Effect of dietary α-linolenic acid and vitamin E on the fatty acid composition, storage stability and sensory traits of rabbit meat

The Use of Grape By-Products as a Feed Additive Enhances the Oxidative Stability of Rabbit Meat

The use of agro-industrial by-products in livestock nutrition is of increased interest to the feed industry. Some of the by-products are rich in bioactive compounds that could lead to an increase in the quality of animal meat products. This study aimed to evaluate the effects of dietary incorporation of grape pomace (GP), a by-product rich in polyphenols, on growth and on the oxidation status and the fatty acid profile of rabbit meat. Forty-eight male rabbits (Oryctolagus cuniculus) (aged 55 ± 3 d and ca 2.3 kg) divided into three groups of 16 were used in the trial. The rabbits were housed in pairs in wire-mesh cages (26 × 46 × 35 cm) giving n = 8 for each diet treatment. The first group was fed a basal diet (CTR) (ca 18% protein and ca 4% fat), the second was given a basal diet supplemented with 5 g GP per head per day (low-GP) and the third group was fed a basal diet supplemented with 10 g GP per head per day (high-GP). The trial lasted three weeks, and the animals were weighed weekly. The rabbits were slaughtered, and the weight and the pH of the carcasses was measured immediately after slaughter and after 24 h of cooling at 4 °C. The pH of the stomach and cecum was measured. A sample of Longissimus Dorsi (LD) was collected and stored at -80 °C for the analysis of proximate composition, thiobarbituric acid reactive substances (TBARs) and fatty acid profile (FA). The diet did not influence the growth or the pH of the stomach and cecum of the rabbits. The chemical composition of the meat was similar in all groups, with a mean protein of 22.3% and fat of 0.95%. The fatty acid profiles of the LD were not influenced by the diet, and the most abundant FAs were C16:0, C18:2n6 and C18:1c9. Feeding GP to the rabbits gave a linear decrease of TBARs in the meat, indicating a reduction in oxidative stress. The TBARs' reduction was 60% in the meat of the rabbits given high-GP compared to CTR. In conclusion, GP could be used in rabbit diets without any negative influence on meat quality but with an increase in oxidation stability that could enhance meat shelf-life.

Effects of Diets Containing Extruded Linseed and Padina pavonica Algae on Meat Rabbit: Carcass Performance and Meat Quality

This study investigated the effects of dietary supplementation with extruded linseed (ELS) and Padina pavonica algae extract (PP) on rabbit carcass and meat quality. Ninety-six rabbit carcasses from two production cycles were analyzed. In the first cycle (C1), rabbits were fed a control diet (1CNT), the same diet supplemented with 5% ELS (1ELS5%), and supplemented with 3.5% ELS and 0.2% PP (1LPP3.5%). In the second cycle (C2), the diets varied in composition and supplementation levels: a different control diet (2CNT), the same diet with 5% ELS (2ELS5%), and with 5% ELS and 0.2% PP (2LPP5%). Meat analyses were performed on Longissimus thoracis et lumborum (LTL) muscle for physical properties and on thigh meat (THM) for proximate composition, vitamin E, coenzyme-Q10, cholesterol, fatty acid profile, and mineral content. No significant differences in LTL physical quality were observed in C1, although LTL was brighter in C2 (p < 0.001). THM in C2 had higher fat content (p < 0.001). Dietary supplementation with ELS and PP extract significantly increased polyunsaturated fatty acids (n-3 PUFAs) and improved the n-6/n-3 ratio (p < 0.001) in rabbit meat, demonstrating their positive impact on meat quality.

Higher Oxygen Content Affects Rabbit Meat's Quality and Fatty Acid Profile in a Modified Atmosphere

After 7 days of storage, the quality of the meat packed in both systems (MAP and VAC) was satisfactory; however, after 14 and 21 days, there was a noticeable decline in quality, as evidenced by changes in the water percentage and color parameters (L∗, a∗, and b∗). However, muscles stored in the MAP1 had the highest tenderness. The results indicated that as the storage time increased (up to 21 days), the share of C14:0 (P < 0.001) and C16:0 (P < 0.001) acids in the fat of the LTL muscles decreased. Only the share of C18:0 (P = 0.001) and C20:1 (P = 0.015) acids was significantly influenced by the packaging method. The highest iodine level was found in MAP1 21 days after packaging (85.68). The ratio of n-6/n-3, PUFA/SFA, AI, and TI indexes, which indicate a higher nutritional quality of fat, varied only with storage time without being affected by the gas mixture (P > 0.05). The H/H level differed significantly with the storage time (P < 0.001), with no effect of the gas mixture (P = 0.133). After the 21-day storage period, the controlled atmosphere led to an increase in the concentration of MUFA and PUFA and a decrease in SFA, according to the study of the fatty acid profile.

Dietary supplementation with n-3 polyunsaturated fatty acids: Effects on reproductive and productive performance and meat quality in rabbit breeding

Rabbit breeding has many critical aspects related to reproduction, production, and animal welfare, which reduce its profitability as well as consumer attractiveness. Dietary supplementation with n-3 polyunsaturated fatty acids (PUFA) seems to be a good nutritional strategy to improve several aspects of rabbit breeding, enhance animal welfare and produce a new functional food considered healthy for human consumption. For this reason, the main available scientific research regarding the physiological effects of n-3 PUFA rich products supplemented to the rabbit diet will be reviewed. In particular, consequences on the reproductive performances of both doe and buck, the productive parameters, and the meat quality will be analysed.

Chlamydomonas agloeformis from the Ecuadorian Highlands: Nutrients and Bioactive Compounds Profiling and In Vitro Antioxidant Activity

Green microalgae are single-celled eukaryotic organisms that, in recent years, are becoming increasingly important in the nutraceutical, cosmetic, and pharmaceutical fields because of their high content of bioactive compounds. In this study, a particular green microalga was isolated from freshwater highland lakes of Ecuador and morphologically and molecularly identified as Chlamydomonas agloeformis (ChA), and it was studied for nutritional and nutraceutical properties. The phenolic composition and the fatty acids profile of lyophilized cells were determined. The methanolic extract was analyzed for the phenolic compounds profile and the antioxidant capacity by means of in vitro tests. Finally, Human Microvascular Endothelial Cells (HMEC-1) were exploited to explore the capacity of ChA to reduce the endothelial damage induced by oxidized LDL-mediated oxidative stress. The extract showed a good antioxidant ability thanks to the high content in polyphenolic compounds. The observed decrease in HMEC-1 cells endothelial damage also was probably due to the antioxidant compounds present in the extract. Based on the outcomes of our in vitro assays, ChA demonstrated to be a promising source of bioactive compounds possessing exceptional antioxidant capacities which make it a prospective functional food.

In Vitro Characterization of Antioxidant, Antibacterial and Antimutagenic Activities of the Green Microalga Ettlia pseudoalveolaris

Recently, green microalgae have gained importance due to their nutritional and bioactive compounds, which makes them some of the most promising and innovative functional foods. The aim of this study was to evaluate the chemical profile and the in vitro antioxidant, antimicrobial and antimutagenic activity of an aqueous extract of the green microalga Ettlia pseudoalveolaris, obtained from the freshwater lakes of the Ecuadorian Highlands. Human microvascular endothelial cells (HMEC-1) were used to determine the ability of the microalga to reduce the endothelial damage caused by hydrogen peroxide-induced oxidative stress. Furthermore, the eukaryotic system Saccharomyces cerevisiae was used to evaluate the possible cytotoxic, mutagenic and antimutagenic effect of E. pseudoalveolaris. The extract showed a notable antioxidant capacity and a moderate antibacterial activity mostly due to the high content in polyphenolic compounds. It is likely that the antioxidant compounds present in the extract were also responsible for the observed reduction in endothelial damage of HMEC-1 cells. An antimutagenic effect through a direct antioxidant mechanism was also found. Based on the results of in vitro assays, E. pseudoalveolaris proved to be a good source of bioactive compounds and antioxidant, antibacterial and antimutagenic capacities making it a potential functional food.

Nutritional significance and health benefits of omega-3, -6 and -9 fatty acids in animals

The balance between omega-3 (ω-3), omega-6 (ω-6) and omega-9 (ω-9) fatty acids (FAs) is very important because these types of oils constitute essential components for the formation of the cell membrane, also they are precursors for a large number of substances in the body. One of the most important strategies for improving the increment of polyunsaturated FAs in poultry and animal meat is the dietary administration of these FAs. Additionally, the different sources of ω-3 or 6 in the diet improve the performance, public health and physiological aspects including anti-oxidative properties and immunity. ω-3 FAs have anti-inflammatory characteristics due to their ability to reduce cytokines liberation. High-level of ω-6 FAs is always associated with an increased incidence of dangerous disorders like depression and heart disease. These FAs showed a tremendous series of beneficial impacts like improved cholesterol levels and a decreased occurrence of coronary heart diseases. This article includes some information on the use of ω-3, ω-6 and ω-9 FAs in animal and human diets. These oils are vital for the physiological and health aspects, and the information mentioned here will improve our understanding of the functions and roles of these FAs in the body.

The Effect of the Housing System, Season and the Linseed Oil Ethyl Esters Additive on Selected Blood Parameters in Rabbits

The composition of the diet, including the amount and type of lipid supplements, influences the products formed in the digestive tract, their levels in the blood and their deposition in the tissues. One example of a plant rich in polyunsaturated fatty acids is flax (Linum usitatissimum). The aim of the presented work was to evaluate the effect of the linseed oil ethyl esters additive and environmental conditions on the selected rabbit blood parameters. The study included two types of animal maintenance (laboratory conditions and external conditions) and two seasons (summer and winter), a total of four study stages. At each stage, a control group and an experimental group were specified. The feed supplement in the form of esterified linseed oil was administered to the experimental animals for two months. The blood samples were collected at the beginning of the experiment, as well as at the end of treatment. Moreover, blood samples were collected also after two months from the end of the experiment. During the experiment, morphological and biochemical parameters of the rabbits’ blood were examined. The results of the content of fatty acids were determined in the erythrocytes and serum blood samples and grouped into saturated and unsaturated fatty acids, especially omega-3 and omega-6 fatty acids. In an internal study, the influence of housing conditions and season on selected morphological and biochemical parameters of rabbit blood was confirmed. Furthermore, expected beneficial changes in the fatty acid profile in erythrocytes and blood serum were observed as a result of supplementation. A significant increase in omega-3 fatty acids was noted as well as a substantial decrease in the ratio of omega-6 to omega-3 fatty acids (p < 0.01). Most importantly, the linseed oil ethyl ester supplement used did not adversely affect the health of the rabbits, as evidenced by biochemical and blood morphological indices remaining within, known so far, reference limits or showing only slight fluctuations (p > 0.05). However, the obtained results extend the database of hematological blood parameters in rabbits, thus, contributing to improvements in laboratory diagnostics for fur animals.

Dietary Plukenetia conophora seed alters muscle cholesterol, antioxidant enzymes, and fatty acids in growing rabbits

The influence of dietary inclusion of Plukenetia conophora seed (PCS) on growth, carcass, muscle antioxidant enzymes, fatty acids, meat quality, and sensory attributes of Longissimus thoracis et lumburum muscle in rabbits was examined. Seventy-two, 28 d old male New Zealand rabbits (750 ± 20 g) were randomly allotted to diets containing either no PCS (PCS-0), 2.5% PCS (PCS-2.5) or 5% PCS (PCS-5) for eight weeks, and euthanized. PCS-5 rabbits had higher (P < 0.05) body and carcass weights than the PCS-0 rabbits. Dietary PCS improved feed efficiency in rabbits. Muscle antioxidant enzymes activities and total phenols were higher while muscle cholesterol was lower (P < 0.05) in supplemented meat than the PCS-0 meat. The concentration of C22:6n-3, C20:5n-3 and C18:3n-3 was higher (P < 0.05) in the supplemented meat than the PCS-0 meat. Sensory attributes, carbonyl, and TBARS values and physicochemical properties of meat did not differ among diets. Supplementation of PCS-5 enhances muscle n-3 fatty acids without impairing the sensory properties, and oxidative stability of rabbit meat.

Poultry Meat and Eggs as an Alternative Source of n-3 Long-Chain Polyunsaturated Fatty Acids for Human Nutrition

The beneficial effects of n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) on human health are widely known. Humans are rather inefficient in synthesizing n-3 LC-PUFA; thus, these compounds should be supplemented in the diet. However, most Western human diets have unbalanced n-6/n-3 ratios resulting from eating habits and the fact that fish sources (rich in n-3 LC-PUFA) are not sufficient (worldwide deficit ~347,956 t/y) to meet the world requirements. In this context, it is necessary to find new and sustainable sources of n-3 LC-PUFA. Poultry products can provide humans n-3 LC-PUFA due to physiological characteristics and the wide consumption of meat and eggs. The present work aims to provide a general overview of the main strategies that should be adopted during rearing and postproduction to enrich and preserve n-3 LC-PUFA in poultry products. The strategies include dietary supplementation of α-Linolenic acid (ALA) or n-3 LC-PUFA, or enhancing n-3 LC-PUFA by improving the LA (Linoleic acid)/ALA ratio and antioxidant concentrations. Moreover, factors such as genotype, rearing system, transport, and cooking processes can impact the n-3 LC-PUFA in poultry products. The use of a multifactorial view in the entire production chain allows the relevant enrichment and preservation of n-3 LC-PUFA in poultry products.

The Effect of the Season, the Maintenance System and the Addition of Polyunsaturated Fatty Acids on Selected Biological and Physicochemical Features of Rabbit Fur

Simple Summary

Rabbit furs are a valuable material used in the fur industry. Many studies show beneficial effects of omega-3 acids supplementation on the skin and coat of animals. The aim of the study was to show the impact of environmental conditions and dietary supplementation with ethyl esters of linseed oil on the quality of the rabbit hair coat. The experiment was carried out in four stages: laboratory (summer and winter) and outdoor (summer and winter). The experimental rabbits were given an addition of ethyl linseed oil to their feed (during 2 months). To assess biological and physico-mechanical properties of the coat samples and to determine fatty acid profile and histological evaluation, the hair samples were collected three times: before the study, after two months of treatment, and after two months from the end of supplementation. The obtained results show that the environmental conditions have a major impact on the quality of the rabbit coat. The best results of hair heat protection were obtained from animals kept outdoors. Administration of linseed oil ethyl esters had a positive effect on the hair fatty acid profile.

Abstract

The aim of the study was to show the impact of environmental conditions and dietary supplementation with ethyl esters of linseed oil on the quality of the rabbit hair coat. The research was divided into 4 stages: laboratory (summer and winter) and outdoor (summer and winter). In each stage of the research, animals were divided into control and experimental groups. The animals were fed in accordance with the feeding standards of reproductive rabbits during the period of sexual dormancy. The rabbits from the experimental groups during the first two months were given an addition of ethyl linseed oil to the feed. In the experiment, linseed oil was cold-pressed directly in the laboratory. Three samples of hair were collected: before the study, after two months of treatment, and after two months from the end of supplementation. The hair coat biological properties, such as share of individual hair fractions (%), heat transfer index (HTI), hair diameter (μm), as well as physico-mechanical properties such as breaking force (N), breaking stress (kg/cm²) and elongation (%) were performed. Moreover, the histological structure of hair and histological hair evaluation were performed. The fatty acid profile was determined in the hair as well. The obtained results of the content of individual fatty acids were grouped into saturated fatty acids and unsaturated fatty acids. In addition, omega-3 and omega-6 were distinguished from the group of unsaturated acids. The environmental conditions have a major impact on the quality of the rabbit coat. The best results of hair thickness and their heat protection were obtained from animals kept outdoors. The studies did not show an influence of the administered preparation on the quality of the rabbit coat. The hair became thinner, but more flexible and tear-resistant. Administration of linseed oil ethyl esters had significant, beneficial changes in the fatty acid profile in hair and hair sebum were observed. There was a significant increase in omega-3 acids, and a significant decrease in the ratio of omega-6 to omega-3 acids.

Tissue Antioxidant Status and Lipid Peroxidation Are Related to Dietary Intake of n-3 Polyunsaturated Acids: A Rabbit Model

Polyunsaturated fatty acid (PUFA) metabolism and tissue distribution is modulated by the oxidation of these molecules. This research aimed to investigate the implication of dietary n-3 PUFA supplementation (precursor and long-chain PUFA) on the PUFA profile and oxidative status of the liver, testis, and brain of adult rabbit bucks. Twenty New Zealand White rabbit bucks were divided into four experimental groups (n = 5 per group) and were fed different diets for 110 days: control (CNT), standard diet containing 50 mg/kg alpha-tocopheryl acetate (vitamin E); CNT+, standard diet + 200 mg/kg vitamin E; FLAX, standard diet + 10% flaxseed + 200 mg/kg vitamin E; or FISH, standard diet + 3.5% fish oil + 200 mg/kg vitamin E. Antioxidants (enzymatic and non-enzymatic), oxidative status (malondialdehyde and isoprostanoids), and n-3 and n-6 PUFAs of tissues were analysed. A chain mechanism of oxidant/antioxidant molecules, which largely depended on the particular PUFA composition, was delineated in the different organs. The liver showed an oxidant/antioxidant profile and lipid pathways widely modulated by PUFA and vitamin E administration; on the other hand, the testis' oxidative profile rather than its lipid profile seemed to be particularly affected, an outcome opposite to that of the brain (modulation operated by dietary PUFA).

Effect of the type of packaging on the shelf life of ground rabbit meat

Rabbit meat consumption has increased worldwide due to its health benefits in humans but few studies addressed the stability of this food matrix. The effect of two types of packaging (vacuum, VP; and polystyrene tray overwrap with PVC/polyvinyl plastic film, PT) was evaluated on the microbial stability (psychrotrophic; PSY, lactic acid bacteria; LAB, initial coliforms counts) and physicochemical (pH, thiobarbituric acid reactive substances (TBARS), total volatile basic Nitrogen (TBV-N), color and drip loss) changes of ground rabbit meat during its storage at 4 ± 1 °C. VP packaging delayed PSY growth, lipid oxidation, protein degradation and undesirable color changes compared to PT samples. Shelf life of ground rabbit meat in vacuum condition could be around 10 days of storage, while PT samples presented a shorter shelf life of around 5 days. However, sensory studies must be performed in order to assure the exact shelf life of the final product.

The Composition of Fatty Acids in Ostrich Meat Influenced by the Type of Packaging and Refrigerated Storage

Ostrich meat is a high-quality dietetic product, however, it is very sensitive to deterioration during storage. The aim of this study was to assess the effect of packaging systems on the fatty acid (FA) profiles in ostrich meat during refrigerated storage. The systems were: Vacuum packaging (VP) and modified atmosphere packaging (MAP) in two combinations of gases: MAP1 (40% O₂/40% CO₂/20% N₂) and MAP2 (60% O₂/30% CO₂/10% N₂). Samples were taken from the M. ilifibularis (IF) muscles of eight ostriches in each treatment group. The packs were stored in a refrigerator at 2 °C and analyzed at 0, 4, 8, 12 and 16 days. The packaging conditions and storage time had an impact on the concentration of bioactive compounds such as polyunsaturated fatty acids (PUFA), including n-3 such as C18:3, C20:5 (EPA) and C22:6 (DHA). The least changes in composition of n-3 and the sum of PUFA were recorded in ostrich meat packaged in vacuum, followed by that packaged using MAP1 and MAP2. The sum of n-6 PUFAs decreased significantly by 2.1% for MAP2, and only by 0.7% for vacuum packaging as the experiment progressed. A significant deterioration of these compounds was observed in all package systems, especially from day 12 until day 16 of storage.

Effects of dietary levels of brown seaweeds and plant polyphenols on growth and meat quality parameters in growing rabbit

Growth performances, carcass characteristics and meat quality parameters from growing rabbit fed with two levels of dietary brown seaweed (Laminaria spp) and plant polyphenols were investigated. One hundred and forty-four New Zealand White rabbits were allotted into three dietary treatments containing 0 (C), 0.3% (T1), and 0.6% (T2) of brown seaweed and plant polyphenols mixture for 42 days. Growth performances and carcass weight were improved in T1 group. Vitamin A and E content in Longissimus thoracis and lumborum (LTL) and Semimembranosus (SM) muscle were enhanced in the treated groups. In the SM muscle, the oxidative stability was improved in rabbit fed with both dosages of dietary supplement, and the cholesterol content tended to be lower in T1 than in T2 and C groups. The LTL and SM muscle sensory characteristics were improved. In conclusion, dietary integration with a low dosage of brown seaweed and plant polyphenols is a valid strategy for enhance growth performance and produce healthier rabbit meat.

The Effect of Substitution of Palm Fat with Linseed Oil on the Lipid Peroxidation, Antioxidative Capacity and Intestinal Morphology in Rabbits (Oryctolagus cuniculus)

Simple Summary

By changing the source of fat in the diet of animals, the fat content of animal products, such as meat, could be improved. The addition of linseed oil, with a high proportion of polyunsaturated fatty acids, especially n-3 α-linolenic acid, is often used in animal nutrition. Rabbit diet manipulation is effective in increasing or changing the level of fatty acids such that meat could become a functional food for humans. Since polyunsaturated fatty acids are susceptible on oxidation, an effect on animal health could arise. Therefore, we conducted a trial replacing palm fat (saturated fatty acids) with linseed oil (polyunsaturated fatty acids) in the rabbit diet to compere the oxidative status and histology of intestinal tissues. There was no significant effect in the substitution of linseed oil on the malondialdehyde concentration in urine and plasma, antioxidative capacity of water soluble or lipid soluble antioxidants, or intestinal morphology. Therefore, with an appropriate dietary strategy, the content of rabbit meat can be improved without reducing animal welfare.

Abstract

This experiment was conducted to investigate the effect of different dietary fatty acids (saturated or polyunsaturated fatty acids) supplementation on the oxidative status and intestinal morphology of adult rabbits (Oryctolagus cuniculus). Twenty-four “slovenska kunka” rabbits were randomly assigned to two different dietary treatments (12 rabbits per treatment) and fed the experimental diets between 80 and 102 days of age. The palm fat (PALM) diet with 6% palm fat and linseed (LINSEED) diets with 6% linseed oil were used. To evaluate the oxidative status of rabbits, the malondialdehyde concentration in urine and plasma and concentration of water and lipid soluble antioxidants in plasma were measured. The antioxidative capacity of the gastrointestinal tract was evaluated by measuring concentration of water and lipid soluble antioxidants in tissues and contents of the intestine. The histological structure of the small intestine and caecum was analyzed via histomorphometric analysis. No significant differences were found in either of those parameters. In summary, rabbits were exposed to high levels of polyunsaturated fatty acids with a high predisposition to oxidation, but their health and welfare were not endangered.

Effects of vitamin and mineral premix withdrawal from diets on carcass and meat quality of feedlot steers

The primary objective of the present study was to assess the effects of vitamin and mineral premix (VMP) withdrawal from the diets 30 and 60 days ahead of slaughter on carcass and meat quality of Holstein Friesian steers. A total of 45 animals at 16 to 17 months of age were used and the selected animals were divided into three experimental groups: control group (fed with a diet with VMP), VMP withdrawal 30 days ahead of slaughter (VMP30 group), and VMP withdrawal 60 days ahead of slaughter (VMP60 group). Meat samples were taken at 24 h postmortem from the 13th rib section and meat quality was evaluated on the Longissimus dorsi thoracis (LT) muscle. After slaughter, carcass yield and meat drip loss, cooking loss, thawing loss, and shear force traits were determined. Meat pH and color parameters were measured at 24, 48, 72, 96, 120, and 144 h of postmortem. The fatty acid composition in 13th rib section' adipose tissue was determined. The hot and cold carcass weights, carcass yield and chilling loss were not affected by the withdrawal of VMP from the diet. Withdrawal of VMP from the diets 30 and 60 days ahead of slaughter did not have any significant effects on ultimate pH, drip loss, cooking loss, thawing loss, shear force, and meat color. Additionally, dry matter, crude protein, ash, fat contents, moisture-protein ratio of the meat samples, and fatty acid profiles were not affected by VMP30 and VMP60 treatments. It was concluded based on present finding VMP could be withdrawn safely from the diets 30 and 60 days ahead of slaughter without any negative effects on carcass and meat quality traits of feedlot steers. Withdrawal of VMP may reduce feeding costs and environmental damages generated by animal breeding systems.

Rabbit metabolic response and selected meat quality traits: Evaluation of dietary PLX® 23 and LycoBeads® feed supplement

Effects of dietary supplementation of verbascoside and lycopene, alone and in combination, on some blood parameters, plasma oxidative status and meat quality traits in intensively reared rabbits were investigated. The test lasted 60 days and was conducted on 200 weaned-rabbits, divided into four groups of 50 animals each (5 animals each cage × 10 repetitions). The control group (CON) received a fattening feed without any feed supplements, whereas the experimental groups received the following: the first, an integration in 22 g of PLX^® 23 (Lippia citriodora extract; VB group) per ton of feed; the second, an integration in 100 g of LycoBeads^® (Solanum lycopersicum extract; LIC group) per ton of feed; and the third, an integration of both feed supplements in combination at the same doses (LIC+VB group). The dietary supplementation with Lippia citriodora and Solanum lycopersicum resulted in an improvement of the blood lipid profile, oxidative plasma markers, and hepatic and renal activity of treated growing rabbits. Feed additives also produced meat with a lower content in SFA and an increased PUFA content, and inhibited the lipid oxidation improving the oxidative stability of rabbit meat. The dietary supplementation, even reporting no effects on productive parameters and carcass yield, showed an improvement on several blood parameters, as indicator of animal welfare, and on quality and healthy meat markers.

Comparative evaluation of the quality and fatty acid profile of meat from brown hares and domestic rabbits offered the same diet

Since animal diets have a strong influence on meat quality, a comparative study on farmed brown hares and domestic rabbits offered the same diet was undertaken to assess the physical and chemical properties of their meat. Ten brown hares and ten domestic rabbits were used to characterize the traits of meat from the foreleg, hind leg, and Longissimus lumborum muscles. The study indicated higher protein content in hare meat than in rabbit meat. The meat of hares had a concentration of heme iron that was more than twice as high as that of rabbits. Lower SFA and MUFA content and higher PUFA content contributed to the superior PUFA/SFA ratio in hares. An unfavorable n-6/n-3 ratio but superior atherogenic and thrombogenic indices was observed for hare meat. The higher TBARS of hares indicated a higher susceptibility of hare meat to lipid oxidation. Hare meat was also characterized by a higher water holding capacity and higher color indices (redness and chroma).

Effect of diet and packaging system on the oxidative status and polyunsaturated fatty acid content of rabbit meat during retail display

The aim of this study was to evaluate the combined effect of two dietary lipid sources (sunflower vs. linseed oil) and three packaging methods (PVC film - BAG vs. modified atmosphere CO₂ 20% + 80% O₂ - MAP vs. and vacuum - VAC) on the oxidative status and polyunsaturated fatty acid content of rabbit loins (Longissimus thoracis et lumborum muscle), at days 1, 4 and 10 of simulated retail display. The diet, storage time and packaging method affected the oxidative status of rabbit meat under retail display. As expected, storage time, independently on the other factors, significantly reduced the antioxidant content of loin meat. Accordingly, TBARs values significantly increased during storage, as well as the dietary supplementation of linseed. The fatty acid profile of the fresh loin closely respected that of the diets. At day 10, oxidative status and fatty acid profile of MAP samples could be yet considered optimal.

Increasing meat product functionality by the addition of milled flaxseed Linum usitatissimum

BACKGROUND

Functional meat products are still rare on the market because it is difficult to incorporate new ingredients and obtain both a healthy and acceptable product. Flaxseed is known for its beneficial properties and, in the present study, it was used as an ingredient in the production of homogenised and liver sausages (0%, 5% and 10% flaxseed addition).

RESULTS

Homogenised and liver sausages with the addition of 5% flaxseed were given the highest scores by the consumers, although the colour changed with the addition of flaxseed. The spreadability and hardness of the liver sausages increased with the addition of flaxseed, whereas the texture of homogenised sausages did not change. Addition of flaxseed improved the fatty acids profile from a health point of view for both products, as a result of increasing n-3 fatty acids and overall polyunsaturated fatty acids content. Values for thiobarbituric acid reactive substances were higher in products with flaxseed and were observed to increase during storage.

CONCLUSION

The results of the present study indicate that it is possible to obtain products that are acceptable by consumers and, at the same time, are more healthy. A high level of α-linolenic acid in the sausages at a level of addition of 5% allows the product to be labelled with information regarding their high omega-3 fatty acid content. However, those products are more susceptible to oxidation. © 2016 Society of Chemical Industry.

Influence of Dietary Supplementation with Prebiotic, Oregano Extract, and Vitamin E on Fatty Acid Profile and Oxidative Status of Rabbit Meat

The effect of dietary supplementation with vitamin E, oregano, and prebiotic on fatty acids and oxidative profiles of rabbit meat (loin and hind leg) was evaluated. New Zealand white rabbits weaned at 30 days of age were fed with one of six diets until 80 days of age: standard diet includingω3 polyunsaturated fatty and conjugated linolenic acids sources (S) and five diets adding vitamin E (150 ppm, E), oregano water extract (2 g/kg feed diet, O), prebiotic (THEPAX® 1.5 g/kg feed diet, T), vitamin E plus prebiotic (TE), and oregano water extract plus prebiotic (TO), respectively. The lipid oxidative status (TBARS) showed lower values with respect to S, mainly when vitamin E was administered. In particular, all the experimental diets decreased TBARS values with respect to the control group in the loin, but no effect was found in the hind leg. In all feed samples, the amounts of fatty acid classes increased in the following order: polyunsaturated fatty acids > monounsaturated fatty acid > saturated fatty acid. The dietary supplementations did not affect the fatty acid composition of meat. The experimented diets compared to the control were not able to provide a selective increase of bioactive fatty acid in meat samples; however, the six nutritional strategies led to highly nutritional rabbit meat with an interesting value of theω6/ω3 ratio.

Effect of a dietary supplementation with linseed oil and selenium to growing rabbits on their productive performances, carcass traits and fresh and cooked meat quality

The present experiment tested a dietary supplementation with linseed oil and selenium to growing rabbits. The basal diet (B) contained 3% sunflower oil, while it was substituted with 3% linseed oil in the experimental feed (S). The selenium (Se) content of the two diets was 0.10 vs. 0.46 mg/kg. Rabbits were fed with B diet from the age of 18 days. One group was fed with the B diet until 11 weeks of age (group B), whereas the experimental groups were fed with S diet for 1, 2, 3 or 4 weeks (groups S1, S2, S3 and S4, respectively), before slaughtering (11 weeks of age). Live performance and carcass traits of rabbits, fatty acid (FA) profile and selenium content of their hind leg (HL) and Longissimus thoracis et lumborum (LTL) meat were considered in this study. In addition, the effect of two different cooking methods on the nutritional value of the enriched HL meat was also assessed. The tested dietary supplementation only minimally affected the live performance and carcass traits of rabbits. The S supplementation significantly reduced the Σ n-6 FA and increased the Σ n-3 FA of the HL meat and LTL meat, compared to the B diet (p < 0.001); thus, n-6/n-3 ratio was improved (p < 0.001). In addition, HL meat and LTL meat of S fed rabbits were significantly enriched in Se reaching a twofold increase in both meat cuts (p < 0.01). Therefore, the S supplementation improved the functional value of the rabbit meat. The heat treatment affected cooking loss, Se and vitamin E contents as well as the oxidative status of the HL meat (p < 0.001), with the different cooking methods providing different results. In addition, even if the beneficial C20:5 n-3 and C22:6 n-3 decreased with cooking, the n-6/n-3 ratio remained unaffected.

Dietary <i>Lippia citriodora</i> extract in rabbit feeding: effects on quality of carcass and meat

Abstract. Due to consumer demand, in recent years considerable attention has been focused on the use of natural compounds in animal feed. The aim of this study was to evaluate the effect of dietary natural extract from Lippia citriodora (commonly named "limoncina"), titrated in verbascoside, on quality, measured as oxidative stability, fatty acid composition, alpha-tocopherol and retinol content and sensory traits of rabbit meat. Forty-five New Zealand white rabbits were randomly assigned to three age- and body-weight-balanced feeding groups of 15 animals each in which a conventional pelleted diet (CON) was supplemented with 1 or 2 kg t−1 (low natural-extract (LNE) and high natural-extract (HNE) groups, respectively) of Lippia citriodora extract for 55 days. No influence on carcass characteristics and the chemical composition of meat was observed. A trend for a positive effect on alpha-tocopherol tissue content (P = 0.07) and on thiobarbituric reactive substance (TBARS) values was observed (P = 0.063) in Longissimus Lumborum muscle from the HNE group. The fatty acid profile of the meat was affected by dietary treatment with a significant decrease (P = 0.001) in saturated fatty acids and an increase (P = 0.01) in polyunsaturated fatty acids in both treated groups compared to the CON group. The supplementation with natural extract at the highest dosage improved the tenderness and juiciness of meat, highlighting a better consistency than CON and LNE groups. In conclusion, this study shows that the natural extract used has the potential to improve rabbit meat in order to produce functional food, without altering the chemical and physical characteristics of meat.

The quality of carp (Cyprinus carpio L.) cultured in various Polish regions

BACKGROUND

Although environmental factors greatly affect the quality of carp meat, no regulations impose labelling the place of cultivation of freshwater fish. That is why the purpose of this study was to determine the quality of carp meat cultivated in several regions of Poland as well as to assess the necessity of implementing such regulations.

RESULTS

The influence of the cultivation region on colour, nutrition value, health safety and sensory quality of carp meat was assessed. The analysis included colour measurement, determination of fatty acid profile and sensory evaluation of carp muscle. Moreover, microbiological analysis of the fish surface was performed. The results show that the place of cultivation does not influence the lightness (L*) of fillet, but has an impact on other colour parameters (a*, b*). The microbiological quality of fish from all studied farms was satisfactory, since no pathogenic microorganisms were observed on the fish surface. The fatty acid profile was fairly varied (P < 0.01), depending on the place of cultivation.

CONCLUSION

Since final results seem ambiguous, further analyses of quality features of carp from various regions and cultures should be performed, before any recommendation for the necessity of labelling the place and method of cultivation should be suggested.

Growth performance, meat quality and Fatty Acid metabolism response of growing meat rabbits to dietary linoleic Acid

An experiment was conducted to determine the effects of different amounts of dietary linoleic acid (LA) on growth performance, serum biochemical traits, meat quality, fatty acids composition of muscle and liver, acetyl-CoA carboxylase (ACC) and carnitine palmitoyl transferase 1 (CPT 1) mRNA expression in the liver of 9 wks old to 13 wks old growing meat rabbits. One hundred and fifty 9 wks old meat rabbits were allocated to individual cages and randomly divided into five groups. Animals in each group were fed with a diet with the following LA addition concentrations: 0, 3, 6, 9 and 12 g/kg diet (as-fed basis) and LA concentrations were 0.84, 1.21, 1.34, 1.61 and 1.80% in the diet, respectively. The results showed as follows: the dietary LA levels significantly affected muscle color of LL included a* and b* of experimental rabbits (p<0.05). The linear effect of LA on serum high density lipoprotein cholesterol was obtained (p = 0.0119). The saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) contents of LL decreased and the polyunsaturated fatty acids (PUFAs) content of LL increased with dietary LA increase (p<0.0001). The PUFA n-6 content and PUFA n-3 content in the LL was significantly affected by the dietary LA levels (p<0.01, p<0.05). The MUFAs content in the liver decreased and the PUFAs contents in the liver increased with dietary LA increase (p<0.0001). The PUFA n-6 content and the PUFA n-6/n-3 ratio in the liver increased and PUFA n-3 content in the liver decreased with dietary LA increase (p<0.01). The linear effect of LA on CPT 1 mRNA expression in the liver was obtained (p = 0.0081). In summary, dietary LA addition had significant effects on liver and muscle fatty acid composition (increased PUFAs) of 9 wks old to 13 wks old growing meat rabbits, but had little effects on growth performance, meat physical traits and mRNA expression of liver relative enzyme of experimental rabbits.

Dietary Spirulina (Arthrospira platensis) and Thyme (Thymus vulgaris) supplementation to growing rabbits: effects on raw and cooked meat quality, nutrient true retention and oxidative stability

The study evaluated the effect of Spirulina and Thyme dietary supplementation on rabbit meat quality, nutrient true retention and protection against oxidative stress. Rabbits in the control group (C-C) received a non-supplemented pellet throughout the experiment (5-11weeks of age). In the other groups, the pellet contained 5% Spirulina (S), 3% Thyme (T), or both (ST) for either the entire (groups S-S, T-T, ST-ST) or only the final part of the growing period (8-11weeks: groups C-S, C-T, C-ST). Spirulina supplementation increased the γ-linolenic acid content of rabbit meat, whereas Thyme improved the oxidative stability of raw and freeze-dried meat.