Reducing dark-cutting in pasture-fed beef steers by high-energy supplementation

Dark-cutting in muscles of the beef carcass is due to low muscle glycogen levels at slaughter and occurs particularly in autumn and winter in grass-fed cattle in southern Australia. The aim of these experiments was to investigate the effect of supplementary feeding of cattle grazing pasture during winter on muscle glycogen levels. The first experiment involved 70 cattle allocated to two stocking rates grazing improved perennial ryegrass and subterranean clover pastures [high stocking rate (HSR) v. low stocking rate (LSR)] by two pasture feeding regimes (control, pasture only v. pasture supplemented with a high-energy ration for 4 weeks) plus a feedlot treatment (fed high-energy ration in pens with no pasture for 11 weeks). Muscle biopsies were collected from the M. semitendinosus (ST) and M. semimembranosus (SM) muscles and analysed for muscle glycogen. The ST muscle glycogen content for supplemented animals increased (P < 0.05) over the feeding period but there was no effect (P > 0.05) of supplementation on the muscle glycogen content of the SM or on the muscle glycogen content of the ST or SM of cattle in the feedlot treatment, relative to control cattle. HSR cattle tended to have lower muscle glycogen in the ST compared to LSR cattle across both feeding regimes. The second experiment used 60 cattle allocated to two treatments (control, pasture only v. pasture supplemented with a high-energy ration for 3 weeks). The treatments were applied to cattle grazing improved perennial ryegrass and subterranean clover pastures and muscle biopsies were collected weekly from the SM and ST. Supplementation resulted in a linear increase (P < 0.05) in muscle glycogen levels over the 3 weeks in both the SM and ST muscles. These results indicate that feed quality has a major impact on muscle glycogen levels in the SM and ST of cattle destined for slaughter. At times of the year when pasture quality is poor or quantity is lacking, supplementation with a high-energy supplement has the potential to dramatically increase muscle glycogen and reduce the incidence of dark-cutting beef.

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Muscle glycogen storage after prolonged exercise: effect of the glycemic index of carbohydrate feedings

Journal of Applied Physiology ◽

10.1152/jappl.1993.75.2.1019 ◽

1993 ◽

Vol 75 (2) ◽

pp. 1019-1023 ◽

Cited By ~ 137

Author(s):

L. M. Burke ◽

G. R. Collier ◽

M. Hargreaves

Keyword(s):

Glycemic Index ◽

Muscle Glycogen ◽

Glycogen Content ◽

Vastus Lateralis ◽

Glycogen Storage ◽

Carbohydrate Intake ◽

Total Carbohydrate ◽

Muscle Glycogen Content ◽

Exercise Effect ◽

Muscle Biopsies

The effect of the glycemic index (GI) of postexercise carbohydrate intake on muscle glycogen storage was investigated. Five well-trained cyclists undertook an exercise trial to deplete muscle glycogen (2 h at 75% of maximal O2 uptake followed by four 30-s sprints) on two occasions, 1 wk apart. For 24 h after each trial, subjects rested and consumed a diet composed exclusively of high-carbohydrate foods, with one trial providing foods with a high GI (HI GI) and the other providing foods with a low GI (LO GI). Total carbohydrate intake over the 24 h was 10 g/kg of body mass, evenly distributed between meals eaten 0, 4, 8, and 21 h postexercise. Blood samples were drawn before exercise, immediately after exercise, immediately before each meal, and 30, 60, and 90 min post-prandially. Muscle biopsies were taken from the vastus lateralis immediately after exercise and after 24 h. When the effects of the immediate postexercise meal were excluded, the totals of the incremental glucose and insulin areas after each meal were greater (P < or = 0.05) for the HI GI meals than for the LO GI meals. The increase in muscle glycogen content after 24 h of recovery was greater (P = 0.02) with the HI GI diet (106 +/- 11.7 mmol/kg wet wt) than with the LO GI diet (71.5 +/- 6.5 mmol/kg). The results suggest that the most rapid increase in muscle glycogen content during the first 24 h of recovery is achieved by consuming foods with a high GI.

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A major locus (RN) affecting muscle glycogen content is located on pig Chromosome 15

Mammalian Genome ◽

10.1007/s003359900012 ◽

1996 ◽

Vol 7 (1) ◽

pp. 52-54 ◽

Cited By ~ 26

Author(s):

P. Mariani ◽

K. Lundström ◽

U. Gustafsson ◽

A. -C. Enfält ◽

R. K. Juneja ◽

...

Keyword(s):

Muscle Glycogen ◽

Glycogen Content ◽

Chromosome 15 ◽

Major Locus ◽

Muscle Glycogen Content

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Muscle Glycogen Content and Lactate Uptake in Exercising Muscles

Metabolic Adaptation to Prolonged Physical Exercise ◽

10.1007/978-3-0348-5523-5_16 ◽

1975 ◽

pp. 130-134 ◽

Cited By ~ 12

Author(s):

B. Essén ◽

B. Pernow ◽

P. D. Gollnick ◽

B. Saltin

Keyword(s):

Muscle Glycogen ◽

Glycogen Content ◽

Muscle Glycogen Content ◽

Lactate Uptake

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Lactate and Pyruvate Release from Muscle during Prolonged One Leg Exercise with a Normal and Low Muscle Glycogen Content

Clinical Science ◽

10.1042/cs087s074 ◽

1994 ◽

Vol 87 (s1) ◽

pp. 74-74

Author(s):

G van Hall ◽

B Saltin ◽

WHM Saris ◽

AJM Wagenmakers

Keyword(s):

Muscle Glycogen ◽

Glycogen Content ◽

Muscle Glycogen Content ◽

Leg Exercise ◽

Lactate And Pyruvate

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Leucine-Enriched Essential Amino Acids Augment Muscle Glycogen Content in Rats Seven Days after Eccentric Contraction

Nutrients ◽

10.3390/nu9101159 ◽

2017 ◽

Vol 9 (10) ◽

pp. 1159 ◽

Cited By ~ 2

Author(s):

Hiroyuki Kato ◽

Kyoko Miura ◽

Katsuya Suzuki ◽

Makoto Bannai

Keyword(s):

Amino Acids ◽

Muscle Glycogen ◽

Glycogen Content ◽

Eccentric Contraction ◽

Essential Amino Acids ◽

Muscle Glycogen Content

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1047 Effects of Training and Testosterone on Muscle Glycogen Content In Streptozotocin-Induced Diabelic Female Rats

Medicine & Science in Sports & Exercise ◽

10.1249/00005768-199305001-01050 ◽

1993 ◽

Vol 25 (Supplement) ◽

pp. S186

Author(s):

H. A. Kolzer ◽

E. van Breda ◽

P. Geurlen ◽

H. Kuipers ◽

J. F.C. Glatz

Keyword(s):

Muscle Glycogen ◽

Glycogen Content ◽

Female Rats ◽

Muscle Glycogen Content

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Relationship between changes in core body temperature in lambs and post-slaughter muscle glycogen content and dark-cutting

Animal Production Science ◽

10.1071/an12379 ◽

2014 ◽

Vol 54 (4) ◽

pp. 459 ◽

Cited By ~ 7

Author(s):

D. G. Pighin ◽

W. Brown ◽

D. M. Ferguson ◽

A. D. Fisher ◽

R. D. Warner

Keyword(s):

Lactic Acid ◽

Body Temperature ◽

Meat Quality ◽

Muscle Glycogen ◽

Glycogen Content ◽

Core Body Temperature ◽

Correlation Coefficients ◽

Significant Negative Correlation ◽

Muscle Glycogen Content ◽

Core Body

Pre-slaughter stress may decrease muscle glycogen content, a key element for a suitable low ultimate pH and prevention of dark-cutting meat. Body temperature monitoring is a tool used in research on animal stress, as an indicator of stress events. Possible relationships between body temperature of sheep and post-mortem muscle glycogen were investigated in this study. Body temperature was measured with intravaginal loggers inserted into each animal at 3 days pre-slaughter, to record body temperature every 3 min over a period of 3 days. Blood samples were collected from each animal at exsanguination for measurement of glucose and lactic acid concentrations. The muscle content of glycogen and lactic acid were determined in samples of M. longissimus collected at the level of the 13th rib, at 1 h post-slaughter. A plot of body temperature versus time showed a rise in body temperature from all animals during events such as mustering, loading onto the truck, unloading at the abattoir, during pre-slaughter handling and at slaughter. Pearson’s correlation coefficients were determined between (1) the main temperature increments occurring between farm and slaughter; and (2) post-slaughter muscle glycogen and lactate levels. A significant negative correlation was detected between elevation in core body temperature due to physical stress of sheep and muscle glycogen levels at slaughter. A low correlation was detected between body temperature and blood glucose or lactate concentrations. Further research should examine the relationship between core body temperature and meat quality in order to better understand the complex relationship between animal stress and meat quality.

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Progressive increase in human skeletal muscle AMPKα2 activity and ACC phosphorylation during exercise

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00101.2001 ◽

2002 ◽

Vol 282 (3) ◽

pp. E688-E694 ◽

Cited By ~ 95

Author(s):

T. J. Stephens ◽

Z.-P. Chen ◽

B. J. Canny ◽

B. J. Michell ◽

B. E. Kemp ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Glycogen ◽

Human Skeletal Muscle ◽

Glycogen Content ◽

Vastus Lateralis ◽

Moderate Intensity ◽

Moderate Intensity Exercise ◽

Western Blots ◽

Muscle Glycogen Content ◽

Muscle Creatine

The effect of prolonged moderate-intensity exercise on human skeletal muscle AMP-activated protein kinase (AMPK)α1 and -α2 activity and acetyl-CoA carboxylase (ACCβ) and neuronal nitric oxide synthase (nNOSμ) phosphorylation was investigated. Seven active healthy individuals cycled for 30 min at a workload requiring 62.8 ± 1.3% of peak O2consumption (V˙o 2 peak) with muscle biopsies obtained from the vastus lateralis at rest and at 5 and 30 min of exercise. AMPKα1 activity was not altered by exercise; however, AMPKα2 activity was significantly ( P < 0.05) elevated after 5 min (∼2-fold), and further elevated ( P < 0.05) after 30 min (∼3-fold) of exercise. ACCβ phosphorylation was increased ( P < 0.05) after 5 min (∼18-fold compared with rest) and increased ( P< 0.05) further after 30 min of exercise (∼36-fold compared with rest). Increases in AMPKα2 activity were significantly correlated with both increases in ACCβ phosphorylation and reductions in muscle glycogen content. Fat oxidation tended ( P = 0.058) to increase progressively during exercise. Muscle creatine phosphate was lower ( P < 0.05), and muscle creatine, calculated free AMP, and free AMP-to-ATP ratio were higher ( P < 0.05) at both 5 and 30 min of exercise compared with those at rest. At 30 min of exercise, the values of these metabolites were not significantly different from those at 5 min of exercise. Phosphorylation of nNOSμ was variable, and despite the mean doubling with exercise, statistically significance was not achieved ( P = 0.304). Western blots indicated that AMPKα2 was associated with both nNOSμ and ACCβ consistent with them both being substrates of AMPKα2 in vivo. In conclusion, AMPKα2 activity and ACCβ phosphorylation increase progressively during moderate exercise at ∼60% of V˙o 2 peak in humans, with these responses more closely coupled to muscle glycogen content than muscle AMP/ATP ratio.

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