Influence of finishing systems and sampling site on fatty acid composition and retail shelf-life of lamb
- 1 January 2010
- journal article
- research article
- Published by CSIRO Publishing in Animal Production Science
- Vol. 50 (8), 775-781
- https://doi.org/10.1071/an10025
Abstract
Thirty 7-month-old crossbred lambs (Poll Dorset × Border Leicester × Merino) finished over 5 weeks on either low quality pasture or grain-with-hay on a farm in southern Victoria were assessed for carcass parameters, muscle fat composition and retail colour stability. Lambs on the grain diet had a mix of barley grain (80%) and lentils (20%) at 800 g/head.day (air-dry basis ~ad libitum) with cape weed (Arctotheca calendula) hay available at all times. Lambs under grazing had predominantly rye grass (Lolium perenne) and barley grass (Hordeum leporinum) available ad libitum. Carcass weight tended to be higher (P = 0.14) in grain-fed lambs than in grass-fed lambs, but fatness indicated by GR (total muscle + fat tissue thickness at 11 cm from midline) did not differ between feeding systems. Fatty acid composition was determined in the loin from the forequarter (M. longissimus thoracis) and lumbar (M. longissimus lumborum) regions and from the leg region (M. semimembranosus). This showed that grain-finished lamb had higher muscle fat (P < 0.001) and omega-6 fatty acid (P < 0.001) content. Alpha-linolenic acid, eicosapentaenoic acid (EPA) or total omega-3 fat did not differ (P > 0.05) between feeding groups. Saturated fatty acids were greater (P < 0.01) in both loin sampling sites than the leg. The levels of EPA, docosahexaenoic acid and docosapentaenoic acid were lower (P < 0.01) in the forequarter (9%) or lumbar (11%) sites than the leg sampling site. The distribution pattern of fatty acids across the three sampling sites did not differ between feed types. Retail colour stability determined over 4 days of display (only performed in muscle from the lumbar site), evaluated by the redness (HunterLab a*-value) and metmyoglobin formation (reflectance ratio at 630 : 580-nm wavelengths) was superior for grass-fed lamb compared with short-term grain-finished lamb. The results demonstrate that the health claimable omega-3 fat mainly EPA or total omega-3 fat content in lamb was not altered by short-term grain finishing compared with lamb finished under pasture grazing conditions.Keywords
This publication has 20 references indexed in Scilit:
- Effects of intensive or pasture finishing in spring and linseed supplementation in autumn on the omega-3 content of lamb meat and its carcass distributionAnimal Production Science, 2010
- Short-term docosapentaenoic acid (22 : 5n-3) supplementation increases tissue docosapentaenoic acid, DHA and EPA concentrations in ratsBritish Journal of Nutrition, 2009
- Long‐chain omega‐3 fatty acids in red meatNutrition & Dietetics, 2007
- Australian consumers: A marketer's perspectiveNutrition & Dietetics, 2007
- Very long chain n‐3 polyunsaturated fatty acids in the food chain in the UK and the potential of animal‐derived foods to increase intakeNutrition Bulletin, 2006
- Effect of diet finishing mode (pasture or mixed diet) on antioxidant status of Charolais bovine meatMeat Science, 2004
- The effect of breed-production systems on the myosin heavy chain 1, the biochemical characteristics and the colour variables of Longissimus thoracis from seven Spanish beef cattle breedsMeat Science, 2001
- Fatty acid content and composition of UK beef and lamb muscle in relation to production system and implications for human nutritionMeat Science, 1998
- Influence of dietary vitamin E on the oxidative stability and quality of pig meat.Journal of Animal Science, 1995
- Discolouration in pre‐packaged beef: measurement by reflectance spectrophotometry and shopper discriminationInternational Journal of Food Science & Technology, 1973