The effect of dietary treatment on meat quality and on consumer perception of sheep meat eating quality
D. W. Pethick A G , R. Davidson B , D. L. Hopkins C , R. H. Jacob A G , D. N. D’Souza D , J. M. Thompson E and P. J. Walker FA Division of Veterinary and Biomedical Sciences, Murdoch University, Murdoch, WA 6150, Australia.
B WAMMCO International, PO Box 4059, Victoria Park, WA 6979, Australia.
C NSW Department of Primary Industries, PO Box 129, Cowra, NSW 2794, Australia.
D Alltech, 68–70 Nissan Drive, Dandenong South, Vic. 3175, Australia.
E School of Rural Science and Natural Resources, The University of New England, Armidale, NSW 2351, Australia.
F Department of Primary Industries Victoria, Victorian Institute of Animal Science, Private Bag 7, Sneydes Road, Werribee, Vic. 3030, Australia.
G Department of Agriculture WA, Baron-Hay Court, South Perth, WA 6151, Australia.
H Corresponding author. Email: d.pethick@murdoch.edu.au
Australian Journal of Experimental Agriculture 45(5) 517-524 https://doi.org/10.1071/EA03255
Submitted: 22 November 2003 Accepted: 19 August 2004 Published: 27 June 2005
Abstract
The aim of this experiment was to test the effects of dietary treatment on sheep meat eating quality as perceived by untrained Australian consumers. Six-month-old Suffolk × Merino lambs (n = 192) were allocated to 1 of 4 nutritional treatments for 60–77 days and were fed: (i) an irrigated perennial ryegrass–clover–kikuyu sward; (ii) irrigated perennial ryegrass–clover–kikuyu pasture for 48–61 days then poor quality straw for the last 12–16 days; (iii) a mixed ration treatment consisting of a high-energy pelleted diet (40% barley grain, 30% wheat grain, 15% hay and 12% lupin grain); or (iv) irrigated pasture for 37–51 days followed by a moderate-energy pelleted diet (36% wheat grain, 35% hay and 24.5% lupin grain) for 23–26 days. The starting liveweight of lambs was 31.5–35.5 kg and the final hot carcass weight was 19–20 kg. The nutritional treatment finishing system employing straw feeding for the last 12–16 days was associated with a loss of liveweight during this period, a decreased tissue depth at the GR site and a decreased content of intramuscular fat and glycogen in muscle. Untrained Australian consumers were asked to rate samples (scale 0–100) of the M. longissimus thoracis et lumborum (LL) from lambs for tenderness, liking of flavour, juiciness and overall liking and then classify the meat as unsatisfactory, good everyday or better than everyday. Straw feeding was also associated with significantly reduced consumer scores for juiciness (P<0.05) and liking of flavour (P<0.10) with no changes in tenderness and overall liking. There was no significant difference in the consumer acceptance of the LL obtained from lambs finished on pasture v. grain-based diets. It is concluded that nutritional finishing systems should be selected to prevent animals from losing weight pre-slaughter and that decisions on pasture v. grain based feeding systems be based on the cost of production.
Acknowledgments
The manager and staff of Cosign are acknowledged for their skills in sample preparation for consumer testing. The skilled technical assistance and dedication of Malcolm Boyce, Barbara Waldoch, Ken Chong, Tim Hilder and Andrew Blakey is gratefully acknowledged. The manager and staff of the Veterinary School farm are thanked for arranging the irrigated pasture paddocks and intensive feeding facilities. Research students at Murdoch University, Alexandra Pugh, Kelly Pearce and Jeisane Accioly, are thanked for their generous help at slaughter. Alan Duff is thanked for allowing us to purchase the store lambs used in this study. The manager and staff at Hillside Meats are gratefully acknowledged for their enormous cooperation during the slaughter and bone-out periods.
Braggins TJ
(1996) Effect of stress-related changes in sheep meat ultimate pH on cooked odor and flavor. Journal of Agricultural and Food Chemistry 44, 2352–2360.
| Crossref | GoogleScholarGoogle Scholar |
Brennand CP, Lindsay RC
(1992) Distribution of volatile branched fatty acids in various lamb tissues. Meat Science 31, 411–421.
| Crossref | GoogleScholarGoogle Scholar |
Brewer M,
Zhu L,
Bidner B,
Meisinger D, McKeith F
(2001) Measuring pork color: effects of bloom time, muscle, pH and relationship to instrumental parameters. Meat Science 57, 169–176.
| Crossref | GoogleScholarGoogle Scholar |
Cabassi P
(1990) The prediction of lamb carcass composition from objective measurements of fatness taken at slaughter chain speed with the Aus-meat sheep probe. Proceedings of the Society of Animal Production 18, 164.
Duncan WRH, Garton GA
(1978) Differences in proportions of branched chain fatty acids in subcutaneous triglycerides of barely fed lambs. The British Journal of Nutrition 40, 29–33.
| Crossref |
PubMed |
Gardner GE,
Kennedy L,
Milton JTB, Pethick DW
(1998) Metabolism of glycogen and the ultimate pH of muscle in Merino, first-cross and second-cross wether lambs as affected by low stress and commercial slaughter. Australian Journal of Agricultural Research 50, 175–181.
Gardner GE,
McIntyre BL,
Tudor G, Pethick DW
(2001) The impact of nutrition on bovine muscle glycogen metabolism following exercise. Australian Journal of Agricultural Research 52, 461–470.
| Crossref | GoogleScholarGoogle Scholar |
Garton GA,
Hovell FDD, Duncan WRH
(1972) Influence of dietary volatile fatty acids on the fatty acid composition of lamb triglycerides, with special reference to th effect of propionate on the presence of branched chain components. The British Journal of Nutrition 28, 409–416.
| Crossref |
PubMed |
Hopkins DL, Fogarty N
(1998) Diverse lamb genotypes-2. Meat pH, colour and tenderness. Meat Science 49, 477–488.
| Crossref | GoogleScholarGoogle Scholar |
Immonen K,
Kauffman RG,
Schaefer DM, Puolanne E
(2000) Glycogen concentrations in bovine longissimus dorsi muscle. Meat Science 54, 163–167.
| Crossref | GoogleScholarGoogle Scholar |
Perry D,
Shorthose WR,
Ferguson DM, Thompson JM
(2001) Methods used in the CRC program for the determination of carcass yield and beef quality. Australian Journal of Experimental Agriculture 41, 953–957.
| Crossref | GoogleScholarGoogle Scholar |
Pethick DW, Rowe JB
(1996) The effect of nutrition and exercise on carcass parameters and the level of glycogen in skeletal muscle of Merino sheep. Australian Journal of Agricultural Research 47, 525–537.
| Crossref | GoogleScholarGoogle Scholar |
Pleasants AB,
Thompson JM, Pethick DW
(2005) A model relating a function of tenderness, juiciness, flavour and overall liking to the eating quality of sheep meat. Australian Journal of Experimental Agriculture 45, 483–489.
Prescott J,
Young O, O’Neill L
(2001) The impact of variations in flavour compounds on meat acceptability: a composition of Japanese and New Zealand consumers. Food Quality and Preference 12, 257–264.
| Crossref | GoogleScholarGoogle Scholar |
Thompson JM,
Gee A,
Hopkins DL,
Pethick DW,
Baud SR, O’Halloran WJ
(2005) Development of a sensory protocol for testing palatability of sheep meats. Australian Journal of Experimental Agriculture 45, 469–476.
Wong E,
Johnson CB, Nixon LN
(1975) The contribution of 4-methylactanoic (hircinoic) acid to mutton and goat meat flavour. New Zealand Journal of Agricultural Research 18, 261–266.
Young OA,
Berdague J-L,
Viallon C,
Rousset-Akrim S, Theriez M
(1997) Fat borne volatiles and sheep meat odour. Meat Science 45, 183–200.
| Crossref | GoogleScholarGoogle Scholar |
