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Heat-induced gelation properties of the semimembranous muscle from induced DFD (dark, firm and dry) and normal pigs were characterized to evaluate the effect of muscle pH on strength and cooking loss of gels induced by a heating at 0.7C/min. The pH of muscle slurries (10% protein with 2% Nacl) were adjusted to 5.5, 6.0, 6.5, or 7.0 with 1 M 2-[N-Morpholino] ethanesulfonic acid buffer. Muscle with a high initial pH (DFD) had lower cooking losses at all adjusted pHs. Force required to penetrate the gel (Pf), force required to move plunger through the gel (Fp), and viscosity index of the gel were consistently higher for DFD muscle at each adjusted pH except pH 5.5. These results indicate that ultimate pH influences the thermal gelation properties of a meat product if the pH is ≥ 6.0. DFD muscle had desirable protein functionality and cooking yield.

This study was conducted to evaluate the effects of belly thickness on processing, sensory and visual characteristics, moisture and fat of bacon made from 45 bellies of various thicknesses. Belly thickness had a linear effect (P < 0.05) on raw, cured, and cooked weights, and water and fat content. A linear relationship (P < 0.05) was observed between belly thickness and slice integrity, appearance, and lean-to-fat ratio of bacon. Saltiness, texture and mouthfeel, bacon flavor intensity, and off-flavor intensity were unrelated to raw belly thickness.

Effects of heating rate (3°C or 0.7°C/min) and pH (5.5, 6.0, 6.5, or 7.0) on thermal gelation properties of different muscle systems were evaluated (10% protein, 2% NaCl) using pork, beef, fish, and chicken and turkey (breast and thigh) muscles. Results indicated that, at pH 6.5 and 7.0, force required to rupture the gel (Pf), force required to move plunger through the gel (Fp), and viscosity index (Ni), using a slow heating rate, were higher than with rapid heating. All muscles (except breast muscles with the slow heating rate) yielded higher (P

Myofibril gels with 5, 7, or 10% protein and 2% NaCl were prepared from pork, beef, fish, chicken and turkey muscles using a heating rate of 0.7°C/min and pH 6.0 to compare the thermal gelation properties of myofibrillar protein from different species. The force required to rupture gel (Pf), force required to move plunger through gel (Fp), viscosity index (Ni), and elasticity (Ea) increased and cooking loss decreased with increasing protein contents. Myofibrils of chicken breast and thigh had lower and fish and turkey thigh had higher cooking loss at protein contents of 7% or 10%.

Thermal gelation properties of myosin, actin, myofibrils (MF), sarcoplasmic protein (SP) and connective tissue (CTS) from pork semimem-branosus and chicken breast (CB) were evaluated. Gels were prepared at pH 6.0, 2% NaCl and cooked to 70°C at 0.7°C/min. Pork myosin had a higher gel strength and a lower cooking loss than CB myosin at 7% protein. Actin from both species did not form a measurable gel. MF gels from pork and CB had the lowest cooking loss while CTS and SP had the highest cooking loss. Difference in gel strength between muscle and MF+SP+CTS at 7% protein was not consistent with that at 10% protein.

Five barrows and five gilts of each of two breeds (Meishan [Ms] and Yorkshire [Y]) were slaughtered at birth and at 41, 71, 123, and 171 d of age and five gilts of each breed were slaughtered at 260 d of age. Major organ and visceral weights were obtained immediately postmortem (PM), whereas carcass characteristics, carcass composition, femur measurements, and two individual muscle weights were obtained 24 h PM. Linear and quadratic regression coefficients on age differed between the two breeds, in favor of Y barrows and gilts, for live weight, carcass weight, longissimus muscle area (LMA), liver, heart, spleen, and kidney weights, and femur cross-sectional, medullary, and cortical areas (P

We evaluated population management programs for controlling chronic wasting disease (CWD) in wild white-tailed deer in Illinois between November 2002 and March 2008. The intervention consisted of measures of deer removal from three deer population control programs: Illinois Department of Natural Resources culling, deer population control permits and nuisance deer removal permits. We included in the analysis a total of 14,650 white-tailed deer CWD test results. These data also included location and demographic data collected from both deer harvested in the interventions as well as deer from hunter harvests and deer vehicle collisions. We quantified intervention pressures as the number of years of intervention, the total number of deer removed and the average number of deer removed per year. We accounted for temporal and spatial variations of intervention by using mixed logistic regression to model the association between intervention pressures and CWD prevalence change. The results showed that deer population management intervention as practiced in Illinois during the study period was negatively associated with CWD prevalence and the strength of association varied depending on age of deer and the measure of intervention pressure. The population management programs showed a more consistent association with reduced CWD prevalence in fawn and yearling white-tailed deer than in adult deer. Our results also suggested that frequent and continuing intervention events with at least moderate intensity of culling were needed to reduce CWD prevalence. A longer study period, however, is needed to make a more definite conclusion about the effectiveness of similar population management programs for controlling CWD in wild white-tailed deer.

Chronic wasting disease (CWD) is a prion disease that leads to neurodegeneration and death in cervids. CWD management in Illinois has been based on selectively culling deer herds in CWD infected an...

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy caused by prions, and affects deer, elk and moose. CWD was first reported in Illinois in 2002 and continues to spread. Spa...

Special fed veal calves (N = 75) were slaughtered in study 1 and assigned to the following treatments; control (C), electrical stimulation (ES) immediately postmortem for 20 s (ES20–IP) or 40 s (ES40–IP), and ES 10 min postmortem for 20 s (ES20–10) or 40 s (ES40–10) using a Jarvis BV 80 electrical stimulator. Temperature, pH and 24 h carcass traits were evaluated. ES durations of 40 s produced more desirable carcass traits. In study 2, 40 calves were slaughtered and assigned to C or ES40–IP treatments. Temperature, pH, carcass characteristics, purge loss, percent free water, color stability, Warner-Bratzler shear force and palatability of biceps femoris slices were evaluated. ES reduced (P < 0.05) pH (at 45 min, 3 h and 24 h) and decreased (P < 0.05) percentage free water, but did not affect color stability, palatability or shear force values of veal from study 2. Low voltage ES enhanced postmortem pH decline in both studies (especially in study 1) and improved the 24 h (postmortem) longissimus characteristics of veal in study 1.

Boneless pork loins sliced into 1.9 cm fresh chops were dipped to retain 0, 1.5 or 3% sodium lactate (SL) and packaged in polyvinylchloride (PVC) or vacuum-packaged (VP), Color of fresh chops was monitored visually and objectively. Boneless pork loins were cured by injection with 0, 1.5 or 3% SL, or were dipped after slicing to retain 0, 1.5 or 3% SL. Cure for the dipped loins contained no SL. Color and aerobic plate count (APC) of vacuum-packaged chops were evaluated over 70 days of retail storage (4C). Visual color was darker (P 0.05) from controls. No consistent trends were found in APC of cured chops. Injection of SL prior to cooking darkened the color of cured pork loin chops.

Effects of porcine somatotropin (pST) on growth and carcass characteristics of Meishan (Ms) and Yorkshire (Y) barrows given 3 mg of pST or saline daily were determined for two end points. First, 26 Ms and 26 Y barrows were treated from 119 d of age until the Y barrows reached 108 kg. Second, another 18 Ms barrows were treated to 108 kg BW. Age- and weight-matched treatments were analyzed. Results for both groups indicated pST effects (P < .05) for feed conversion (+) and intake (-), dressing percentage (-), percentage of carcass fat (-) and protein and water (+), leaf fat (-), backfat (BF) thickness (-), longissimus muscle area (LMA; +), skin thickness (+), muscle firmness and marbling scores (-), organ weights (+), belly (-), clear plate (-), ham (+), and total boneless cuts (BC; +). Somatotropin effects were also present for loin (-) and boneless Boston butt (BBB; +) in the age-matched group and for ADG (+), carcass weight (-), loin (-), jowl (-), and tenderloin (+) in the weight-matched group. Breed effects (P < .05), in favor of Y barrows, in both treatments existed for ADG (+) and feed intake (+), carcass weight (+), dressing percentage (+), LMA (+), skin thickness (-), muscle color and firmness scores (-), muscling score (+), all wholesale cuts (WC; +) except clear plate (age-matched), all trimmed cuts (TC; +) except picnic shoulder (weight-matched), and all BC (+). Breed effects, in favor of Y barrows, were also determined for carcass length (+), percentage of carcass ash (-), leaf fat (+), average BF thickness (+), and heart (-) and liver (-) weights in age-matched animals and percentage of carcass fat (-), protein (+), water (+), leaf fat (-), 10th rib, average, and P2 BF thicknesses (-), marbling score (-), femur length (-), and liver weights (+) in weight-matched animals. A higher response to pST (P < .05) was determined in Ms barrows than in Y barrows for percentage of carcass protein (+), liver (+), and heart (+) in the age-matched treatment and 10th rib BF thickness (-) and heart weight (+) in the weight-matched treatment. Yorkshire barrows treated with pST had more improved values for color score (+; age-matched) and BBB (+; weight-matched).

Fresh (FL) and precooked (PL) longissimus chops and fresh semi-membranosus/adductor (SM) roasts were evaluated to determine acceptability of marinated pork. Citric acid and sodium acid pyrophosphate lowered pH (CAP), sodium acid pyrophosphate attained intermediate pH (SAP), and sodium tripolyphosphate increased pH (TPP). In FL and SM cuts, TPP improved sensory characteristics, water-holding capacity (WHC) and processing yields. CAP reduced microbial growth in FL chops and improved tenderness in SM roasts. In PL cuts, TPP improved juiciness and reheating yields. Marinating at low pH reduced microbial growth; marinating at high pH improved sensory properties, WHC, fresh pork processing yields and precooked pork juiciness and reheating yields.

Samples from subcutaneous, intermuscular and internal fat depots of 30 crossbred pig carcasses with tenth rib fat thickness ranging from 1.5 to 4.3 cm were used to evaluate the relationships of backfat thickness and fat depot composition (moisture, lipid and cholesterol contents). Moisture and cholesterol were highest and lipid content was lowest in intermuscular fat while cholesterol was lowest (P < 0.05) in subcutaneous fat when compared to the other fat depots. Significant (P < 0.01) linear effects of tenth rib fat depth on moisture and lipid contents of all fat depots were observed. Linear effects (P < 0.05) of tenth rib fat thickness on cholesterol content of subcutaneous and internal fat depots were observed on both a wet and dry bases. However, the linear effect (P < 0.05) of tenth rib fat depth on cholesterol content in the intermuscular fat depot was observed only on a dry basis. When the three fat depots were combined, increased tenth rib fat depth resulted in decreased moisture and cholesterol contents on a dry basis while percentage lipid increased (P < 0.05).

Pork and beef muscles were used to evaluate assay and storage condition effects on yields of salt soluble protein (SSP). Assay conditions included pH (5.5, 6.0 or 6.5), extraction volume (6, 9, 12 or 15 X sample weight), homogenization time (30, 60, 90 or 120 set) and centrifugal force (2500, 4000 or 5500 ×g). Storage conditions included postmortem aging (4°C for 0, 7 or 14 days) and freezing conditions (rapid freezing, slow freezing, and freezing-thawing-freezing). Highest yield of SSP was obtained using pH 6.0, extraction volume 15 X sample weight, centrifugation at 4000 ×g and homogenization time 90 to 120 set for both pork and beef. Freezing conditions did not affect measurement of SSP. Aging beef for 7 and 14 days postmortem reduced the yield of SSP; however, such differences were not observed for pork.

It is well known that a carbohydrate-rich diet promotes lipogenesis via induction of hepatic lipogenic enzymes, whereas chronic physical exercise reduces body fat. The purpose of this study was to investigate whether exercise training can decrease diet-induced hepatic lipogenic enzymes and total body fat composition. Female Sprague-Dawley rats were randomly divided into exercise trained (T) and sedentary (S) groups. Training was performed on a treadmill for 8 weeks for up to 25 m/minute, 15% grade for 90 minutes/day, 5 days/week. The T and S groups were further divided into four dietary treatments. Fifty percent of the calories for each diet were from a basal ingredient and the other 50% were from either cornstarch (C), glucose (G), fructose (Fr), or fat (Fa). T significantly decreased body fat and increased body water content in all dietary groups (p < 0.01), but had no effect on body weight. Fr rats had significantly heavier liver weight than did the remaining groups. Activities of hepatic fatty acid synthase, ATP-citrate lyase (CL), malic enzyme (ME), pyruvate kinase, and glucose-6-phosphate dehydrogenase were significantly higher in Fr and lower in Fa compared with C and G. Training significantly increased activities of CL and ME in Fa, but had little effect on these enzymes in other groups. These data suggest that the fat-reducing effect of conventional exercise training is elicited by regulatory mechanisms other than by a reduction of hepatic lipogenic enzymes.

Fifty growing pigs were used in two experiments to evaluate the effects of cannulation and hyperalimentation on performance and body composi- tion responses. Surgical implantation of a cannula into the greater curvature of the stomach and subsequent management associated with maintenance of the cannula did not result in a reduction (P > ,051 of voluntary feed intake. Cannulation did not negatively affect gain (P > .05). Over the entire trial, feed efficiency was not changed by cannulation (P > .05). Cannulation itself did not affect protein or fat deposition (P > .05) in the carcass. Hyperalimentation to approximately 120% of control intake resulted in increased daily gain (P .05) compared with that of control animals, Hyperalimentation decreased protein deposi- tion (P < .05) and tended to increase fat deposition.

Biochemical and biophysical research tools are used to define the developmental dynamics of numerous cell lineages from a variety of tissues relevant to meat quality. With respect to the adipose cell lineage, much of our present understanding of adipogenesis and lipid metabolism was initially determined through the use of these methods, even though the in vitro or molecular environments are far removed from the tissues of meat animals. This concise review focuses on recent cellular and molecular biology-related research with adipocytes, and how the research might be extended to the endpoint of altering red meat quality. Moreover, economic and policy impacts of such in animal production regimens is discussed. These issues are important, not only with respect to palatability, but also to offer enhanced health benefits to the consumer by altering content of bioactive components in adipocytes.

Knowledge of the genetic control of pork quality traits and relationships among pork quality, growth, and carcass characteristics is required for American swine populations. Data from a 2 x 2 diallel mating system involving Landrace and Duroc pigs were used to estimate heritabilities and genetic correlations among growth (ADG), real-time ultrasonic (US) measures of backfat thickness (BF) and longissimus muscle area (LMA), carcass characteristics, and various pork quality traits. Data were collected from 5,649 pigs, 960 carcasses, and 792 loin chops representing 65, 49, and 49 sires, respectively. Genetic parameters were estimated by REML assuming animal models. Heritability estimates were moderate to high for ADG, USBF, USLMA, carcass BF, and LMA, percentage of LM lipid (IMF), pork tenderness, and overall acceptability. Estimates were low to moderate for percentage of cooking loss, pH, shear force, percentage of LM water, water-holding capacity (WHC), pork flavor, and juiciness. Genetic correlations between US and carcass measures of BF and LMA indicate that selection based on US data will result in effective improvement in carcass characteristics. Selection for increased LMA and(or) decreased BF using US is, however, expected to result in decreased IMF and WHC, increased percentage of LM water and shear value, and in decreased juiciness, tenderness, and pork flavor. Average daily gain was favorably correlated with IMF and unfavorably correlated with shear force. Selection for increased ADG is expected to improve WHC but to decrease the percentage of LM water, with an associated decrease in juiciness. The results of this study suggest the feasibility of including meat quality in selection objectives to improve product quality. Favorable genetic correlations between IMF and eating quality traits suggest the possible merit of including IMF in the selection objective to improve, or restrict change in, pork eating quality.

This experiment was designed to test whether changing the type and amount of added dietary fat would affect performance or meat quality. Dietary fat was added as tallow or extruded full-fat soybeans (FFS). Isoenergetic diets containing 10% FFS, 20% FFS, or 4% tallow were fed for 3 or 6 wk before slaughther. A conventional corn-soybean meal diet served as a no-added-fat control. Each of the seven dietary groups contained 20 pigs, equally distributed among four pens, with barrows and gilts segregated. Significance of treatment, sex, and interaction effects were evaluated for 34 meat quality, composition, and sensory evaluation traits. Treatment x sex interactions were not detected (P greater than .05). Treatment main effects were detected for percentage of fat and water in the bacon and for lipid oxidation in bacon and the longissimus muscle. The 6 df for treatment were partitioned into six contrasts to test for the trends within and between diets. A trend toward reduced fat and increased moisture in bacon was detected in the 10% FFS diet over time (P less than .05). In general, lipid oxidation of bacon and longissimus muscle increased with level of FFS in the diet, length of time on the diet, and storage time of the meat. Although statistically significant, the magnitude of these effects was small and did not affect the sensory characteristics of longissimus muscle samples. It was concluded that short-term feeding of FFS before slaughter did not adversely affect animal growth or meat quality.

Marinades of different pH were prepared from 0.1M phosphate buffers ranging in pH from 3.25 to 10.15, 0.1M sodium chloride, 0.4M phosphoric acid or 0.7M acetic acid. Beef cores were marinated and composition, texture, and structural properties were evaluated. Low and high muscle pH after marinating had positive effects on texture and resulted in increased water-binding capacity, moisture content and decreased cooking losses. Electron microscopy indicated a loss of the M-line at low pH and a loss of Z-line material at high pH. Overall, both high and low marinade pH altered the textural properties of meat although, more rapid changes occurred at lower pH.

In this study we examined the adaptations of adult lean and obese Zucker rats to a very low calorie diet (VLCD) or simple starvation. Lean rats were fed the VLCD or starved until they lost 31% of their starting weight. Obese rats were subjected to the same two treatments until they had lost about 52% of their initial weight. Weights of five skeletal muscles, three fat pads, and three organs were determined. Compared to the lean rats, obese rats relied to a greater extent on catabolism of fat stores for energy and to a lesser extent on lean body mass during both types of food restriction. Obese rats on the VLCD lost significantly less skeletal muscle, but not cardiac muscle, than the starved rats. Both the VLCD and starved groups experienced a 27–28% loss of cardiac muscle mass. This “protein-sparing” effect of the VLCD was seen in both the tissue weights and protein contents of skeletal muscle. Lean rats were not as capable of minimizing muscle losses during the rapid body weight loss due to the VLCD. In conclusion, obese Zucker rats have an enhanced ability to conserve skeletal muscle when fed a VLCD, but cardiac muscle is not “spared” in the same manner as skeletal muscle.

As research funding becomes more competitive, it will be imperative for researchers to break the mentality of a single laboratory/single research focus and develop an interdisciplinary research team aimed at addressing real world challenges. Members of this team may be at the same institution, may be found regionally, or may be international. However, all must share the same passion for a topic that is bigger than any individual's research focus. Moreover, special consideration should be given to the professional development issues of junior faculty participating in interdisciplinary research teams. While participation may be "humbling" at times, the sheer volume of research progress that may be achieved through interdisciplinary collaboration, even in light of a short supply of grant dollars, is remarkable.

1. The effects of different amounts of passive stretch per day and number of days of stretch on muscle hypertrophy in the chicken patagialis (PAT) muscle were determined. 2. Stretch for 24 hr per day (h/d) resulted in a more rapid hypertrophy both on a wet and dry tissue basis (P less than 0.001) than stretch for 4 h/d. 3. Stretch increased PAT weight 43% and 25% in 24 h/d and 4 h/d treatments, respectively, after 10 days of stretch, but by day 25 of stretch there was no difference between treatments. 4. In a second experiment, the PAT muscle was hypertrophied and then the effects of intermittent stretch (4 h/d) on regression of hypertrophy (muscle atrophy) were investigated. 5. Intermittent stretch (4 h/d) for 5 and 10 d significantly (P less than 0.001) inhibited regression of hypertrophied muscle. 6. The results of the present study indicate that stretch-induced hypertrophy can be modulated by varying the amount of stretch applied per day. 7. Intermittent stretch can be used to inhibit the regression which occurs when a continuous stretch stimulus is removed. 8. Intermittent stretch is a useful model for investigating mechanisms of muscle hypertrophy and inhibition of muscle atrophy.

The most important sensory attribute affecting consumer acceptability is tenderness, which is a complex trait. Aging is the practice of holding meat at low temperatures to improve tenderness. In order to assess consumer quality attributes, cattle were selected to represent a range of quality grades from Utility to Prime. Steaks from these cattle were aged in vacuum bags for 0, 7, or 14 d, cut, and cooked on open hearth grills to 70 °C. Sensory evaluation was completed by consumers (n= 522). Warner–Bratzler (WB) shear and various physical characteristics were also determined. Shear values decreased with aging time and tenderness increased. Consumers perceived the majority of change in tenderness occurred during the first 7 d of aging while change in WB shear was similar during the first 7 d and the second 7 d of aging. Aging had no effect (P > 0.05) on juiciness, flavor, pH, lipid content, or water content of steaks.

We have investigated the hypothesis that there is local regulation of insulin-like growth factor (IGF) gene expression during skeletal muscle growth. Compensatory hypertrophy was induced in the soleus, a predominantly slow-twitch muscle, and plantaris, a fast-twitch muscle, in 11- to 12-wk-old female Wistar rats by unilateral cutting of the distal gastrocnemius tendon. Animals were killed 2, 4, or 8 days later, and muscles of the nonoperated leg served as controls. Muscle weight increased throughout the experimental period, reaching 127% (soleus) or 122% (plantaris) of control values by day 8. In both growing muscles, IGF-I mRNA, quantitated by a solution-hybridization nuclease-protection assay, rose by nearly threefold on day 2 and remained elevated throughout the experimental period. IGF-II mRNA levels also increased over controls. A more dramatic response was seen in hypophysectomized rats, where IGF-I mRNA levels rose by 8- to 13-fold, IGF-II values by 3- to 7-fold, and muscle mass increased on day 8 to 149% (soleus) or 133% (plantaris) of the control contralateral limb. These results indicate that signals propagated during muscle hypertrophy enhance the expression of both IGF genes, that modulation of IGF-I mRNA levels can occur in the absence of growth hormone, and that locally produced IGF-I and IGF-II may play a role in skeletal muscle growth.

The Illinois Spring Barrow Show, a large annual carcass show of performance-tested pigs, may provide an indication of phenotypic trends in the pork industry over time. Objectives of this study were 1) to investigate time trends in live and carcass weights (LWT, CWT), dressing percentage (DP), length (LEN), loin muscle area (LEA), backfat (BF), muscle color, firmness and marbling (C,F,M) scores, estimated fat-standardized lean yield (FSL), FSL/d of age (LDOA) and FSL/d on test (LDOT) and 2) to assess use of carcass characteristics to predict DP. Data on 5,983 barrows exhibited between 1968 and 1989 were analyzed. Linear regressions expressed as change/yr (1977 to 1989, all P < .001) were .56 kg (LWT), .53 kg (CWT), .11 % (DP), .50 mm (10th rib BF), −49 g (wt-adj. FSL), 2.0 g (wt-adj. LDOA, 1977 to 1983) and −2.2 g (wt-adj. LDOT, 1984 to 1989). There were only small changes in LEN, C, F and M. Between 1968 and 1976, LEA increased .42 cm2/yr, then decreased .23 cm2/yr until 1984, increased .34 cm2/yr to 1988 and fell 1.2 cm2 in 1989 (all P < .001). Models including year, breed and their interaction (YB), ± linear and quadratic regressions on LWT, CWT, 10th rib BF, LEA and LEN, were used to assess the amount of variability in DP that could be accounted for by these carcass measures. R2 values (model effects in parentheses) were .16 (YB ± LWT), .28 (YB + CWT ± BF ± LEA) and .31 (YB + CWT + LEN ± [BF + LEA]). In conclusion, performance tested carcass show barrows have become heavier and fatter over time. Lean growth rate has decreased over the past 5 yr. Tenth rib fat and loin muscle area had no value as predictors of dressing percentage. Dressing percentage was not useful as a predictor of lean growth rate or lean yield.

Zinc (Zn(2+)), a multifunctional micronutrient, was recently shown to lower the affinity of cell-associated insulin-like growth factor (IGF) binding protein (IGFBP)-3 and IGFBP-5 for both IGF-I and IGF-II, but to increase the affinity of the cell surface type 1 IGF receptor (IGF-1R) for the same two ligands. However, there is a need for data concerning the effects of Zn(2+) on soluble IGFBPs and the type 2 IGF receptor (IGF-2R). In the current work, we demonstrate that Zn(2+) affects the affinity of IGFBP-5 secreted by myoblasts but not IGFBP-4. Zn(2+), at physiological levels, depressed binding of both IGF-I and IGF-II to IGFBP-5, affecting (125)I-IGF-I more than (125)I-IGF-II. Both (125)I-IGF-I and (125)I-IGF-II bound to high and low affinity sites on IGFBP-5. Zn(2+) converted the high affinity binding sites of IGFBP-5 into low affinity binding sites. An IGF-I analog, (125)I-R(3)-IGF-I, did not bind to the soluble murine IGFBP-5. Zn(2+) also decreased the affinity of the IGF-2R on L6 myoblasts. In contrast, Zn(2+) increased IGF-I, IGF-II and R(3)-IGF-I binding to the IGF-1R by increasing ligand binding affinity on both P(2)A(2a)-LISN and L6 myoblasts. Soluble IGFBP-5 and IGFBP-4 depressed the binding of (125)I-IGF-I and (125)I-IGF-II to the IGF-1R, but did not affect binding of (125)I-R(3)-IGF-I. By depressing the association of the IGFs with soluble IGFBP-5, Zn(2+) partitioned (125)I-IGF-I and (125)I-IGF-II from soluble IGFBP-5 onto cell surface IGF-1Rs. This effect is not seen when soluble L6-derived IGFBP-4 is present in extracellular fluids. We introduce a novel mechanism by which the trace micronutrient Zn(2+) may alter IGF distribution, i.e. Zn(2+) acts to increase IGF-1R binding at the expense of IGF binding to soluble IGFBP-5 and the IGF-2R.

The ultrasound time-domain correlation (UTDC) technique involves the determination of a similarity factor, the correlation coefficient. For this application, UTDC was used to calculate the maximum correlation coefficient between RF echo signals of porcine muscle tissue obtained at different times and for different echo spacings. The porcine muscle samples were procured from a slaughterhouse and data acquisition began within 1.5 h post mortem. The echo signals were obtained with a customized ultrasound data acquisition system and analyzed using a 486 PC. The results indicated that observed trends in the correlation coefficient could be used to determine muscle activity post mortem and to determine when this activity stopped, which was approximately 10 h post mortem. An explanation of the methods used and results obtained is presented. >

Semitendinosis muscle specimens, approximately 2.54-cm thick and weighing 200 g, were exposed to high-intensity ultrasound for periods of 0, 2, 4, 8, and 16 min. Four specimens were used at each period for a total of 20 specimens. A magnetorestrictive transducer produced CW ultrasound at a frequency of 25.9 kHz in a stainless steel tank filled with degassed saline. The semitendinosus meat specimens were cut either cross-sectionally or longitudinally to the muscle fibers. The cross-sectional cuts of the meat specimens were exposed to the ultrasound for periods of 2, 4 and 8 min while the longitudinal cuts were exposed for periods of 2, 4, 8 and 16 min. Tenderness was measured by Warner-Bratzler shear force by removing six 1.3-cm-diameter cores from each meat sample. For the samples exposed for 2 and 4 min, there was a statistically significant decrease in Warner-Bratzler shear force, which indicates an increase in tenderness for these specimens. These results suggest that high-intensity ultrasound is capable of tenderizing meat as assessed by an objective shear force measurement. >

Beef patties (raw, raw freeze-dried, cooked, and cooked freeze-dried) were prepared for treatment with supercritical carbon dioxide extraction (SC-CO). Each type of patty was then assigned to one of four treatments: control, static extraction at 170 atm/50°C, dynamic extraction at 170 atm/50°C and dynamic extraction at 544 atm/40°C. Freeze drying of the patties prior to SC-CO2 extraction improved removal of fat and cholesterol. Freeze drying enhanced (P 0.05) on cholesterol extraction. Supercritical fluid extraction could be effective to reduce the fat and cholesterol content of preformed meat products, without requiring communication of the sample.

Fresh ground pork was formulated with sodium lactate (SL) (0, 1.5 or 3%) and sodium chloride (0, 0.5, 1, l.5, 2, 2.5 or 3%) to evaluate effects on sensory characteristics. Aerobic plate count (APC) over retail storage (25 days) was evaluated on samples rated in the mid-range (±0.5 S.D. of mean) of salty flavor intensity (SI) by a trained sensory panel. SL increased (P

1. 1. Clearance of infused lipid was observed in six mature resting horses, 2 to 6 hr after receiving a meal of alfalfa hay. 2. 2. Intralipid®, a 10% triglyceride emulsion, was infused at a rate of 0.2 ml/kg into the jugular vein. 3. 3. Blood samples were obtained for 80min post-infusion and assayed for plasma triglyceride concentration. 4. 4. Clearance rate of the infused lipid was very slow (mean t 1 2 = 269 min). 5. 5. The clearance rate of the infused lipid in these horses was much slower than has been observed in other species. 6. 6. The slow clearance of infused triglyceride in horses may suggest an inability to efficiently metabolize lipoproteins.

Fatty acid (FA) composition and cholesterol (CHL) content from control and Ractopamine (Rac) treated pigs were evaluated. Lipids were extracted from the longissimus (LD) and subcutaneous fat (SC) and methyl esters of the FA were formed for gas chromatography. CHL content of the LD was determined using direct saponification. Pigs were fed 0, 5, 10 or 20 ppm Rac for about 40 kg of grain prior to slaughter. Rac had no consistent effect on the FA composition of SC or muscle (neutral or polar) lipids. CHL content in the LD of treated animals was about 9% lower (P < 0.01) than controls. Rac reduced the CHL content of the LD and had limited effect on the FA profile of muscle or SC fat.

To assess the effects of pH, heating rate and endpoint temperature on instrumental and visual color of ground beef, pH was adjusted to 5.2–6.4, samples were heated at 0.7°C or 3°C/min to 55, 60, 65, 70, 75 or 80°C in a water bath. Cooking rate had no effect on cook loss, instrumental or visual color. Regression equations for linear, quadratic and/or cubic effects of pH and/or endpoint temperature were significant for most color indices. Amount of variance explained by the model and R 2 was increased by adding the calculated percentages of metmyoglobin and/or deoxymyoglobin to the regression models. The predicted sensory brownness score (0=very pink, 7.5=intermediate pink/brown, 15=intense brown) for samples with pH 5.75 cooked to 70°C was 9.75. Samples with a pH of 5.5 achieved this brownness score at 67°C. Samples with a pH of 5.2 achieved this brownness at 58°C.

Thirty pork carcasses were used to evaluate the interrelationships between compositional end points and the accuracy of predicting various end points from one another. Right sides were fabricated into Boston butt, picnic, anterior belly, posterior belly, anterior loin, posterior loin, and ham. Carcass composition was determined on the right side using physical dissection and chemical analyses of soft tissue. Left sides were ground (whole-side grind). Linear measures and chemical composition were made on left sides. Using dissectable components, high (r >.85) correlations occurred between percentage of fat-free lean and percentage of lipid, percentage of dissectable fat, and lipid in the whole-side grind; between weights of dissectable lean and fat-free lean; and between weights of lipid in the whole-side grind and lipid, dissectable fat, and dissectible lean. Dissectable lean percentage and fat (percentage and weight) could be predicted using weight of lipid, weight of fat-free lean, and side weight. Any physical measure could be accurately estimated from any compositional end point (r 2 =.79 to.93). Regression equations using 10th-rib linear measures and hot carcass weights predicted compositional end points with R 2 ≥.80, with the exception of dissectable lean (R 2 =.56).