Fatty acid composition of meat and estimated indices of lipid metabolism in different poultry genotypes reared under organic system

Abstract

According to EC regulation 889/08, different European countries should draw up a list of slow-growing strains adapted to an organic system, and in the meantime, provide this information to operators and the European Union commission. Thus, the aim of the present work was to evaluate the effect of poultry genotype on fatty acid composition and lipid indices of poultry meat. Six poultry genotypes (100 birds each), each with a different growth rate (slow-growing: Leghorn, Ancona, Cornish×Leghorn; medium-growing: Kabir, Naked neck; fast-growing: Ross), were reared under an organic system. Breast meat fatness, fatty acid composition, and indices were largely related to genotype, as slow-growing strains had higher elongase, thioesterase, and Δ5/Δ6 desaturase indices accompanied by a lower Δ9. Differences in the fatty acid profiles were observed by varying contents of total saturated fatty acids, with a higher value seen in Leghorn chickens and a lower value seen in commercial lines. On the contrary, Leghorn and Ancona chickens exhibited higher amounts of stearic acid and total polyunsaturated fatty acids compared with commercial genotypes, both in the total content and in the different fractions (total n-3 and total n-6). Despite the increased consumption of fresh forage, the lower linolenic acid in meat of the slow-growing strain could be explained by the higher conversion of this fatty acid to its long-chain derivatives.

Effect of genotype on estimated indexes of fatty acid metabolism in rabbits

“…In beef, some authors have suggested that different concentrations of palmitoleic acid between breeds could be attributed to increased Δ 9 -desaturase activity (Sturdivant et al, 1992;Laborde et al, 2001). The results of the present study confirm those obtained in our previous chicken study, in which this enzymatic complex was always lower in pure breeds than in commercial hybrids (Dal Bosco et al, 2012). Malau-Aduli et al (1998) observed that Jersey cattle had greater indices of Δ 9 -desaturase in C16 fatty acids and elongase and less Δ 9 -desaturase in C18 fatty acids than Limousine cattle.…”

“…To evaluate the activity of both Δ 5 -desaturase and Δ 6 -desaturase, the enzymes catalysing the formation of LCPn-6 and LCPn-3 starting from the precursors LA and ALA, the following equation was used (Dal Bosco et al, 2012): Δ 5 -Δ 6 -desaturase=[(C20:2n-6+C20:4n-6+EPA+C22:5n-3+DHA)/(LA+ALA+C20:2n-6+C20:4n-6+EPA+ C22:5n-3+DHA)]×100.…”

“…Where the effect of feeding on such enzyme activity has been assessed, the ALA elongation/desaturation ability of different genetic lines has been poorly investigated, although in chickens, the genotype seems to play an important role in this synthesis (Dal Bosco et al, 2012).…”

Comparison of the Growth Performance and Carcass Characteristics of Two Slow-Growing Broiler Genotypes Fed Diets Supplemented with Dry Oregano (Origanum vulgare L.) or Lemon Balm (Melissa officinalis L.) Leaves under the Organic System

“…Slow-growing birds are more adapted to natural systems, and the quality of their meat is more appropriate for a specialty or gourmet market [6,7] . Thus, some researchers [3,8] stated that slow-growing chickens possess a good aptitude for pasture, which enhances the dietary intake of bioactive substances (i.e vitamins, antioxidants, and fatty acids) contained in the forage. In addition, the free-range chicken can consume young vegetative plant material and live protein sources, such as insects, worms, and grubs, which could reduce the feed cost that accounts for approximately 70% of the total variable costs [9,10] stated that compared with conventional free-range and organic systems, the pastured poultry is likely to induce considerably greater levels of pasture consumption, and thus it is an ideal system to evaluate the nutritional impact of pasture intake in broiler performance and carcass quality.…”

“…EC regulation 1804/99 and the Network for Animal Health and Welfare in Organic Agriculture's final recommendation [2] suggest using local, slow growing breeds for their higher rusticity and capacity to use outdoor areas and pasture [3] . Slow-growing genotypes, which were designed for outdoor production [4] , have growing period of at least 81 days according to European organic programs [5] .…”