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.     

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).     

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.     

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).     

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.     

Development of backfat and individual fat layers in the pig and its relationship with carcass lean

The development of backfat (total and individual layers) was monitored in 140 Yorkshire pigs (71 castrates and 69 gilts) during a growing period extending from 14·5 kg to 137·0 kg live weight using a serial slaughter procedure. The allometric coefficient (b) for fat thickness was calculated at several locations extending from the shoulder to the M. gluteus medius at the mid-line and lateral to the mid-line. The relationships between backfat (total and individual layers) and the yield of trimmed boneless meat were also obtained from 80 carcasses.

Total backfat was the thickest at the shoulder, decreased gradually to the last rib, increased at the maximum loin, decreased to the middle of the M. gluteus medius and then increased posterior to the M. gluteus medius. The development of total backfat relative to weight at slaughter was generally slowest at the shoulder (b = 0·555−0·767), most rapid in the region extending from the 5/6 last rib to the last rib b = 0·729−0·810) and intermediate at the loin and in the region of the M. gluteus medius (b = 0·609−0·834). The development of the middle fat layer (b = 0·609−1·107) was more rapid than that of the outer layer (b = 0·500−0·817), the inner layer being intermediate (b = 0·515−0·966). Consistent with the rate of development observed for the individual fat layers, at light weights, the outer layer was usually more predominant, particularly at positions above the M. longissimus, whereas, at heavier weights, the middle layer became predominant.

It was observed that backfat (total or individual layers) measurements, which were the most precise predictors of yield of trimmed boneless meat, that is, measurements from the 5/6 last rib to the last rib (RSE = 4·6−3·1), also had the most rapid rate of development. Furthermore, the middle layer of backfat which exhibited the fastest rate of development of all three individual layers (b = 0·609−1·107), also contributed the most to the observed precision (RSE = 4·6−3·1).     

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.     

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.     

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.     

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.     

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.     

A modified hot processing strategy for beef: effects on fresh meat quality

A modified hot processing (MHP) strategy for beef carcasses using known chilling technology to maintain quality in the higher priced cuts while retaining lower value cuts for further, immediate hot processing was evaluated. Following high voltage electrical stimulation, paired sides from 36 carcasses were either conventionally processed (CP) or reduced in a manner similar to the French pan traité cut. The sides were help in a pre-chiller for 1 h prior to blast chilling at −20°C for 3 h at an air speed of 2·3 m s⁻¹, followed by chilling at 2°C for the remainder of the 24 h period. Overall, MHP of beef carcass sides had minimal effects on fresh meat quality in the longissimus thoracis et lumborum (LTL) and the semimembranosus (SM) muscles despite removing over 50% of the carcass side weight in the form of lower value cuts. Sarcomere length was significantly shorter (P ≤ 0·05) in the anterior (AL) and posterior (PL) LTL which was attributed to the removal of skeletal restraint and carcass weight. The increase in shear value in the AL, location of MHP sides although statistically significant (P ≤ 0·05) would not likely be percieved by consumers. Hence a non-traditional method of processing carcasses by treating low value and high value primal cuts separately, may be viable.     

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.     

Fatty acid composition of subcutaneous and intramuscular adipose tissues and M. longissimus dorsi of Wagyu cattle

Three experiments were conducted to document the fatty acid composition of tissues from purebred Wagyu cattle from Japan and North American crossbred Wagyu. In experiment 1, subcutaneous (s.c.) adipose tissues (n = 23) were obtained from Japanese cattle representing the five Japanese fat quality grades. The monounsaturated:saturated fatty acid ratio (MUFA:SFA) was greatest in fat quality grade 5 samples (2·57) and least in the fat quality grade 3 samples (2·08; P < 0·05). In experiment 2, M. longissimus dorsi and the associated intramuscular (i.m.) and s.c. adipose tissues were obtained from carcasses of Wagyu crossbred steers (1/2–7/8) raised in the USA. Fatty acid composition varied among depots, but the MUFA:SFA ratio in s.c. adipose tissue (1·46) was not different from values reported for other breeds of cattle. In experiment 3, samples of M. longissimus dorsi ribsteaks were obtained from three regions in Japan. Samples from the Gunma region had the greatest (P < 0·05) MUFA:SFA ratio (2·10), relative to samples from the Kagoshima (1·82) and Miyazaki (1·65) regions. The data indicate that beef from purebred Wagyu cattle raised in Japan is enriched in monounsaturated fatty acids, and that the degree of enrichment depends upon the region of Japan from which the samples were obtained.     

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.     

Tenderness of pork muscles as influenced by chilling rate and altered carcass suspension

Tenderness improvements in porcine muscles (M. longissimus dorsi, LD; M. semimembranosus, SM; M. biceps femoris, BF) were evaluated in a total of 72 carcasses by using combinations of three different chilling rates (fast, delayed fast, slow) and two different suspension methods (Achilles tendon, pelvic bone).

Tenderness was improved by fast chilling in LD, SM and BF by the pelvic suspension as compared to conventional suspension in the Achilles tendon (P < 0·05). The lengthening of the sarcomeres in SM and BF as produced by pelvic suspension exceeded those found in LD, without having proportional additional effect on the tenderness. While the pelvic-induced tenderization did not change significantly by delayed fast chilling, additional tenderization in BF and SM was obtained by combining pelvic suspension with slow chilling. In conventionally suspended sides, tenderness was unaffected by delayed fast chilling—with slow chilling, however, improvements were observed in LD and SM to a similar extent as obtained by the pelvic suspension. In the LD muscle, the tenderizing effect produced by treatments was largest in muscles having pH values 45 min post stunning above 6·1 (P < 0·05).     

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).     

Indigenous legume fermentation: Effect on some antinutrients and in-vitro digestibility of starch and protein

Indigenous fermentation of coarsely ground dehulled black-gram dhal slurry at 25, 30, and 35°C for 12 and 18 h reduced the levels of phytic acid and polyphenols significantly (P < 0·05). The unfermented legume batter had high amounts of phytic acid (1000 mg/100 g) and polyphenols (998 mg/100 g), and these were reduced to almost half in the product fermented at 35°C for 18 h. In-vitro digestibility of starch and protein improved significantly (P < 0·05) with increase in the temperature and period of fermentation. A significant (P < 0·01) and negative correlation found between the in-vitro digestibility and the anti-nutrient further strengthens these findings.     

Calpains from thaw rigor muscle

Pre-rigor beef M. Longissimus lumborum and diaphragma were frozen at −70 °C and thawed at different temperatures and the activities of extracted calpains and the toughness of heated meat compared with those in chilled muscle.

Fresh muscle contained about 14 μg of μ-calpain/g and was unaffected by freezing, but was reduced after thawing. Rapid thawing at 30 °C for 20 min reduced the μ-calpain to 14%. When cooked from the frozen state, extensive shortening occurred and tender meat was obtained.

By storing at −3 °C for 1 day, thaw-shortening was prevented, but tougher meat obtained. The μ-calpain decreased to 70% whilst the m-calpain was unaffected. Toughness decreased after further storage at −3 °C, as did the μ-calpain. The latter changes were similar to those during development of rigor mortis and ageing of non-shortened meat stored at 4 °C. Variation in calpain activity, rather than in sarcomere length, are likely to be the cause of toughness variation in thaw rigor muscle.     

Physico-chemical and organoleptic properties of patties from hot, chilled and frozen goat meat

The effects of processing hot versus chilled goat meat, as such and after freezing in chunk or mince forms, were studied in relation to physico-chemical and organoleptic properties of patties. The differences in the pH of the meat samples were non-significant (P < 0·05) at 3–4 h post mortem (PM) at room temperature (30°C) and after 24 h at 4°C. The yield of the broiled patties, prepared from hot meat at 3–4 h PM, was significantly lower (P<0·05) as compared to those from chilled meat. However, this trend was reversed, if processing of hot meat into patties was done within 1–2 h PM. Freezing of chilled meat in chunk or mince forms gave significantly higher (P < 0·05) cooking yields than freezing of hot meat in similar forms.

The organoleptic scores of the raw-cooked patties were similar for all treatments. Freezing of precooked patties at −10°C for 10 days, thawing and reheating did not reduce most of the sensory scores significantly (P<0·05). Moisture, protein and fat contents of the broiled patties were not significantly (P<0·05) affected by the treatments. Standard plate count of hot versus chilled meat, for all levels of processing and storage, were within acceptable limits.