Acute CSF interleukin-6 trajectories after TBI: associations with neuroinflammation, polytrauma, and outcome.

Traumatic brain injury (TBI) results in a significant inflammatory burden that perpetuates the production of inflammatory mediators and biomarkers. Interleukin-6 (IL-6) is a pro-inflammatory cytokine known to be elevated after trauma, and a major contributor to the inflammatory response following TBI. Previous studies have investigated associations between IL-6 and outcome following TBI, but to date, studies have been inconsistent in their conclusions. We hypothesized that cohort heterogeneity, temporal inflammatory profiles, and concurrent inflammatory marker associations are critical to characterize when targeting subpopulations for anti-inflammatory therapies. Toward this objective, we used serial cerebrospinal fluid (CSF) samples to generate temporal acute IL-6 trajectory (TRAJ) profiles in a prospective cohort of adults with severe TBI (n=114). We examined the impact of injury type on IL-6 profiles, and how IL-6 profiles impact sub-acute (2weeks-3months) serum inflammatory marker load and long-term global outcome 6-12months post-injury. There were two distinct acute CSF IL-6 profiles, a high and low TRAJ group. Individuals in the high TRAJ had increased odds of unfavorable Glasgow Outcome Scale (GOS) scores at 6months (adjusted OR=3.436, 95% CI: 1.259, 9.380). Individuals in the high TRAJ also had higher mean acute CSF inflammatory load compared to individuals in the low TRAJ (p⩽0.05). The two groups did not differ with respect acute serum profiles; however, individuals in the high CSF IL-6 TRAJ also had higher mean sub-acute serum IL-1ß and IL-6 levels compared with the low TRAJ group (p⩽0.05). Lastly, injury type (isolated TBI vs. TBI+polytrauma) was associated with IL-6 TRAJ group (χ(2)=5.31, p=0.02). Specifically, there was 70% concordance between those with TBI+polytrauma and the low TRAJ; in contrast, isolated TBI was similarly distributed between TRAJ groups. These data provide evidence that sustained, elevated levels of CSF IL-6 are associated with an increased inflammatory load, and these increases are associated with increased odds for unfavorable global outcomes in the first year following TBI. Future studies should explore additional factors contributing to IL-6 elevations, and therapies to mitigate its detrimental effects on outcome.

The use of blood lactate concentration as an indicator of temperament and its impact on growth rate and tenderness of steaks from Simmental × Angus steers.

The objective of this study was to evaluate the use of blood lactate concentration as an objective measure of beef cattle temperament and determine if the temperament of steers affected growth rate and tenderness of beef steaks. Angus×Simmental steers (n=154) were evaluated for blood lactate (BL), exit velocity (EV) and chute score (CS), and humanely harvested. Carcass characteristics were assessed and loin samples were obtained for tenderness evaluation. All measures of the temperament were significantly correlated to each other (r=0.14-0.47; P≤0.04). Steaks from steers in the medium BL classification were significantly more tender than steaks from steers from the high BL classification. The steers with faster EV tended to result in steaks with higher shear force values (P=0.07). The steers classified as fast growing resulted in steaks with lower shear force values (P=0.02) compared to steaks from steers classified as slow growing. Results suggest that the temperament contributes to variations in growth rate, blood lactate, and tenderness.

Effects of late gestation supplementation of rumen undegradable protein, vitamin E, zinc, and chlortetracycline to ewes on indices of immune transfer and productivity.

Late gestation supplementation of feed additives, such as rumen undegradable intake protein (RUIP), vitamin E, Zn, and chlortetracycline, has inconsistently improved ewe/lamb productivity. In 3 experiments, Western white-faced ewes were supplemented for at least 30 d during late gestation with 204 g/(ewe.d) on a DM basis of high (HS; 12.5% RUIP, 880 IU/kg of vitamin E, 176 mg/kg of Zn supplied by an AA complex, and 352 mg/kg of chlortetracycline) or low (LS; 7.56% RUIP and no supplemental vitamin E, Zn, or chlortetracycline) supplements. Ewes of different age (Exp. 1; 3- vs. 6-yr-old; n = 52) and BCS (Exp. 2; good vs. poor BCS; 3.0 and 1.7 +/- 0.5, respectively; n = 40) were supplemented individually in a 2 x 2 factorial arrangement of treatments for 29 d. Thereafter, each ewe was group fed the appropriate supplement until lambing (14 +/- 7 d). Ewe intake, colostral IgG, ewe and lamb parainfluenza type 3 (PI(3)) titers, milk production, ewe BW and BCS change, and lamb production were measured in both experiments. In Exp. 3, approximately 600 ewes were group fed HS or LS over 2 yr. Ewe BW, ewe BCS, lamb production, and lamb survival was measured in Exp. 3 with groups within year as the experimental unit. In Exp. 1, lambs born to 3-yr-old ewes fed the HS had greater (P = 0.01) anti-PI(3) antibody titers than lambs born to 3-yr-old ewes fed the LS. Three-year-old ewes had greater (P < 0.01) DMI than 6-yr-old ewes. In Exp. 1 and 2, d 3 and 10 milk production differences (P

Growth implants reduced tenderness of steaks from steers and heifers with different genetic potentials for growth and marbling.

The objective of this study was to evaluate the effect of growth implants on the carcass characteristics and tenderness of steers and heifers with different genetic potentials for growth, lean meat yield production, and marbling. Two experiments were conducted. Experiment 1 evaluated Angus steers sired by bulls with high EPD for retail product yield or marbling. Implant treatment was imposed randomly within sire groups. Loins (Institutional Meat Purchasing Specifications 180) were collected from each carcass and cut into three 2.54-cm steaks aged for 7, 14 and 21 d to evaluate tenderness. The second experiment evaluated steers and heifers of British and Continental breed descent. Steers and heifers were slaughtered after 120 d on feed. Loin sections were collected, and one 2.54-cm steak aged 7 d was used for tenderness analysis. When implants were used in Angus steers, HCW and LM area increased, whereas internal fat and marbling decreased (P < 0.01). In Angus steers, sire type did not affect shear force values of steaks; however, implant use significantly increased shear force values (P < 0.01). Carcasses from cattle of Continental breed descent were significantly heavier than carcasses of British breed descent with larger LM area, slightly less fat, and a reduced yield grade (P < 0.01). Also, steer carcasses were heavier than heifer carcasses with larger LM (P < 0.05), but no effect of sex on fat depth, internal fat, yield grade or marbling was observed. No significant interactions were seen between growth implant and breed or between growth implant and sex for shear force values. Shear force values were significantly less for steaks from steers and heifers of British decent compared with steers and heifers of Continental descent (P < 0.01). Steaks from implanted steers and heifers had significantly (P < 0.01) greater shear force values than steaks from steers and heifers not implanted. Use of growth implants in growing cattle resulted in significantly heavier carcass weights, larger LM area, and reduced internal fat. However, implant use also reduced the amount of marbling along with contributing to reduced tenderness. Complicating the tenderness issue is the increased shear force values reported for heifers as well as steers of Continental breed descent. Use of implants may contribute to tenderness variability because of different animal responses to implants.

Effect of muscle location, fiber direction, and slice thickness on the processing characteristics and tenderness of beef stir-fry strips from the round and chuck.

The objective was to assess different beef muscles for use as stir-fry. Inside round, outside round, eye of round, knuckle, chuck clod, and chuck tender were obtained from six beef carcasses. Different slice thickness (2, 4, or 8mm) and muscle fiber direction were evaluated. Slices were cooked from frozen on a flat grill and then cut into strips for shear and sensory testing. While meat cut had little effect on shear values of these thin slices, increasing slice thickness greatly affected tenderness and cook yield. The sensory panel found that strips from the knuckle were more tender and juicy, with less connective tissue and with a better flavor than that of slices from the eye of round and outside round. Increasing slice thickness resulted in detection of greater amounts of connective tissue but did not result in a significant difference in the perception of tenderness. Fiber direction was also of importance. Slices removed perpendicular to the fiber direction had shear values up to 50% lower than slices removed parallel.

Functionality of cow beef in coarse and fine ground model systems.

Patties and sausage batters were made from trimmed brisket, chuck, striploin, hindshank, silverside, thick flank and rib trim from grass-fed Friesian cows. Functionality of each meat cut was determined from cook yield and true stress and strain of cooked sausage batters and cook yield, dimensional changes and peak force of cooked patties. Colour of raw and cooked slices from the meat cuts and cooked batters was evaluated using a colorimeter and a consumer panel. Composition of raw meat from all cuts was similar; chuck and rib trim had higher pH values and were more red than meat from other cuts. Cooked batters from striploin, chuck and hindshank had higher stress and strain values than gels from other cuts. Patties made from thick flank and striploin were the softest and had the highest cook yield. Batters and patties made from meat with higher salt soluble protein content retained more water and fat on cooking, were more cohesive and had higher bind strengths. Manufacturers can use functionality characteristics to select meat for specific products.

Supplemental safflower oil affects the fatty acid profile, including conjugated linoleic acid, of lamb.

The objective of this study was to determine whether increasing levels of dietary safflower oil would alter unsaturated fat (especially CLA) and tocopherol content of lamb, animal performance, carcass characteristics, or color stability of lamb muscle tissue. Targhee x Rambouillet wethers (n = 60) were assigned to one of three diets (four pens per treatment with five lambs per pen) in a completely random design. Diets were formulated with supplemental safflower oil at 0 (control), 3, or 6% (as-fed basis) of the diet. Diets containing approximately 80% concentrate and 20% roughage were formulated, on a DM basis, to be isocaloric and isonitrogenous and to meet or exceed NRC requirements for Ca, P, and other nutrients. A subsample of 12 wethers per treatment was selected based on average BW (54 kg) and slaughtered. Carcass data (LM area, fat thickness, and internal fat content) and wholesale cut weight (leg, loin, rack, shoulder, breast, and foreshank), along with fatty acid, tocopherol, and color analysis, were determined on each carcass. The LM and infraspinatus were sampled for fatty acid profile. Increasing safflower oil supplementation from 0 to 3 or 6% increased the proportion of linoleic acid in the diet from 49.93 to 55.32 to 62.38%, respectively, whereas the percentage of oleic acid decreased from 27.94 to 23.80 to 20.73%, respectively. The percentage of oil in the diet did not (P > or = 0.11) alter the growth and carcass characteristics of lambs, nor did it alter the tocopherol content or color stability of meat. Increasing levels of safflower oil in lamb diets decreased (P < 0.01) the weight percentage of oleic acid in the infraspinatus and LM, and increased linoleic acid (P < 0.01). Oil supplementation increased (P < 0.01) the weight percentage of various isomers of CLA in muscle, with the greatest change in the cis-9,trans-11 isomer. Supplementation of sheep diets with safflower oil, up to 6% of the diet, resulted in increasing levels of unsaturated fatty acids and CLA in the lean tissue, without adversely affecting growth performance, carcass characteristics, or color stability of lamb.

Meat color stability affected by barley variety fed in finishing diet to beef steers.

Angus crossbred steers were assigned randomly to one of four finishing diets based on corn, Chinook, Logan, or H3 barley. Steers were harvested and after a 72-h chill, carcass quality and yield grade data were collected. Beef ribs were removed from 72 carcasses for further analysis. Ribs were aged in vacuum bag at 2°C for 14 days. After aging three adjacent steaks (3.18cm) were removed to determine color stability, tenderness, proximate analysis and pH. Diets fed to steers had no effect on quality and yield grade or tenderness of beef steaks. Steaks from steers fed Logan barley variety were significantly less red at 10 days of storage (Hunter a*=24.06) than steaks from steers fed the other barley varieties (Chinook a*=26.4; H3 a*=28.05) or corn (a*=26.14). Identification of barley varieties that affect color stability could result in designing diets specifically for improved color and increase the use of barley as a finishing grain.

Effects of barley variety fed to steers on carcass characteristics and color of meat.

This study evaluated the effect of barley varieties in the diets of finishing steers on carcass composition, fat, and lean color and the fatty acid profile of subcutaneous fat. Crossbred steers (391 kg initial BW) were assigned randomly to one of five finishing diets composed primarily of corn (n = 9), Morex barley (n = 9), Steptoe barley, (n = 9), or two experimental barley varieties SM3 (n = 9) and SM5 (n = 9). Grains were cracked prior to feeding. Diets were formulated (DM basis) to be isonitrogenous (2.24% N) and isocaloric (2.01 Mcal/kg NEm and 1.35 Mcal/kg NEg). Steers were slaughtered according to industry-accepted procedures when it was visually estimated that 70% of carcasses would grade USDA Choice. After a 24-h chill at 4 degrees C, carcass quality and yield grade data were collected by trained, experienced university personnel. Objective color (L*, a*, and b*) of both the LM and subcutaneous fat were measured, and samples of subcutaneous fat were removed from the 10th- to 12th-rib region for fatty acid analysis. Diet did not affect hot carcass weight (P = 0.15), fat thickness (P = 0.58), LM area (P = 0.57), percentage of internal fat (P = 0.52), yield grade (P = 0.96), marbling (P = 0.73), or quality grade (P = 0.10). However, the LM from steers fed diets formulated with Morex and SM5 barley varieties tended to be lighter (higher L* values, P = 0.08) than the LM from steers fed the corn-based diet. Additionally, fat from steers fed corn tended to be more yellow (higher Hunter b* values, P = 0.09) than fat from steers fed barley-based diets. Although grain source had only minimal effects on the fatty acid composition of subcutaneous fat samples, pentadecanoic acid (15:0) was greater (P < 0.05) in fat from steers fed SM3 and Steptoe barley varieties than in fat from steers fed corn. Stearic acid (18:0) concentrations were higher (P < 0.05) in fat samples from steers fed corn than in those fed the experimental barley lines (SM3 and SM5). Conversely, fat samples from steers fed Steptoe and SM5 barley had greater (P < 0.05) gadoleic acid (20:1) concentrations than fat from steers fed corn or Morex variety. Although the variety/line of barley included in the finishing diet may affect LM and fat color, grain-source (barley vs. corn) had little effect on beef carcass quality and yield grades and did not greatly alter the fatty acid composition of subcutaneous fat.

Heating method and final temperature affect processing characteristics of beef semimembranosus muscle.

The effect of thawing and cooking regimes on the processing characteristics and colour of cooked roast beef made from frozen beef cap-on inside round (semimembranosus, adductor and gracilus muscle) was investigated. After thawing in air or water, the cap was removed and the insides were pumped (110%), tumbled (30 min continuously) and then cooked in either constant-temperature water baths or baths where a 10 °C difference was maintained between the roast and the water to an internal temperature of 63 or 80 °C. Purge was higher for insides thawed in air. Insides that were cooked at a constant temperature had higher cook yields the same was seen for lower end-point temperatures. Colour of raw insides thawed in water was slightly redder than insides thawed in air. Thawing and cooking regime did not affect the colour of cooked slices but the higher the end temperature, the higher the Hunter L and the lower the Hunter a and b values. Data from this research suggests that roast beef manufacturers should evaluate thawing and cooking procedures to ensure they optimize their process.

Meat and storage effects on processing characteristics of beef roasts.

Two experiments were done to determine the effect of storage conditions and meat cut on the processing characteristics of beef roasts. The first experiment examined the effect of storage condition (fresh/frozen), cap on/off, thawing regime and holding time post thawing on purge, brine uptake, cook yield and colour of raw and cooked roasts. The second experiment examined the effect of meat cut (insides/flats) and chilled storage for up to 8 weeks on processing characteristics of roast beef. Purge was greater for insides stored frozen without cap and air thawed. Frozen thawed cuts had increased brine retention after injection, after tumbling and after cooking. Flats had less purge and higher cook yields when manufactured into roast beef. Raw and cooked colour was not significantly affected by most factors investigated. Raw meat was more red than meat that had been frozen.

Processing characteristics of beef roasts made from high and normal pH bull inside rounds.

The processing characteristics of roasts manufactured from either high or normal pH bull inside rounds (semimembranosus and adductor muscles), which had been stored chilled or frozen, were investigated. Roasts were injected with a salt/phosphate brine and cooked to an internal temperature of 63 °C in a 70 °C water bath. High-pH meat that had been frozen had less purge than normal pH meat. However, pH did not affect purge from chilled meat. Meat pH and storage conditions did not affect retention of pumped brine. Cook yields were significantly (P<0.05) higher for roasts made from high pH meat (103.8 vs 98.8%). Raw and cooked meat colour was affected by meat pH but not storage condition. Cooking reduced the effect of pH on meat colour but cooked roasts manufactured from high pH meat were redder than roasts manufactured from normal pH meat.

Processing and sensory characteristics of cooked roast beef: effect of breed, age, gender and storage conditions.

Two separate experiments investigated the effect of breed (Bos indicus, Bos indicus×and Bos taurus), gender/age and chilled and frozen storage on the processing characteristics of roasts made from inside rounds (semimembranosus, adductor and gracilis muscles). Roasts were injected with a salt/phosphate brine and cooked to an internal temperature of 63 °C. Freezing the meat increased purge lost from the raw meat. Country of origin had no significant effect on cook yield. Sensory evaluations with a US consumer panel indicated only slight sensory differences due to country of origin and breed but a significant effect from storage regime. Tenderness comparisons between breeds were confounded by country of origin and indicated that roast beef from inside rounds from Brahman cattle had lower WBS values than roast beef made from inside rounds from British cattle. Although breed and age/gender often significantly affected processing characteristics of the roasts, differences were small and would have little practical or economic importance for selecting the type of meat for this market sector.

Meat cut and injection level affects the tenderness and cook yield of processed roast beef.

The effect of muscle cut used and brine injection level on the processing characteristics of small pre-cooked roast beef was determined. Meat cuts (inside, outside, eye of round, knuckle, clod, chuck roll and brisket) were cut into small roasts (750 g) and injected at three levels (110, 125 and 150% over raw roast weight) with a non-injected control. Muscle cuts from the chuck can be used to successfully manufacture cooked mini roast beef. However, the use of small roasts resulted in cook yields that are considerably less than what was expected with large intact muscle roasts. Some variation in tenderness between the muscles was seen, but when muscles were injected there was a significant increase in tenderness and a reduction in the variability in tenderness within the muscle. Roasts injected to 125% above green weight resulted in the highest cook yields.

Recovery of proteins from beef bone and the functionality of these proteins in sausage batters.

Four solutions [4% sodium chloride (control), 4% sodium chloride with 0.3% sodium tripolyphosphate (STP), 0.3% tetrasodium pyrophosphate (TTP) or 0.05 M sodium hydroxide (NaOH)] were used to extract proteins from beef bones. Three bone solution ratios (1:1, 1:4 or 1:10), three bone types [vertebra (lumbar), rib (4-7) and leg (femur)] and two methods of protein recovery from the extraction slurries [dialysis against 0.03 M potassium phosphate buffer (pH 5.3) and acid precipitation] were evaluated. Solutions containing phosphates or NaOH were more effective in extracting protein than sodium chloride alone. Total protein recovery was highest from vertebra bones while extraction of proteins from leg bones resulted in the lowest recovery. A solution to bone ratio of 1 to 10 recovered more total protein from vertebra or rib bones than leg bones. Dialysis recovered more total protein from extraction solutions when the protein concentration was low. Acid precipitation, however, worked best if the protein concentration in the extraction solution was high. Extraction procedures resulted in some myosin degradation. Proteins extracted from beef bone materials and recovered by dialysis, performed equally as well as other commercially available proteins when added to a finely comminuted sausage product.

Rapid post-mortem glycolysis and delay chilling of turkey carcasses cause alterations to protein extractability and degradation of breast muscle proteins.

SDS-PAGE banding patterns of myofibrillar protein samples from turkey breast muscle with pH < or =5.8 at 15 min post-mortem (rapid glycolyzing) contained 133, 142, and 165 kDa bands that were absent in samples from carcasses with pH >6.0 at 15 min post-mortem (normal glycolyzing). These extra protein bands contained fragments of myosin as identified by Western blot analysis. Myosin fragments were also observed in protein samples from breast muscle not allowed to cool until 110 min post-mortem (delay chilled). In addition to myosin degradation, neublin degradation was more extensive in samples from rapid glycolyzing carcasses than for normal controls. Creatine kinase and glycogen phosphorylase were present in myofibrillar protein extracts of rapid glycolyzing carcasses in higher quantities than in normal controls. Results of this study provide insight into the molecular basis for previously reported reductions in meat quality of rapid glycolyzing and delay chilled turkey meat.

Rapid postmortem pH decline and delayed chilling reduce quality of turkey breast meat.

Effects of rapid postmortem metabolism and delayed chilling on turkey breast meat quality were assessed using color measurements, protein extractability, and gelation characteristics. Based on 15 min postmortem breast muscle pH, tom turkey carcasses were classified as rapid glycolyzing (RG), pH < 5.80, or normal glycolyzing (NG), pH > 6.00. Two carcasses per group with similar ultimate pH values were selected on four occasions for a total of 16 carcasses. One half of each carcass was immersion-chilled at 20 min postmortem, the other half was maintained at body temperature for 110 min and then chilled. Breast meat from RG carcasses had higher carcass temperature (15 min) and lower protein (sarcoplasmic and myofibrillar) extractability than breast meat from NG carcasses. Delayed chilling increased all breast meat color values (L*, a*, b*), and decreased protein extractability and cook yield compared to breast meat from immediately chilled carcass halves. The true strain of cooked gels was reduced for RG carcasses. Delayed chilling reduced both true strain and stress of meat gels. There were no interactions between the rate of postmortem pH decline and initiation of chilling, indicating that reductions in meat quality due to delayed chilling were independent of the carcass classification for rate of postmortem glycolysis. Results indicate that factors that affect both rate of postmortem glycolysis and carcass temperature decline are important to turkey breast meat quality.

Effects of raw binder system, meat cut and prior freezing on restructured beef.

The effect of different meat cuts or previously frozen meat on processing properties of restructured beef bound with alginate or Fibrimex(TM) was investigated. Inside rounds, chuck tenders, chuck clods and tri-tip were used to manufacture restructured logs. Steakettes manufactured with alginate had significantly (P<0.05) higher particle bind in the raw state but Fibrimex had greater bind between meat pieces after cooking. Choice of cut or use of previously frozen meat to manufacture restructured steakettes had no effect on any of the processing parameters measured. Steakettes made with Fibrimex were lighter, redder and yellower than those made with alginate. Redness and yellowness of steakettes decreased with retail storage time. However, the change in redness and yellowness over time was similar for both binders. Use of previously frozen meat resulted in a darker, less red steakette. When alginate was used to manufacture steakettes, cut had no affect on the acceptability of steakettes. However, when Fibrimex was used steakettes made from clod and tip were preferred by a consumer panel to steakettes made from tender and inside round.

Effect of comminution method and raw binder system in restructured beef.

The effect of particle size, method of particle size reduction (grinding, flaking, slicing) and alginate or Fibrimex(™) binding systems on processing properties of restructured beef were investigated. The size of semimembranosus muscles was reduced with a meat slicer, grinder or flaker (Comitrol) through machine openings that were 2, 4 and 8 mm in size. Bind of meat pieces in raw and cooked beef steakettes were measured. Sensory evaluation to determine the effect of method of size reduction on texture of beef steakettes was done only on steakettes manufactured with alginate. Beef steakettes manufactured with the alginate binding system had significantly (p < 0.05) higher raw bind values than did the beef steakettes manufactured with Fibrimex. Slicing meat for the manufacture of restructured beef steakettes resulted in a higher raw bind than did either grinding or flaking the meat. Significant (p < 0.05) interactions were observed for the bind of cooked steakettes between binder and method of size reduction and binder and opening size. When alginates were used to make restructured steakettes the bind of the cooked product was less (p < 0.05) when meat was sliced than when it was ground or flaked. However, when Fibrimex was used, bind was stronger when sliced meat was used. The alginate system resulted in higher binds for cooked product when particle size was smaller but with the Fibrimex system bind was higher when particle sizes were larger. A consumer panel on alginate restructured steakettes showed no preference for the texture produced by the different methods of particle size reduction.

Effects of chopping time, meat source and storage temperature on the colour of New Zealand type fresh beef sausages.

The colour stability of finely chopped fresh sausages made from post-rigor, pre-rigor salt added (1.5% w/w) or pre-rigor no salt added beef mince was evaluated using a Hunter Miniscan (L (∗) a (∗) b (∗)) and sensory colour panel. Batters were chopped for various times and sausages stored at -1.5 °, + 4.0 ° and + 8.0 °C. Regardless of meat source or chopping time, colour stability was greatest at -1.5 °C. Panellists found the colour of all sausages stored at -1.5 °C acceptable for at least six days. Sausages made from unsalted pre-rigor mince had markedly better colour stability than those made from the other meats, especially when stored at 4 °C or 8 °C.