Influence of pasture intake on the fatty acid composition, and cholesterol, tocopherols, and tocotrienols content in meat from free-range broilers

Effect of genotype and outdoor enrichment on productive performance and meat quality of slow growing chickens

The optimization of animal welfare, meat quality, environmental impact, and economic sustainability in alternative poultry farming can be achieved by modulating several productive factors and improving the synergy between the chicken genotype and the outdoor environment. The objective of the study was to characterize 4 slow-growing chicken genotypes reared in free range conditions. Eight hundred chickens (SGs; 25 chickens/replicates/genotype/enrichment) belonging to the following genotypes, Red JA57 (RJ), Naked Neck (NN), Lohmann Dual meat-type (LD), and an Italian crossbreed (Robusta Maculata x Sasso, CB). were utilised and slaughtered at 81 d: The grazing areas were alternatively provided with enrichment constituted by strips of sorghum plants (ENR) or only grass (NO ENR). Productive performance (daily weight gain, daily feed intake, feed conversion ratio, live weight) were recorded weekly. Behaviour observations (walking and grass pecking), carcass and meat quality of breast and drumstick were also assessed in 15 chickens/replicate/genotypes/enrichment. Results demonstrated that both LD and CB showed the highest walking activity, but the different strains were differently capable of using the foraging resources (eating grass). The better productive performance was recorded in RJ followed by NN, CB and LD. In LD and CB, the different walking activities also affected the physico-chemical profiles (lower pHu, WHC, and lipids) of the breast and drumstick. The oxidative status was worse in CB than in the other groups (lower tocols, higher carbonyls), in both meat cuts. Fatty acid profile was also related to the genetic strain: a higher amount of n-3 polyunsaturated fatty acids was recorded both in the breast and drumstick of RJ and NN. The Healthy Fatty Index resulted excellent in all the chicken genotypes. In conclusion, the environment/animal interaction resulted as an important factor affecting the adaptability of genotypes to an extensive rearing system. All four genotypes, to different extents, showed good adaptability and production performance, with the exception of LD and CB, which were too light for the commercial supply chain requirements.

Impact of long-term feeding a high level of Spirulina combined with enzymes on growth performance, carcass traits and meat quality in broiler chickens

This study evaluates the effect of prolonged feeding with a high inclusion level of Spirulina, combined with peptidases, on broiler chicken's growth performance, digesta viscosity, carcass attributes and meat quality. The experiment involved 120 male broilers divided into 40 battery brooders, each housing 3 birds. Post 7-day acclimatisation with a corn and soybean-based diet, the birds were provided with one of four diets: a corn and soybean meal-based diet (CON), a mix incorporating 15% Spirulina (SP), a Spirulina-rich mix supplemented with 0.025% of commercial VemoZyme® P (SPV), or a Spirulina-rich mix supplemented with 0.10% of porcine pancreatin (SPP). The CON group had higher body weight and weight gain (p < 0.001) and a lower feed conversion ratio (p < 0.001) from day 7-21, compared to the Spirulina-fed groups. Spirulina-fed chickens significantly increased ileum viscosity (p < 0.05). Spirulina also elevated the weight (p < 0.05) of the duodenum and the length (p < 0.001) of the entire gastrointestinal tract compared to CON. Breast and thigh muscles from Spirulina-fed broilers displayed higher values of yellowness (b*) (p < 0.001), pigments (p < 0.05), and n-3 PUFA (p < 0.01), while n-6/n-3 ratio (p < 0.001) and α-tocopherol (p < 0.001) decreased relative to the CON. In conclusion, the introduction of a high level of Spirulina into broiler diets for an extended duration, has the potential to diminish birds' growth performance, possibly due to increased digesta viscosity. However, it does enhance the nutritional quality of the meat.

Nutritional value of meat lipid fraction obtained from mallard duck (Anas platyrhynchos) reared in semiextensive conditions for hunting purposes

The mallard duck or wild duck (Anas platyrhynchos) is the world's most widespread and numerous dabbling duck, being traditionally hunted across many countries in Europe and North America. This study aims to provide a detailed characterization of mallard duck's meat lipid fraction obtained from farmed specimens, reared for hunting purposes, under semiextensive conditions. The mallard's duck meat total lipid content averaged 2.0 and 4.26 g/100 g of fresh meat in breast and leg meat portions, and its meat comprised 23 individual fatty acids (FA) and 3 dimethylacetals (DMA), independently of the sex or meat portion. The oleic (C18:1 cis-9), palmitic (C16:0), stearic (C18:0), linoleic (C18:2n-6), arachidonic (C20:4n-6), palmitoleic (C16:1 cis-9), and cis-vaccenic (C18:1 cis-11) acids were the predominant FA (representing >1% of total fatty acids in both breast and leg meat portions and independently of the sex), and together, these 7 fatty acids were accountable for 92.4 to 96.5% of total FA plus DMA in mallard duck meat. The monounsaturated, saturated and polyunsaturated fatty acids were accountable for 40.4, 35.0, and 21.0% of total FA plus DMA in breast and 54.6, 38.7, and 5.7% of total fatty acids in leg, while total DMA were liable for 3.6 and 0.9% of total FA plus DMA in breast and leg, respectively. The mallard duck meat total cholesterol content averaged 49.8 and 57.1 mg/100 g of fresh meat for breast and leg meat portions. Five tocochromanols were quantified in mallard duck meat, affording it with a total vitamin E content of 5.48 and 3.63 µg/g of fresh meat in breast and leg portions. The sex had no influence (P > 0.05) on mallard's duck meat lipid composition, but meat portion had a strong influence on mallard's duck meat lipid composition, influencing total lipid, total cholesterol, total vitamin E contents, FA partial sums, FA ratios (exception made for the n-6/n-3 ratio), and all nutritional lipid indices. The breast meat presented lower total lipid and total cholesterol contents, better FA ratios and nutritional quality indices and higher vitamin E content, being regarded as a healthier meat than leg. The study presented herein shows that mallard duck production in semiextensive conditions, similar to those used herein, could be used for the production of mallard duck beyond hunting. A production of duck's meat under natural or organic production practices, oriented to a market niche within the gourmet/organic markets.

Weighted gene co-expression network analysis identified hub genes critical to fatty acid composition in Gushi chicken breast muscle

BACKGROUND

The composition and content of fatty acids in the breast muscle are important factors influencing meat quality. In this study, we investigated the fatty acid composition and content in the breast muscle of Gushi chickens at different developmental stages (14 weeks, 22 weeks, and 30 weeks). Additionally, we utilized transcriptomic data from the same tissue and employed WGCNA and module identification methods to identify key genes associated with the fatty acid composition in Gushi chicken breast muscle and elucidate their regulatory networks.

RESULTS

Among them, six modules (blue, brown, green, light yellow, purple, and red modules) showed significant correlations with fatty acid content and metabolic characteristics. Enrichment analysis revealed that these modules were involved in multiple signaling pathways related to fatty acid metabolism, including fatty acid metabolism, PPAR signaling pathway, and fatty acid biosynthesis. Through analysis of key genes, we identified 136 genes significantly associated with fatty acid phenotypic traits. Protein-protein interaction network analysis revealed that nine of these genes were closely related to fatty acid metabolism. Additionally, through correlation analysis of transcriptome data, we identified 51 key ceRNA regulatory networks, including six central genes, 7 miRNAs, and 28 lncRNAs.

CONCLUSION

This study successfully identified key genes closely associated with the fatty acid composition in Gushi chicken breast muscle, as well as their post-transcriptional regulatory networks. These findings provide new insights into the molecular regulatory mechanisms underlying the flavor characteristics of chicken meat and the composition of fatty acids in the breast muscle.

Effect of botanical composition of free-range areas on production results and selected meat quality parameters of organic Yellowleg Partridge chickens

The aim of the conducted research was to assess the impact of the botanical composition of free-range areas on the production results and selected quality parameters of the meat of fattening chickens of the Polish Yellowleg Partridge (Ż-33) breed in organic farming. Three hundred mixed-sex Ż-33 chicks were assigned to three groups: RP1 – free-range area with natural meadow vegetation, RP2 – free-range area sown with a mixture of plants containing ingredients stimulating growth, RP3 – free-range area sown with a mixture of plants rich in carotene. During the experiment, the production results (the weight of the birds, feed consumption, feed conversion ratio per g of weight gain, and mortality) were monitored. Observations were also performed on the behaviour in the free-range areas. On the 140th day of the experiment, a simplified slaughter analysis was carried out, the meat pH was measured, the colour of the muscles was also determined, as well as the water holding capacity and drip loss of the meat. In the meat samples, the content of nutrients and fatty acids was determined, and the peroxidizability index (PI) was calculated. Birds feeding in the RP2 free-range areas were characterised by higher body weight, better feed conversion, and higher dressing percentage compared to birds having access to the RP1 and RP3 free-range areas. On the other hand, the RP3 group Ż-33 chickens were characterised by a higher share of leg muscles and a tendency towards lower fat content in the carcass. It was also found that the meat of birds from the RP2 and RP3 groups was characterised by a higher pH24 compared to Ż-33 chickens from the RP1 group. Access to the RP2 free-range area modified the fatty acid profile, mainly in the leg muscles, reducing the palmitic acid and MUFA content and increasing the PUFA content. It can therefore be assumed that the plant species sown in the RP2 free-range area positively influenced the production results and the quality of the meat of fattening chickens feeding on them. It is therefore appropriate to carry out further studies on the type of vegetation sown in free-range areas in order to improve the efficiency and quality of the meat of organic fattening chickens.

Intake of nutrients (polyunsaturated fatty acids, tocols, and carotenes) and storage efficiency in different slow-growing chickens genotypes reared in extensive systems

An extensive rearing system (ERS) for poultry requires an outdoor run, which enhances the foraging activity of chickens. Slow-growing (SG) strains are more adapted to ERS than fast-growing (FG); and generally, have higher levels of bioactive compounds in their meat. The aim of this paper was to assess the storage efficiency of n-3 and n-6 polyunsaturated fatty acids (PUFA), tocols and carotenes in the meat of seven commercial SG genotypes (SG1-7). One hundred SG chicks/strain of both sexes were included and their walking activity (High- or Low-W) was classified: SG1-4, HW comprised more than 10% of the time budget, and SG5-7, less than 10% (LW). Chickens were reared in pens (4 pens/strain) with indoor (0.10 m2/bird) and outdoor (4 m2/bird) areas, and they were fed the same diet ad libitum (starter feed for 1-21 d, grower feed from 22 d to slaughter at 81 d). The chickens were weighed weekly; feed consumption and grass intake were also estimated. At 81 days of age, 32 chickens/genotype were selected on the basis of the average weight (1:1, M:F) and slaughtered. The breast, thigh and drumstick meat were excised from 30 carcasses/genotype, sampled and stored at -20°C until analysis. Nutrients (e.g., n-3, n-6, carotenes and tocols) of feed, grass and meat were analyzed. The storage efficiency of nutrients was estimated as the ratio between the amount deposited in the body muscles (OUT) and the dietary intake (feed and grass, IN). The genotype affected chickens foraging behavior and the intake of nutrients. For SG1, SG2 and SG3, more than 50% of the intake of n-3 came from grass, whereas in the other genotypes, less than 20%. Accordingly, chickens that foraged more showed better meat nutritional profiles (less fat, more n-3 and antioxidants), which, in ERS, was ascribed to grass ingestion. However, the storage efficiency of nutrients into meat was inversely correlated with the grass intake: strains with higher grass intake (SG1, SG2, and SG3) had lower storage rates. Several hypotheses were proposed to explain these trends.

1H NMR as a simple methodology for differentiating barn and free-range chicken eggs

The conventional intensive system produces cheap and safe chicken eggs, but exposes the animals to stress due to overcrowding on farms. This work compared the ¹HNMR lipidic profile of chicken eggs produced in conventional and free-range systems. Sample preparation consisted of a single-step extraction and centrifugation, and the ¹H NMR experimental time was just 3 min per sample. Eggs from free-range chickens had higher concentrations of ω-3 and ω-6 polyunsaturated fatty acids. The ratio between the signals at δ2.85 and 4.14 from bis-allylic polyunsaturated fatty acids and glycerol moiety, respectively, was able to correctly classify 93.8 % of the samples. These results were similar to those of PLS-DA, used for comparative purposes. Therefore, the proposed method could be easily used to assist quality control and fraud prevention in the egg industry. Free-range eggs had higher concentrations of cholesterol but, as they are smaller, similar amounts to conventional ones.

Chemical Composition of the “Galo de Barcelos” (Barcelos Rooster Raw Meat)

Simple Summary

The assessment of traditional products is important for the sustainability of agricultural systems and the preservation of a unique gastronomic heritage. The present study aims to determine the chemical composition of “Galo de “Barcelos”” (“Barcelos” Rooster) raw meat, used in the preparation of the typical Portuguese dish “Roasted Rooster from “Barcelos””, in order to evaluate and protect this gastronomic and cultural tradition. The influence of the genotype on the final product was verified, concerning total protein, and fat contents, and a favorable ratio of n-6/n-3 fatty acids of the Sasso line was compared to the “Amarela” breed, contributing to the promotion of its gastronomic potential.

Abstract

Ten roosters produced according to “Barcelos Confraria” rules and ten roosters of autochthonous “Amarela” breed, reared on a similar traditional production system, were analyzed, and the chemical profile of two of the most significant meat portions, breast and drumstick, was determined. The results demonstrated that the “Barcelos” rooster raw meat is rich in proteins (22.3%) and fat (4.31%), particularly in monounsaturated fatty acids (39.1%). Significant differences (p ≤ 0.01) were observed, with the breast having a higher protein content (25.1 vs. 19.7%) and less fat (1.9% vs. 6.7%), compared to the drumstick. The fatty acid profile revealed (SFA 30.0%, MUFA 39.1%, and PUFA 24.6%) a similar composition to the roosters reared in the traditional or organic production systems, such as the “Amarela” autochthonous rooster. The “Barcelos” rooster can be regarded as a highly nutritional meat, with an interesting chemical profile ensuring a high-quality traditional product to consumers.

Adaptability Challenges for Organic Broiler Chickens: A Commentary

Simple Summary

Organic poultry shows an increasing productive trend, rising from 3% in 2017 to 8% in 2019. Regulation EU 848/2018 puts great emphasis on the ability of broilers to adapt to outdoor systems as being essential for organic production. Organic poultry operators meet with regulatory constraints, consumer concerns, and challenges in terms of nutrition, welfare, health, and sustainability. The present commentary considers recent studies on and innovations in these topics that can affect organic production in addition to recent studies on animal adaptability to this production system. It reflects on the concept of broiler adaptability to organic systems not only as a classic genotype–environment interaction but as a necessary prerequisite for facing these relevant challenges.

Abstract

As organic and conventional poultry production increased in the last decade, so did consumers’ concerns, sustainability requirements, and animal welfare as well as health issues. According to Reg. EU 848/2008 on organic production, poultry must be adapted to organic outdoor systems and cope with all the regulatory constraints in terms of nutrition, health, and welfare. Adaptability must take into account the above challenges, constraints, and concerns. Chicken adaptability should not only mean being able to use pasture and outdoor areas, but also mean being able to overcome, or be resilient to, the challenges of organic farming without compromising welfare, performance, and product quality. This commentary identifies solutions to the new challenges that organic poultry chains must face in future productive scenarios, detects consumer viewpoints to provide a perspective on organic poultry production, and summarizes as well as defines chicken adaptability to organic production, assessing the main factors of chicken adaptability.

Effect of Dietary Laminaria digitata with Carbohydrases on Broiler Production Performance and Meat Quality, Lipid Profile, and Mineral Composition

Simple Summary

Seaweeds represent promising alternatives to unsustainable conventional feed sources, such as cereals, incorporated in poultry diets. Brown macroalgae (e.g., Laminaria digitata) correspond to the largest cultured algal biomass worldwide and are rich in bioactive polysaccharides, minerals, and antioxidant pigments. However, their utilization as feed ingredients is limited due to the presence of an intricate gel-forming cell wall composed of indigestible carbohydrates, mainly alginate and fucose-containing sulfated polysaccharides. Therefore, supplementation with carbohydrate-active enzymes is required to disrupt the cell wall and allow seaweed nutrients to be digested and absorbed in poultry gut. The present study aimed to evaluate if the dietary inclusion of 15% L. digitata, supplemented or not with carbohydrases, could improve the nutritional value of poultry meat without impairing growth performance of broiler chickens. The results show that L. digitata increases antioxidant pigments and n-3 long-chain polyunsaturated fatty acids in meat, thus improving meat nutritional and health values. On the other hand, feeding algae at a high incorporation level impaired growth performance. Feed enzymatic supplementation had only residual effects, although alginate lyase decreased intestinal viscosity caused by dietary L. digitata with potential benefits for broiler digestibility.

Abstract

We hypothesized that dietary inclusion of 15% Laminaria digitata, supplemented or not with carbohydrases, could improve the nutritional value of poultry meat without impairing animal growth performance. A total of 120 22-day old broilers were fed the following dietary treatments (n = 10) for 14 days: cereal-based diet (control); control diet with 15% L. digitata (LA); LA diet with 0.005% Rovabio^® Excel AP (LAR); LA diet with 0.01% alginate lyase (LAE). Final body weight was lower and feed conversion ratio higher with LA diet than with the control. The ileal viscosity increased with LA and LAR diets relative to control but without differences between LAE and control. The pH of thigh meat was higher, and the redness value of breast was lower with LA diet than with control. Meat overall acceptability was positively scored for all treatments. The γ-tocopherol decreased, whereas total chlorophylls and carotenoids increased in meat with alga diets relative to control. The percentage of n-3 polyunsaturated fatty acids (PUFA) and accumulation of bromine and iodine in meat increased with alga diets compared with control. Feeding 15% of L. digitata to broilers impaired growth performance but enhanced meat quality by increasing antioxidant pigments, with beneficial effects on n-3 PUFA and iodine.

The composition of the lipid, protein and mineral fractions of quail breast meat obtained from wild and farmed specimens of Common quail (Coturnix coturnix) and farmed Japanese quail (Coturnix japonica domestica)

The present study was intended to answer 2 scientific hypotheses: 1) the quail species has a significant influence in quail breast meat composition; 2) the wild quail's meat presents healthier composition than their farmed counterparts.

An analysis of the pectoral muscles of wild and captive common quails (Coturnix coturnix) and domestic quails (Coturnix japonica domestica) was performed. The content of fatty acids (FA), amino acids, total cholesterol, and vitamin E, some basic macro- and microminerals in the pectoral muscles of the 2 species of the genus Coturnix were analyzed.

Regarding the quail species influence on meat composition, Japanese Quail (JQ) revealed better lipid composition, characterized by lower saturated FA (SFA; less 3.17 g/100 g of total fatty acids), higher polyunsaturated FA contents (PUFA; more 5.5 g/100 g of total fatty acids) and healthier polyunsaturated FA/saturated FA (P/S) and n-6/n-3 ratios and TI value (1.08, 9.54 and 0.60 vs. 0.76, 12.58, and 0.75, correspondingly). The absence of differences observed on amino acids partial sums and ratios reveals equality between species on protein nutritional quality. On the other hand, Common Quail (CQ) proved to be a better source of copper (0.181 mg/100 g of meat), iron (2.757 mg/100 g of meat), manganese (0.020 mg/100 g of meat), and zinc (0.093 mg/100 g of meat) than JQ.

The comparison of farmed and wild specimens within CQ, showed that wild birds presented lower total cholesterol (less 8.32 mg/g of fresh meat) and total PUFA (less 4.26 g/100 g of total fatty acids), and higher n-3 PUFA contents (more 1.53 g/100 g of total fatty acids), which contributed to healthier P/S and n-6/n-3 ratios, but worst PI (1.60, 8.08, and 113.1 vs. 0.76, 12.58, and 100.8, respectively). The wild species revealed higher α-tocopherol content (2.40 vs. 1.49 µg/g of fresh meat. Differences observed on their mineral composition counterbalance each other.

Under intensive production system and similar feeding and management conditions, the CQ develops better nutritional qualities than JQ. The comparison of wild and farmed species within CQ reveals more similarities than differences. Quail´s meat presents good nutritional quality and introduces variability to human's diet, which is much valued by consumers.

An overview of health challenges in alternative poultry production systems

Due to consumer demand and changing welfare standards on health, ecology, equity, and safety concepts, poultry production has changed markedly over the past 20 y. One of the greatest changes to poultry production standards is now offering poultry limited access to the outdoors in alternative and organic poultry production operations. Although operations allowing access to the outdoors are still only a small portion of commercial poultry production, it may impact the gastrointestinal (GIT) health of the bird in different ways than birds raised under conventional management systems. The present review describes current research results in alternative systems by identifying how different poultry production operations (diet, environmental disruptive factors, diseases) impact the ecology and health of the GIT. Various research efforts will be discussed that illustrate the nutritional value of free-range forages and how forages could be beneficial to animal health and production of both meat and eggs. The review also highlights the need for potential interventions to limit diseases without using antibiotics. These alternatives could enhance both economics and sustainability in organic and free-range poultry production.

Effect of housing system and feed restriction on meat quality of medium-growing chickens

The aim of the study was to evaluate the differences in meat quality of 420 Hubbard JA757 cockerels in relation to the housing system (litter and mobile box) and level of mixed feed (ad libitum [AL], reducing the level by 20% [R20] and 30% [R30]). Three groups of chickens were housed in litter boxes for the entire fattening period (stocking density: 0.094 m²/bird). The other 3 groups were housed in litter boxes until 28 d of age and then relocated into mobile boxes (stocking density: 0.154 m²/bird) on pasture until the end of the experiment at 57 d of age. Restricted groups received a reduced diet level from 29th to 57th d of age. Feed mixture restriction increased the pasture vegetation intake of chickens from 2.63 to 3.50 (R20) and 3.94 g of dry matter/bird/d (R30). Restriction adversely affected the dressing percentage (P < 0.001) and breast yield (P < 0.001), while the leg yield (P < 0.001) was increased with increasing restriction levels. Meat of chickens housed in mobile boxes on a pasture showed lower cooking loss (P < 0.001) and higher redness and yellowness values in the skin (P = 0.030 and P = 0.026; respectively) and meat (P = 0.008 and P < 0.001; respectively). The fragile meat after cooking was observed in chickens reared on litter (P = 0.001). As the level of restriction increased, the number of muscle fibres (P = 0.001) increased, and their cross-sectional area (P = 0.001) and diameter (P = 0.002) decreased. The highest contents of lutein (P = 0.002) and zeaxanthin (P = 0.006) in breast muscle were found in chickens housed in mobile boxes and fed 80% and 70% AL. However, the concentrations of α- and γ-tocopherol (P = 0.006 and P = 0.003) were negatively affected by feed restriction. A 30% reduction in feed level in outdoor housed chickens led to a decrease in oxidative stability (P = 0.024). Feed restriction (R20) in chickens housed in mobile boxes significantly increased the n3 fatty acids content (P = 0.002) and h/H index (P = 0.005) and reduced the n6/n3 ratio (P < 0.001) and atherogenic (P < 0.001) and thrombogenic index (P = 0.003), which possess a health benefits for human. In addition, restriction of mixed feed decreased cholesterol content in breast meat (P = 0.042). It might be concluded that, in terms of meat quality, cereal diet restriction of 20% in medium-growing cockerels housed in mobile boxes on a pasture is beneficial. The higher level of restriction does not lead to further improvement in meat quality indicators.

Impact of different chicken meat production systems on consumers' purchase perception

1. The objective of this study was to evaluate specific sensory attributes of chicken meat from different production systems to evaluate the emotional responses related to information available on the packages, as well as to investigate consumers' perceptions regarding this information.2. The survey was conducted using the Temporal Dominance of Sensations analysis, which identified differences in taste and texture between samples belonging to the organic, conventional and natural systems.3. The specific emotional lexicon for chicken meat, defined by the consumers through the EmoSemio questionnaire, provided a list of positive emotions for packages that indicated some type of information about the rearing or feeding system.4. The qualitative data obtained using the Attitude Questionnaire demonstrated that packaging and labelling are not self-explanatory, posing more doubts for the consumer at the time of purchase. It was shown that packaging and labelling were extrinsic attributes that influenced the evaluation and acceptability of products. Besides that, consumers were interested in buying products that attest to animal welfare, provided that the price is attractive.5. Poultry companies can have a greater chance of making their products more attractive if they learn more about the attitude and expectations of the consumer in relation to the products, as well as the importance of the animal welfare attributes that are communicated.

Influence of dietary Chlorella vulgaris and carbohydrate-active enzymes on growth performance, meat quality and lipid composition of broiler chickens

Herein, we investigated the effect of Chlorella vulgaris as ingredient (10% of incorporation) in broiler diets, supplemented or not with 2 formulations of Carbohydrate-Active enZymes (CAZymes; Rovabio Excel AP and a mixture of recombinant CAZymes, composed by an exo-β-glucosaminidase, an alginate lyase, a peptidoglycan N-acetylmuramic acid deacetylase and a lysozyme), on growth performance, meat quality, fatty acid composition, oxidative stability, and sensory traits. One hundred twenty 1-day-old Ross 308 male birds were randomly assigned to one of the 4 experimental diets (n = 30): corn-soybean meal–basal diet (control), basal diet with 10% C. vulgaris (CV), CV supplemented with 0.005% of a commercial CAZyme cocktail (Rovabio Excel AP), (CV + R), and CV supplemented with 0.01% of a 4-CAZyme mixture previously selected (CV + M) during the experimental period lasted from day 21 to day 35. Body weight gain and feed conversion rate of broilers were not affected by C. vulgaris but digesta viscosity increased more than 2-fold (P < 0.001) relative to the control. In addition, neither cooking loss, shear force, juiciness, flavor nor off-flavor was impaired by dietary treatments (P > 0.05). By contrast, the dietary C. vulgaris increased tenderness, yellowness (b∗) and total carotenoids in breast and thigh meats. However, no additional protective effect against lipid oxidation was observed in meat with the inclusion of microalga. Chlorella vulgaris, independently of CAZymes, had a minor impact on meat fatty acid composition but improved the proportion of some beneficial fatty acids. In summary, our data indicate a slight improvement of broiler meat quality and lipid nutritional value, without impairment of broilers' growth performance, thus supporting the usefulness of this microalga in poultry diets, up to this high level of incorporation. By contrast, the selected CAZyme mixtures used do not significantly improve the release of microalga nutrients in poultry diets, through the disruption of microalga cell wall, which warrants further research.

Lipid Assessment, Cholesterol and Fatty Acid Profile of meat from broilers raised in four different rearing systems

Evaluated lipid and cholesterol concentration and fatty acid profile of raw breast, thigh and drumstick meat from broilers raised in different rearing systems. Were used 200 male broiler carcasses from four different rearing systems (n=50 from conventional intensive; n=50 from organic; n=50 from free-range; and n=50 from antibiotic-free) distributed in a completely randomized design with four rearing systems and 50 replications (carcasses). Breast meat from conventional broilers showed higher lipid (1.47) and cholesterol (34.13) concentration. Thigh and drumstick meat from free-range broilers had higher lipid (7.53/4.73) and cholesterol (45.55/53.65) concentration. Fat contained in breast, thigh and drumstick meat from free-range broilers showed higher levels of polyunsaturated fatty acids. Fat from breast and thigh meat from free-range broilers showed higher total concentration of ω3 and ω6 fatty acids. Fat from thigh meat from organic broilers showed higher levels of EPA (C20:5n3) and DHA (C22:6n3). Fat from drumstick meat from free-range broilers showed higher total concentration of ω3 and ω6 fatty acids. Meat from chickens raised in alternative rearing systems offers less risk to cardiovascular health because it presents lower concentrations of lipids and cholesterol, greater amounts of polyunsaturated fatty acids, which are beneficial for human health.

Impact of dietary incorporation of Spirulina (Arthrospira platensis) and exogenous enzymes on broiler performance, carcass traits, and meat quality

This study assessed the effect of Spirulina (Arthrospira platensis), individually and in combination with exogenous enzymes, on growth performance, carcass traits, and meat quality of broiler chickens. One hundred and twenty Ross 308 male chickens were allocated into 40 battery brooders, with 3 birds per cage, and fed ad libitum a corn-based diet during the first 21 D of the trial. The experimental period lasted from day 21 to 35, during which birds were fed 4 different diets: a corn-soybean basal diet, taken as the control group, a basal diet containing 15% Spirulina (MA), a basal diet containing 15% Spirulina plus 0.005% Rovabio Excel AP (MAR), and a basal diet containing 15% Spirulina plus 0.01% lysozyme (MAL). Body weight gain (P < 0.001) and feed conversion rate (P < 0.001) were improved in control chickens, when compared with those fed with Spirulina. In addition, Spirulina increased the length of duodenum plus jejunum in relation to the other treatment (P < 0.01). Chickens on the MAL diet showed a considerable increase in digesta viscosity (P < 0.05) compared with the control group. Breast and thigh meats from chickens fed with Spirulina, with or without the addition of exogenous enzymes, had higher values of yellowness (b*) (P < 0.001), total carotenoids (P < 0.001), and saturated fatty acids (P < 0.001), whereas n-3 polyunsaturated fatty acid (P < 0.01) and α-tocopherol (P < 0.001) decreased, when compared with the control. In conclusion, the incorporation of 15% Spirulina in broiler diets, individually or combined with exogenous enzymes, reduced birds' performance through a higher digesta viscosity, which is likely associated with the gelation of microalga indigestible proteins. In addition, cell wall of Spirulina was successfully broken by the addition of lysozyme, but not by Rovabio Excel AP. Therefore, we anticipate that the combination of lysozyme with an exogenous specific peptidase could improve the digestibility of proteins from this microalga and avoid their detrimental gelation.

The influence of current food and nutrition trends on dietitians' perceptions of the healthiness of packaged food

OBJECTIVE

To investigate the influence of current food and nutrition trends on dietitians' perceptions of the healthiness of packaged foods.

DESIGN

This observational study used a cross-sectional survey. Participants rated (strongly disagree to strongly agree) the extent to which a range of factors, independent of the energy, nutrient and ingredient content, influenced their perceptions of the healthiness of packaged foods. Two open-ended questions allowed for participants to list additional items they considered important.

SETTING

Online survey.

PARTICIPANTS

Australian dietitians (n 117).

RESULTS

The greatest consensus was a positive influence of the fit within the core food groups and presence of seasonal ingredients, and a negative influence of an increasing number of additives. Mixed opinions were obtained for GM ingredients, locally sourced ingredients, labelling of animal welfare and organic certification. Nutritional indicators received a split where almost half of participants disagreed/strongly disagreed that they positively influenced their perception of healthiness. Content analysis of open-ended responses (n 53, 45 %) revealed four broad categories as important in considering healthiness: 'a whole food approach', 'marketing and labelling', 'product information' and 'context of diet'. A small number of responses (count of 6, 5 %) reported that packaging, advertising and features such as celebrity endorsement were a negative influence.

CONCLUSIONS

Dietitians have a broad concept of the healthiness of packaged foods, which incorporates elements of food safety, wholeness of the ingredients and marketing. Providing unified messages to the consumer can help to build the public perception of dietitians as experts in nutrition advice and counselling.

Modification of the content of n-3 highly unsaturated fatty acid, chemical composition, and lipid nutritional indices in the meat of grass carp (Ctenopharyngodon idella) fed alfalfa (Medicago sativa) pellets

A 120-d feeding trial was conducted to determine the effect of alfalfa (Medicago sativa) feeding on growth and chemical composition, fatty acid content, and nutritional and lipid indices of the meat of grass carp (Ctenopharyngodon idella). Two experimental diets were used: alfalfa pellet (AP) diet and artificial grain diet (GD). Final weight, feed conversion rate, and protein efficiency ratio were significantly greater in the GD group (P < 0.05). However, no differences in the length and condition factor were observed. The composition of the meat differed between treatments. The protein content was significantly greater in the AP group (P < 0.05), while the lipid and cholesterol contents were significantly greater in the GD group (P < 0.05). A greater proportion of saturated, n-6 polyunsaturated, and n-6 highly unsaturated fatty acids was obtained in the GD group. The AP group accumulated a greater concentration of eicosapentaenoic (EPA), docosapentaenoic (DPA), and docosahexaenoic (DHA) acids (P < 0.05). The fatty acid composition of the meat determined a significant decrease in the thrombogenicity index and saturation index (S/P) in the AP group (P < 0.05). The Elongase index was greater in the GD group (P < 0.05). In contrast, the AP group had a greater index of Δ9 Desaturase and Δ5 + Δ6 Desaturase for n-3 and n-6 fatty acids (P < 0.05). These results suggest that alfalfa feeding decreases the growth of C. idella but improves the quality of meat by increasing the protein, EPA, and DHA contents. It also reduces cholesterol content and improves nutritional indices.

Performance, Behavior, and Welfare Status of Six Different Organically Reared Poultry Genotypes

In alterative rearing systems, the use of outdoor space has a crucial role. It is well known that only some commercial poultry genotypes are suitable to be reared in these systems. It is necessary to find a balance between productive performance and adaptability. The aim of this study was to evaluate the productive performance, behavior, and welfare status of six poultry genotypes reared in an organic system. One hundred males/genotype (Hubbard RedJA (A), CY5XJA87 (CY), M22XJA87 (M), Ranger Classic (R1), Ranger Gold (R2), and Rowan Ranger (R3)) were reared from 1 to 81 days of age. The number of culled birds was recorded daily, whereas live weight and feed consumption were recorded weekly. Behavior evaluation was undertaken through a computerized system one week before slaughtering; the breast yield and muscle/bone ratio of the drumstick was also evaluated in refrigerated carcasses. The results showed that A and R3 had good adaptability, showing active behaviors and satisfactory productive performance 3083.6 g and 3022.1 g, respectively. Although CY and M achieved the best productive performance, they did not appear adapted to the organic system due to a higher frequency of static behaviors (rest and roost), mortality, footpad dermatitis, breast blisters, and poor feather condition.

Visceral composition, carcass yield and meat quality parameters of free-range broilers with diets containing different levels of crushed sugarcane

ABSTRACT The aim of this study was to evaluate the visceral composition, cuts, and meat quality of two strains of free-range chickens fed diets containing crushed sugar cane. 448 chickens were distributed at 35 days of age, in two randomized blocks design, in 4x2 factorial, with four levels of replacement in the feed (0; 15; 30 and 45%) by sugarcane and two strains (Pesadão and Label Rouge), in two repetitions per block of fourteen birds per experimental unit. In 30 minutes after slaughter, the parameter a* was higher for animals of the Pesadão strain relation to the Label Rouge lineage. A quadratic effect was observed with increasing levels of sugarcane on the L* parameter of breast meat; and linear effect on parameter b* of the breast skin. Within 24 hours after slaughter, a quadratic effect of sugarcane levels was observed on the b* parameter of the breast meat. The increase in sugarcane levels linearly reduced the weight of heart, liver, chest, thigh plus drumstick, wing, carcass yield and relative heart weight of the animals. A quadratic effect was observed with increase in sugarcane levels over the relative weight of abdominal fat, the lowest fat content was observed in animals that consumed up to 30% of sugarcane in the feed. The use of sugarcane as an alternative feedstuff in up to 45% in the diet maintains the quality of meat and reduces the abdominal fat content, however, decreases the carcass yield.

Effects of cassava foliage on feed digestion, meat quality, and antioxidative status of geese

As the by-product of cassava, cassava foliage (CF) has been widely used in livestock feed. However, little information is available on its utilization for geese. In this study, we aimed to investigate the effects of CF on the feed digestion, meat quality, and antioxidative status of geese. A total of 108 male Hainan indigenous geese (28-days-old) with similar body weight were randomly and evenly divided into 3 groups, and the geese were fed for 42 D on either the control diet (CON) consisting of ground maize, soybean meal, and wheat bran, or the experimental diet composed of ground maize, soybean meal, and wheat bran supplemented with 5% (CF1) or 10% (CF2) CF. Dietary nutrient digestibility, physicochemical properties, amino acid and fatty acid composition of meat, and antioxidative status of geese were evaluated. The results showed that supplementation of CF in goose diets enhanced the feed digestion and affected the meat quality. In addition, supplementation of CF had beneficial effects on the regulation of amino acid and fatty acid profiles in muscle tissues. Moreover, such supplementation had no significant effect on antioxidative status. Taken together, goose diet containing 5% CF was recommended based on feed efficiency and meat quality.

Effect of cassava foliage on the performance, carcass characteristics and gastrointestinal tract development of geese

Cassava foliage is a by-product of cassava and has been widely used in animal feed. However, little information is available on its utilization for geese. In this study, we investigated the effects of cassava foliage on the performance, carcass characteristics, and gastrointestinal tract development of geese. A total of 108 28-day-old Hainan indigenous male geese with similar body weight were randomly divided into 3 groups with 6 pens of 6 geese per group and fed for 42 D on either the control diet of ground maize, soybean meal, and wheat bran or the experimental diet of ground maize, soybean meal, and wheat bran supplemented with 5% or 10% cassava foliage, respectively. On day 70, their body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio (FCR), carcass characteristics, and gastrointestinal tract development were compared. The results showed that cassava foliage diet significantly improved goose's BW (P < 0.05), ADG (P < 0.05), and ADFI (P < 0.05), affected carcass characteristics such as relative meat content (P < 0.05) and abdominal fat content (P < 0.05), and facilitated goose's gastrointestinal tract development. These findings suggested that incorporating cassava foliage into the diet of geese (day 28-70) could have positive effects, and supplementing 5% cassava foliage was more beneficial than 10%.

Effect of dietary niacin supplementation on performance, total tract nutrient retention, carcass yield and meat lipid profile of growing turkeys

A study was conducted to investigate the influence of dietary high or recommended nicotinic acid (niacin) supplementation on growth performance, total tract nutrient digestibility, hematology, serum chemistry, and lipoprotein concentrations in the serum and meat of growing turkeys. Turkeys were assigned to three treatments on weight equalisation basis with five replicates of eight turkeys in each group. Experimental diets were: no supplemental niacin (Control), a diet supplemented with 60 mg/kg niacin termed as recommended niacin supplementation and a diet supplemented with 180 mg/kg niacin termed as high niacin supplementation (HNS). The experiment lasted for the grower (Day 56–84) and finisher phases (Day 84–112) of the birds. Dietary inclusion of HNS increased (P &lt; 0.01) bodyweight gain, metabolisable energy (Days 84 and 112), dressing percentage and retail cut parts of turkeys (Day 112) in relation to the Control-fed turkeys. Furthermore, least white blood cell count and higher concentrations of packed cell volume, red blood cells and hemoglobin (P &lt; 0.01) were found in turkeys fed HNS on Days 84 and 112. Similarly, turkeys in the HNS group had improved serum constituents including serum protein, uric acid, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphate. The blood and meat lipid profile analysis showed that low density lipoprotein and total cholesterol were least (P &lt; 0.05) in turkeys fed HNS. Collectively, dietary high supplementation of niacin (180 mg/kg) improves production performances, reduces serum and meat fat content and improve indicators of stress resistance ability in growing turkeys.

Effects of aging on characteristics of breast meat from free-range broiler hens at 12 or 70 weeks of age

We evaluated the effect of broiler age and aging process on the meat characteristics of breast fillets from female free-range broilers slaughtered at 12 weeks of age (Wk12) and 70 weeks of age (Wk70). We used breast meat from female ISA Label (n = 60) broilers. Ten samples of each broiler age were aged in an incubator (2°C ± 0.5°C) for 3 and 7 days. Ten samples for each broiler age were analysed 4 h post-slaughter (Control group). Compared with breast meat from Wk12, breast meat from Wk70 showed higher shear force (30.52 N vs 27.19; P = 0.0322) and total collagen (4.33 g/kg vs 3.77 g/kg; P = 0.0149), which were reduced during aging to 15.49 N and 3.92 mg/100 g, respectively. The aging process did not affect the lipid oxidation of breast meat from Wk70. After aging for 3 days, breast meat from Wk70 had similar protein and fat contents to those of meat from Wk12 (21.29% and 1.04%, on average, respectively). Breast meat from Wk70 also showed lower concentrations of docosahexaenoic (0.32% vs 0.65%; P < 0.0001) and eicosapentaenoic (0.01% vs 0.12%; P < 0.0001) fatty acids than meat from Wk12. The use of free-range hen meat is beneficial to the industry because of the lower storage and cooking losses, which may influence the final yield, besides its lower polyunsaturated fatty acid concentration, which makes it less vulnerable to rancidification. Aging for at least 3 days at 2°C is satisfactory to promote the tenderisation of meat from free-range broiler hens.

Growth performance, carcass traits and meat quality of yellow-feathered broilers fed graded levels of alfalfa meal with or without wheat

The effects of 0, 40 and 80 g/kg alfalfa meal on growth performance, carcass traits and meat quality of Chinese yellow-feathered broilers fed diets containing or lacking wheat (0 or 200 g/kg) as part of the energy source, were examined using random design with a 2 × 3 factorial arrangement of treatments. Dressing percentage and semi-eviscerated proportion were lower, and meat color a* (redness) value was higher in birds fed diets containing wheat than diets lacking wheat (P < 0.05). Drip loss was reduced by the addition of alfalfa meal to diets containing or lacking wheat (P < 0.05). Average sensory score of breast meat was higher in chickens fed corn-based diets than in those fed wheat (P < 0.05). Meat from those supplemented with 40 g/kg alfalfa meal had better taste than the other two levels (P < 0.05). The inclusion of wheat significantly reduced the activities of creatine kinase and calpain of breast muscle (P < 0.05). In conclusion, Chinese yellow-feathered broilers fed diets containing wheat had better meat color and lower drip loss than those fed the diets without wheat, and adding 40 g/kg alfalfa meal generally improved meat quality and taste.

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.

Physical and chemical characteristics of spent hen breast meat aged for 7 days

Consumption of poultry meat is increasing worldwide. However, little is known about the consumption and acceptability of meat from older hens and about the physical and chemical characteristics of this type of meat. This study evaluated the effect of broiler age and aging time on the physical properties, tenderness, chemical composition, and lipid profile of breast meat from broilers slaughtered at 6 (commercial age) and 70 weeks of age (broiler hens). The variables analysed were: colour, pH, water-holding capacity, cooking weight loss, shear force, total collagen, myofibrillar fragmentation index, chemical composition, total cholesterol, lipid oxidation, and fatty acid profile. Compared with commercial broilers, meat from broiler hens had higher shear force (from 33.45 N to 14.91 N after 3 days of aging), higher fat content, and lower cholesterol concentration. Additionally, it had more monounsaturated fatty acids and less polyunsaturated fatty acids than meat from commercial broilers. Collagen, fat, cholesterol levels and myofibrillar fragmentation index decreased with aging. The use of broiler hen meat as a raw material may be beneficial to the poultry industry because it has more fat and less cholesterol, higher intracellular water-holding capacity, and lower cooking loss than meat from commercial broilers. Moreover, because of the lower concentration of polyunsaturated fatty acids, broiler hen meat is less susceptible to lipid oxidation. Aging breast fillets for 3 days at 2°C is sufficient to tenderise the meat and reduce the amount of fat and cholesterol, suggesting that aging can be used as a technique to add value to poultry meat products.

Comparison of fatty acid profile in the chicken meat after feeding with narasin, nicarbazin and salinomycin sodium and phyto-additive substances

The purpose of this study was an experimental investigation and a statistical evaluation of the influence of various additives in feed mixtures of broiler chickens on fatty acids content and their ratio in breast and thigh muscles. First feed additive consisted of narasin, nicarbasin and salinomycin sodium, and other five additives were of phytogenic origin. In vivo experiment was realized on the poultry experimental station with deep litter breeding system. A total of 300 one-day-old hybrid chickens Cobb 500 divided into six groups were used for the experiment. The experimental period was divided into four phases, i.e. Starter, Grower 1, Grower 2 and Final, according to the application of commercial feed mixture of soy cereal type. Additive substances used in feed mixtures were different for each group. Basic feed mixtures were equal for all groups. Fatty acid profile of breast and thigh muscles was measured by the method of FT IR Nicolet 6700. Investigated additive substances in the feed mixtures did not have statistically significant effect on fatty acid content and omega-6/omega-3 polyunsaturated fatty acid (PUFA) ratio in breast and thigh muscles. Strong statistically significant relation between omega-6 PUFAs and total PUFAs were proved by experiment. A relation between omega-3 PUFAs and total PUFAs was found only in the group with Biocitro additive.

Transfer of bioactive compounds from pasture to meat in organic free-range chickens

The aim of this study was to analyze the transfer of bioactive compounds from the pasture to the body and meat of organic free-range chickens and to verify the effect of these compounds on the oxidative processes of the meat. Starting at 21 d of age, 100 male naked-neck birds were divided into two homogeneous groups: an indoor group (0.12 m(2)/bird) and an outdoor group (0.12 m(2)/bird indoor and 10 m(2)/bird of forage paddock). At slaughter (81 d of age), blood samples were collected, and the carcasses were stored for 24 h at 4°C (20 birds/group). The grass samples had higher values of carotenoids, tocopherols, and flavonoids respect to standard feed (based on dry matter comparison). The polyunsaturated fatty acid ( PUFA: ) content was also greater in grass, especially the n-3 series (so named because its first double bond occurs after the third carbon atom counting from the methyl at the end of the molecule). The antioxidant profile of the grass improved the antioxidant status of the crop and gizzard contents in the outdoor chickens. The higher antioxidant intake resulted in a higher plasma concentration of antioxidants in outdoor birds; thiobarbituric acid reactive substances ( TBARS: ) and the antioxidant capacity of the plasma were also better in the outdoor than the indoor group. The meat of the outdoor birds had higher levels of antioxidants, mainly due to the higher amount of tocopherols and tocotrienols. Despite the higher antioxidant protection in the drumstick of the outdoor group, the TBARs value was greater, probably due to the kinetic activity of birds, the higher percentage of PUFAs, and the peroxidability index. In conclusion, grazing improved the nutritional value of the meat (PUFA n-3 and the ratio between n-6 and n-3 PUFA) with a minor negative effect on the oxidative stability. Suitable strategies to reduce such negative effects (e.g., reduction of kinetic activity in the last days of rearing) should be studied.

Effect of reduced dietary protein and supplementation with a docosahexaenoic acid product on broiler performance and meat quality

1. Chicken breast meat is a lean meat due to its low content of intramuscular fat (IMF) resulting in an overall lower acceptability by consumers due to a decrease in juiciness, flavour and increased chewiness. Recently, studies performed in pigs suggested the possibility of increasing IMF by decreasing dietary crude protein (CP) content, an effect possibly mediated through an increased lipogenesis. 2. Dietary supplementation with lipids rich in omega 3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) may modulate an increase in the content of these fatty acids in meat from monogastric animals and, thus, promote the daily intake of n-3 LC-PUFA by humans. 3. LC-PUFA are very susceptible to oxidation, resulting in off-flavours that affect meat quality and consumers' acceptability. 4. This trial was conducted to assess the effect of reducing dietary CP, from 21% to 17%, on chicken's meat IMF content and, simultaneously, to evaluate if a complementary supplementation with a proprietary n-3 LC-PUFA source (DHA Gold™) could improve meat quality. These effects were assessed by measuring productive performance and meat quality, oxidative stability, sensory traits and fatty acid profile. 5. A reduction in CP content of broiler diets, from 21% to 17%, balanced for lysine, improved performance while it was not sufficient to increase IMF content in chicken meat. In contrast, DHA Gold™ supplementation had a positive impact both in broiler productive parameters and in meat fatty acid profile. 6. In addition, incorporation of 7.4% of DHA Gold™ in the diet promoted carcass yield but negatively affected chicken meat acceptability by consumers, due to a decrease of meat oxidative stability. 7. Overall the data suggest that neither a dietary supplementation with DHA Gold™ nor a reduction in CP have a direct positive effect in the levels of IMF present in broiler meat.

Modification of Animal Products for Fat and Other Characteristics

This chapter includes information about modification of animal products using biotechnology and the importance of different modifications on the natural composition. The species considered for modified products include beef and dairy cattle, sheep, goats, poultry, and a wide variety of fishes. Moreover, the discussion includes the importance of animal food, nongenetically engineered animal modified food products, genetically engineered animal modified food items primarily for meat, milk, or egg and genetically engineered animal food along the transgenic approach for animal welfare. Modern biotechnology can improve productivity, consistency, and quality of alter animal food, fiber, and medical products. The transgenic technology is potentially valuable to alter characters of economic importance in a rapid and precise way. The food safety issue related to genetic engineering is also included in this chapter. The harm of such modified food and transgenic strategy should also be understood by the reader along with its advantages. In this context, transgenic approaches in animal biotechnology are under discussion that ranges from animal food production to their adverse effects.

Direct supplementation of diet is the most efficient way of enriching broiler meat with n-3 long-chain polyunsaturated fatty acids

1. Concentrations of beneficial omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) in poultry meat can be improved by increasing the concentration of n-3 PUFA in poultry diets. 2. A decrease in flavour quality is, however, usually associated with the dietary supplementation with n-3 PUFA, which is due to the susceptibility of PUFA to oxidation. 3. This experiment was conducted to study the effects of introducing two different n-3 fatty acid sources (extruded linseed and DHA Gold™, a proprietary algal product rich in docosahexaenoic acid), either separately or together, on broiler productive performance, and meat quality, oxidative stability, sensory traits and LC-PUFA profile. 4. Birds given the algal product displayed better productive performances than animals from other groups. 5. The data revealed an improvement in the fatty acid nutritional value of meat from birds receiving the algal product and an inefficient conversion of α-linolenic acid (LNA) into LC-PUFA. 6. Metabolisation of LNA in vivo is not sufficient to improve meat quality in n-3 LC-PUFA and direct supplementation of the diet with n-3 LC-PUFA is a better alternative to modulate an increase in beneficial fatty acids of broiler meat. 7. The overall acceptability of meat was negatively affected by the dietary supplementation with 7.4% of DHA, in contrast to the supplementation with 3.7% of DHA, which showed to be efficient in improving LC-PUFA meat content without affecting its sensory properties.

Effect of Conjugated Linoleic Acid Feeding on the Growth Performance and Meat Fatty Acid Profiles in Broiler: Meta-analysis

The effect of conjugated linoleic acid (CLA) feeding on growth performance and fatty acid profiles in thigh meat of broiler chicken was investigated using meta-analysis with a total of 9 studies. Overall effects were calculated by standardized mean differences between treatment (CLA fed) and control using Hedges’s adjusted g from fixed and random effect models. Meta-regression was conducted to evaluate the effect of CLA levels. Subgroups in the same study were designated according to used levels of CLA, CP levels or substituted oils in diets. The effects on final body weight, weight gain, feed intake and feed conversion ratio were investigated as growth parameters. Total saturated and unsaturated fatty acid concentrations and C16:0, C18:0, C18:2 and C18:3 concentrations in thigh meat of broiler chicken were used as fatty acid profile parameters. The overall effect of CLA feeding on final weight was negative and it was only significant in fixed effect model (p<0.01). Significantly lower weight gain, feed intake and higher feed conversion ratio compared to control were found (p<0.05). CLA feeding on the overall increased total saturated fatty acid concentration in broilers compared to the control diet (p<0.01). Total unsaturated fatty acid concentration was significantly decreased by CLA feeding (p<0.01). As for individual fatty acid profiles, C16:0, C18:0 and C18:3 were increased and C18:2 was significantly decreased by CLA feeding (p<0.01). In conclusion, CLA was proved not to be beneficial for improving growth performance, whereas it might be supposed that CLA is effective modulating n-6/n-3 fatty acids ratio in thigh meat. However, the economical compensation of the loss from suppressed growth performance and increased saturated fatty acids with the benefit from enhanced n-6/n-3 ratio should be investigated in further studies in order to propose an appropriate use of dietary CLA in the broiler industry.

Comparison of meat quality characteristics and oxidative stability between conventional and free-range chickens

The aim of this research was to evaluate quality traits and oxidative stability of meat products from free-range (FR) and conventionally (C) raised chickens as they actually reach consumers in the Italian retail market. Free-range female and male chickens (n = 1,500 + 1,500), medium growing ISA strain, were raised under commercial conditions for 56 (1.8 kg of live weight) and 70 d (3.1 kg of live weight), respectively; C female and male birds (n = 5,000 + 5,000) were a fast growing hybrid (Ross 708) and were separately raised for 39 (1.9 kg of live weight) and 50 d (3.1 kg of live weight), respectively. A total of 96 chickens (equally divided by production system and sex) were slaughtered in 2 separate sessions to obtain the main 2 commercial categories (rotisserie and cut-up, respectively). After slaughtering, 12 carcasses of each treatment group were randomly selected and used to assess quality properties, chemical composition, and oxidation stability of breast and leg meat. The C birds had dramatic higher carcass and breast meat yield, whereas FR had higher wing and leg yields. The FR birds exhibited higher water holding capacity in both breast and leg meat. Although shear force did not differ in breast meat, legs from FR birds were tougher. Fatty acid composition of FR breast and thigh meat of both categories were characterized by a higher polyunsaturated fatty acid n-6-/n-3 ratio. In general, a low lipid oxidation level (peroxide value < 1.3 mEq O2/kg of lipid and TBA reactive substances < 0.2 mg malondialdehyde/kg of sample) was found in breast and legs, regardless of the commercial category. However, the C system significantly increased peroxide value in rotisserie thigh meat, whereas FR led to a significantly higher TBA reactive substances in breast meat. Our results demonstrated that free range can modify the properties of chicken meat and also highlighted the importance of the bird genetic background to select nutritional strategies to improve meat quality traits and oxidative stability in poultry.