Muscle composition of steers treated with the β-agonist, cimaterol

The effect of the β-adrenergic agonist, cimaterol, on the nature and amount of collagen in three individual muscles (Longissimus dorsi, Vastus lateralis and Semitendinosus) from young steers was investigated.

β-Agonist-treated animals showed similar rates of liveweight gain to those of control animals but the weight and protein content of the Longissimus dorsi and Vastus lateralis muscles were significantly increased (muscle weights 1216 versus 1494 g, P < 0·05; 514 versus 642 g, P < 0·01, respectively, for control and cimaterol animals). The Semitendinosus muscle, however, showed no significant increase in weight or protein content (P > 0·05).

The total collagen content and the proportion of heat-soluble collagen varied considerably between muscles, but no significant muscle × treatment interactions were detected (P > 0·05). Cimaterol treatment reduced total muscle collagen content (controls 15·2, cimaterol 12·5mg/g fresh tissue, P < 0·05) and also reduced the percentage of heat-soluble collagen (controls 18·9%, cimaterol 13·0%, P < 0·05).     

Chemical composition and quality attributes of goat meat and lamb

Chemically, goat meat had significantly (P < 0·05) less intramuscular fat and significantly (P < 0·001) more moisture than lamb. The sarcoplasmic protein concentration of the goat meat was significantly (P < 0·001) greater than that of lamb while the myofibrillar protein concentration was similar in the two species.

Goat meat was darker red in colour than lamb. It had significantly (P < 0·001) superior water-holding capacity and less cooking losses than lamb. Meat flavour was significantly (P < 0·05) less strong in goat meat than in lamb.     

Variation in haem pigment concentration and colour in meat from British pigs

Variation in chemically determined total haem pigment concentration and instrumentally determined colour was examined in 223 samples of M. longissimus dorsi (LD) representative of the majority of slaughter pigs currently produced in the UK. Whether pigs were sired by White (Large White or Landrace) or Meat-line boars did not affect any measured characteristic but source breeding company influenced total haem pigment concentration (P < 0·01). Haem pigment concentration was higher in muscles from gilts, compared with castrates, boars being intermediate. Gilts also had darker muscles, based on EEL Reflectance values (P < 0·05), and lower hue values (P < 0·05). When compared with animals fed ad-libitum, restricted-fed pigs had higher concentrations of muscle haem pigment (P < 0·001) and this resulted in meat that was slightly darker (P < 0·05), despite having lower ultimate pH (pHu) (P < 0·05), and had a lower hue value (P < 0·001). Measurements of reflectance, total soluble protein and pHu indicated that differences in the incidence of potentially pale, soft, exudative or dark, firm, dry muscle were unlikely to be important contributors to variation in the colour of the meat in this study.     

Secondary sexual development (Masculinity) of bovine males: 2. Influence on certain meat quality characteristics

Differences in meat quality traits between bulls with secondary sexual development (bulls(+), n = 10), those without this development (bulls(−), n = 10) and steers (n = 10) were investigated. All animals had no permanent incisors (A-age group). Significant differences (P < 0·05) between bulls(+) and bulls(−) were found for the cooking loss percentage of the M. splenius (27·83% versus 31·11%, respectively), iron content of the M. splenius (56·02μg/g versus 49·43μg/g, respectively) and total collagen content of the M. splenius (3·74 versus 4·73 measured as Hyp N/Tot N x 1000, respectively). Drip loss of the wingrib cut (4·01% versus 5·18%, respectively) was also significantly different between bulls(+) and bulls(−). For the M. longissimus thoracis, no significant (P < 0·05) differences in any of the quality-indicating parameters investigated could be found. It is concluded that the M. splenius can be used as an indicator muscle for masculinity, based on meat quality attributes. This is supported by the correlation coefficients obtained between masculinity and the intramuscular collagen content of the M. splenius (r = −0·55) and the iron content of the M. splenius (r = 0·46). For all the other quality attributes investigated, non-significant (P > 0·05) differences between the three sex condition groups were found. It is concluded that the influence of masculinity on meat quality traits of young bulls is of little practical importance in a classification and grading system.     

Comparison of sensory characteristics and fatty acid composition between Wagyu crossbred and Angus steers

Angus (n = 10) and crossbred (3/4 and 7/8) Wagyu (n = 10) steers were fed a diet according to typical Japanese standards for 552 days. The steers were fed to gain approximately 0·90 kg/head/day. Fatty acid composition was determined for subcutaneous and intramuscular adipose tissue, and M. longissimus dorsi muscle. Trained sensory evaluation and a consumer triangle test were performed on M. longissimus dorsi muscle steaks. For subcutaneous and intramuscular tissue. Wagyu adipose tissue possessed higher (P < 0·05) percentages of 14:1, 16:1 and 18:1 and a lower (P < 0·05) percentage of 16:0 and 18:0 than corresponding tissues from Angus steers. Trained sensory panel analysis revealed no differences (P < 0·05) in any of the sensory traits between steaks from Wagyu crossbred and Angus steers. However, a consumer triangle test indicated that consumers can detect a difference between breeds.     

The effect of post-exsanguination infusion on the composition, exudation, color and post-mortem metabolic changes in lamb

Twenty-four lamb carcasses were assigned to three treatment groups: (1) control (Ctr), (2) infused with 10% (vol/wt) of a tenderizing blend (NCa), and (3) NCa plus 0·015 CaCl₂ (WCa). Results indicated that the infused carcass solution was retained in the following order: shoulder > lion > leg. Infusion had no effect (P > 0·05) on drip and cooking losses in refrigerated samples. Samples frozen and then thawed from infused carcasses had greater thaw drip (P < 0·05) and cooking losses (P < 0·01) than control samples. The amounts of drip and cooking losses were in the order: WCa > NCa > Ctr. Frozen storage preserved the red color but lowered the lightness and yellowness of ovine muscles; the opposite effect was observed following refrigerated storage. Infused samples were lighter and yellower than control in both fresh and frozen samples (P < 0·01). WCa had less red color (P < 0·01) than NCa and Ctr at all times and storage conditions. Infusion lowered (P < 0·05) the temperature of carcasses over the first 3 h postmortem (pm) compared with Ctr. The rate of glycolysis was higher in infraspinatus (IS) than in longissimus thoracis et lumborum muscle (LTL or longissimus). In both IS and LTL, glycolysis was completed within the first 6 h postmortem in NCa, whereas in Ctr and WCa, it took 12–24 h for glycolysis to be completed. The rate of glycolysis was in the order: NCa > WCa > Ctr.     

Feeder cattle frame size, muscle thickness and subsequent beef carcass characteristics

Sixty feeder steers were assigned scores for frame size (small, medium or large) and muscle thickness (No. 1, No. 2 or No. 3), fed for 112 days and slaughtered. Grade data were collected for all 60 carcasses; 12 sides (four from each muscle thickness group) were fabricated into boneless, closely trimmed retail cuts and the 12 rounds from each of these sides were also physically separated into muscle, fat and bone. Marbling score and USDA quality grade varied inversely (P < 0·05) with frame size. Carcass quality grades were: 33·3% Choice; 67·7% Good and 0·0% Standard for small-framed cattle; 30·3% Choice, 42·4% Good and 27·3% Standard for medium-framed cattle and 5·5% Choice, 66·7% Good and 27·8% Standard for large-framed cattle. Analysis of variance showed significant (P < 0·05) differences among all muscle thickness groups in the longissimus muscle area and carcass weight but no difference in yield grade between the No. 1 and No. 3 muscle thickness groups; the larger mean longissimus muscle area of carcasses from steers in the No. 1 muscle thickness group was offset by their heavier carcass weight and their greater thickness of fat over the longissimus muscle. However, when analysis of covariance was used to hold fatness or fatness and frame size constant, the difference in yield grade between muscle thickness groups No. 1 and No. 3 was significant (P < 0·05). Also, carcasses from cattle assigned muscle thickness scores of No. 1, as feeders, had the highest (P < 0·05) muscle to bone ratio of the round (4·1 to 1) while carcasses from cattle assigned thickness scores of No. 3, as feeders, had the lowest (P < 0·05) muscle to bone ratio of the round (3·4 to 1).     

Growth and carcass characteristics of Angus and American Wagyu steers

Ten purebred Angus and ten crossbred (3/4–7/8) American Wagyu steers were fed a corn and barley-based diet for 552 days and slaughtered. All USDA and Japanese yield and quality grade factors were evaluated and the amount of extractable lipid and moisture in totally trimmed muscle was determined. Angus steers gained 0·9 kg/head/day and American Wagyus gained 0·7 kg/head/day. This difference in growth rate resulted in Angus steers having a heavier final weight (P < 0·05). Angus steers required less feed per unit of gain than did American Wagyu steers. Adjusted fat thickness over M. longissimus dorsi opposite the 12th rib was approximately 3·5 cm and was not statistically different between the two breeds (P > 0·05). Average ribeye area and kidney, pelvic and heart fat were similar for the two breeds. The calculated USDA yield grade for both breeds exceeded 6. Average USDA marbling score was nearly a degree of marbling higher for American Wagyu than for Angus, but variation within breed groups was high. Average USDA quality grade was well into USDA Prime for all carcasses and did not differ by breed (P > 0·05). Japanese yield grade factors were similar for both breeds except for cold left side weight and the yield estimation which includes an adjustment factor that favors American Wagyu. American Wagyu steers merited a higher Japanese marbling score than did Angus (P < 0·05). Beef color score, firmness, texture and firmness and texture grade were also different between the breeds (P < 0·05). Fat colour, luster and quality were not different (P > 0·05). These data clearly show that some American Wagyu steers have the genetic ability to deposit as much marbling as Japanese Black cattle raised in Japan.     

Microbiological and sensory characteristics of beef loin steaks: Role of subcutaneous fat

Beef loin steaks with the subcutaneous fat attached, without subcutaneous fat and the subcutaneous fat that was removed from steaks were packaged and stored at 4°C ± 1°C in polyvinyl chloride (PVC) film for 0–6 days and in high-oxygen barrier (HOB) film for 0–28 days. Aerobic plate counts (APCs) of subcutaneous fat of intact steaks and of subcutaneous fat that was packaged and stored separately in PVC and HOB films were greater (P < 0·05) than those of comparable lean samples. The APCs of lean of steaks without subcutaneous fat that were packaged and stored in HOB film were lower (P < 0·05) than those of the lean of intact steaks. APCs of the lean of these two types of steaks packaged and stored in PVC film did not differ (P > 0·05). Mean surface discoloration and mean overall appearance scores of intact steaks packaged and stored in HOB film were greater than those of steaks packaged and stored without subcutaneous fat; differences were significant (P < 0·05) after 21 and 14 days, respectively. This difference in surface discoloration was attributed to metmyoglobin formation due to possibly higher levels of oxygen remaining in the packages of steaks without subcutaneous fat than in packages containing steaks with the fat attached.     

Carcass and meat quality of finishing Friesian steers fed the β-adrenergic agonist L-644,969

The effect of the β-adrenergic agonist L-644,969 on selected parameters of carcass and meat quality was examined in Friesian steers. Four groups of 18 steers were individually offered ad libitum a pelleted diet that contained 0, 0·25, 1·0, or 4·0 ppm L-644,969 for 12 weeks prior to slaughter. L-644,969 quadratically increased carcass weight (3·7, 9·3, and 8·5%, P < 0·001) and altered the distribution of lean meat such that a greater (0·3–5%; P < 0·01) proportion was in the more valuable cuts. There were no effects of L-644,969 on carcass-chill loss and on the water-holding capacity of the longissimus thoracis et lumborum (LTL) muscle. The intramuscular-fat concentration of the LTL was decreased (27–50%; P < 0·01) and the effects on muscle ultimate pH were small and commercially unimportant. Fibre-optic-probe measurements of the LTL indicated darker (P < 0·01) meat due to β-agonist treatment. L-644,969 increased the shear force required to cut through cooked muscle from the LTL (159%, 209%, and 217%, P < 0·001). It is concluded that L-644,969 treatment improved the quantity and distribution of lean in the carcass but impaired meat quality, primarily through a reduction in tenderness.     

A modified hot processing strategy for beef: functionality of electrically-stimulated and hot-boned meat preblended with different NaCl concentrations

Chucks from 20 electrically-stimulated hot-boned (HB) and cold-boned (CB) beef carcasses were preblended with different concentrations of NaCl (0, 0·5, 1·0, 1·5 and 2·0% w/w). Preblends were analysed for pH, 2-thiobarbituric acid (TBA) values, protein extraction and emulsifying capacities. Bologna (with and without added sodium tripolyphosphate) and ground meat patties prepared from these preblends were also evaluated for cooking yield, color and texture parameters. Ultimate pH values of HB preblends increased with increasing NaCl concentration. At 1% NaCl, HB had higher ultimate pH than CB preblends (P ≤ 0·05) but preblending HB meat with 2% NaCl reduced TBA values (P ≤ 0·05) because the pH was maintained above 6·0. Higher amounts of protein were extracted from HB than from CB preblends (P ≤ 0·01), but boning and salting treatments did not affect their emulsifying capacities (P > 0·05). Two percent NaCl was required to fully achieve the prerigor salting effect. At this concentration, cooking yields of bologna prepared from HB preblends and phosphate containing bologna prepared from CB preblends were not different (P > 0·05) and were higher than those of bologna without added phosphate made from CB preblends (P ≤ 0·05). No meaningful effects were observed on color and texture parameters. Cooking losses were lower in patties made from HB than CB preblends (P ≤ 0·05) independent of NaCl concentration, but boning and salting treatments had no further effects on color or textural parameters (P > 0·05). Therefore, the superior functional properties of electrically stimulated prerigor meat can be maintained by the addition of 2% NaCl up to 2 h post-mortem.     

Performance and carcass characteristics of bulls as influenced by exogenous hormones

One-hundred and forty-four weanling bulls of Angus (A, n = 48), Simmental x Hereford (SH, n = 8) and Simmental (S, n = 48) breeding were either castrated, left intact, left intact and implanted with Ralgro or left intact and implanted with Synovex S. Cattle were slaughtered after 190, 246 or 315 days of high-energy feeding. The right side of each carcass was electrically stimulated. Steers were inferior to intact treatments for most performance and carcass cutability traits, but steers were superior in marbling and lean quality (P < 0·05). There were no differences (P>0·05) in dressing percentage or ribeye area per 100 kg of carcass weight among treatments. Relative to intact bulls, Ralgro and Synovex S increased carcass masculinity. Implanted intact treatments did not differ from nonimplanted intacts for feed conversion, average daily gain, yield grade characteristics, percent longissimus dorsi chemical fat and 9–10dash11th rib composition (P >0·05).     

A modified hot processing strategy for beef: reduced electrical energy consumption in carcass chilling

A beef processing strategy for improving energy and labour efficiencies, modified hot processing (MHP), was developed in a research abattoir. The work reported herein investigated carcass chilling rates and electrical energy usage in the chilling of carcasses that were processed using this approach. The MHP procedure removes the lower value cuts from the dressed carcass along with associated bone and fat. The remaining high value meat (posterior carcass quarter) is chilled in the usual manner, while the low value cuts are immediately processed (e.g. reduced into pre-blended, salted, chilled meat for emulsion-type products; rendered; directly processed as fresh, hot-boned meat, etc.). Carcasses prepared by the MHP method were dissected to quantify the amounts of lean meat, separable fat and bone removed in the procedure. These data were used with a simple model to predict the amount of chilling energy that could be saved by applying MHP prior to chilling. Electrical power to operate a blast chilling facility containing carcasses that had been processed either by conventional processing or by MHP methods was monitored and recorded, and the resulting data was used to confirm the model result. The MHP procedure reduced the refrigeration load for beef chilling by as much as 51% (P < 0·05). The amount of chilling energy to be saved would depend upon the methods employed to further process the low value tissues, and was calculated to be no less than 7%. The time for the reduced MHP carcass quarters to chill to 10°C at the fat-muscle interface of the longissimus dorsi muscle (12/13 rib) was shorter for MHP carcasses than for conventional carcasses (5·77 h vs 7·08 h, respectively) (P < 0·05). However, the times to chill the deep hip location of MHP hind quarters and conventional beef sides were not significantly different (P < 0·05).     

Evaluation of calcium chloride and lactic acid injection on chemical, microbiological and descriptive attributes of mature cow beef

The effect of calcium chloride, lactic acid or their combination on palatability, microbiological, and flavor characteristics of mature cow semimembranosus muscle was investigated. Regardless of aging time, a 10% injection of equal volumes of 0·3 calcium chloride and 0·3 lactic acid into hot-boned semimembranous muscle improved (P < 0·05) shear force values (approximately 35%) compared to hot- and cold-boned control cuts. Microbiological characteristics for all treatments were similar. Control cuts retained more desirable flavor (beefy and serumy/bloody) and less off-flavor (liver, sour, bitter and astringent) than calcium-chloride- or lactic-acid-injected cuts.     

Chemical and nutritional quality of fermented fish silage containing potato extracts, formalin or ginger extracts

Fermented fish silages were prepared from whole tilapia (Oreochromis niloticus), 15% molasses and 5% Lactobacillus plantarum starter culture. After fermentation for 72 h, potato extracts (PE), formalin or ginger extracts (GE) were added at 5 ml/kg silage as proteolytic inhibitor or lipid antioxidant, and incubated at 30°C for 30 days. The effects of presence or absence of these additives on various protein and lipid quality parameters were periodically examined. PE had a slight and insignificant effect on protein solubilization and proteolytic activity; hence it was not effective as a proteolytic inhibitor. Formalin prevented further hydrolysis of protein and reduced ammonia production. GE proved effective as an antioxidant in fermented tilapia silage, as the thiobarbituric acid value remained low after 30 days' incubation. The tilapia silages were incorporated into dry tilapia diets and the digestibility of nutrients determined. The formalin-treated tilapia silage diet gave significantly reduced (P < 0·5) digestibility of dry matter, nitrogen or lipid compared to the control, PE-treated or GE-treated silage diets.     

Dietary energy and protein effects on partitioning of carcass components in beef cattle

This study evaluated carcass and wholesale cut composition of 20 Angus steers fed two levels of protein (LP = 8% versus HP = 14%) at two levels of energy intake (LE = 1·96 versus HE = 2·67 Mcal ME) at 6·35 kg head⁻¹ d⁻¹ dry matter intake for 238 d using a factorial arrangement (n = 5/diet). The left side of each carcass was physically separated into wholesale cuts and each cut was, in turn, physically separated into the lean, subcutaneous fat, intermuscular fat, bone portions and cavity fat when applicable. Intramuscular fat for the entire side was chemically determined using only the separated lean tissue component. Energy was the greatest source of variation (P < 0·05) on carcass and wholesale cut composition: HE was associated with more total carcass fat (32·4 versus 23·9%) and less lean (56·7 versus 60·2%) and bone (17·9 versus 20·1%) than LE. Protein by energy level interactions (P < 0·05) were observed for carcass subcutaneous fat and carcass lean in addition to brisket subcutaneous fat, round subcutaneous fat and bone. The HP:HE group had the least carcass lean and the most subcutaneous fat followed by the LP:HE group, LP:LE and then HP:LE. This was also the trend for the wholesale cut composition. These results suggest that fat deposition in cattle can be significantly and favorably reduced in wholesale cuts by adjusting the relative balance of dietary protein and energy.     

Meat quality characteristics of springbok (Antidorcas marsupialis). 2: Chemical composition of springbok meat as influenced by age, gender and production region

The effects of age, gender and production region on the chemical, mineral and amino acid composition of the M. longissimus dorsi (LD) muscle of springbok were investigated. There was a significant gender^*region interaction for protein content – for the four production regions it varied between 18.80 and 21.16 g/100 g. The intramuscular fat (IMF) content of the LD muscle varied between 1.32 and 3.46 g/100 g. Females (3.13 ± 0.28 g/100 g) had a higher (P < 0.05) fat content than males (1.35 ± 0.08 g/100 g). The IMF content of the adult (2.45 ± 0.26 g/100 g) and sub-adult (2.50 ± 0.28 g/100 g) categories was higher (P < 0.05) in comparison to that of the lambs (1.32 ± 0.11 g/100 g). An inverse correlation was noted between the IMF and moisture content (r = −0.49, P < 0.001) of the meat. The two main amino acids were glutamic and aspartic acid, which contributed 2.47–2.74 and 2.31–2.54 g/100 g of dry matter, respectively. Phosphorous was the predominant mineral in the LD muscle (122.92–159.78 mg/100 g of dry matter), followed by potassium (119.44–131.25 mg/100 g of dry matter) and calcium (6.57–145.18 mg/100 g of dry matter). Production region had a significant effect on the mineral and amino acid composition of the meat, while the effects of age and gender were found to be insignificant.     

Identification of halothane genotypes by calcium accumulation and their meat quality using live pigs

The three halothane genotypes (NN, Nn, and nm) were identified by measuring the capacity for Ca²⁺ accumulation by sarcoplasmic reticulum in whole muscle homogenate preparations of M. longissimus dorsi with a Ca²⁺ specific electrode at 35°C. Significant differences (P < 0·001) in deterioration (%) of Ca²⁺ accumulation, 12% for NN, 35% for Nn, and 81% for nn pigs, were observed after ageing the whole muscle homogenate preparations for 24 h in ice.

Predictions of meat quality in live pigs (n = 34) based on the values for water-holding capacity, assessed as fluid (g/0·5 g wet wt LD), and pH (fluid) by using small biopsy LD samples (Cheah et al. 1993) were performed on all the halothane genotypes. The halothane genotype NN (n = 11) showed a fluid value of 0·37 ± 0·01 and a pH (fluid) value of 6·62 ± 0·03 as compared with 0·61 ± 0·02 and 5·84 ± 0·04, respectively, for the halothane genotype nn (n = 13). The Nn pigs (n = 10) showed fluid (0·49 ± 0·03) and pH (fluid) (6·19 ± 0·11) values between those values observed for the two homozygotes (NN and nn). Predictions of meat quality in live pigs from biopsy LD muscles were confirmed from assessments on post-mortem LD muscles based on pH₁ and fibre optic probe (FOP) measurements.

The extent of deterioration (%) in Ca²⁺ accumulation showed high correlations with fluid (r = −0·861) and pH (fluid) (r = −0·831) in the biopsy LD samples, and with pH₁ (r = 0·663), FOP (r = −0·812), and drip (%) loss (r = −0·777) in the post-mortem LD samples.     

Prediction of fluid losses from pork using subjective and objective paleness

Meat paleness in pork Longissimus dorsi (LD) 1 day post-mortem (p-m) was measured subjectively using Japanese Pork Colour Scores (JPCS) and objectively using a Colormet fibre-optic (FO) meat probe (400–700 nm). Water-holding capacity (WHC), fluid loss during thin-slicing, and drip loss were measured in unfrozen and in frozen and thawed (FT) samples. FT caused a decrease in WHC, and an increase in slicing and drip loss (P < 0·001). FO interactance (i) was correlated (P < 0·01) with unfrozen WHC (R = 0·55), with FT WHC (r = −0·45 at 440 nm), with FT slicing loss (R = 0·81), with unfrozen drip loss (R = 0·66), and with FT drip loss (R = 0·61). Objective measurements proved that the development of pork paleness takes several days p-m and that paleness is increased by FT. Where fluid losses were predictable from paleness, the FO probe was superior to subjective evaluation by JPCS.     

The effects of electrical stimulation and ageing on beef tenderness

Seventeen beef carcasses from cattle with a range of breeds, ages and body conditions were used in this trial. The four treatments applied to each carcass were control (C), electrical stimulation (ES), ageing for 28 days (A) and electrical stimulation plus ageing for 28 days (ES + A). Post-mortem muscle pH was measured at 0, 0·5, 4 and 24h post-stimulation. Significantly lower muscle pH values (P < 0·01) were achieved by the stimulated carcass side sompared to the unstimulated side at 0·5 (pH 6·47 vs. 6·91) and 4 h (pH 5·96 vs. 6·44) post-stimulation.

Warner-Bratzler shear and taste panel methods were used to assess the tenderness of Longissimus dorsi muscle samples from each of the four treatments. The ES, A and ES + A treatments were significantly more tender (P < 0·01) than the control treatment. The ES and the A treatments resulted in a similar improvement in tenderness compared to the control. The ES + A treatment was significantly more tender (P < 0·01) than the ES treatment alone, but there was no significant difference in tenderness between the A and the ES + A treatments.