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This Article Full Text (PDF) All Versions of this Article: jas.2008-0863v1 87/2/693    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Jaturasitha, S. Articles by Kreuzer, M. Search for Related Content PubMed PubMed Citation Articles by Jaturasitha, S. Articles by Kreuzer, M.

Early deposition of n-3 fatty acids from tuna oil in lean and adipose tissue of fattening pigs is mainly permanent

S. Jaturasitha^*, R. Khiaosa-ard^*,, P. Pongpiachan^* and M. Kreuzer

^* Department of Animal Science, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand ETH Zurich, Department of Agricultural and Food Science, Universitaetstrasse 2, CH-8092 Zurich, Switzerland.

ja.sanchai{at}gmail.com

Abstract

A total of 600 crossbred pigs, whereof 56 were randomly selected for more in depth studies of carcass and pork quality, were employed to test different tuna oil feeding regimes. The focus was put on the efficiency to enrich lean and adipose tissue with n-3 fatty acids and the expression of adverse side-effects on performance, carcass and pork quality. The 4 treatments were 0% tuna oil in diet (T0; control), 1% of unrefined tuna oil in diet fed from 35-90 kg BW (T1), and 3% of unrefined tuna oil in diet offered either during the early (35-60 kg BW; T3-E) or late stage of fattening (75-90 kg BW; T3-L). With this arrangement, pigs consumed equal lifetime amounts of tuna oil (approx. 1.6 kg per pig). None of the tuna oil treatments had significant effects on performance. There were no differences in carcass quality among tuna oil groups except, for group T3-E where carcasses and loin chops were fatter than those of the other groups. Water-holding capacity and texture of the loin as well as firmness and melting properties of the backfat remained widely unaffected by the treatments. Tuna oil feeding resulted in a lighter, less red and less yellow backfat and was found to increase n-3 fatty acids proportion of total fatty acids in all treatments. This especially concerned eicosapentaenoic acid and docosahexaenoic acid, and not -linolenic acid. There was also a slight increase in oleic acid, whereas n-6 fatty acids largely decreased. Feeding tuna oil either during a short period at the end of fattening (T3-L) or permanently during fattening (T1) proved to be similarly efficient in increasing n-3 fatty acid content of lean and adipose tissue (to about 1.6-fold of T0). By contrast, only 2/3 of this increase was found when the same amount of tuna oil had been fed exclusively during early fattening (T3-E). The lower efficiency in T3-E was associated with better sensory flavor, overall acceptability grading and oxidative status. The results show that, particularly under the condition of a continuous supply, much of the n-3 fatty acids ingested in early fattening can be recovered in pork. These findings give farmers flexibility as to when and how pork shall be enriched in n-3 fatty acids with fish oil.

Key Words: fatty acid • omega-3 • pig • pork • tuna oil • fish oil