effect in all 3 experiments. In Exp. 2, untrimmed, natural fall bellies (n=96) from IC and PC barrows fed 0 or 30% or a withdrawal distillers dried grains with solubles (DDGS) program when slaughtered at 5 wk after the second dose (25 wk of age) were used. In Exp. 3, untrimmed, natural fall bellies (n=96) from IC and PC barrows fed the same experimental diets as in experiment 2 but slaughtered at 7 wk after the second dose (27 wk of age) were used. Data from Exp. 2 and 3 were analyzed as a 2×3 factorial arrangement in a randomized complete block design and pen was the experimental unit. Bellies from all 3 experiments were processed using the same protocols. In Exp. 1, IM had the greatest (P<0.0001) boar aroma and flavor scores among all treatments. No differences were detected among the other treatment groups for boar aroma or flavor. Intact males had the least (P<0.0001) desirable cured bacon aroma and flavor among all treatments. No differences were detected among the other treatment groups for bacon aroma or flavor. There were no differences in bacon aroma or off-flavor between IC and PC barrows slaughtered at 5 wk after the second dose regardless of DDGS feeding program. Bacon from PC barrows was saltier (P<0.01) than bacon from IC barrows when slaughtered at 5 wk after the second dose. There were no differences in bacon aroma, off-aroma, bacon flavor, or saltiness between IC and PC barrows slaughtered at 7 wk after the second dose regardless of DDGS feeding program. Total slice area of bacon slices from IC barrows slaughtered at 5 wk after the second dose were less (P<0.01) than PC barrows, but the differences diminished (P=0.16) when slaughtered at 7 wk after the second dose. Overall, panelists successfully detected boar odor and flavor in Exp. 1. Immunological castration was as effective as physical castration at eliminating boar aroma and boar flavor in bacon even when feeding differing DDGS feeding programs or when slaughtered at 5 or 7 wk after the second dose.

Effect of gonadotropin releasing factor suppression with an immunological on growth performance, estrus activity, carcass characteristics, and meat quality of market gilts.

Objectives were to evaluate the administration of an anti-gonadotropin releasing factor (GnRF) analog on suppression of estrus, consistency of feed intake, and growth performance in market gilts and to investigate the impact the physiological changes would have on carcass characteristics and fresh meat quality. Gonadotropin releasing factor stimulates the anterior pituitary to release luteinizing hormone that acts on the ovary to induce follicle development and indirectly initiates ovulation. Improvest (Zoetis, Kalamazoo, MI) contains an incomplete version of naturally occurring GnRF and causes the production of anti-GnRF antibodies that bind to the GnRF receptor and thus render GnRF inactive. This in turn suppresses estrus in female pigs. Gilts were initially separated into 10 blocks based on age and then within each block allotted to a pen (n = 114; 5 pigs/pen) based on BW. Gilts received the first dose at 12 wk of age and the second dose at 16 wk of age, were exposed to a boar daily from 20 to 26 wk of age, and were slaughtered at 26 wk of age (10 wk after second dose). Meat quality was analyzed on the 2 gilts closest to pen average ending live weight in 5 of the 10 blocks. Pen served as the experimental unit for all data analysis. During the 15-wk finishing period, ADG was 0.03 kg greater (P < 0.01) and G:F was 0.009 greater (P = 0.02) in gilts administered GnRF suppression (treated) compared with untreated gilts (control). The majority of improvements in growth performance were observed from 16 to 20 wk of age (4 wk after second dose), as ADG was 0.07 kg greater (P < 0.001) and G:F was 0.021 greater (P < 0.01) in treated gilts compared with control gilts. Ovarian weights were reduced (P < 0.0001) by 64.15% and gilts exhibiting puberty were reduced by 87.80% (P < 0.001) in treated gilts compared with control gilts. Back fat depth was 3.78 mm greater (P < 0.0001) and estimated lean was 1.31 percentage units less (P < 0.0001) in treated gilts compared with control gilts. With the exception of subjective color, there were no differences (P ≥ 0.12) in meat quality parameters between treated and control gilts. Subjective color was darker (P = 0.03) in treated gilts compared with control gilts. These data suggest market gilts treated with an anti-GnRF analog had suppressed estrus and episodical changes in ADFI, while they had improved feed efficiency, increased ADG, and increased back fat depth when compared with gilts without an anti-GnRF analog treatment.

Effect of feeding ractopamine hydrochloride (Optaflexx) with or without supplemental zinc and chromium propionate on growth performance, carcass characteristics, and meat quality of finishing steers.

Objectives of this study were to determine the effects of feeding ractopamine hydrochloride (Optaflexx) with or without supplemental Zn propionate (KemTRACE Zn) and Cr propionate (KemTRACE Cr) to finishing steers on growth performance, carcass characteristics, and meat quality. Angus cross steers (n = 142; BW = 527 ± 14 kg) were blocked by BW into 4 blocks (6 pens/block, 5 to 6 steers/pen). Steers targeted at an average 12th rib back fat thickness of 1.3 cm via ultrasound, by block, were randomly assigned to 1 of 3 dietary supplements for the final 35 d of feeding before slaughter: 1) no supplementation, where analyzed Zn and Cr were 49.82 and 0.98 mg/kg (DM basis), respectively (CONT), 2) 300 mg ractopamine hydrochloride·steer(-1) · d(-1), where analyzed Zn and Cr were 49.38 and 0.96 mg/kg (DM basis), respectively (RAC), or 3) 300 mg ractopamine hydrochloride, 1.0 g of Zn supplied as Zn propionate (KemTRACE Zn), and 3 mg of Cr supplied as Cr propionate (KemTRACE Cr) steer(-1) · d(-1), where analyzed Zn and Cr were 159.73 and 1.25 mg/kg (DM basis), respectively (RAC+TM). All steers were fed the same basal diet of 20% corn silage, 20% dried distillers grains, 50% corn, and 10% mineral-vitamin supplement (DM basis). Data were analyzed as a randomized complete block design with a fixed effect of treatment and a random effect of block. Average daily gain and G:F were increased (P < 0.01) by 16% in steers fed RAC when compared with steers fed CONT. However, ADG and G:F were not different (P ≥ 0.61) between steers fed RAC and RAC+TM. Furthermore, HCW was increased (P = 0.04) by 1.87% (6.61 kg) in steers fed RAC when compared with steers fed CONT, whereas HCW was not different (P = 0.80) between steers fed RAC and RAC+TM. Back fat thickness and marbling were not different (P ≥ 0.14) between steers fed RAC and CONT or (P ≥ 0.34) between steers fed RAC and RAC+TM. Warner-Bratzler shear force tended to be greater (less tender; P = 0.06) in steers fed RAC when compared with steers fed CONT yet was not different (P = 0.34) between steers fed RAC and RAC+TM. However, meat quality, as measured by pH, objective color, and moisture composition, did not differ (P ≥ 0.55) between steers fed RAC and CONT. Although steers fed RAC had improved ADG, feed efficiency, and HCW in this study, feedlot growth performance and carcass characteristics were not further improved by additional supplemental Zn and Cr.

Effects of immunological castration (Improvest) on further processed belly characteristics and commercial bacon slicing yields of finishing pigs.

Objectives were to compare fresh belly characteristics, further processed belly characteristics, and commercial bacon slicing yields of immunologically castrated (IC) barrows, IC barrows fed ractopamine hydrochloride (IC+RAC), physically castrated (PC) barrows, intact males, and gilts. One hundred eighty-eight bellies from pigs housed in single sex pens (n = 48) slaughtered at 130 kg ending live weight were evaluated for flop distance, length, width, thickness, and fatty acid composition. Bellies were injected, thermally processed, and sliced according to standard protocols at a USDA federally inspected facility. Complete slices were sorted by trained plant personnel. Then, sliced bellies were individually packaged to maintain anatomical orientation. The effects of treatments were analyzed as a generalized linear mixed model with pen of pigs serving as the experimental unit for all comparisons. Belly thickness was not different (P ≥ 0.11) in bellies from IC barrows (3.74 cm) compared with bellies from IC+RAC (3.60 cm), PC barrows (3.94 cm), or gilts (3.64 cm); however, bellies were 0.42 cm thicker (P < 0.01) in IC barrows compared with intact males. Iodine value was not different (P ≥ 0.06) in bellies from IC barrows (68.26) compared with bellies from IC+RAC (69.78), PC barrows (67.55), or gilts (69.45); however, iodine value was 2.32 units less (P < 0.01) in IC barrows compared with intact males. Green weight was not different (P ≥ 0.09) in bellies from IC barrows (4.88 kg) compared with bellies from IC+RAC (5.11 kg), PC barrows (5.10 kg), or gilts (4.79 kg); however, green weight was 0.56 kg greater (P < 0.0001) in IC barrows compared with intact males. Pump uptake and cooked yield was not different (P ≥ 0.15) among treatment groups. Slicing yield (as a percentage of green weight) was decreased (P ≤ 0.01) in bellies from IC barrows (93.61%) compared with bellies from PC barrows (98.42%) or gilts (98.19%); however, slicing yield was not different (P ≥ 0.11) among bellies from IC barrows, IC+RAC, or intact males. Overall, fresh belly characteristics of IC barrows were analogous to PC barrows and gilts, but commercial slicing yields of bacon manufactured from IC barrows were less than both PC barrows and gilts.

Effects of immunological castration and distiller's dried grains with solubles on carcass cutability and commercial bacon slicing yields of barrows slaughtered at two time points.

Male pigs were randomly assigned to a castration method at birth and allotted to 48 pens (28 pigs/pen). Physically castrated (PC) barrows were castrated at 2 d of age; immunologically castrated (IC) barrows were administered Improvest (GnRF analog diphtheria toxoid conjugate; Zoetis, Kalamazoo, MI) at 16 and 20 wk of age. Distiller's dried grains with solubles (DDGS) feeding strategies included either 0% DDGS (control), 30% DDGS (30% DDGS) fed from 6 wk of age to slaughter, or 30% DDGS fed from 6 wk of age to second dose of Improvest and then fed 0% DDGS until slaughter (withdrawal). Four barrows closest to the median pen weight at 4.5 wk after second dose were selected for evaluation; two were randomly selected and slaughtered at 5 wk and the other two at 7 wk after second dose. Data from each slaughter time were analyzed independently as a 2 × 3 factorial design with pen as the experimental unit. At 5 wk after second dose, bone-in lean cutting yields were 2.63% units greater (P < 0.01) in IC when compared to PC. Bellies were thicker (P < 0.01) and tended to have greater belly flop distances (P = 0.07) in PC compared to IC, however iodine values (IV) were not altered (P = 0.84). Carcass traits (P ≥ 0.10), cutting yields (P ≥ 0.43), and fresh belly characteristics (P ≥ 0.08) were minimally affected by DDGS feeding strategy. Bacon slicing yields (percentage of green weight) were 6.10% units less (P < 0.01) in IC compared with PC. At 7 wk after second dose, bone-in lean cutting yields were 1.57% units greater (P = 0.03) in IC compared with PC. Distiller's grains feeding strategy had no effect (P ≥ 0.83) on boneless carcass cutting yields in IC; while in PC, these yields were 2.32% units less (P < 0.02) in control-fed barrows when compared to other feeding strategies (castration method × feeding strategy; P = 0.03). Bellies from PC tended to be thicker (P = 0.07) and have similar flop distances (P = 0.44) and IV (P = 0.54) when compared with IC. Iodine value was greater (P = 0.03) in 30% DDGS-fed barrows compared with control-fed barrows. Bacon slicing yields (percentage of green weight) were 4.27% units less (P = 0.05) in IC compared with PC. These data suggested that while bacon slicing yield was reduced in IC barrows fed control and 30% DDGS compared with PC barrow counterparts, withdrawal of DDGS improved bacon slicing yields of IC barrows.

Effects of retail style or food service style packaging type and storage time on sensory characteristics of bacon manufactured from commercially sourced pork bellies.

UNLABELLED: Objectives were to characterize differences in pork bellies that were stored frozen for different durations prior to processing and characterize sensory properties of the bacon derived from those bellies when stored in either retail or food service style packaging. Bellies (n = 102) were collected from 4 different time periods, fresh bellies (never frozen) and bellies frozen for 2, 5, or 7 mo, and manufactured into bacon under commercial conditions. Food service bacon was packaged in oxygen-permeable polyvinyl lined boxes layered on wax-covered lined paper and blast frozen (-33 °C) for 45 or 90 d after slicing. Retail bacon was vacuum-packaged in retail packages and refrigerated (2 °C) in the dark for 60 or 120 d after slicing. At the end of respective storage times after slicing, bacon was analyzed for sensory attributes and lipid oxidation. Off-flavor and oxidized odor of bacon increased (P < 0.01) with increasing storage time in both packaging types. Lipid oxidation increased (P < 0.01) as storage time increased from day 0 to day 45 in food service packaged bacon from frozen bellies, but was unchanged (P ≥ 0.07) with time in food service packaged bacon from fresh bellies. Lipid oxidation was also unchanged (P ≥ 0.21) over time in retail packaged bacon, with the exception of bellies frozen for 5 mo, which was increased from day 0 to day 90. Overall, off-flavor, oxidized odor, and lipid oxidation increased as storage time after processing increased. Freezing bellies before processing may exacerbate lipid oxidation as storage time after processing was extended. PRACTICAL APPLICATION: Bacon can be packaged and managed several different ways before it reaches the consumer. This research simulated food service (frozen) and retail packaged (refrigerated) bacon over a range of storage times after slicing. Off-flavor and oxidized odor increased as storage time after processing increased in both packaging types. Lipid oxidation increased as storage time after slicing increased to a greater extent in food service packaging.