Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-24T08:07:11.906Z Has data issue: false hasContentIssue false
  • English
  • Français

Effect of concentrate finishing on the carotenoid content of perirenal fat in grazing sheep: its significance for discriminating grass-fed, concentrate-fed and concentrate-finished grazing lambs

Published online by Cambridge University Press:  18 August 2016

S. Prache ,
A. Priolo  and
P. Grolier
S. Prache*
Affiliation:
Unité de Recherches sur les Herbivores, INRA Clermont-Ferrand/Theix 63122 St-Genès-Champanelle, France
A. Priolo
Affiliation:
Unité de Recherches sur les Herbivores, INRA Clermont-Ferrand/Theix 63122 St-Genès-Champanelle, France
P. Grolier
Affiliation:
Unité Maladies Métaboliques et Micronutriments, INRA Clermont-Ferrand/Theix 63122 St Genès Champanelle, France
*
† E-mail: [email protected]
Get access

Abstract

Carotenoid pigments are good biomarkers of grass-feeding in sheep. However, as grazing lambs may be concentrate-finished, we investigated the effect of concentrate finishing after grazing on the carotenoid concentration of fat in sheep, and its significance for discriminating lamb production systems. In experiment 1 with 32 lambs, four feeding treatments were compared: G = grazing, C = feeding a concentrate-based diet, GSC = short concentrate-finishing period after grazing, and GLC = long concentrate-finishing period after grazing. The concentrate supply was regulated to have similar average daily gain for all treatments. In experiment 2, 42 ewes were given a low carotenoid diet after pasture feeding, for 0, 8, 22, 42, 84 or 126 days. The feeding level was adjusted to maintain body weight and body condition score. The nature and concentration of carotenoids was analysed by HPLC on diets and lambs’ perirenal fat. The reflectance spectrum of perirenal fat was measured at slaughter. Lutein was the only carotenoid in lamb fat. In experiment 1, the intensity of light absorption by lutein was linearly related with its concentration in the fat (P < 0·001) and was negatively correlated with the duration of the finishing period. The design of experiment 2 avoided the confounding effect of fat gain during the finishing period and examined the effect of the duration of this period by itself. There was no effect of stall-feeding duration on the intensity of light absorption by carotenoids in the fat in experiment 2, demonstrating that the effect of stall-feeding duration in fattening lambs was mediated via a dilution of existing fat with whiter fat rather than through pigments coming out of the fat. The concentration of lutein and the intensity of its light absorption in the fat decreased with lamb body-weight gain during the finishing period (P < 0·01 and P < 0·05 respectively) and increased with plasma carotenoid content at the end of the grazing period (P < 0·001). Because of the inter-individual variability in carotenoid absorption, the use of the reflectance spectrum of the fat alone may cause some concentrate finished grazing lambs to be classified as C lambs shortly after the beginning of the stall-feeding period, whereas others may be considered as G lambs for a long period of time. However, the combined use of plasma carotenoid content at slaughter together with the reflectance spectrum of the fat improves reliability in the discrimination of grass-fed, concentrate-fed and concentrate-finished grazing lambs, by taking advantage of the differences in the rate of reduction in carotenoid concentration in blood and fat.

Keywords

carotenoidsgrazinglamb (meat)tracer techniques
Type
Growth, development and meat science
Information
Animal Science , Volume 77 , Issue 2 , October 2003 , pp. 225 - 233
Copyright
Copyright © British Society of Animal Science 2003

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Crouse, J. D., Cross, H. R. and Seideman, S. C. 1984. Effects of a grass or grain diet on the quality of three beef muscles. Journal of Animal Science 58: 619–625.Google Scholar
Khachik, F., Beecher, G. R., Goli, M. B. and Lusby, W. R. 1992. Separation and quantification of carotenoids in foods. Methods in Enzymology 213: 347–359.Google Scholar
Kemp, J. D., Mayhuddin, M., Ely, D. G., Fox, J. D. and Moody, W. G. 1981. Effects of feeding systems, slaughter weight and sex on organoleptic properties and fatty acid composition of lamb. Journal of Animal Science 51: 321–330.Google Scholar
Kirton, A. H., Crane, B., Paterson, D. J. and Clare, N. T. 1975. Yellow fat in lambs caused by carotenoids pigmentation. New Zealand Journal of Agricultural Research 18: 267–272.Google Scholar
Knight, T. W., Death, A. F., Lambert, M. G. and McDougall, D. B. 2001. The rate of reduction in carotenoid concentration in fat of steers fed a low carotenoid ration, and the role of increasing carcass fatness. Australian Journal of Agricultural Research 52: 1023–1032.Google Scholar
Lyan, B., Azais-Braesco, V., Cardinault, N., Tyssandier, V., Borel, P., Alexandre-Gouabau, M. C. and Grolier, P. 2001. A simple method for clinical determination of 13 carotenoids in human plasma using an isocratic HPLC method. Journal of Chromatography B 751: 297–303.Google Scholar
Mangels, A. R., Holden, J. M., Beecher, G. R., Forman, M. R. and Lanza, E. 1993. Carotenoid content of fruits and vegetables: an evaluation of analytic data. Journal of the American Dietetic Association 93: 284–296.Google Scholar
Melton, S. L. 1990. Effects of feeds on flavor of red meat: a review. Journal of Animal Science 68: 4421–4435.Google Scholar
Prache, S. and Theriez, M. 1999. Traceability of lamb production systems: carotenoids in plasma and adipose tissue. Animal Science 69: 29–36.Google Scholar
Prache, S., Priolo, A., Tournadre, H., Jailler, R., Dubroeucq, H., Micol, D. and Martin, B. 2002. Traceability of grass-feeding by quantifying the signature of carotenoid pigments in herbivores meat, milk and cheese. Proceedings of the 19th general meeting of the European Grassland Federation, La Rochelle, 27-30 May , pp. 592–593.Google Scholar
Prache, S., Priolo, A. and Grolier, P. 2003. Persistence of carotenoid pigments in the blood of concentrate-finished grazing sheep: its significance for the traceability of grassfeeding. Journal of Animal Science 81: 360–367.Google Scholar
Priolo, A., Micol, D. and Agabriel, J. 2001. Effects of grass feeding systems on ruminant meat colour and flavour. A review. Animal Research 50: 185–200.Google Scholar
Priolo, A., Micol, D., Agabriel, J., Prache, S. and Dransfield, E. 2002. Effect of grass or concentrate feeding systems on lamb carcass and meat quality. Meat Science 62: 179–185.Google Scholar
Priolo, A., Prache, S., Micol, D. and Agabriel, J. 2002. Reflectance spectrum of adipose tissue to trace grass feeding in sheep: influence of measurement site and shrinkage time after slaughter. Journal of Animal Science 80: 886–891.CrossRefGoogle ScholarPubMed
Rousset-Akrim, S., Young, O. A. and Berdagué, J. L. 1997. Diet and growth effects in panel assessment of sheepmeat odour and flavour. Meat Science 45: 169–181.Google Scholar
Statistical Analysis Systems Institute. 1987. SAS user’s guide: statistics, sixth edition. SAS Inst. Inc., Cary, NC.Google Scholar
Yang, A., Larsen, T. W. and Tume, R. K. 1992. Carotenoid and retinal concentrations in serum, adipose tissue and liver and carotenoids transport in sheep, goats and cattle. Australian Journal of Agricultural Research 43: 1809–1817.Google Scholar