Fatty acid profile, and chemical composition of Longissimus muscle of bovine steers and bulls finished in pasture system

The objective of this work was to evaluate the conjugated linoleic acid content (CLA), the fatty acid profile, and the chemical composition of the Longissimus muscle (LM) of steers and bulls finished in pasture systems. Fourteen 1/2 Nelore×1/2 Aberdeen Angus cattle were studied. The animals were slaughtered at approximately 20 months of age, with an approximate final liveweight of 480kg. Moisture, ash, fat, crude protein, cholesterol, and fatty acid contents of Longissimus muscle were determined. Steer muscle had a higher lipid content (3.38%) than that of bulls (1.71%). Total n-3 fatty acids were higher in bulls. The amounts of CLA in steer and bull fat were similar, but the CLA content in steer muscle was higher (47.99mg100g(-1) in LM) than that in bull muscle (23.24mg100g(-1) in LM).     

Comparison of M. longissimus dorsi pigment concentration from implanted and control Angus and Limousin bulls and steers

M. longissimus dorsi total pigment concentration, visual color score and 24-h pH values were evaluated in a 2(3) factorial design that included bulls versus steers, Zeranol implants versus control and Angus versus Limousin comparisons. Bulls had greater total pigment concentration than steers (3.25 versus 2·90 mg/g; P < 0·01) and darker colored lean (P < 0·01). Twenty-four hour pH values did not differ between bulls and steers. Zeranol implanting and breed had no effect on total pigment concentration or visual color score; however, Limousin had higher (P < 0·05) 24-h pH values than Angus. The initial slaughter group (N = 10; average age = 256 days) had 34% less total pigment than the final slaughter group (N = 48; average age = 458 days). The correlation between visual color score and total pigment concentration was -0·65. These results indicate that the darker colored lean from bulls is due in part to an increase in pigment concentration.     

Use of the Hennessy Grading Probe (GP) for predicting the meat, fat and bone yields of beef carcasses

Left sides of 36 bulls, 22 cows, 57 steers and 38 heifer carcasses were weighed hot (HCWL) and were probed with the Hennessy Grading Probe (HGP) at five sites to give four subcutaneous fat depths, two M. longissimus dorsi depths and one total tissue depth measurement. A fat depth (GR) over the 10th rib was also measured by ruler probe. The left sides were later separated by knife into saleable eat (90% visual lean), fat trim and bone. Probe readings of subcutaneous fat thickness at the fatter rump sites (BF, 5-7 cm lateral to the perianal region over the M. biceps femoris; SC8, 8 cm lateral to the prominence of the sacral crest) were smaller than ruler measurements at the same sites. Probe eye muscle depth measurements were smaller than measurements taken at the same site by ruler. The BF measurement taken by probe, combined with HCWL, gave the best prediction of percentage fat trim (RSD = 2·0% for steers and 2·2% for heifers) and edible meat yield (RSD = 2·0% for steers and 2·6% for heifers) in the left sides of all the measurements studied, either singly or in combination. A major problem was to find a measurement site where subcutaneous fat was not removed from some carcasses during hide removal.     

Characterization of cutability and palatability attributes among different slaughter groups of beef cattle

Fifteen slaughter cattle from five groups (Charolais crossbred bulls, Brahman crossbred steers, Holstein steers, mixed-Exotic crossbred heifers and Hereford-Angus crossbred steers) were randomly selected from a commercial feedlot. Time-on-feed was 108, 114, 102, 108 and 145 days for the aforementioned groups, respectively. Carcasses from Charolais crossbred bulls had the highest percentage yield of chuck and round, but the lowest percentage yield of loin; hereford-Angus crossbred steers had the lowest percentage yield of round and Holstein steers had the lowest percentage yield of rib. Carcasses from Charolais crossbred bulls had the highest percentage yield of major retail-ready subprimals and lean trim, Hereford-Angus crossbred steers had the highest percentage yield of fat trim and Holstein steers had the highest percentage yield of bone from the major wholesale cuts. Mean percentage yields of closely trimmed, boneless retail cuts were highest for carcasses from the bulls and lowest for carcasses from the Hereford-Angus steers. Although Holstein steer carcasses had less fat trim than Brahman-crossbred steers mixed-Exotic heifers, this advantage was largely offset by their higher percentage of bone. Loin steaks from carcasses of Charolais crossbred bulls, Holstein, mixed-Exotic heifers were comparable (P > 0·05)with those of Hereford-Angus steers for shear force and sensory panel tenderness ratings. However, loin steaks from carcasses of Brahman-crossbred steers had significantly higher (P < 0·05) shear force values (least tender) and lower (P < 0·05) tenderness and overall palatability ratings. No diffeerences (P > 0·05) were found for flavor desirability of loin steaks among any of the groups. For bottom round steaks, Hereford-Angus steers received the highest palatability ratings while those from Holstein steers received the lowest palatability ratings.     

Secondary sexual development (Masculinity) of bovine males: 1. Influence on carcass composition, cutability, economic value and certain muscles

Differences in carcass composition, cutability, economic value of the carcass and distribution of certain muscle groups, between bulls with secondary sexual characteristics (bulls(+)), those without (bulls(−)), and steers were investigated. Two carcass mass groups (250–300 and 301–350 kg) were compared. Five carcasses of either mass group were studied within each sex condition group. Bulls(+) had a higher meat percentage (P < 0·05) than bulls(−) or steers. They also had a lower bone percentage than steers (P < 0·05), but non-significant differences were found between bulls(+) and bulls(−) for bone percentage. Significant differences (P < 0·05) between sex condition groups were found for percentages of hindquarter, as well as for distribution of high-priced cuts. Steers had the most favourable distribution and bulls(+) the least favourable. Bulls(−) were intermediate.

Masculinity significantly (P < 0·05) influenced the distribution of the chuck, neck, brisket and hind shin cuts, whilst mass had a significant effect on the percentage hind shin and percentage thin flank. It was found that the M. rhomboideus was the only muscle of those studied that was significantly affected by masculinity and it was concluded that this muscle could be used as an indicator of the masculinity of the carcass.

The economic values of the carcasses of steers, bulls without secondary sexual development and bulls with secondary sexual development differed non-significantly.     

Colour of subcutaneous adipose tissue and M. longissimus dorsi of high index dairy and beef×dairy cattle slaughtered at two liveweights as bulls and steers

The objectives of this study were (a) to compare muscle and adipose tissue colour of male progeny of two strains of high genetic merit Friesian cows (New Zealand [NZF] and Irish [DAF]) with those of beef (Belgian Blue)×dairy (Holstein-Friesian) [BBHF] male progeny; (b) to compare bulls and steers (gender) of these genotypes and (c) to examine the effects of slaughter weight (SW) on these quality traits. Bulls (n=48) and steers (n=48) of the three genotypes were grown to nominal target liveweights of 550 kg (light) and 630 kg (heavy). Adipose tissue from the NZF genotype was more yellow (P<0.05) than from DAF or BBHF, regardless of gender or SW. For longissimus dorsi (LD) pH, bulls and heavy animals had higher pH (P<0.05) than steers or light animals, respectively, while NZF and BBHF bulls had higher pH than steers. LD muscle from the BBHF genotype had lighter colour (P<0.05) and lower haem pigments (P<0.01) than NZF or DAF progeny. There was no difference in muscle `L' value between light bulls and steers but heavy bulls had darker muscle than heavy steers. There was an interaction between genotype, gender and SW for LD redness. Thus, NZF animals were most red when slaughtered as light or heavy bulls, but there were no differences between genotypes slaughtered as light or heavy steers. These data demonstrate differences in colour of beef, especially from progeny of NZF, which produced the most yellow adipose tissue and the most red muscle tissue.     

The usefulness of muscle color and pH for segregating beef carcasses into tenderness groups

A total of 3435 beef carcasses from animals 11 to 14 months of age (472 bulls, 978 heifers, 1985 steers) were evaluated over a ten year period to determine the usefulness of measurements of muscle color and pH for segregating carcasses into tenderness groups. All carcasses were aged for 6 days at 2°C. Color and pH measurements were obtained on the longissimus? muscle. A loin steak from the eleventh-twelfth thoracic vertebrae interface was microwaved to approximately 70°C to determine shear force values. Steers had the lowest ultimate pH and shear force values and bulls had the highest (P=0·0001). Steers also had lighter colored lean (P=0·0001) than bulls and heifers (i.e. higher mean colorimeter readings). Arbitrary segregation of carcasses into tenderness groups based on shear force values (?6·0 tender; >6·0 tough) resulted in the tender group having higher colorimeter readings (17·40 versus 16·76, P=0·0001) and ultimate pH values (5·70 versus 5·69, P=0·02) and lower shear force values (4·89 versus 7·65, P<0·0001). Year and breed effects were observed in all three traits (P=0·0001). However, time trends were not detected and the range in shear force values among breeds was relatively narrow (6·02-6·74). Subjective color scores, colorimeter readings, and ultimate pH values accounted for 48% or less of the variation in shear force values in all sex, year, and breed groups indicating that generally none of these traits were highly related to tenderness in a linear fashion. Arbitrary segregation of carcasses into tenderness groups based upon shear force value resulted in consistently higher shear force values for the toughh group (SV>6·0) and lower values for the tender group (SV?6·0) (P<0·05) than the overall mean shear force value in all sex groups. Plotting of colorimeter readings and ultimate pH values against shear force values resulted in peaks within the range of colorimeter readings 8·5-16·5 and pH values 5·8-6·19. Segregation of carcasses with colorimeter readings within the range 8·5-16·5 was effective in segregating the tough ess steer and heifer carcasses and the tender bull carcasses, while segregation based upon pH values between 5·8 and 6·19 was effective in segregating the tough carcasses in all sex groups. Segregation based on both color and pH appeared to offer little advantage over the use of pH alone. Segregation of beef carcasses with ultimate longissimus pH values between 5·8 and 6·19 appears to be an easy, nondestructive, practical means to effectively remove the majority of tough carcasses (shear value >6·0) in all three sex groups, regardless of breed.     

Cholesterol Content of Beef Bone Marrow and Mechanically Deboned Meat

Marrow from cervical, lumbar and femur bones of 5 steers and 5 cows fed only on native range (grass fed) and 5 steers and 5 cows fed a finishing ration (grain fed) was analyzed for cholesterol content. The cholesterol content of the marrow was significantly different when diet or anatomical locations were compared. Bovine marrow from grass-fed animals averaged 119.6 mg/100g and marrow from grain-fed animals averaged 150.6 mg/100g marrow. The cholesterol content of marrow from the cervical, lumbar, and femur was 190.1, 124.1, and 91.0 mg/100g marrow, respectively. Mechanically deboned meat (MDM) and beef lean had a mean cholesterol content of 153.3 and 50.9 mg/100g tissue. Spinal cord material in MDM can account for the increased concentration of cholesterol in some MDM samples over the values for lean and marrow.     

CARCASS CHARACTERISTICS, SENSORY PROPERTIES AND MINERAL CONTENT OF MEAT FROM BULLS AND STEERS

Thirty-three bulls and 22 steers were slaughtered and subsequent carcasses were evaluated for carcass characteristics. Longissimus muscle samples were analyzed for sensory properties and concentrations of Cu, Fe and Zn. Bulls produced carcasses with older maturity characteristics, larger ribeyes, less fat and produced longissimus steaks that were less tender and had more organo-leptically detectable connective tissue than steaks from steers. Zn concentration was significantly correlated to skeletal maturity, fat thickness, ribeye area, connective tissue and tenderness before adjusting for sex. After adjusting for sex, mineral content did not significantly correlate as well with many carcass or sensory properties as before adjusting for sex.     

Effect of feeding regimen, breed and sex condition on carcass composition and feed efficiency

Eighty bulls and eighty steers representing four breed types (7/8 Angus. 7/8 Simmental, 7/8 Simmental × 7/8 Angus and 7/8 Simmental × 7/8 Hereford) were randomly assigned to two diets by sex class and breed type. Exotic breeds produced heavier, leaner, more muscular carcasses, with lower USDA quality grades and darker colored, coarser textured lean. Angus 9-10-11th rib composition showed that Angus tended to have less lean, more bone and the most fat when compared to the Simmental and Simmental crosses. Feeding the deferred diet resulted in carcasses with (P < 0·05) less fat, lower USDA quality grade, smaller ribeyes, more sensory panel detectable connective tissue, higher cooking losses and higher Instron shear values. Sex class caused differences (P < 0·05) in feed efficiency, carcass traits and sensory properties.     

B-Vitamine (Thiamin,Vitamin B6 and Pantothensäure) im Muskelgewebe wachsender Rinder der Rasse Deutsches Fleckvieh in Abhängigkeit von Mastendmasse und Fütterungsintensität

In a comparative slaughter experiment the thiamin, vitamin B₆ and pantothenic acid content of lean tissue of foreloin of growing cattle was determined by whole body analyses. 54 bulls, 45 heifers and 45 steers were fed until a live mass of 200 kg, 350 kg, 425 kg (only heifers) 500 kg and 575 kg, 650 kg, respectively (only bulls and steers). One half of each carcass was divided into 13 cuts and afterwards the cuts were each divided into lean, adipose and bone tissue and tendons. The lean tissue of the foreloin was subjected to analysis of thiamin, vitamin B₆ and pantothenic acid. The mean thiamin content of 0.75 mg kg_-1 fresh matter (200 kg live mass) decreased with rising live mass and under intensive feeding conditions in bulls and steers to 0.53 mg and in heifers to 0.61 mg. Restrictively feeding caused a mean thiamin content of 0.60 mg per kg fresh matter in bulls, steers and heifers. Under both feeding conditions in the lean tissue of the foreloin on average a vitamin B₆ content of 2.6 mg (bulls), 3.1 mg (heifers) and 3.0 mg kg^?1 fresh matter (steers) was analysed. A mean content of pantothenic acid of 2.6 mg kg^?1 fresh matter was determined in bulls independent of live mass and feeding intensity. In heifers the content of pantothenic acid on average was 3.0 mg under intensive feeding system and 2.6 mg under low feeding conditions, whereas steers reached contents of 2.7 mg (high feeding) and 2.2 mg kg^?1 fresh matter (low feeding).     

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.     

Fatty acids, cholesterol and protein content of nutria (Myocastor coypus) meat from an intensive production system in Uruguay

This study describes the total lipids, protein and fatty acids in the meat, liver, brain and adipose tissue of five male and five female nutria (Myocastor coypus). The animals were reared on a specialized farm in Uruguay. Total lipid content was between 1.41% and 1.84% in males and females. Total cholesterol content was between 70.1 mg and 72.7 mg/100 g of wet tissue. The protein content was between 19.56% and 22.34% in males and females. No significant differences (P > 0.05) were detected between males and females for total lipid, cholesterol or protein. Total, saturated, monounsaturated and polyunsaturated fatty acid values were higher (P < 0.001) in female than in male thigh muscle. Pectoral muscle had more (P < 0.05) saturated and monounsaturated fatty acids in females than in males. Subcutaneous adipose tissue from females had the highest (P < 0.01) total, saturated and monounsaturated but not polyunsaturated fatty acids while abdominal adipose tissue from males had more polyunsaturated fatty.     

Cutability comparisons of Charolais crossbred bulls and steers

Seventy-two sides (eighteen sides from each sex-breed group) from carcasses of half-blood or three-quarters-to-seven-eighths-blood Charolais bulls or steers of known history and age, handled alike from weaning to slaughter, were used. All cattle were fed in a commercial feedlot (average days-on-feed was 186) and slaughtered in a commercial packing plant. Comparisons were made for percentages of (1) untrimmed wholesale cuts, (2) partially boneless subprimals (trimmed of fat in excess of 1·9 cm), (3) partially boneless retail-ready cuts (trimmed of fat in excess of 0·95 cm) and (4) boneless retail-ready cuts (trimmed of fat in excess of 0·95 cm). Bulls had higher percentages than steers of chuck and round at all stages of trim. Steers had higher percentages of untrimmed, wholesale loin and partially boneless shortloin (1·9 cm fat) than bulls but steer percentages of shortloin cuts trimmed to 0·95 cm of fat did not differ from those of bulls. Bulls averaged 48·05%, while steers averaged 45·45%, major boneless, closely trimmed retail-ready cuts. After the lean trim was adjusted to 25% chemical fat, bulls had 27·70% lean trim and 5·65% fat trim while steers had 24·30% lean trim and 12·15% fat trim. No difference in the percentage of retail-ready cuts was attributable to breed; however, the three-quarters-to-seven-eighths-blood Charolais group had a lower percentage of standardized fat trim and a slightly higher percentage of bone than the half-blood group.     

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.     

Electrical Stimulation and 48 Hours Aging of Bull and Steer Carcasses

Bull (n = 30) and steer (n = 30) carcasses were measured for meat quality in the longissimus muscle after 48 hr on electrically stimulated (ES) sides or after 6 days on their unstimulated counterparts. Electrical stimulation and 48 hr aging had the same tenderizing effect as a 6 day aging period on both bulls and steers. Compared to meat from steers, that from bulls was tougher and had higher ultimate pH values and collagen contents. On an overall quality basis however, ES meat aged for 48 hrs was equivalent to nonstimulated meat aged for 6 days.     

Variation in the carcass characteristics of commercial British cattle

Classification records for 1,150,000 beef carcasses, a one-third sampleof those classified by the Meat and Livestock Commission between 1973 and 1976, were used to examine the variation in weight, fatness and conformation of commercial British cattle. The overall ratio of male cattle (steers and young bulls) to heifers was 2·35 and young bulls comprised 4% of male cattle. There were only minor changes in the carcass characteristics over the three-year period considered. Mean carcass weights for steers (S), heifers (H) and young bulls (YB) were 264, 219 and 236 kg, respectively. Carcass subcutaneous fat percentages (SF(e)) were estimated from the distribution of carcasses between fat classifications. SF(e) for the three sexes were 8·21 (S), 8·81 (H) and 6·24 (YB). Regressions of SF(e) on carcass weight (kg) were 0·031 (S), 0·041 (H) and 0·026 (YB). There were important differences in the characteristics of carcasses from abbattoirs in different regions of the country. Carcass weights for steers ranged from 248 kg (northern England) to 280 kg (northern Scotland). Cattle slaughtered in northern Scotland were also fattest: SF(e) were 9·51 (S) and 10·2 (H). Using classification records, together with results from MLC dissection studies, national waste fat production in 1976 was estimated to be 48,000 t.     

Mineral content of longissimus dorsi thoracis from water buffalo and Zebu-influenced cattle at four comparative ages

The longissimus dorsi thoracis (LDT) of 64 water buffalo and 68 Zebu-influenced cattle was used to determine the mineral content variation (mg/100g of fresh tissue) according to species, age (7, 17, 19 and 24 months-of-age, MOA) and gender (steers and bulls). Buffalo LDT had higher concentrations of K, Mn, Fe, Zn and Cu at weaning (P<0.05). Phosphorous content was higher (P<0.05) at post-weaning ages. Mineral profile was affected by age without clear trends; the Na and K contents increased at 24 MOA. The age×species, age×gender and species×gender interactions affected (P<0.05) Fe content that ranged from 1.74 to 2.56mg/100g fresh tissue. Meat from both species contributes with more of 25% of K, P, Fe and Zn of the daily requirement for an adult.     

Effects of oestradiol-17β implantation on performance, carcass traits, meat sensory traits and endocrine aspects of bulls and steers

Twenty-eight Simmental bull calves were randomly allotted to one of three treatments at birth. Ten bulls (IB) and nine steers (IS), castrated within 3 days of birth, were implanted with oestradiol (E(2)). The remaining calves were non-implanted, control bulls (CB). Calves were implanted within 3 days of birth and at 200-day intervals until slaughter at 14·8 months of age and at a mean carcass weight of 381·6 kg. Blood samples were taken every 14 days from 9·8 through 14·8 months and serum was analyzed for E(2) and testosterone (T) levels. Carcasses were chilled in a 3 to 7°C cooler. Carcass data were obtained and aged longissimus dorsi steaks were evaluated by a trained sensory panel and a Warner-Bratzler shear (WBS) device. Scrotal circumferences were smaller (P < 0·0.5) for IB than for CB. Control bulls had heavier weaning weights (P < 0·05) than IB and higher (P < 0·05) feedlot gains than IS. Implanted steers required more (P < 0·05) feed/unit of gain than CB and IB. Implanting bulls with E(2) increased (P < 0·05) serum E(2) levels and tended (P < 0·10) to reduce T levels. Serum E(2) in IS and IB were drastically increased (P < 0·05) for 4 to 6 weeks following re-implantation during the feedlot phase, then sharply declined. Implanted steer carcasses had more youthful maturity scores than CB carcasses. The incidence of hear ring (dark, coarse, band formation) was greater (P < 0·05) for IB than for IS, probably because of the thinner fat cover (P < 0·05) on IB. Ribeye areas were smaller (P < 0·05) and yield grades were higher for IS than for CB. Testicle weights were not significantly different between IB and CB, although variability was greater for IB. Carcass masculinity was least (P < 0·05) for IS, and IB were less (P < 0·05) masculine than CB. The only difference in longissimus dorsi sensory traits was that steaks from IB were juicier than steaks from CB. Also, WBS values were lower (P < 0·05) for IS than for CB.     

Palatability characteristics of loin steaks from Charolais crossbred bulls and steers

Loins from 1/2-blood or 3/4- to 7/8-blood Charolais bulls (n = 60) and steers (n = 64) were obtained at 24 h post mortem from electrically stimulated sides and, at 12 days post mortem, steaks were removed and frozen. Shear force values were higher (P < 0·001) and sensory panel evaluations of tenderness and overall palatability were lower (P < 0·001) for steaks from bulls than from steers. No differences (P > 0·05) in connective tissue amount or off-flavour were detected for steaks from bulls versus steers. Significant correlations between carcass secondary sex characteristics and sensory panel evaluations of tenderness were noted, but the coefficients were not of a magnitude to be considered predictive of tenderness.