Biomedical subjects

J B Morgan

Publications and source records attributed to J B Morgan.

At least 19 recordsLinked to original sources

PubMed2006

Effects of supplemental manganese on performance of growing-finishing pigs and pork quality during retail display.

Crossbred barrows and gilts (n = 168) were used to test the effects of supplemental Mn during the growing-finishing period on performance, pork carcass characteristics, and pork quality during 7 d of retail display. Pigs were blocked by BW and allotted within blocks to pens (5 pigs/pen in blocks 1, 2, 5, and 6, and 4 pigs/pen in blocks 3 and 4). A total of 36 pens was randomly assigned to 1 of 6 dietary treatments, where the basal diets were formulated with (PC) or without (NC) Mn in the mineral premix, and supplemented with 0 or 350 ppm (as-fed basis) of Mn from MnSO4 or a Mn-AA complex (AvMn). Pigs were slaughtered at a commercial pork packing plant when the lightest block of pigs averaged 113.6 kg. During fabrication, boneless pork loins were collected and transported to Oklahoma State University, where 2.5-cm-thick LM chops were packaged in a modified atmosphere (80% O2 and 20% CO2) and subsequently placed in display cases (2 to 4 degrees C) under continuous fluorescent lighting (1,600 lx) for 7 d. Pig performance was not (P > or = 0.44) affected by supplemental Mn; however, during the grower-II phase, pigs fed the basal diets including Mn consumed less (P < 0.02) feed and tended to be more efficient (P < 0.09) than pigs fed the basal diets devoid of Mn. Throughout the entire feeding trial, neither dietary nor supplemental Mn altered (P > or = 0.22) ADG, ADFI, or G:F. Chops from pigs fed the diets supplemented with MnSO4 received greater (P < or = 0.05) lean color scores and had a redder (greater a* and hue angle values), more vivid color than chops from pigs fed the diets supplemented with AvMn. Additionally, LM chops from pigs fed the PC diets supplemented with MnSO4 were darker (lower L* values; P < 0.05) than chops from pigs fed the NC diets or PC diets supplemented with 0 or 350 ppm of AvMn. Even though discoloration scores were similar during the first 4 d of display, chops from pigs fed the PC diets supplemented with MnSO4 were less (P < 0.05) discolored on d 6 and 7 of retail display than chops from pigs fed the PC or NC diets and diets supplemented with AvMn (dietary treatment x display time, P = 0.04). Results of this study indicate that feeding an additional 350 ppm of Mn from MnSO4 above the maintenance requirements of growing-finishing pigs does not beneficially affect live pig performance but may improve pork color and delay discoloration of pork during retail display.

Animal Feed↗

PubMed2006

Growth performance, carcass composition, quality, and enhancement treatment of fresh pork identified through deoxyribonucleic acid marker-assisted selection for the Rendement Napole gene.

Progeny (n = 70) from unrelated, DNA tested, Rendement Napole carrier (RN-/rn+) Hampshire sires, and DNA tested, Rendement Napole normal (rn+/rn+) Yorkshire dams were genotyped for the segregating RN- allele via DNA marker-assisted methodology. Six slaughter groups ensued, with littermates all being represented within the same slaughter group. Boneless pork loins were removed from right carcass sides after a 48-h chill at 2 degrees C. The anterior portions of the loins were not enhanced, whereas the posterior sections were enhanced with a solution containing 0.5% sodium chloride and 0.5% sodium tripolyphosphate to 110% of their initial weight. Carcasses of carrier pigs had less (P < 0.05) 10th rib fat depth and a greater (P < 0.01) percentage carcass lean than carcasses of normal pigs. Postmortem LM pH of carrier pigs was lower (P < 0.002) at 3, 6, 12, and 24 h, and tended to be lower (P = 0.062) at 48 h compared with that of normal animals. Samples of LM from carrier pigs had greater (P < 0.01) glycolytic potential values, drip loss percentages, and a* values, and lower pH values at fabrication than LM from normal pigs. No genotype differences (P > 0.05) were found for LM lactate, L*, or b* values. Nonenhanced semimembranosus samples from carrier pigs exhibited greater (P < 0.05) purge loss percentages and L* values, and lower (P < 0.01) pH values than samples from normal pigs. Enhanced LM samples exhibited greater (P < 0.05) drip and purge loss percentages, greater pH, and lower L* values at fabrication, regardless of Napole status. These findings suggest that the Napole gene has a positive influence on carcass leanness but detrimental effects for lean quality, which were often further compounded when meat was subjected to enhancement treatment.

Animals↗

PubMed2005

Effects of grazing program and subsequent finishing on gene expression in different adipose tissue depots in beef steers.

This experiment was conducted to examine the effects of grazing program and subsequent finishing on gene expression in adipose tissue from steers. Twenty Angus x Angus-Hereford steer calves (initial BW = 231 +/- 25 kg) were allotted randomly to one of two winter grazing treatments: 1) grazing winter wheat pasture to achieve a high rate of BW gain (HGW); or 2) grazing dormant tallgrass native range (NR). Steers in the NR treatment were provided 0.91 kg.steer(-1).d(-1) of a 41% CP (as-fed basis) cottonseed meal supplement. Following the grazing period, steers were assigned randomly to feedlot pens. Steers were fed to a common endpoint of 1.27 cm of backfat between the 12th and 13th rib. Four steers from each treatment were slaughtered at the end of the grazing period, and the remaining steers from each treatment (n = 6) were slaughtered at the predetermined compositional endpoint. Intramuscular and s.c. fat samples were collected from LM sections of each steer at the 12th-/13th-rib interface on the left side. Pools of RNA were prepared for HGW and NR s.c. adipose tissue from steers slaughtered immediately after grazing. Suppression subtractive hybridization was performed followed by dot-blot hybridization screening to confirm differential expression of subtracted transcripts. Transcripts confirmed to be differentially expressed were subjected to dideoxy chain-termination sequencing. Quantitative reverse transcription PCR was performed on three differentially expressed clones: osteonectin, ferritin heavy chain, and decorin. Osteonectin, ferritin heavy chain, and decorin gene expression was greater (P < 0.05) in s.c. than in i.m. adipose tissue of finished steers. A depot x background interaction for osteonectin (P < 0.01) and ferritin heavy chain (P = 0.03) gene expression was observed for steers slaughtered after grazing, indicating that nutritional management can affect gene expression in adipose tissue depots differently. No differences resulting from prefinishing nutritional background (HGW or NR) were noted in osteonectin, ferritin heavy chain, or decorin gene expression in i.m. adipose tissue collected from finished steers, which might have resulted from feeding steers to the same compositional endpoint. Our data suggest that nutritional background alters gene expression in adipose depots, and that depots are influenced differently.

Adipose Tissue↗

PubMed2004

Does weaning influence growth and health up to 18 months?

BACKGROUND: National and international recommendations for the age of introducing solid foods (weaning) are founded on insufficient evidence and little is known about the short and medium term consequences associated with early or late weaning. AIMS AND METHODS: Data from over 1600 infants from five prospective randomised trials conducted in the UK between 1993 and 1997 were used to determine the influence of weaning < or =12 weeks or >12 weeks on growth and health outcomes (diarrhoea and vomiting, lower respiratory chest infections, atopy, sleep patterns) up to 18 months post-term, in term appropriate for gestational age (AGA), term small for gestational age (SGA), and preterm infants. RESULTS: Term infants weaned < or =12 weeks were heavier at 12 weeks of age than those weaned after 12 weeks, but showed slower gain in weight, length, and head circumference between 12 weeks and 18 months than those weaned after 12 weeks; by 18 months, there were no significant differences in size between the two groups. A similar pattern was seen in preterm infants. Breast fed term infants were more likely to be sleeping though the night at 9 months if they were weaned before 12 weeks. No weaning effects or interactions were observed for health outcomes. CONCLUSIONS: We found little evidence that weaning before or after 12 weeks influences health outcomes up to 18 months. Early weaned infants were larger at 12 weeks than later weaned infants but the growth trajectories of the two groups "converged" by 18 months. These findings do not exclude the later emergence of programmed effects of weaning practices.

Animals↗

PubMed2004

Influence of ceftiofur sodium biobullet administration on tenderness and tissue damage in beef round muscle.

The effect of a biobullet (BB) containing freeze-dried ceftiofur sodium antibiotic on the presence of injection lesions, tissue damage, and histological properties, as well as Warner-Bratzler shear force (WBSF), of the biceps femoris was investigated. Steer calves (n = 25) were individually identified and assigned randomly to a product administration treatment date (7, 14, 21, 28, or 35 d before slaughter). At each pre-slaughter ceftiofur BB administration time, identified steers (n = 5) were humanely placed into a standard commercial restraining chute, where a BB implant was administered from a distance of 6.09 m. Following a standard finishing period (120 d), steers were transported to a commercial beef processing and humanely slaughtered. Following a 36-h postmortem chilling (1 degree C) period, carcasses were graded and fabricated according to industry-accepted procedures. Paired muscle samples were individually identified, collected, and aged for 14 d postmortem. Muscles were dissected into 1.27-cm strips, followed by observation and palpation for the presence of injection site lesions. Preslaughter administration times of 7 and 14 d resulted in the presence of injection lesions (80 and 20%, respectively). In addition to the control samples, no muscle damage was observed in cattle treated with BB implants 21, 28, or 35 d before slaughter. Warner-Bratzler shear force measurements taken near lesions of BB steaks and in areas 5.08 cm from lesions of control steaks tended to be higher (P < 0.10) than for other BB and control sample locations. Concentrations of insoluble and soluble collagen were higher (P < 0.05) at the site of the lesion center in lesion-afflicted vs. with control steaks. Histological determinations of the relative proportions of muscle, connective tissue, and fat were altered (P < 0.05) in BB lesion-afflicted steak cores; however, these differences were negated outside the core location of BB-treated and control steaks. It seems that using the ceftiofur BB implant system within 14 d of slaughter does create injection site lesions and increase WBSF; however, when the BB implant system, containing 100 mg of freeze-dried ceftiofur sodium, was used according to the recommended procedure (> or = 30 d preslaughter), tissue damage, alterations in histological and collagen properties, and increased meat toughness were not observed.

Animals↗

PubMed2004

Characterization of certified Angus beef steaks from the round, loin, and chuck.

Beef carcasses (n = 150) of A-maturity were selected randomly to determine baseline shear force and sensory panel ratings, assess variation in tenderness, and evaluate mean value differences between Certified Angus Beef (CAB), commodity Choice, and Select steaks. Three steaks were removed from the triceps brachii (TB), longissimus lumborum (LL), gluteus medius (GM), semimembranosus (SM), biceps femoris (BF), and quadriceps femoris complex (QF), and assigned to Warner-Bratzler shear (WBSF) and sensory panel analyses. As anticipated, marbling score and measured percentage of i.m. fat were greatest (P < 0.05) for CAB, intermediate (P < 0.05) for Choice, and least (P < 0.05) for Select carcasses. A muscle x quality level interaction (P < 0.05) was observed for WBSF values and sensory panel tenderness ratings. The TB, LL, GM, and BF steaks from CAB carcasses had lower (P < 0.05) WBSF than Select steaks from the same muscles. Even though WBSF values did not differ (P > 0.05) between CAB and Choice QF and TB steaks, the LL and GM steaks from CAB carcasses were more tender (P < 0.05) than Choice-grade LL and GM steaks. The TB from Select carcasses had higher (P < 0.05) WBSF values than TB steaks from CAB or Choice carcasses, but sensory panel ratings indicated that quality level showed little consistency among the GM, SM, BF, and QF. Trained sensory panelists rated CAB LL steaks more tender (P < 0.05) than LL steaks from Choice and Select carcasses, and Choice LL steaks were evaluated as more (P < 0.05) tender than those from Select carcasses. These results demonstrate that the influence of marbling on tenderness was more evident in muscles of middle meats than in end cuts, particularly in muscles of the round.

Adipose Tissue↗

PubMed2003

Factors associated with weaning in full term and preterm infants.

BACKGROUND: The optimal age for the introduction of solid foods (weaning) in infants is poorly researched yet may have implications for both short and longer term health. Many parents do not comply with current guidelines. OBJECTIVE: To determine and compare the age at weaning in term appropriate size for gestational age (AGA), small for gestational age (SGA), and preterm infants, and factors associated with weaning age in these groups. DESIGN: Data from > 2000 infants from seven prospective randomised trails conducted between 1990 and 1997 were used to address the objectives. RESULTS: Most infants, term AGA, SGA, or preterm, received solids before 4 months of age. Only 2% of term infants were exclusively breast fed to 6 months of age. Formula fed infants received solids on average two weeks earlier than breast fed infants. Preterm infants were significantly more likely, and term SGA infants less likely, to receive solids at both 6 and 12 weeks after term than term AGA infants. Weight at 6 weeks of age was a stronger predictor of earlier weaning than either birth weight or weight gain from birth to 6 weeks in term infants. In preterm infants, formula feeding and maternal smoking were associated with earlier weaning. CONCLUSIONS: Infants born in the mid 1990s were weaned on average earlier than the 4 months recommended by the Department of Health. Earlier weaning was associated with less positive health behaviours. Further research is required to provide evidence based weaning guidelines, including specific advice for SGA and preterm infants, and to investigate longer term consequences of weaning practices.

Birth Weight↗

PubMed2003

Weaning preterm infants: a randomised controlled trial.

OBJECTIVE: To assess the effect on growth and iron status in preterm infants of a specially devised weaning strategy compared with current best practices in infant feeding. The preterm weaning strategy recommended the early onset of weaning and the use of foods with a higher energy and protein content than standard milk formula, and foods that are rich sources of iron and zinc. SUBJECTS AND DESIGN: In a blinded, controlled study, 68 preterm infants (mean (SD) birth weight 1470 (430) g and mean (SD) gestational age 31.3 (2.9) weeks) were randomised to either the preterm weaning strategy group (n = 37) or a current best practice control group (n = 31), from hospital discharge until 1 year gestation corrected age (GCA). MAIN OUTCOME MEASURES: Weight, supine length, occipitofrontal head circumference, and intakes of energy, protein, and minerals were determined at 0, 6, and 12 months GCA. Levels of haemoglobin, serum iron, and serum ferritin were assayed at 0 and 6 months GCA. RESULTS: Significant positive effects of treatment included: greater increase in standard deviation length scores and length growth velocity; increased intake of energy, protein, and carbohydrate at 6 months GCA and iron at 12 months GCA; increased haemoglobin and serum iron levels at 6 months GCA. CONCLUSIONS: The preterm weaning strategy significantly influenced dietary intakes with consequent beneficial effects on growth in length and iron status. This strategy should be adopted as the basis of feeding guidelines for preterm infants after hospital discharge.

Age Factors↗

PubMed2002

Factors affecting the introduction of complementary foods in the preterm infant.

OBJECTIVES: The aim of the study was to identify current infant feeding practices among carers of preterm infants. DESIGN: Structured interviews on milk and complementary feeding practices were conducted with mothers of preterm infants at intervals until infants were 12 months corrected age. SETTING: Recruitment took place in three local Surrey hospitals over a 2 y period. SUBJECTS: Two-hundred and fifty-three preterm infants (139 male, 114 female) including 33 sets of twins and three sets of triplets were recruited. RESULTS: Forty-nine percent of the preterm infant group received first solid foods (the commencement of 'weaning') before the current Department of Health (DoH) guideline. The mean+/-s.e.m. weaning age from birth was 17.1+/-0.23 weeks. Ninety-five percent of the infants were weaned before the DoH guideline when the data was examined from term (mean 11.5+/-s.e.m. 0.21 weeks). Twenty-one percent were weaned before the DoH guideline for preterm infants which is that 'the infant weighs at least 5 kg' (mean 5.61+/-s.e.m. 0.01 kg). Human milk-fed infants were significantly lighter at weaning than combined milk-fed infants (5.32+/-0.12 vs 5.72+/-0.01 kg; P<0.05) even though they were weaned at a similar age. Infant formula-fed infants (mean weaning age from term 10.2+/-0.47 weeks) were weaned significantly earlier than both human milk-fed (11.9+/-0.49 weeks; P<0.05) and combined milk-fed (11.9+/-0.25 weeks; P<0.005) infants. CONCLUSIONS: The introduction of complementary foods varied widely between carers of preterm infants and compliance with DoH guidelines was poor. Further studies on preterm infants are necessary to see if weaning practices affect long-term growth and morbidity and to provide a basis for the development of appropriate recommendations. SPONSORSHIP: This work was funded by the MAFF Food Intolerance Programme.

Age Factors↗

PubMed2002

National Beef Quality Audit-2000: survey of targeted cattle and carcass characteristics related to quality, quantity, and value of fed steers and heifers.

The National Beef Quality Audit-2000 was conducted to assess the current status ofthe quality and consistency of U.S. fed steers and heifers. Between May and November 2000, survey teams assessed hide condition (n = 43,415 cattle for color, brands, mud/manure), bruises (n = 43,595 carcasses), offal and carcass condemnation (n = 8,588 cattle), and carcass quality and yield information (n = 9,396 carcasses) in 30 U.S. beef packing plants. Hide colors were black (45.1%), red (31.0%), yellow (8.0%), Holstein (5.7%), gray (4.0%), white (3.2%), brown (1.7%), and brindle (1.3%). Brand frequencies were no (49.3%), one (46.2%), and two or more (4.4%), and brands were located on the butt (36.3%), side (13.7%), and shoulder (3.6%). Most cattle had no (18.0%) or a small amount (55.8%) of mud/manure on their hides, and they had no (77.3%) horns. Most carcasses (53.3%) were not bruised, 30.9% had one bruise, and 15.8% had multiple bruises. Bruise location and incidence were round (14.9%), loin (25.9%), rib (19.4%), chuck (28.2%), and brisket, flank, and plate (11.6%). Condemnation item and incidence were liver (30.3%), lungs (13.8%), tripe (11.6%), heads (6.2%), tongues (7.0%), and carcasses (0.1%). Carcass evaluation revealed these traits and frequencies: steer (67.9%), heifer (31.8%), and bullock (0.3%) sex-classes; dark-cutters (2.3%); A (96.6%), B (2.5%), and C or older (0.9%) overall maturities; and native (90.1%), dairy-type (6.9%), and Bos indicus (3.0%) breed-types. Mean USDA yield grade traits were USDA yield grade (3.0), carcass weight (356.9 kg), adjusted fat thickness (1.2 cm), longissimus muscle area (84.5 cm2), and kidney, pelvic, and heart fat (2.4%). USDA yield grades were Yield Grade 1 (12.2%), Yield Grade 2 (37.4%), Yield Grade 3 (38.6%), Yield Grade 4 (10.4%), and Yield Grade 5 (1.3%). Mean USDA quality grade traits were USDA quality grade (Select85), marbling score (Small23), overall maturity (A66), lean maturity (A65), and skeletal maturity (A67). Marbling score distribution was Slightly Abundant or higher (2.3%), Moderate (4.8%), Modest (13.1%), Small (33.3%), Slight (43.3%), and Traces (3.4%). USDA quality grades were Prime (2.0%), Choice (49.1%), Select (42.3%), Standard (5.6%), and Commercial, Utility, Cutter, and Canner (0.9%). This information will help the beef industry measure progress compared to the past two surveys and will provide a benchmark for future educational and research activities.

Animals↗

PubMed2001

Effects of supplemental vitamin D3 on feed intake, carcass characteristics, tenderness, and muscle properties of beef steers.

Research was conducted to determine the effects of supplemental dietary vitamin D3 on DMI, carcass traits, Warner Bratzler shear (WBS) force, calpastatin activity, plasma minerals, pH (0, 3, 12, and 24 h after slaughter), water-holding capacity (WHC), and sensory characteristics of three muscles. Pre-slaughter vitamin D3 treatments included no supplemental vitamin D3, 6 x 106 IU (MIU) of vitamin D3 for 4 d, or 6 MIU of vitamin D3 for 6 d. Cattle were slaughtered and carcasses were chilled for 48 h before removal of steaks from the longissimus, gluteus medius, and biceps femoris muscles. Steaks were aged at 2 degrees C for 7, 14, or 21 d before cooking to a final internal temperature of 70 degrees C for WBS and sensory panel analysis. Dry matter intake was lower for steers supplemented with vitamin D3 for 4 or 6 d. Live and carcass weights were lower (P < 0.05) in steers supplemented with vitamin D3. Supplementing 6 MIU/6 d of vitamin D3 decreased (P < 0.05) WBS values of gluteus steaks (pooled over aging times). Longissimus steaks from steers supplemented with vitamin D3 for 6 d had lower (P < 0.05) WBS force values than these steaks from control steers or steers fed vitamin D3 for 4 d at 7 d postmortem. Biceps femoris steaks from steers receiving vitamin D3 for 4 d had higher WBS values than steaks from control steers at 14 and 21 d postmortem. Feeding vitamin D3 at 6 MIU for 6 d decreased (P < 0.05) the percentage of steaks that had WBS values > or = 3.86 kg for all steaks. Feeding vitamin D3 had no effect on palatability traits evaluated by trained panelists. Blood Ca concentrations were greater (P < 0.05) when vitamin D3 was fed and with increased vitamin D3 feeding time. Feeding vitamin D3 for 6 d (vs 4 d) delayed pH decline for all muscle types after 0, 3, and 12 h postmortem. Water-holding capacity was increased (P > 0.02) after 0 h, 24 h, and 21 d postmortem when vitamin D3 was fed and was greater at 0 and 24 h if vitamin D3 was fed for 6 d rather than 4 d. These data suggest that supplementing 6 MIU of vitamin D3 will decrease DMI and improve beef tenderness through increased blood plasma Ca concentrations and WHC.

Animals↗

PubMed2001

Blood lipids and body fat in Bahraini women.

OBJECTIVE: The aim of this study was to examine some biomedical parameters of a representative sample from the population of overweight and obese, and average weight Bahraini women visiting 2 health centers in Bahrain. METHODS: This study was conducted over a period of 4 months in 2 health centers in the urban city of Muharraq in Bahrain, namely Muharraq Health Center and Shaikh Salman Health Center. The association was examined between body mass index, and the distribution of body fat determined by the waist hip ratio. Serum triglycerides, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, as well as glucose levels were measured. RESULTS: The 2 groups of pre-menopausal women selected for this study were of similar age (mean of 30.4 and 30.7 years) but differed significantly in their body mass index values; however, their mean waist hip ratio was similar (0.80 and 0.82). The type of obesity shown by these Bahraini women was not associated with an elevation of serum glucose concentrations, or with significant differences in either serum cholesterol or triglyceride concentrations. There was however, a statistically significant difference between the 2 groups with respect to the level of high-density lipoprotein cholesterol, which was lower in the obese group, compared with the lean counterparts. Furthermore, the ratio of high-density lipoprotein to low-density lipoprotein cholesterol was significantly lower in the obese subjects, compared with the controls. CONCLUSION: Obesity in a group of Bahraini women was associated with indices predisposing to coronary heart disease, and this has public health implications.

Adult↗

PubMed2001

Rational use of in vitro P-glycoprotein assays in drug discovery.

P-glycoprotein (Pgp) affects the absorption, distribution, and clearance of a variety of compounds. Thus, identification of compounds that are Pgp substrates can aid drug candidate selection and optimization. Our goal was to evaluate three assays used to determine whether compounds are Pgp substrates. Sixty-six compounds were tested in monolayer efflux, ATPase, and calcein-AM assays. Assay results yielded two categories of compounds. Category I (n = 35) exhibited concordance across the assays. Category II (n = 31) revealed differences among the assays that related to the apparent permeability (P(app)) of the compounds. Within category II, two groups were discerned based on the absence (group IIA, n = 10, nontransported substrates) or presence (group IIB, n = 21, transported substrates) of monolayer efflux. Detection of efflux (group IIB) was associated with compounds having low/moderate P(app) values (mean = 16.6 nm/s), whereas inability to detect efflux (group IIA) was associated with compounds having high P(app) values (mean = 535 nm/s). The calcein-AM and ATPase assays revealed Pgp interactions for highly permeable group IIA compounds but were less responsive than monolayer efflux for low/moderate P(app) compounds of group IIB. All assays detected substrates across a broad range of P(app), but the efflux assay was more prone to fail at high P(app), whereas the calcein-AM and ATPase assays were more prone to fail at low P(app). When P(app) is low, efflux is a greater factor in the disposition of Pgp substrates. The efflux assay is more reliable at low/moderate P(app) and is the method of choice for evaluating drug candidates despite low throughput and reliance on liquid chromatography with tandem mass spectrometry.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2000

Using live estimates and ultrasound measurements to predict beef carcass cutability.

Commercial slaughter steers (n = 329) and heifers (n = 335) were selected to vary in frame size, muscle score, and carcass fat thickness to study the effectiveness of live evaluation and ultrasound as predictors of carcass composition. Three trained personnel evaluated cattle for frame size, muscle score, fat thickness, longissimus muscle area, and USDA quality and yield grade. Live and carcass real-time ultrasound measures for 12th-rib fat thickness and longissimus muscle area were taken on a subset of the cattle. At the time of slaughter, carcass ultrasound measures were taken at "chain speed." After USDA grade data were collected, one side of each carcass was fabricated into boneless primals/subprimals and trimmed to .64 cm of external fat. Simple correlation coefficients showed a moderately high positive relationship between 12th rib fat thickness and fat thickness measures obtained from live estimates (r = .70), live ultrasound (r = .81), and carcass ultrasound (r = .73). The association between estimates of longissimus muscle area and carcass longissimus muscle area were significant (P < .001) and were higher for live evaluation (r = .71) than for the ultrasonic measures (live ultrasound, r = .61; carcass ultrasound, r = .55). Three-variable regression equations, developed from the live ultrasound measures, explained 57% of the variation in percentage yield of boneless subprimals, followed by live estimates (R2 = .49) and carcass ultrasound (R2 = .31). Four-variable equations using frame size, muscle score, and selected fat thickness and weight measures explained from 43% to 66% of the variation for the percentage yield of boneless subprimals trimmed to .64 cm. Live ultrasound and(or) live estimates are viable options for assessing carcass composition before slaughter.

Abattoirs↗

PubMed2000

National Beef Tenderness Survey-1998.

Fifty-six retail stores representing 15 retail chains and 14 foodservice facilities in eight U.S. cities were sampled to determine the tenderness of beef steaks at retail and foodservice levels based on Warner-Bratzler shear (WBS) values and consumer evaluation panels. Retail consumer panels were conducted at five universities. Each retail and foodservice steak was evaluated using 10-point scales. Steaks were divided into the following quality groups for statistical analysis: Prime, Top Choice, Choice, Select, and Lean or No Roll. Quality group had no effect on WBS values of retail clod, chuck roll, top round, bottom round, eye of round, top loin, top sirloin, or ribeye steaks but did (P < .05) affect values for the T-bone/porterhouse. The percentages of retail top round, eye of round, and bottom round steaks with a WBS force > 3.9 kg were 39.6, 55.9, and 68.0, respectively. Foodservice ribeye, top loin, and top sirloin steaks had WBS values less than 3.4 kg for all quality groups, with Prime ribeye steaks having lower (P < .05) WBS values than ribeyes from the other quality groups. With the exception of the retail ribeye steak, quality group did not affect consumer sensory ratings of retail and foodservice steaks. Average postfabrication aging times were 32 d for foodservice subprimals and 19 d for retail cut subprimals. These data indicate that improvements in the tenderness of retail cuts from the round are needed. Finally, quality group had little or no effect on consumer sensory evaluations and WBS values of retail and foodservice steaks used in this study.

Animals↗

PubMed1999

Vitamin D3 supplementation of beef steers increases longissimus tenderness.

The objectives of these experiments were to determine 1) the effectiveness of supplemental vitamin D3 (VITD) on altering plasma and muscle calcium levels, 2) whether VITD supplementation improves Warner-Bratzler shear force (WBS) values of steaks from feedlot beef steers, and 3) the tenderness response curve of longissimus steaks from steers supplemented with VITD. In Exp. 1, 20 crossbred steers were assigned randomly to one of four treatment diets consisting of either 0, 2.5, 5.0, or 7.5 x 106 IU of VITD per day for 10 d. Blood samples were obtained daily during this supplementation period and 5 d thereafter (d 11 to 15). Between d 6 and 13, a linear increase (P < .01) in ionized plasma calcium concentrations was observed in steers supplemented with VITD. Compared to unsupplemented steers, serum calcium concentrations of the steers receiving 7.5 x 106 IU of VITD per day were increased 8 to 48%. In Exp. 2, longissimus samples from crossbred steers (n = 118) that were supplemented with either 0 or 5 x 106 IU of VITD per day for 7 d were obtained and aged for 7, 14, or 21 d. Following the initial 7-d postmortem aging period, VITD supplementation lowered (P < .01) WBS (.58 kg) and increased sensory tenderness rating (.6 units) compared to cuts originating from unsupplemented steers. In Exp. 3, 44 steers were supplemented with either 0 or 7.5 x 106 IU of VITD per day for 10 d immediately prior to slaughter. Results indicated that plasma and longissimus calcium concentration were higher (P < .05) for steers that received supplemental VITD. Compared with unsupplemented cuts, VITD supplementation improved WBS of cuts aged for either 7 or 14 d (P = .02 and P = .07, respectively). Sensory panelists rated samples from VITD supplemented steers as more tender than their unsupplemented counterparts. Activation of calpain proteases could be responsible for the observed tenderization due to the supplementation of VITD.

Animal Feed↗

PubMed1999

Sources and extent of microbiological contamination of beef carcasses in seven United States slaughtering plants.

This study determined microbiological loads of beef carcasses at different stages during the slaughtering to chilling process in seven (four steer/heifer and three cow/bull) plants. Potential sources of contamination (feces, air, lymph nodes) were also tested. Each facility was visited twice, once in November through January (wet season) and again in May through June (dry season). Carcasses were sampled by aseptic excision of surface tissue (100 cm2) from the brisket, flank, and rump (30 samples each) after hide removal (pre-evisceration), after final carcass washing, and after 24-h carcass chilling. The samples were analyzed individually by standard procedures for aerobic plate counts (APC), total coliform counts (TCC), Escherichia coli biotype I counts (ECC), and presence of Salmonella. Incidence of Salmonella was higher on dry feces of older compared to younger animals, fresh feces of younger compared to older animals, and on cow/bull carcasses compared to steer/heifer carcasses. Most factors and their interactions had significant (P < or = 0.05) effects on the bacterial counts obtained. Depending on plant and season, APC, TCC, and ECC were < or =10(4), < or =10(2), and < or =10(1) CFU/cm2 in 46.7 to 93.3, 50.0 to 100.0, and 74.7 to 100.0% of the samples, respectively. TCC exceeded 10(3) CFU/cm2 in 2.5% (wet season) and 1.5% (dry season) of the samples. ECC exceeded 10(2) CFU/cm2 in 8.7%, 0.3%, and 1.5% of the pre-evisceration, final carcass-washing, and 24-h carcass-chilling samples, respectively, during the wet season; the corresponding numbers during the dry season were 3.5%, 2.2%, and 3.0%, respectively. These data should serve as a baseline for future comparisons in measuring the microbiological status of beef carcasses, as the new inspection requirements are implemented.

Abattoirs↗

PubMed1998

National Beef Quality Audit-1995: survey of producer-related defects and carcass quality and quantity attributes.

The National Beef Quality Audit-1995 was conducted to evaluate the progress of the beef industry since the time of the National Beef Quality Audit-1991 in improving quality and consistency of beef. Nine plants were assigned for auditing to Colorado State University, Oklahoma State University, and Texas A&M University. Personnel from each institution visited three of their nine plants twice, once in the spring/summer and once in the fall/winter. Data were collected on 50% of each lot on the slaughter floor and 10% in the cooler during a single day's production (one or two shifts, as appropriate). Of the cattle audited on the slaughter floor, 47.7% had no brands, 3.0% had a shoulder brand, 16.8% had a side brand, 38.7% had a butt brand, and 6.2% had brands in multiple locations. Data revealed that 51.6% of the carcasses had no bruises, 30.9% had one bruise, 12.8% had two bruises, 3.7% had three bruises, .9% had four bruises, and .1% had more than four bruises. In addition, 7.2% of the bruises evaluated were located on the round, 41.1% were on the loin, 20.8% on the rib, and 30.8% on the chuck. Livers, lungs, tripe, heads, tongues, and whole carcasses were condemned at rates of 22.2, 5.0, 11.0, .9, 3.8, and .1%, respectively. Mean USDA yield grade and quality grade traits were as follows: USDA yield grade, 2.8; carcass weight, 338.4 kg; adjusted fat thickness, 1.2 cm; longissimus muscle area, 81.9 cm2; kidney, pelvic, and heart fat, 2.1%; USDA quality grade, High Select; overall maturity, A60; and marbling score, Small-minus.

Animal Identification Systems↗