Comparative transcatheter occlusion of patent ductus arteriosus: multicenter collaborative study across pediatric and veterinary cardiology centers.

INTRODUCTION/OBJECTIVE: Transcatheter therapeutics have revolutionized treatment of patent ductus arteriosus (PDA). Greater understanding of corrective interventions across species can advance best practices, protocols, and outcomes while minimizing adverse events. The objective of this study was to describe characteristics and outcomes in children and dogs undergoing transcatheter PDA occlusion. ANIMALS, MATERIALS AND METHODS: This was a multicenter, retrospective cohort study from two pediatric and three veterinary centers. Demographics, procedural characteristics, and outcomes were assessed. RESULTS: Data included 202 children and 106 dogs treated from July 2019 to June 2021. Forty-five (23%) children and 19 (18%) dogs had congestive heart failure prior to catheterization. Transvenous and transarterial approaches for deployment were most used in children and dogs, respectively. All children had percutaneous vascular access compared to 17 (16%) dogs. Intraprocedural anticoagulation was standard for children (100% of 165 reported), but not for dogs (2/103). The median (interquartile range) pulmonary ostium diameter in children was 2.2 mm (1.5-3.0 mm) and 3.0 mm (2.0-4.2 mm) in dogs when all body sizes were considered (P<0.001). Amplatzer™ Duct Occluder was most commonly used in children (64/202, 32%); the Amplatz® Canine Duct Occluder was used in dogs (96/100, 96%). Closure was manual compression in all children, whereas vessel ligation was most used in dogs (74/104, 73%). Successful device deployment was achieved in 197 (98%) children and 98 (93%) dogs (P=0.03). Major reasons for failure included device embolization in six (2.9%) children and PDA morphology concerns in four (3.8%) dogs. CONCLUSIONS: Transcatheter PDA occlusion is successful in children and dogs. Study data might be useful for optimizing transcatheter therapeutics and animal models for interventional cardiology.

Impact of myoglobin oxygenation state prior to frozen storage on color stability of thawed beef steaks through retail display.

Consumers consider beef color to be an indicator of freshness and therefore it is a major factor when purchasing beef. The ideal conditions for maintaining color throughout retail display following frozen storage have yet to be well established. Therefore, the objective of this study was to determine the effects of myoglobin oxygenation levels (especially high oxygenation) during freezing on color stability of thawed steaks during retail display (RD) and to determine the impact that frozen storage duration, aging, and packaging films have on meat color after thawing under RD conditions. USDA Choice strip loins (n = 36) were aged for 4 or 20 d. Steaks were randomly assigned to a myoglobin oxygenation level [deoxymyoglobin (DeOxy; packaged within 3 min), oxygenation (Oxy; oxygenated in air for 30 min), or high oxygenation (HiOxy; packaged for 24 h in 80% O2)]. Steaks were then vacuum packaged in oxygen permeable or impermeable film and immediately frozen (-10 °C). Following either 0, 2, 4, or 6 months of frozen storage at -5 °C, steaks were removed from the packaging and immediately placed under simulated RD conditions for 7 d. During RD, instrumental color and subjective color were measured every day after the initial 24 h thaw period. Steaks were analyzed for instrumental color (L*, a*, b*), a*:b* ratio, percentage oxymyoglobin, metmyoglobin, and deoxymyoglobin, delta E, redness ratio, subjective discoloration, and lipid oxidation. For all days of RD, steaks that were frozen for 0 months had higher a* values (greater redness) than steaks frozen for 6 months which typically had the lowest a* values (P < .0001). HiOxy steaks frozen for 6 months had the lowest amounts of percentage oxymyoglobin than all other frozen storage periods and myoglobin oxygenation levels on days 4-7 of RD (P < .05). The HiOxy steaks frozen for 4 and 6 months had higher percentage metmyoglobin than DeOxy and Oxy, regardless of packaging (P < .05). Delta E, discoloration, and lipid oxidation were greatest for HiOxy steaks compared to Oxy and DeOxy (P < .05). Extended storage brought about detrimental color effects for all differing levels of myoglobin oxygenation. The HiOxy steaks through the first few days of RD and frozen for under 6 months provided had bright cherry red color, similar to that of DeOxy and Oxy. However, with extended frozen storage and RD, HiOxy steaks had worse color characteristics (more discoloration) than the other myoglobin oxygenation levels.

Haematobia irritans parasitism of F1 yak × beef cattle (Bos grunniens × Bos taurus) hybrids.

The horn fly Haematobia irritans (Diptera: Muscidae) is a blood obligate ectoparasite of bovids that causes annual losses to the U.S. beef cattle industry of over US$1.75 billion. Climate warming, the anthropogenic dispersion of bovids and the cross-breeding of beef cattle with other bovid species may facilitate novel horn fly-host interactions. In particular, hybridizing yaks [Bos grunniens (Artiodactyla: Bovidae)] with beef cows (Bos taurus) for heterosis and carcass improvements may increase the exposure of yak × beef hybrids to horn flies. The present paper reports on the collection of digital images of commingled beef heifers (n = 12) and F1 yak × beef hybrid bovids (heifers, n = 7; steers, n = 5) near Laramie, Wyoming (∼ 2200 m a.s.l.) in 2018. The total numbers of horn flies on beef heifers and F1 yak × beef heifers [mean ± standard error (SE): 88 ± 13 and 70 ± 17, respectively] did not differ significantly; however, F1 yak × beef steers had greater total horn fly abundance (mean ± SE: 159 ± 39) than female bovids. The present report of this experiment is the first such report in the literature and suggests that F1 yak × beef bovids are as susceptible as cattle to horn fly parasitism. Therefore, similar monitoring and treatment practices should be adopted by veterinarians, entomologists and producers.

Effects of different antioxidants on quality of beef patties from steers fed low-moisture distillers grains.

This research evaluated the effects of different antioxidants on overall quality of beef patties from steers fed distillers grains. Crossbred steers (n = 24) were fed corn, 40% Dry distillers grains plus solubles, or 40% modified distillers grains plus solubles - Dry Matter basis). Patties were made from ground chuck of individual animals and 4 antioxidant treatments were evaluated (CONTROL - no antioxidant, 0.3% ROSEMARY, 0.25% ACEROLA, and 0.6% CITRUS). Diets minimally affected quality attributes. Patties treated with ROSEMARY were shown significant lighter in color than other treatments on day 6. Patties treated with CITRUS were the reddest on days 5 and 6 of display. ACEROLA and CITRUS provided better lipid stability during display when compared to CONTROL and ROSEMARY. Treatment CITRUS reduced APC growth by 2 log when compared to all other treatments (P < 0.01). Although patties treated with CITRUS had higher off-flavor intensity, no effect was observed for overall desirability. Patties treated with 0.6% of CITRUS provided optimal overall quality.

Evaluation of palatability and muscle composition of novel value-added beef cuts.

The aim of this study was to evaluate the muscle profile of novel added-value beef cuts including the caudal tip of the M. infraspinatus (Bonanza Cut; TIP) and M. subscapularis (SUB) and two traditional sirloin steak cuts, M. gluteus medius (top sirloin; GLM) and M. rectus femoris (sirloin tip; REC). Samples were subjected to Warner-Braztler Shear Force (WBSF), sensory, cooking loss, and proximate analysis. The muscle TIP had superior values of subjective tenderness, juiciness, and slight off-flavor intensity when compared to all other muscles. The TIP and SUB were similar in WBSF. Cooking loss and moisture values of raw samples were lowest for TIP. Results suggest that TIP can provide enhanced eating experience for consumers and improved marketability for the meat industry.

Effects of finishing diets containing wet distillers grains plus solubles on beef quality attributes and fatty acid profile.

The objective of this study was to evaluate the effects of feeding wet distillers grains plus solubles (WDGS) on quality attributes of three beef muscles (longissimus lumborum, psoas major, and infraspinatus). Ninety-six, yearlings crossbred steers were randomly assigned to one of three dietary treatments (Corn, 15%, or 30% WDGS - DM basis) and fed for 133 d. No significant differences were observed in marbling score (P=0.89), marbling texture (P=0.70), and marbling distribution (P=0.36). Greater concentrations of PUFA and lower levels of 18:1(n-7) were observed in beef from steers fed 30% WDGS when compared to other treatments. Lipid oxidation was also greater in beef from steers fed 30% WDGS (P≤0.05). No significant differences were observed in sensorial attributes and Warner-Bratzler shear force (WBSF) for all muscles (P>0.05). Feeding WDGS increased PUFA and lipid oxidation, which may lead to shorter shelf life.

Impact of feeding de-oiled wet distillers grains plus solubles on beef shelf life.

Research was conducted to determine the effect of feeding de-oiled wet distillers grains plus solubles (WDGS) on beef fatty acid profile, retail shelf life and development of oxidation products during retail display (RD). A total of 336 crossbred yearling steers (initial BW = 351.08 ± 19.05 kg) were fed 1 of 7 dietary treatments: an all corn control (1:1 blend of dry rolled and high moisture corn), 35%, 50%, or 65% inclusion of WDGS, either full-fat or de-oiled. Within each treatment 15 Choice carcasses were randomly selected ( = 105), strip loins were obtained, aged 7 and 21 d, and representative steaks from each strip loin were placed in RD conditions for 7 d. Fatty acid profiles were determined (mg/100 g tissue basis) and differences ( ≤ 0.05) were found in the C16:1, C18:1T, C18:2 and total polyunsaturated fatty acids (PUFA) among dietary treatments. Palmitoleic acid (C16:1) was predominant ( < 0.0001) in the corn control group, intermediate in the 35% de-oiled WDGS group, but no differences ( > 0.05) were observed between all other diets. Elaidic acid (C18:1T) was greater ( = 0.01) in the 65% full-fat WDGS group, least for the corn control group, and intermediate for all other diets. Linoleic acid (C18:2) was greater ( = 0.0001) in all 3 full-fat WDGS groups and 65% de-oiled WDGS group (290.98 mg/100 g, on average), intermediate in the 50% and 35% de-oiled WDGS groups (231.08 and 227.16 mg/100 g, respectively) and least for the corn control group (177.70 mg/100 g). The PUFA content was greater ( < 0.01) in all 3 full-fat WDGS groups and 65% de-oiled WDGS group (337.13 mg/100 g, on average), intermediate in the 50% and 35% de-oiled WGDS groups (274.77 and 273.84 mg/100 g, respectively) and least for the corn control group (223.98 mg/100 g). Dietary treatment did not alter discoloration ( = 0.30) or lipid oxidation ( = 0.36). Shear force decreased with age and RD ( < 0.0001) but dietary treatment had no effect on shear force ( = 0.93). In general, feeding 35% and 50% de-oiled WDGS had intermediate PUFA content relative to a corn control or full-fat WDGS diet. Feeding de-oiled WDGS did not seem to increase beef shelf life and does not negatively alter beef quality parameters in relation to full-fat WDGS.

Beef palatability and its relationship with protein degradation and muscle fibre type profile in longissimus thoracis in Alentejana breed from divergent growth pathways.

The traditional beef production in the South of Portugal is based on a discontinuous growth (DG) system that requires lower external inputs and could enhance meat quality and financial returns to cattle producers. This system allows farmers to take advantage of the bull's compensatory growth when the pasture is abundant and finishes the cattle on concentrates for 2 to 3 months before slaughter. The fast gain rate before slaughter could be a valuable strategy to improve tenderness and to reduce its inconsistency in beef production. Therefore, the aim of this study was to evaluate the effects of production system (continuous growth (CG) v. DG) on longissimus thoracis muscle properties from Alentejana bulls. In total, 40 Alentejana male calves were allocated to two distinct feeding regimes: in the CG system, animals were fed concentrate plus hay and slaughtered at 18 months of age, whereas in the DG system, animals were fed on hay until 15 months of age and then fed the same diet provided to the CG group until 24 months of age. The DG system had a positive impact on meat tenderness (P<0.001) and global acceptability (P<0.001). DG bulls had greater fibre cross-sectional area (CSA) of glycolytic fibres (P<0.05) and relative area of the muscle (RA) occupied by type IIX fibres (P<0.01) and greater levels of α-actinin (P<0.05) and myosin light chain 2 (P<0.01) proteins, and pH24h (P<0.01) than CG bulls. The latter had greater CSA of type I (P<0.05) and type IIA (P<0.01) and greater RA of type IIA (P<0.05) and oxidative (P<0.05) than CG bulls. The compensatory growth production system had a positive impact on meat tenderness and global acceptability, overcoming the negative effects of slaughter of the bulls at a later age. The DG beef system could be a worthwhile strategy of beef production in Mediterranean areas due to the low-quality pasture in summer.

Repercussions of growth path on carcass characteristics, meat colour and shear force in Alentejana bulls.

The aim of this study was to evaluate the carcass and meat characteristics of eight muscles from bulls with distinct growth paths. A total of 40 Alentejana male calves were allocated to two distinct feeding regimes. In the continuous growth (CG) system, the animals were fed concentrates plus hay and were slaughtered at 18 months of age. On the other hand, in the discontinuous growth (DG) system, the animals were fed hay until 15 months of age; the cattle were then fed the same diet provided to the CG group from 15 to 24 months of age. The DG reduced hot carcass weight, fatness and dressing %, but the proportions of fat, bone and muscle tissues in the leg were not affected. In contrast, there was a positive impact of compensatory growth on supraspinatus, triceps brachii, semitendinosus, biceps femoris muscle tenderness, overcoming the negative effects of age at slaughter. The reasons for such improvement in meat tenderness were not related to intra-muscular fat content or myofibrillar protein degradation values. An association between tenderness and muscle collagen properties was not established. The results indicate that the compensatory growth has a muscle-dependent effect.

Genome wide association study of cholesterol and poly- and monounsaturated fatty acids, protein, and mineral content of beef from crossbred cattle.

The objectives were to determine the variation explained by the BovineSNP50v2 BeadChip for cholesterol (CH), polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), protein, and minerals in beef cattle, and to identify chromosomal regions that harbor major allelic variants underlying the variation of these traits. Crossbred steers and heifers (n=236) segregating at the inactive myostatin allele on BTA2 were harvested and steaks were sampled from the M. semitendinosus and the M. longissimus thoracis et lumborum for nutrient analysis. A Bayes C algorithm was employed in genome-wide association analysis. The resulting posterior heritability (SD) estimates ranged from 0.43 (0.10) to 0.71 (0.08) for lipid traits and 0.05 (0.08) to 0.75 (0.06) for mineral traits. Across cuts, correlations between genomic estimated breeding values (GEBV) were similar for CH, MUFA and PUFA. The top 0.5% 1-Mb windows for all traits explained up to 9.93% of the SNP variance. Slight differences did exist between cuts and between different measurement scales of fatty acids.

The effects of freezing and thawing rates on tenderness, sensory quality, and retail display of beef subprimals.

The objective of this study was to evaluate processing methods for frozen beef subprimals; the effects of freezing and thawing rates on tenderness, sensory properties, and retail display were evaluated. There were 6 treatments: fresh, never frozen 14 d wet aged (14D); fresh, never frozen 21 d wet aged (21D); blast frozen-fast thawed (BF); blast frozen-slow thawed (BS); conventionally frozen-fast thawed (CF); and conventionally frozen-slow thawed (CS). All frozen beef subprimals were aged for 14 d before freezing. Three beef subprimal cuts, rib eye roll (n=90), strip loin (n=90), and top sirloin butt (n=90), were used with 3 replications of 5 samples per treatment per week (total of 9 wk, n=270). Blast freezing occurred by placing spacers between the boxes of meat on pallets at -28°C with high air velocity for 3 to 5 d. Conventional freezing occurred with boxes of meat stacked on pallets and placed in a -28°C freezer with minimal air movement for at least 10 d. Fast thawing of subprimals (to an internal temperature of -1°C to 1°C) occurred by immersion in a circulating water bath (<12°C) for 21 h, and slow thawing of subprimals occurred over a 2-wk period by placing individual subprimals on tables at 0°C. Steaks (2.5 cm thick) were cut from the longissimus thoracis (LT), longissimus lumborum (LL), and gluteus medius (GM) for Warner-Bratzler shear force (WBS), trained sensory evaluation, and retail display. For LL and GM beef steaks, frozen treatments were equal or lower in WBS values to 14D and 21D beef steaks. No differences were detected in WBS among the treatments applied to GM beef steaks (P=0.08). There were no differences in sensory tenderness among the LL, LT, and GM (P>0.05). All LL and LT beef steaks had approximately 4 d to 40% discoloration, and all GM steaks had over 3 d to 40% discoloration. Steaks from the LL and LT began to discolor at about 3 d, and the GM began to discolor after 1 d. For all beef subprimals, purge loss during storage and thawing was significantly greater for the slow-thawed subprimals (P<0.01), and all fast-thawed subprimals were equal or superior to 14D and 21D (P<0.01) in storage and thawing purge. During retail display, the greatest purge loss occurred in fast-thawed treatments (P<0.01). Overall, freezing rate did not affect purge loss, and neither freezing nor thawing rates had significant meaningful effects on WBS, and sensory properties were comparable with fresh, never-frozen subprimals.

Effects of feeding modified distillers grains plus solubles on marbling attributes, proximate composition, and fatty acid profile of beef.

Wet distillers grains contain approximately 65% moisture. A partially dried product [modified distillers grains plus solubles (MDGS)] contains about 50% moisture. However, both have similar nutrient composition on a dry matter basis. The objective of this study was to investigate the effects of finishing diets varying in concentration of MDGS on marbling attributes, proximate composition, and fatty acid profile of beef. Yearling steers (n = 268) were randomly allotted to 36 pens, which were assigned randomly to 0, 10, 20, 30, 40 and 50% MDGS (DM basis) and fed for 176 d before harvest. The 48-h postmortem marbling score, marbling texture, and marbling distribution were assessed by a USDA grader and 1 ribeye slice (longissimus thoracis) 7 mm thick was collected from each carcass for proximate and fatty acid analyses. Treatments did not significantly alter marbling score or marbling distribution (P ≥ 0.05). United States Department of Agriculture Choice slices had coarser marbling texture when compared with USDA Select. Although dietary treatment affected marbling texture, no consistent pattern was evident. Diets did not influence fat content, moisture, or ash of the ribeye (P ≥ 0.05). For treatments 0, 10, 30, 40 and 50%, there were positive linear relationships between marbling score and fat percentage in the ribeye (P ≤ 0.05), and all slopes were similar (P = 0.45). Feeding MDGS linearly increased stearic, linoelaidic, linoleic, linolenic, PUFA, and n-6 fatty acids. As dietary MDGS increased, linear decreases were observed in all n-7 fatty acids and cubic relationships were detected for the 18:1 trans isomers [trans-6-8-octadecenoic acid (6-8t), elaidic acid (9t), trans-10-octadecenoic acid (10t), and trans vaccenic acid (11t)]. No effects were observed for saturated fatty acids containing 6 to 14 carbons. Feeding MDGS resulted in increased PUFA, trans, and n-6 fatty acids, minimal effects on marbling texture, and no effects on the relationship of marbling to intramuscular fat content relationship.

Beef quality of calf-fed steers finished on varying levels of corn-based wet distillers grains plus solubles.

Calf-fed crossbred steers (n = 94) were randomly allocated to 3 dietary treatments (0%, 15%, or 30% wet distillers grains plus solubles, WDGS; DM basis) and fed for 167 d to determine the effects on quality attributes of beef. At 48 h postmortem, marbling score, marbling texture, and marbling distribution were assessed by a USDA grader. After grading, one rib eye slice (longissimus thoracis) ¼7 mm thick was excised from each carcass, trimmed of subcutaneous fat, and analyzed for fatty acid profile and lipid content. At 7 d postmortem, 48 top blades (infraspinatus), strip loins (longissimus lumborum), and tenderloins (psoas major) (16 per treatment) were removed from shoulder clods and short loins and 2 steaks were obtained to measure mineral content, fatty acid profile (except strip loins), trained sensory analysis, objective color, and lipid oxidation. Finishing diet did not influence the content of total lipid (P = 0.19) or marbling, marbling texture, or marbling distribution (P = 0.46, 0.84, 0.40, respectively). Feeding WDGS created a linear increase (P < 0.01) of PUFA in all three muscles (longissimus thoracis showed 4.90%, 5.91%, and 6.23% PUFA for 0%, 15%, and 30% WDGS, respectively). Similar responses were observed for 18:2(n-6) and total n-6 fatty acids. Conversely, lower proportions of 18:1(n-7) fatty acid were observed in beef from animals fed 30% WDGS (P < 0.01). Total trans fatty acids increased linearly in strip loin and top blade steaks (P < 0.01), whereas proportions of 16:0 and 14:1(n-5) fatty acids decreased in all muscles (P < 0.01) as WDGS increased. Diet did not affect mineral content of top blades or strip loins. For tenderloin steaks, S concentration was lower when 30% of WDGS was fed (P = 0.05). No effects on sensory attributes and Warner-Bratzler shear force were observed (P > 0.50), except a minimal effect on strip loin juiciness (5.32, 4.86, and 5.52 for 0%, 15%, and 30% WDGS, respectively; P = 0.02). Top blade and tenderloin steaks from cattle fed 30% WDGS were significantly less red (lower a* values) on d 3 of simulated retail display (P < 0.04). Inclusion of 30% WDGS in the diet resulted in higher levels of oxidation after 7 d of retail display for top blade and strip loin steaks (P < 0.01). Feeding WDGS to calf-fed steers altered fatty acid profile, increased oxidation, and decreased color stability during retail display.

Evaluation of performance, carcass characteristics, and sensory attributes of beef from finishing steers fed field peas.

Whole field peas were fed at 0, 10, 20, and 30% of DM to 139 yearling steers (British cross; 409 ± 31 kg of initial BW) for a 119-d finishing period. Carcass data and Choice grade strip loins (n = 98) were collected from a commercial abattoir in Lexington, Nebraska. Consumer sensory and Warner-Bratzler shear force analyses were performed on 2.5-cm strip steaks. No differences (P ≥ 0.17) were observed in final BW, ADG, DMI, and G:F of steers. Likewise, no differences (P ≥ 0.23) were observed for HCW, LM area, fat thickness at the 12th rib, yield grade, and marbling scores. However, KPH responded quadratically to increasing dietary amount of field peas (P = 0.02). Regarding the sensorial analysis, feeding peas linearly increased subjective tenderness (P < 0.01) and led to a quadratic response of overall like ratings (P = 0.01) and flavor like ratings (P = 0.12). Feeding peas did not alter (P ≥ 0.64) juiciness, but decreased shear force values linearly when quantities were increased (P = 0.02). These data suggest that feeding peas does not affect steer performance or carcass characteristics differently from dry-rolled corn, but does improve objective and subjective tenderness, overall desirability, and flavor of beef. Field peas could be fed to cattle and give positive attributes to the quality of the meat up to 30% inclusion in the diet.

Effect of cooking method, distiller's grains, and vitamin E supplementation on the vitamin content of value cuts from beef steers fed wet distiller's grains and solubles and supplemental vitamin E.

Vitamin E, thiamin, riboflavin, niacin, vitamin B(6), and vitamin B(12) concentrations of flat iron steaks and petite tenders from steers fed finishing rations containing 0% and 40% corn wet distiller's grains and solubles (WDGS) with and without supplemental vitamin E were determined. Feeding treatment groups were: 0% WDGS with basal vitamin E, 0% WDGS with supplemental vitamin E (500 IU daily), 40% WDGS with basal vitamin E, and 40% WDGS and supplemental vitamin E. Cattle can be fed 40% WDGS diets more economically than corn diets. The incorporation of 40% WDGS, with and without vitamin E, was hypothesized to have little effect on the vitamin concentrations of these value meat cuts. Flat iron steaks and petite tenders were broiled and/or grilled to 70 degrees C internal temperature. Mean cooking yields ranged from 68.7% to 78.2%. The majority of the vitamin concentrations of broiled and of grilled meat were significantly different (P < 0.05) from that of raw meat. Vitamin E concentrations of raw and cooked meat from steers that received supplemental vitamin E were significantly higher (P < 0.05) than those fed basal vitamin E. Significant differences in thiamin, riboflavin, vitamin B(6), and vitamin B(12) concentrations in raw flat iron steaks and in vitamin B(6) in raw petite tenders were observed by WDGS. Thiamin, vitamin B(6), and vitamin B(12) concentrations of broiled flat iron steaks were significantly different (P < 0.05) than grilled. A few differences in vitamin concentrations of the flat iron steaks and petite tenders were observed by WDGS, vitamin E supplementation, and cooking treatments, but most of the vitamin concentrations were statistically similar.

Mapping of intramuscular tenderness and muscle fiber orientation of muscles in the beef round.

Intramuscular tenderness variation and muscle fiber orientation of beef M. adductor femoris (AF), M. biceps femoris (BF), M. gracilis (GL), M. pectineus (PT), M. sartorius (SR), M. semimembranosus (SM), M. semitendinosus (SO), M. vastus intermedius (VI), M. vastus medialis (VM), and M. vastus lateralis (VL) were investigated. The USDA Choice boxed beef subprimals were purchased and aged for 14 d from boxed date. The AF, BF, GL, PT, SR, SM, SO, VI, VM, and VL (n = 10 each) were fabricated from subprimals. Crust-frozen AF, BF, SO, SM, and VL were cut into 2.54-cm steaks perpendicular to the long axis and grilled (71 degrees C). The PT, SR, VI, and VM were grilled (71 degrees C) as whole muscles, whereas the GL was grilled after cutting into anterior and posterior regions. Grilled muscles were cut into equal size sections perpendicular to long axis of muscles. Location-specific cores were prepared from each steak/section, and Warner-Bratzler shear force (WBSF) was measured. The muscle fiber orientations of BF, PT, and VI were bipennate, SR and SO were fusiform, and AD, SM, VL, GL, and VM were unipennate. The overall mean WBSF values for BF, SO, AF, SM, PT, SR, GL, VI, VM, and VL were 5.62, 4.86, 4.18, 4.90, 3.76, 4.44, 4.75, 4.78, 4.24, and 6.53 kg, respectively. Based on WBSF values, PT was tender, BF and VL were tough, and VM, VI, SM, GL SR, AF, and SO were intermediate. The first 2 proximal steaks of long head BF were more tender than the rest (P < 0.05). In the SO, the tenderness decreased from the middle of the muscle to both ends (P < 0.05). The anterior sides of the long head BF and SO were tougher than their posterior sides (P < 0.05).The first 4 steaks of the SM were more tender than the rest of the muscle (P < 0.05). There was a significant tenderness increment from the middle of the AF and SR to both ends of each muscle (P < 0.05). The medial side of the VI was more tender than its lateral side (P < 0.05). The VM had its smallest shear force value at the most distal end compared with the rest (P < 0.05). Dry or moist heat oven roasting, as compared with grilling, significantly tenderized SO (P = 0.002) and VL (P < 0.0001) muscles. There were no significant WBSF value differences along the PT and between anterior and posterior regions of the GL. Based on WBSF ratings, PT, SR, VM, GL, and VI could be merchandized as single muscle steaks or medallions and the first 2 to 4 steaks of long head BF, SM, and AF could be marketed as premium-quality steaks. This detailed information on intramuscular tenderness and muscle fiber orientation variations of the round muscles could be used in a value added strategy for the beef round.

Application of exogenous enzymes to beef muscle of high and low-connective tissue.

Exogenous enzymes tenderize meat through proteolysis. Triceps brachii and Supraspinatus were randomly assigned to the seven enzyme treatments, papain, ficin, bromelain, homogenized fresh ginger, Bacillus subtilis protease, and two Aspergillus oryzae proteases or control to determine the extent of tenderization (Warner-Bratzler shear and sensory evaluation) and mode of action (myofibrillar or collagen degradation). Sensory evaluation showed improvement (P<0.0009) for tenderness and connective tissue component and all except ginger had a lower shear force than the control (P<0.003). Ginger produced more off-flavor than all other treatments (P<0.0001). Only papain increased soluble collagen (P<0.0001). Control samples were only significantly less than ficin for water soluble (P=0.0002) and A. oryzae concentrate for salt soluble proteins (P=0.0148). All enzyme treatments can increase tenderness via myofibrillar and collagenous protein degradation with no difference among high and low-connective tissue muscles.

Efficacy of performing Warner-Bratzler and slice shear force on the same beef steak following rapid cooking.

The ability to perform Warner-Bratzler and slice shear force on the same beef top loin steak was investigated. Three, 2.54-cm steaks from top loins (n=99) were allotted to either Warner-Bratzler only (WBS), slice shear force only (SSF), or Warner-Bratzler and slice shear force (WBS/SSF). Steaks were thawed at 2 degrees C for 48h prior to cooking. Steaks were cooked to 71 degrees C using a conveyor convection oven and allowed to cool at room temperature for a minimum of 4h. Steaks allotted to WBS used six 1.27-cm cores and steaks allotted for WBS/SSF used four cores. Steaks allotted to SSF and WBS/SSF used one, 1 cm x 5 cm slice. Correlations among WBS and SSF for all steaks ranged from 0.49 to 0.69 (P<0.0001). When correlations were generated for steak location within the top loin, the relationships among WBS and SSF performed in the same steak ranged from 0.53 to 0.70 (P<0.05). These results indicate that it may be feasible to conduct WBS and SSF on the same top loin steak, and that the steak taken 2.54 cm from the 13th rib is the optimal location for this combination of procedures.