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

Effect of Organic Production System on the Performance and Meat Quality of Two Purebred Slow-Growing Chicken Breeds

The objective of the study was to compare the effect of organic and conventional rearing systems on the productivity and meat quality of Yellowleg Partridge (Ż-33) and Rhode Island Red (R-11) chickens. A total of 492 sexed experimental birds (Gallus domesticus) were assigned to four groups. In groups I-C and III-C, the Ż-33 and R-11 chickens were reared under intensive conditions following conventional farming principles. In groups II-O and IV-O, the Ż-33 and R-11 chickens were kept according to organic farming principles. Body weight, feed conversion (kg/kg gain) and mortality were recorded throughout the study. On day 140 of rearing, the native breed chickens were subjected to simplified slaughter analysis, and meat pH, muscle colour, water holding capacity and chilling loss were determined. The meat samples were analysed for the chemical composition and profile of fatty acids, and the peroxidizability index (PI), thrombogenic index (TI) and atherogenicity index (AI) were calculated. The organically raised chickens were characterised by higher body weight (P≤0.01), better feed conversion (P≤0.01) and more favourable fatty acid profile of the muscles compared to the conventionally reared birds. Under organic conditions, the R-11 chickens showed better productivity but slightly poorer fatty acid profile of the muscles compared to the Ż-11 chickens.

A Note on Fatty Acids Profile of Meat from Broiler Chickens Supplemented with Inorganic or Organic Selenium

This investigation evaluated, in broiler chickens Pectoralis and Gastrocnemius muscles, the effect of the dietary supplementation with sodium selenite (0.3 ppm) versus selenomethionine (0.3 ppm), on the fatty acids composition, lipids indices, and enzymes indexes for desaturase, elongase, and thioesterase. The selenium reduced, in both muscles, the content of atherogenic fatty acids, C14:0 and C16:0, while it increased the C18:1 level. On the other hand, selenium increased, in both muscles, the content of C18:3n3 and EPA, but not DPA and DHA. No selenium effect was detected for PUFA/SFA, n-6, n-3, n-6/n-3, and atherogenic and thrombogenic indices. As for the enzyme indexes, a selenium effect is only detected for thioesterase. Taken together, the results highlight the potential effect of dietary selenium, mainly selenomethionine, in the modulation of the composition of fatty acids in chicken meat, in particular, reducing the content of atherogenic fatty acids and increasing the health promoting n-3 PUFA.

Difference in fatty acid composition and related nutritional indices of meat between two lines of slow-growing chickens slaughtered at different ages

Abstract. The fatty acid profile and the related indices of the nutritional quality of breast and thigh muscles were studied in two lines of chickens – La Belle (LB) and White Plymouth Rock (WPR) – slaughtered at the age of 9 and 18 weeks. The fatty acid profile was more affected by the age than the line of the birds; however, the influence of both differed between the breast and thigh. The content of total saturated fatty acids (SFAs) increased in the thigh (P <  0.01), while that of the monounsaturated fatty acids (MUFAs) decreased with age in both muscles (P <  0.001). This corresponded to the significant decrease in C18:1 in the older chickens and the lower desaturase activity (P <  0.001). The contents of C20:4n-6, C22:5n-3 and C22:6n-3 and the total amount of polyunsaturated fatty acids (PUFAs) in breast were higher (P < 0.001) at the age of 18 weeks. A similar pattern in the individual and total PUFA was observed in the thighs. The effect of line was more visible in the breast, leading to a lower C14:0 content and C20:5n-3 and a higher C18:0 content in the WPR chickens (P <  0.001), corresponding to the higher elongase and thioesterase indices in these birds. Both atherogenic (AI) and thrombogenic (TI) indices were lowered, while the ratio of hypocholesterolemic ∕ hypercholesterolemic fatty acids (h ∕ H) and polyunsaturated ∕ saturated fatty acids (P ∕ S) increased in the breast of the birds at 18 weeks. In breast and thigh meat, the ratio of n-6 ∕ n-3 PUFA decreased in the older chickens (P <  0.001).

Activity, Expression, and Substrate Preference of the Δ(6)-Desaturase in Slow- or Fast-Growing Rabbit Genotypes

In the present paper liver fatty acid Δ(6) desaturation (fads2) activity was analyzed in two rabbit strains with slow- (S, 27.5 g/day) or fast-growing (F, 48.5 g/day) rate. The fatty acid profile of the liver showed a different PUFA profile in the two strains with a lower n-6/n-3 ratio in the S rabbits. The expression of fads2 was 2-fold higher in S than in F rabbits, whereas enzyme activity was higher in F and more oriented toward the desaturation of linoleic acid (90%). In contrast, S showed a higher preference for linolenic acid (38.9 vs 10%). This study identified a single difference in the fads2 amino acid sequence between these two strains. Such a difference consists in the substitution of Gly104 to Ser104 in the sequence of F fads2. These results indicate for the first time that genetic selection for performance may affect the preference for PUFA toward desaturation of linoleic/linolenic acid.

The Growth Performance, Carcass Characteristics, and Meat Quality of Egg-Type Male Growing Chicken and White-Mini Broiler in Comparison with Commercial Broiler (Ross 308)

The present study was conducted to compare the growth performance, carcass characteristics, and meat quality of the egg-type male growing chicken (EM), white-mini broiler (WB), and commercial broiler (Ross 308, CB). A total of 360 1-d-old chicks were reared together using a completely randomized design with 4 replicates for each group under the identical feeding and rearing conditions. The ADG and gain:feed were the highest in CB, intermediate in WB, and the lowest in EM (p<0.05), and the live and carcass weights of CB and EM were significantly higher than those of WB (p<0.05). The pH of breast meat from WB and CB was significantly higher (p<0.05) than that from EM with a similar body weight. The EM had the lowest moisture (p<0.05) and the highest protein content (p<0.05), whereas the fat and ash contents were not different among groups. The mystiric acid (C14:0), palmitoleic acid (C16:1 ω7), and oleic acid (C18:1 ω9) levels were significantly higher in breast meat from CB (p<0.05). The monounsaturated fatty acid (MUFA) content showed the highest (p<0.05) levels in CB. In contrast, the polyunsaturated fatty acid (PUFA) contents of breast meat, including linoleic acid (C18:2 ω6) and arachidonic acid (C20:4 ω6), were higher (p<0.05) in EM and WB than in CB. In conclusion, the EM and WB had less growth performances in comparison with CB, but they each had some unique features (taste, flavor, and physiological characteristics) when raised under the identical rearing and feeding conditions.

Quality Assessment of the Breast Meat from Woorimatdag (TM) and Broilers

The objective of this study was to compare the characteristics that define the quality of Woorimatdag^TM (WM, a certified meat-type commercial Korea indigenous chicken breed) and a commercial broiler breed (Ross, CB). Two hundred WM and 200 CB chickens that were 1-d-old and mixed sex were obtained from a commercial hatchery and randomly assigned to floor pens (20 chickens per pen, 3.0×2.0 m) and raised under the same environmental conditions. WM breast meat contained significantly higher crude protein and ash as well as lower crude fat than CB breast meat (p<0.05). WM breast meat had slightly higher alanine, histidine, isoleucine, and glycine as well as lower phenylalanine content than CB breast meat (p<0.05), and the WM breast meat had a low ratio of unsaturated to saturated fatty acid composition (p<0.05). However, arachidonic acid composition was higher in the WM than the CB breast meat. In addition, the inosin-5’-monophosphate content was also higher in the WM compared with the CB breast (p<0.05). The WM breast meat had higher total collagen content compared with CB breast meat. WM soup taste received higher scores with regard to sensory evaluation compared with CB soup (p<0.05). From these results, we conclude that higher amount of protein and flavor precursors and lower amount of fat in the breast meat of WM could be attractive by consumer when compared with CB.

Comparison of Performance, Meat Lipids and Oxidative Status of Pigs from Commercial Breed and Organic Crossbreed

Simple Summary

In recent years, the development of alternative rearing methods, capable of satisfying requests regarding product quality, yet also taking animal welfare and environmental protection into consideration, is becoming an increasingly important consumer demand. When pigs are reared in free range and organic systems, outdoor access is given to pigs; and such rearing conditions increases energy demand for activity and thermoregulation, which reduces growth rate, but improves some meat quality characteristics, such as leaner meat with lower C14:0 and higher C20:1n9, and oxidative stability.

Abstract

The aim of this research was to determine the effect of rearing systems for pig production, as concerns performance, meat lipid content, the fatty acid profile, histidinic antioxidants, coenzyme Q10, and TBARs. One hundred pigs were assigned to one of three treatments: intensively reared commercial hybrid pig (I), free range commercial hybrid pig (FR) or organically reared crossbred pig (O), according to organic EU Regulations. I pigs showed the best productive performance, but FR and O increased: C20:1n9, Δ9-desaturase (C18) and thioesterase indices in meat. Lipid, dipeptides and CoQ10 appeared correlated to glycolytic and oxidative metabolic pathways. We can conclude that all studied parameters were influenced by the rearing system used, and that differences were particularly evident in the O system, which produced leaner meat with higher oxidative stability. In this respect, the organic pig rearing system promotes and enhances biodiversity, environmental sustainability and food quality.

The occurrence of giant fibres in different muscles of two chicken genotypes

1. The occurrence of Giant Fibres (GF) in three muscles (Pectoralis major (PM), Iliotibialis lateralis and Semimembranosus) with different types of energy metabolism was studied in slow- and fast-growing chicken strains. 2. A total of 20 one-day-old Leghorn chicks (slow-growing) and 20 broiler (Ross 508) chicks (fast-growing) were reared to 100 and 45 d, respectively. 3. A small percentage of GF was seen in pre rigor muscle samples even at 3 min post mortem in both genotypes and in all muscle types studied. 4. From 3 min to 24 h post mortem GF increased both in Leghorn and broiler chickens but to a different extent according to muscle type and genotype. 5. The highest GF 24 h post mortem value was found in the PM muscles belonging to the fast-growing broiler line. 6. It was concluded that every type of muscle can develop GF, but this phenomenon is more evident in the PM especially in animals selected for increased growth rate.