Register      Login
Animal Production Science Animal Production Science Society
Food, fibre and pharmaceuticals from animals
Shopping Cart: ( empty )
You are here: Home > Journals > AN > EA03256
RESEARCH ARTICLE
Contents Vol 45(5)

Effects of animal age on the eating quality of sheep meat

D. W. Pethick A F , D. L. Hopkins B , D. N. D’Souza C , J. M. Thompson D and P. J. Walker E
+ Author Affiliations
- Author Affiliations

A Division of Veterinary and Biomedical Sciences, Murdoch University, Murdoch, WA 6150, Australia.

B New South Wales Department of Primary Industries, PO Box 129, Cowra, NSW 2794, Australia.

C Alltech, 68–70 Nissan Drive, Dandenong South, Vic. 3175, Australia.

D School of Rural Science and Natural Resources, The University of New England, Armidale, NSW 2351, Australia.

E Department of Primary Industries Victoria, Victorian Institute of Animal Science, Private Bag 7, Sneydes Road, Werribee, Vic. 3030, Australia.

F Corresponding author. Email: d.pethick@murdoch.edu.au

Australian Journal of Experimental Agriculture 45(5) 491-498 https://doi.org/10.1071/EA03256
Submitted: 22 November 2003  Accepted: 15 November 2004   Published: 27 June 2005

Abstract

The aim of this work was to test the effects of animal age on consumer perceptions of sheep meat quality. Experiment 1 tested eating quality scores (tenderness, liking of flavour, juiciness and overall liking) derived from untrained consumers of grilled M. longissimus lumborum (LL) or M. biceps femoris (BF) derived from Merino ewes ranging from 8.5 to 68.5 months of age. The ewes were derived from one farm and all received a pelleted diet (60% hay, 30% lupin grain and 10% barley grain) that sustained growth between 118 and 173 g/day for at least 22 days pre-slaughter. In experiment 2 consumer testing of grilled LL and roasted BF and M. semimembranosis (SM) was conducted on a commercial line of 12-month-old White Suffolk × Merino lambs (0 erupted incisor teeth) v. a line of Merino yearling sheep about 22 months old (with either 2 or 4 erupted incisor teeth). The results of experiment 1 showed a significant effect of muscle (LL>BF, P<0.001) and a cubic effect of animal age on the consumer scores for grilled steaks. The cubic relationship was due to meat from lamb (8.5 months) and hogget (20 months) having higher scores than those of older animals. There was a close relationship between the objective measures of tenderness and the consumer tenderness score (r2 = 0.53, P<0.001). Results of experiment 2 indicated no significant difference between the grilled LL for the crossbred lamb and 22-month-old (2–4 teeth) Merino yearling sheep. However, the consumer scores for the roasted BF and SM were significantly depressed in the 2–4 tooth yearling Merino categories. In conclusion, this work clearly underpins the current Australian definition of lamb, lamb having better eating-quality attributes than older animals with fully erupted permanent incisor teeth, particularly in muscles from across the carcass. However, this work also highlights the eating quality attributes of older sheep (6 or more permanent incisor teeth) particularly for the LL, and suggests that negative influences of flavour associated with older sheep meat are minimal when the product is served in the absence of subcutaneous and intermuscular fat. Finally, the results suggest the possibility of a new ‘yearling’ sheep meat category based on animals in the 2–4-tooth dentition category.


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 Mr Malcolm Boyce, Mrs Barbara Waldoch, Mr Ken Chong, Mr Robert Davidson, Mr Tim Hilder and Mr Andrew Blakey is gratefully acknowledged. Research students at Murdoch University are thanked for their generous help at slaughter: Ms Alexandra Pugh, Ms Kelly Pearce and Ms Jeisane Accioly. The Hewitt family is thanked for supply, managing and finishing the sheep on their farm near York, Western Australia. The manager and staff at Hillside Meats are gratefully acknowledged for their enormous cooperation during the slaughter and bone out periods.


References


Batcher OM, Dawson EH, Poinnter MR, Gilpin GL (1962) Quality of cooked and raw lamb meat as related to fatness and age of animal. Food Technology 16, 102–110. open url image1

Bouton PE, Harris PV, Ratcliff D, Roberts DW (1978) Shear force measurements on cooked meat from sheep of various ages. Journal of Food Science 43, 1038–1039. open url image1

Campion DR, Field RA, Riley ML, Smith GM (1976) Effect of weight on carcass merit of very heavy market ram lambs. Journal of Animal Science 43, 1218–1224. open url image1

Carpenter ZL, King GT (1965) Tenderness of lamb rib chops. Food Technology 19, 1706–1708. open url image1

Corbett JL, Furnival EP, Southcott WH, Park RJ, Shorthose WR (1973) Induced cryptorchidism in lambs. Effects on growth rate, carcass and meat characteristics. Animal Production 16, 157–163. open url image1

Channon HA, Thatcher LP, Leury BJ (1997) The effect of age and nutrition on meat flavour of lean, heavy weight cryptorchid and wether lambs. In ‘Proceedings of the 43rd international congress of meat science and technology’. pp. 268–269. (Auckland, New Zealand)

Gee A (2001) ‘SMEQ protocols for consumer testing.’ (Meat and Livestock Australia: Sydney)

HAM (1998) ‘Handbook of Australian meat.’ (Aus-Meat Ltd: Brisbane)

Hopkins DL, Walker PJ, Thompson JM, Pethick DW (2005) Effect of sheep type on meat and eating quality of sheep meat. Australian Journal of Experimental Agriculture 45, 499–507. open url image1

Jeremiah LE (2000) The effects of chronological age, slaughter weight, and gender on lamb: a review. Technical Bulletin 2000–1E, 1–19. open url image1

Jeremiah LE, Smith GC, Carpenter ZL (1971) Palatability of individual muscles from ovine leg steaks as related to chronological age and marbling. Journal of Food Science 36, 45–47. open url image1

Jeremiah LE, Tong AKW, Gibson LL (1998) The influences of lamb chronological age, slaughter weight and gender on consumer acceptance. Sheep and Goat Research Journal 14, 206–213. open url image1

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 | open url image1

Pethick DW, Cummins L, Gardner GE, Jacobs RH, Knee BW, McDowell M, McIntyre BL, Tudor G, Walker PJ, Warner RD (2000) The regulation of glycogen level in the muscle of ruminants by nutrition. Proceedings of the New Zealand Society of Animal Production 60, 94–97. open url image1

Pethick DW, Davidson RH, Hopkins DL, Jacob RH, D’Souza DN, Thompson JM, Walker PJ (2005) The effect of dietary treatment on meat quality and on consumer perception of sheep meat eating quality. Australian Journal of Experimental Agriculture 45, 517–524. open url image1

Pethick DW, Rowe JB, Tudor G (1995) Glycogen metabolism and meat quality. In ‘Recent advances in animal nutrition in Australia’. (Eds JB Rowe, JV Nolan) pp. 97–103. (University of New England: Armidale)

Picard B, Lefaucheur L, Berri C, Duclos MJ (2002) Muscle fibre ontogenesis in farm animals. Reproduction, Nutrition, Development 42, 1–17.
| Crossref | GoogleScholarGoogle Scholar | PubMed | open url image1

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. open url image1

Shaw FD, Baud SR, Richards I, Pethick DW, Walker PJ, Thompson JM (2005) New electrical stimulation technologies for sheep carcasses. Australian Journal of Experimental Agriculture 45, 575–583. open url image1

Thompson JM (2002) Managing meat tenderness. Meat Science 60, 365–369.
| Crossref |
open url image1

Thompson JM (2004) The effects of marbling on flavour and juiciness scores of cooked beef, after adjusting to constant tenderness. Australian Journal of Experimental Agriculture 44, 645–652.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Thompson JM, Gee A, Hopkins DL, Pethick DW, Baud SR, O’Halloran WJ (2005a) Development of a sensory protocol for testing palatability of sheep meats. Australian Journal of Experimental Agriculture 45, 469–476. open url image1

Thompson JM, Hopkins DL, D’Souza DN, Walker PJ, Baud SR, Pethick DW (2005b) The impact of processing on sensory and objective measurements of sheep meat eating quality. Australian Journal of Experimental Agriculture 45, 561–573. open url image1

Thompson JM, Pleasants AB, Pethick DW (2005c) The effect of design and demographic factors on consumer sensory scores. Australian Journal of Experimental Agriculture 45, 477–482. open url image1

Trout GR (1991) A rapid method for measuring pigment concentration in porcine and other low pigmented muscles. In ‘Proceedings of the 37th international congress of meat science and technology’. pp. 1198–1201. (Kulmbach: Germany)

Woodhams PR, Kirton AH, Jury KE (1966) Palatability characteristics of crossbred lambs as related to individual Southdown sires, slaughter age and carcass fatness. NZ Journal of Agricultural Research 9, 268–275. open url image1

Young OA, Berdagué J-L, Viallon C, Rousset-Akrim S, Theriez M (1997) Fat-borne volatiles and sheepmeat odour. Meat Science 45, 183–200.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Young OA, Braggins TJ (1993) Tenderness of ovine Semimembranosis: is collagen concentration or solubility the critical factor. Meat Science 35, 213–220.
| Crossref | GoogleScholarGoogle Scholar | open url image1