Factors influencing beef eating quality 1. Effects of nutritional regimen and genotype on organoleptic properties and instrumental texture

2001 ◽  
Vol 72 (2) ◽  
pp. 269-277 ◽  
Author(s):  
K. D. Sinclair ◽  
G.E. Lobley ◽  
G.W. Horgan ◽  
D.J. Kyle ◽  
A.D. Porter ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Vastus Lateralis ◽  
Biceps Femoris ◽  
Experimental Period ◽  
Metabolizable Energy ◽  
Eating Quality ◽  
Beef Tenderness ◽  
Dietary Regimen ◽  
Commercial Practice

AbstractAn experiment was conducted to determine if growth rate, as affected by level of feeding, during a 10-or 20-week period prior to slaughter could influence the tenderness and palatability of beef from young (approx. 14 months old at the start of experiment) steers. Steers, comprising 18 Aberdeen Angus (AA), 18 Charolais (CH) and 18 Holstein (HO) purebreds, were allocated, within genotype, to one of three levels of feeding: (a) moderate ((M/M) 750 kJ metabolizable energy (ME) per day per kg M0·75), (b) high ((H/H) 1050 kJ ME per day per kg M0·75) both for 20 weeks; or (c) moderate for the first 10 weeks followed by high for the remaining 10 weeks (M/H). The steers were slaughtered at a fixed age (approx. 19 months old) and samples ofm. longissimus lumborum(from all three genotypes) m. vastus lateralis and m. biceps femoris (from AA and CH only) separated, vacuum packed and stored at 2ºC for both 7 and 14 days before freezing. These cuts were subsequently assessed by a 12 member taste panel and texture analysis performed using Volodkevitch-type jaws.Growth rates during the final 10 weeks of the experimental period differed between dietary regimen (M/M = 0·87; M/H = 1·25; and H/H = 1·02 kg/day; s.e.d. = 0·08;P< 0·001). Steers offered the M/M level of feeding grew more slowly (0·97 kg/day) than those offered the M/H and H/H level of feeding (1·20 kg/day; s.e.d. = 0·06;P< 0·001) over the entire 20 week experimental period. In spite of these differences in growth rate, there were no consistent effects on beef tenderness and general palatability. Mean growth rates for CH, HO and AA steers were 1·21, 1·13 and 1·03 kg/day (s.e.d. = 0·06;P< 0·05). Beef samples from AA steers consistently scored better for various sensory attributes than those from CH and HO steers; this may have been due, in part, to level of carcass fatness and rate of carcass cooling post mortem. Accounting for factors such as genotype within the experimental design and slaughtering animals at a relatively constant age reduced the variance associated with each sensory attribute to 0·6 of that observed in commercial practice. The data suggest that there is little opportunity to improve beef eating quality by increasing growth rate by dietary means in steers provided that moderate levels of gain (equivalent to the UK average) are maintained.

The effects of age at slaughter, genotype and finishing system on the organoleptic properties and texture of bull beef from suckled calves

1998 ◽  
Vol 66 (2) ◽  
pp. 329-340 ◽  
Author(s):  
K. D. Sinclair ◽  
A. Cuthbertson ◽  
A. Rutter ◽  
M. F. Franklin
Keyword(s):  
Growth Rates ◽  
High Growth ◽  
Biceps Femoris ◽  
Eating Quality ◽  
Post Mortem ◽  
Beef Tenderness ◽  
Standard Product ◽  
Longissimus Lumborum ◽  
Age Limit ◽  
The Uk

AbstractAn experiment was devised to examine the effect of animal age at slaughter, within genotype and finishing system, on bull beef eating quality characteristics to assess the 15 month age limit imposed for bulls at slaughter by the Meat and Livestock Commission specification for improved beef eating quality. The experiment was a factorial design using bulls of two crossbred genotypes (Aberdeen Angus × and Charolais ×), offered two diets (silage-based and barley-based) and slaughtered at two abattoirs. Bulls were slaughtered from approximately 10 months of age on seven dates (ages) at 6-week intervals. Bulls given barley were slaughtered on date numbers 1 to 5 (43 to 67 weeks of age) and bulls given silage on date numbers 2 to 7 (49 to 79 weeks of age). On each slaughter date and at each abattoir the first four commercial steers which followed the bulls on the slaughterline and met the United Kingdom (UK) modal carcass specification R 4L were selected as abattoir, slaughter date and industry representative controls. At 48 h post mortem samples of m. longissimus lumborum; m. biceps femoris; and m. semimembranosus were recovered from all bull and steer carcasses, vacuum packed and stored at 2°C for a fiirther 12 days before freezing and subsequent assessment by a 12 member taste panel and texture analysis using a Warner Bratzler shear jig.Bulls achieved high growth rates during the finishing period averaging 1·22, 1·55, 1·41 and 1·98 kg/day for silage-fed Angus × bulls; barley-fed Angus × bulls; silage-fed Charolais × bulls; and barley-fed Charolais × bulls, respectively (s.e.d. = 0·08; P < 0·05). Age at slaughter had no significant effect on beef tenderness from young bulls in this study. Similarly, no significant differences in beef tenderness either between genotypes or diets were detected. Bulls, however, produced meat which had lower mechanical shear force values (10·2 v. 11·9 kg for m. biceps femoris; P < 0·001) and was considered to be more tender (P < 0·001), less flavoursome (F < 0·001) and more acceptable (P < 0·01) than that produced by steers.It was concluded that beef aged for 14 days post mortem and recovered from young bulls which have achieved high growth rates can be at least as good as that representative of the UK standard product. The 15-month age limit for bulls ensures that commercially produced bulls achieve high lifetime growth rates and will produce beef of a quality comparable with that achieved in this study.

Improving the pre-weaning nutrition of calves by supplementation of the cow and/or the calf while grazing low quality pastures. 2. Calf growth, carcass yield and eating quality

2001 ◽  
Vol 41 (6) ◽  
pp. 715 ◽  
Author(s):  
D. W. Hennessy ◽  
S. G. Morris ◽  
P. G. Allingham
Keyword(s):  
Growth Rate ◽  
Phase I ◽  
Meat Quality ◽  
Cottonseed Meal ◽  
Phase Ii ◽  
Growth Rates ◽  
Phase Iii ◽  
Eating Quality ◽  
Growth Phases ◽  
Calf Growth

Tender, juicy and flavoursome are desirable meat traits in the grading system of Meat Standards Australia. There are 3 critical growth phases affecting these traits in domestic trade cattle: birth to weaning (phase I), weaning to feedlot entry (phase II), and feedlot finishing (phase III). In the study reported in this paper we examined the effects of supplementary feeding of cows and/or calves in phase I on calf growth rate during each of the 3 growth phases and assessed whether differences in early growth were recorded in carcass weights and meat quality at slaughter (16.5 months old). The calves were weaned on to high quality pastures (phase II) and then finished in a feedlot on a grain-based diet (phase III). One-hundred Hereford cows with Angus-sired calves, and 24 Hereford cows, with Hereford-sired calves were allocated to treatments in a 2 × 3 factorial study of calf growth rate during phase I. The treatments consisted of nil or 4.2 kg twice-a-week of cottonseed meal to the cows for 145 days from calving to mid-lactation, and calves either had access to a high protein barley-based supplement in a ‘creep’ from 75, or from 150 days old until weaning. There were 4 replicate groups for each treatment during phase I with 24 paddocks. Weaners were grazed as a single herd during phase II of the study and separated into 10 feedlot pens in phase III. At slaughter, after phase III, M. longissimus et laborum muscle was sampled from half the carcasses and graded by a taste panel according to Meat Standards Australia. Calves, suckled by cottonseed meal-supplemented cows, were heavier at weaning than those calves suckled by non-supplemented cows (201 v. 170 kg; phase I) with a trend for younger calves with access to ‘creep’ feeding (from 75 days old) to be heavier than calves without access to ‘creep’ feed (196 v. 175 kg). During phase II, liveweight change was higher for weaners from non-supplemented cows than for weaners from supplemented cows (679 v. 593 g/day). During phase III this trend was reversed in favour of weaners from cottonseed meal-supplemented cows (1.54 v. 1.46 kg/day). Similarly, carcasses of calves from cottonseed meal-supplemented cows were also heavier than other carcasses from other calves (226 v. 212 kg) with a greater depth of rib fat (7.0 v. 5.8 mm). In contrast to carcass weight, M. longissimus et laborum muscle samples from calves which did not have access to supplement during phase I were assessed as being more tender, more flavoursome and having a higher overall Meat Standards Australia score than M. longissimus et laborum muscle from calves that had access to supplements. The carryover effects of nutrition from the preweaning growth phase of calves highlight the importance of early life nutrition for achieving higher carcass weights and meat quality. However, the findings that M. longissimus et laborum samples from calves with lower growth rates before weaning were more tender and graded higher than samples from calves with higher growth rates was both unexpected and unexplained.

The effects of two methods of increasing age at slaughter on carcass and muscle traits and meat sensory quality in pigs

2001 ◽  
Vol 72 (1) ◽  
pp. 87-94 ◽  
Author(s):  
B. Lebret ◽  
H. Juin ◽  
J. Noblet ◽  
M. Bonneau
Keyword(s):  
Growth Rate ◽  
Sensory Quality ◽  
Feeding Strategy ◽  
Average Daily Gain ◽  
Biceps Femoris ◽  
Carcass Composition ◽  
Eating Quality ◽  
Large White ◽  
Significant Difference ◽  
Ad Libitum

AbstractThe aim of this study was to investigate the effects of a 30-day increase in age of pigs slaughtered at 110 kg body weight (BW) on carcass and m. longissimus dorsi (LD) and m. biceps femoris (BF) traits, and meat sensory quality. A total of 60 pigs from two genotypes: synthetic line ✕ (Large White ✕ Landrace) (SL) and Duroc ✕ (Large White ✕ Landrace) (D) were used, each genotype containing five groups of six littermates (three castrated males and three females). At the average BW of 30 kg, littermates of the same sex were allocated to three groups. Pigs of group AL were offered ad libitum a standard growing-finishing diet (13·6 MJ/kg digestible energy, 9·5 g/kg of lysine) from 30 up to 110 kg BW. The R1 pigs received the same diet at 0·75 of the ad libitum intake of their AL littermates. The R2 pigs were submitted to both energy and protein restrictions in order to get the same growth rate as the R1 pigs and the same body composition as the AL pigs. Results were similar in both genotypes. In agreement with the protocol, age at slaughter was increased by 30 days in R1 and R2, and AL and R2 pigs had comparable carcass composition. Compared with AL, average daily gain was decreased in R1 and R2 pigs, and food efficiency was decreased in R2, but remained unaffected in R1 pigs. Intramuscular fat (IMF) concentration was decreased in the R1 pigs, especially in BF (15·5 v. 19·7 mg/g), while it was increased in the LD of the R2 pigs, particularly in the D animals (24·2 v. 17·4 mg/g), compared with AL pigs. Meat quality parameters (rate and extent of pH fall, reflectance and drip loss) were similar in the three feeding regimens. The taste panel did not find any significant difference between feeding regimens for tenderness, juiciness, flavour, flour sensation after mastication and mouth coating of the meat, despite the differences reported in IMF concentration. This suggests that, for the genotypes used in this experiment, an increase of 30 days in the age at slaughter greatly influences the carcass and/or the muscle chemical composition, depending on the feeding strategy applied to reduce the growth rate but does not strongly modify the meat eating quality.

The effect of breed and dietary energy concentration on lamb growth, carcass composition and meat quality

1996 ◽  
Vol 1996 ◽  
pp. 109-109
Author(s):  
M.I. Mustafa ◽  
G.M. Webster ◽  
Gillian M. Povey
Keyword(s):  
Growth Rate ◽  
Meat Quality ◽  
Tissue Growth ◽  
Carcass Composition ◽  
Metabolizable Energy ◽  
Energy Concentration ◽  
Eating Quality ◽  
Lamb Growth ◽  
Different Levels

Previous trials at Newcastle have shown that plane of nutrition affects the growth performance, carcass composition and eating quality of lambs (Mustafa and Webster, 1995). It has also been found that lean tissue growth rate, a characteristic it is possible to manipulate nutritionally, influences meat quality in pigs and cattle (Whipple et al., 1990; Blanchard et al., 1995), although no similar studies have been undertaken with growing lambs. This experiment was designed to study the effect of four diets with different levels of metabolizable energy (ME) but with the same crude protein and undegradeable protein (DUP) levels on growth, carcass composition, tissue growth rate and meat quality characteristics of lambs of two breeds.

The effect of breed and dietary energy concentration on lamb growth, carcass composition and meat quality

1996 ◽  
Vol 1996 ◽  
pp. 109-109
Author(s):  
M.I. Mustafa ◽  
G.M. Webster ◽  
Gillian M. Povey
Keyword(s):  
Growth Rate ◽  
Meat Quality ◽  
Tissue Growth ◽  
Carcass Composition ◽  
Metabolizable Energy ◽  
Energy Concentration ◽  
Eating Quality ◽  
Lamb Growth ◽  
Different Levels

Previous trials at Newcastle have shown that plane of nutrition affects the growth performance, carcass composition and eating quality of lambs (Mustafa and Webster, 1995). It has also been found that lean tissue growth rate, a characteristic it is possible to manipulate nutritionally, influences meat quality in pigs and cattle (Whipple et al., 1990; Blanchard et al., 1995), although no similar studies have been undertaken with growing lambs. This experiment was designed to study the effect of four diets with different levels of metabolizable energy (ME) but with the same crude protein and undegradeable protein (DUP) levels on growth, carcass composition, tissue growth rate and meat quality characteristics of lambs of two breeds.

The influence of rate of lean and fat tissue development on pork eating quality

1999 ◽  
Vol 68 (3) ◽  
pp. 477-485 ◽  
Author(s):  
P. J. Blanchard ◽  
M. Ellis ◽  
C. C. Warkup ◽  
B. Hardy ◽  
J. P. Chadwick ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Crude Protein ◽  
Subcutaneous Fat ◽  
Growth Period ◽  
Intramuscular Fat ◽  
Tissue Growth ◽  
Eating Quality ◽  
Fat Tissue ◽  
Ad Libitum

AbstractThe influence of plane of nutrition and diet on the eating quality of fresh pork was investigated in a study involving 721 animals. Boars and gilts of three genotypes (0, 0·25 and 0·50 Duroc inclusion level) were reared from 30 to 90 kg on seven feeding regimens (combinations of diet formulation and feeding level) to achieve different rates of lean and fat tissue growth during two growth periods (30 to 60 or 75 kg; 60 or 75 kg to 90 kg), respectively. A diet of conventional energy and protein (CEP, 14·2 MJ/kg digestible energy, 205 g/kg crude protein, 10 g/kg lysine) was given using combinations of ad libitum and restricted feeding to produce six treatment groups with variation in lean and fat growth rates. An additional treatment group was given food ad libitum on a higher energy and lower protein diet (HELP, 14·7 MJ/kg digestible energy, 166 g/kg crude protein, 7·0 g/kg lysine) between 30 and 90 kg. Dissected carcass composition at 90 kg was predicted from equations based on P2 fat depth, which were developed from full-side and ham joint dissections on sub-samples of animals. Representative sub-samples of animals were dissected at start (30 kg) and at interim weights (60 or 75 kg) to allow lean and subcutaneous fat growth rates to be calculated for all or parts of the growth period. The feeding regimes produced substantial variation in live-weight gain (DLWG) (744 to 914 g/day) and lean tissue growth rate (LTGR 345 to 417 g/day) and subcutaneous fat growth rate (SFGR 81 to 97 g/day), between 30 and 90 kg, and in longissimus dorsi intramuscular fat content (10·37 to 23·87 g/kg). Pigs given the HELP diet had the highest intramuscular fat and the best eating quality. Pigs offered the CEP diet ad libitum throughout the growth period produced more tender but less juicy meat than those given food restrictedly (0·8 or 0·9 of ad libitum). The correlations between DLWG, LTGR and SFGR for the whole or parts of the growth period and sensory characteristics, although often positive, were generally low, suggesting weak relationships.

Factors influencing beef eating quality 2. Effects of nutritional regimen and genotype on muscle fibre characteristics

2001 ◽  
Vol 72 (2) ◽  
pp. 279-287 ◽  
Author(s):  
C.A. Maltin ◽  
G.E. Lobley ◽  
C.M. Grant ◽  
L.A. Miller ◽  
D.J. Kyle ◽  
...  
Keyword(s):  
Growth Rate ◽  
Muscle Fibre ◽  
Growth Rates ◽  
Experimental Period ◽  
Type I ◽  
Feeding Level ◽  
Overall Acceptability ◽  
Fibre Size ◽  
Fibre Number ◽  
Fibre Characteristics

AbstractEighteen purebred steers of three genotypes, Aberdeen Angus (AA), Charolais (CH) and Holstein (HO), were divided within genotype into three groups of six animals and offered one of three different levels of feeding either moderate (M/M) or high (H/H) both for 20 weeks or moderate for the first 10 weeks followed by high for the remaining 10 weeks (M/H). Growth rates during the final 10 weeks of the experimental period differed between dietary regimen (M/M = 0·87; M/H = 1·25; and H/H = 1·02 kg/day; s.e.d. = 0·08;P< 0·001). Over the entire 20 week experimental period animals offered the M/M level of feeding grew more slowly (0·97 kg/day) than those offered the M/H and H/H level of feeding (1·20 kg/day; s.e.d. = 0·06;P< 0·001). Mean growth rates for CH, HO and AA steers were 1·21, 1·13 and 1·03 kg/day (s.e.d. = 0·06;P< 0·05). The animals were all slaughtered at a fixed age of 18 months, according to the Meat and Livestock Commission Blueprint for beef and, 48 h post mortem, samples of m. longissimus lumborum (LL) and m. vastus lateralis (VL) were removed for analyses.Muscle fibres were classified histochemically, according to their contractile and metabolic properties, and muscle fibre size was measured. Fibre type frequency was calculated and, in LL, the total fibre number of the muscle was estimated. There was little impact of feeding level, or consequentially growth rate, on muscle fibre frequency and size. The effects seen were confined mainly to LL where there were significant differences between the M/M and H/ H groups with respect to fast twitch glycolytic fibres (mean % frequency (M/M = 40·1 and H/H = 44·3; s.e.d. = 1·4;P< 0·01); mean % area (M/M = 51·9 and H/H 56·0; s.e.d. = 1·5;P< 0·05)) and apparent total fibre number (M/ M = 35·0; and H/H = 41·9 ✕ 104; s.e.d. = 1·7;P< 0·05) which were greater in H/H than in M/M groups. However, in both LL and VL the predominant differences were related to genotype; in particular, overall fibre size was smallest in CH, while slow oxidative (SO; type I) fibre area was highest in AA. For LL, analysis across all animals showed a positive relationship between SO area, % area, % frequency and overall acceptability of meat at 14 days as evaluated by a trained sensory panel. No such relationship was observed for VL. The data suggest that in this study manipulation of feeding level has only a small impact on muscle fibre characteristics and that the differences between genotype and muscle type may be more important in determining the variability of overall acceptability than growth rate.

The Concentration of Dietary Casein Required for Normal Mandibular Growth in the Rat

1989 ◽  
Vol 68 (5) ◽  
pp. 840-842 ◽  
Author(s):  
C. Bozzini ◽  
A.C. Barcelo ◽  
R.M. Alippi ◽  
T.L. Leal ◽  
C.E. Bozzini
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Experimental Period ◽  
Growth Patterns ◽  
Male Rats ◽  
Mandibular Growth ◽  
Four Dimensions ◽  
Initial Values ◽  
Linear Dimensions ◽  
Dietary Casein

To determine a suitable casein concentration for normal, undeformed mandibular growth, we placed weanling male rats on diets containing graded levels of casein between 0% and 30% for 19 days. Some weanlings were killed so that initial values could be established. Ten linear dimensions corresponding to the six skeletal units of the mandible were evaluated so that their growth rates at the end of the experimental period could be established. Other dimensions were also evaluated for study of the growth rate of the bone as a whole. The macroscopic growth of the mandible showed a sigmoidal relationship with dietary casein concentration, most of the measurements reaching a plateau at 20% casein. Within the skeletal units, four dimensions corresponding to the alveolar and symphyseal regions did not change with age and were not affected by the casein content of the diet. The remaining six dimensions-corresponding to condylar, coronoid, angular, and basal regions of the mandible-increased with age and were related positively to dietary casein concentration. Their growth patterns were not uniform, although all of them reached maximal values when the diet contained 20% casein. Therefore, deformation of the mandible appears to occur in rats fed diets with a casein concentration lower than 20%. It appears that a dietary casein concentration of 20% is required for normal, undeformed mandibular growth.

Effects of skeletal separation method and postmortem ageing on carcass traits and shear force in cull cow beef

2006 ◽  
Vol 86 (3) ◽  
pp. 351-361 ◽  
Author(s):  
I. B. Mandell ◽  
C. P. Campbell ◽  
V. M. Quinton ◽  
J. W. Wilton
Keyword(s):  
Shear Force ◽  
Vastus Lateralis ◽  
Lumbar Vertebrae ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Thoracic Vertebra ◽  
Longissimus Muscle ◽  
Beef Tenderness ◽  
Separation Techniques ◽  
Cull Cow

Sixty-six cull cow carcasses were subjected to skeletal separation methods for improving beef tenderness as evaluated using shear force. Forty-one carcasses were used to evaluate the effect on longissimus muscle shear force from skeletal separation at various sites including: (1) the 11th thoracic vertebra, (2) the 12th thoracic vertebra, and (3) the 6th thoracic and 5th lumbar vertebrae. Longissimus muscle steaks from the posterior and anterior loin and posterior rib were aged for 2, 7, 14, and 28 d. Twenty-five carcasses underwent skeletal separation processing in the round with severing of the ischium and the junction between 4th/5th sacral vertebrae. Semimembranosus, semitendinosus, biceps femoris, vastus lateralis, and rectus femoris muscles were processed into steaks and aged for 2, 7, 14, and 28 d. Skeletal separation techniques involving thoracic and lumbar vertebrae decreased (P < 0.04) shear force in the posterior rib and anterior loin but not in the posterior loin. Shear force continued to decrease (P < 0.01) as postmortem ageing duration increased. The semimembranosus was the only muscle in the round in which shear force decreased (P < 0.01) with skeletal separation. Postmortem ageing for at least 14 d decreased (P < 0.06) shear force in semimembranosus and vastus lateralis steaks while there were no further decreases in shear force after 7 d ageing for semitendinosus and rectus femoris steaks. Skeletal separation increased (P < 0.10) sarcomere length in all muscles studied. Skeletal separation techniques have the potential to improve tenderness in the longissimus and semimembranosus muscles, which may increase utilization of cull cow beef. Key words: Beef, cow, shear, tendercut, longissimus, round

Comparison of copper sulphate pentahydrate growth rates determined by different methods

1990 ◽  
Vol 55 (7) ◽  
pp. 1691-1707 ◽  
Author(s):  
Miloslav Karel ◽  
Jiří Hostomský ◽  
Jaroslav Nývlt ◽  
Axel König
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Fluidized Bed ◽  
Growth Rates ◽  
Copper Sulphate ◽  
Crystal Growth Rate ◽  
Effect Of Temperature ◽  
Rotating Disc ◽  
Shape Factors ◽  
Data Treatment

Crystal growth rates of copper sulphate pentahydrate (CuSO4.5 H2O) determined by different authors and methods are compared. The methods included in this comparison are: (i) Measurement on a fixed crystal suspended in a streaming solution, (ii) measurement on a rotating disc, (iii) measurement in a fluidized bed, (iv) measurement in an agitated suspension. The comparison involves critical estimation of the supersaturation used in measurements, of shape factors used for data treatment and a correction for the effect of temperature. Conclusions are drawn for the choice of values to be specified when data of crystal growth rate measurements are published.

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