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.     

Dietary supplementation with pioglitazone hydrochloride and l-carnosine improves the growth performance,muscle fatty acid profiles and shelf life of yellow-feathered broiler chickens

The present study aimed to investigate the effects of dietary pioglitazone hydrochloride (PGZ) and l-carnosine (LC) supplementation on the growth performance, meat quality, antioxidant status, and meat shelf life of yellow-feathered broiler chickens. Five hundred broiler chickens were randomly assigned into 4 experimental diets using a 2 × 2 factorial arrangement with 2 PGZ supplemental levels (0 and 15 mg/kg) and 2 LC supplemental levels (0 and 400 mg/kg) in basal diets for 28 d. The feed-to-gain ratio decreased whereas the average daily gain increased with PGZ supplementation. Greater dressing percentages, contents of intramuscular fat (IMF) in breast and thigh muscles, C18:3n-6, C18:1n-9 and monounsaturated fatty acid (MUFA) percentages of thigh muscle were observed with PGZ addition. Additionally, significant synergistic effects between PGZ and LC on the C18:1n-9 and MUFA contents were found. Supplementation with LC decreased drip loss, cooking loss and total volatile basic nitrogen, and increased the redness (a∗) value, the superoxide dismutase and glutathione peroxidase activities in thigh muscles. Moreover, the malondialdehyde content decreased when diets were supplemented with LC, and there was a synergistic effect between PGZ and LC. Additionally, the mRNA abundance of lipogenesis-related genes, such as peroxisome proliferator-activated receptor γ (PPARγ), PPARγ co-activator 1α and fatty acid-binding protein 3, increased with PGZ supplementation, and relevant antioxidation genes, such as nuclear factor erythroid-2-related factor 2 and superoxide dismutase 1, were enhanced with LC supplementation. In conclusion, the results indicated that the supplementation of PGZ and LC could improve the growth performance, antioxidant ability, IMF content, and meat shelf life of yellow-feathered broiler chickens.     

Heterotrophic Aurantiochytrium sp. supplementation to layer diets sustainably increases the omega-3 concentration of eggs

ABSTRACT

1. The consumption of adequate amounts of the long-chain polyunsaturated omega-3 fatty acids (n-3 LC-PUFA) has been associated with beneficial effects on human health. Eggs are commonly consumed worldwide, and their omega-3 content can be easily altered by changing the diets of laying hens and so represent an important target for enrichment.

2. In this study, the effect of supplementing laying hens with DHA-rich, Aurantiochytrium limacinum at three different inclusion levels was investigated over a 24-week period.

3. Significant increases in egg DHA concentrations were observed after four weeks and were maintained for the duration of the 24-week study. The supplemented eggs in the current study had a DHA content of 82, 101, and 129 mg/yolk when supplemented with 0.25%, 0.5% and 1% treatments, respectively, which meets the EU criteria to be considered ‘high in omega-3?.

4. Using the sustainably grown protist Aurantiochytrium limacinum to supplement layer diets increased the egg DHA concentration and decreased the n-6/n-3 ratio, improving the nutritional value of the eggs for human consumers.     

Effects of dietary supplementation with conjugated linoleic acid on fatty acid composition and lipid oxidation in chicken breast meat

We investigated the effects of dietary conjugated linoleic acid (CLA) on fatty acid composition and lipid oxidation in breast meat of broiler chickens. Broiler chickens (28-day-old females) were fed diets containing experimental oils at 20 g/kg diet for 28 days. The experimental oils consisted of either a 2:0, 1:1, or a 0:2 (wt : wt) ratio of safflower oil (high linoleic acid content) to a commercial CLA mixture. In this study, dietary CLA supplementation significantly increased the composition and content of CLA in chicken meat. The predominant CLA in meat from birds with supplemented diets was the cis -9, trans -11 isomer. The proportion of saturated fatty acid in meat significantly increased with increasing CLA supplementation, with a corresponding decrease in monounsaturated fatty acid. Dietary CLA also reduced thiobarbituric acid reactive substances (TBARS) values in raw meat during storage at 4°C for 5 days. These results provide evidence that CLA feeding is a practical strategy not only for adding nutritional benefits to chicken meat but also for improving meat quality including oxidative stability.     

Effect of dietary zinc proteinate supplementation on growth performance, and skin and meat quality of male and female broiler chicks

1. An experiment was conducted to evaluate the effect of dietary zinc proteinate (ZP) supplementation on growth performance and on skin and meat quality of male and female broiler chicks.

2. A total of 240 1-d-old male and 240 1-d-old female broiler chicks were randomly distributed into 24 floor pens (12 replicate pens/sex; 20 birds/pen) and were given either 0 (Control diet) or 40?mg/kg ZP (ZP 40), resulting in a 2?×?2 factorial arrangement of treatments.

3. The growth performance of male and female broiler chicks was not affected by the ZP supplementation, but the males showed significantly higher growth performance than did females.

4. ZP supplementation increased the total thickness of skin in both sexes, and males had thicker skin than females. It also increased the collagen content of skin, but not that of meat. Males had higher skin collagen contents than did females, but no sex difference was found in the meat collagen contents.

5. ZP supplementation did not affect the shear force values of skin and meat; however, males had higher shear force values of back skin than females. ZP supplementation increased the zinc contents of thigh meat and plasma in both sexes. Males had higher zinc contents in back skin than females.

6. It is concluded that dietary ZP supplementation could increase the skin quality of broiler chicks in both sexes, particularly in female broilers, without any effect on growth performance. Male broilers have better growth performance and skin quality than females.     

Comparative evaluation of carcass traits and meat quality in native Aseel chickens and commercial broilers

1. A comprehensive study was conducted to analyse the meat quality attributes, composition and carcass traits in Aseel chickens and commercial broilers at market age on the basis of physiological age. A total of 20 Aseel (26 and 56 weeks) and 20 broiler (6 weeks) chickens were divided into two groups on a live weight basis, i.e. large (≥2.5 kg) and small (<2.5 kg) with 10 birds in each subgroup.

2. The pH of meat did not show any significant variation between Aseel and broiler chickens. The meat from heavier birds had significantly higher pH. Shear force value and hydroxyproline contents were significantly higher in Aseel chickens. Aseel birds had significantly higher red (a*) colouration and lower lightness (L*) than broiler chickens.

3. The texture and acceptability of Aseel meat were significantly higher.

4. Scanning electron microscopy revealed that muscle fibres in Aseels were arranged in a more coiled pattern making the muscle tough. A larger amount of connective tissue was also observed between the muscle fibres compared with the broiler chickens.

5. The dressing percentage was significantly higher in larger chickens. Commercial broilers recorded significantly higher meat proportion and lower proportion of bone. The meat:bone ratio was 1.07:1.0 in Aseel and 1.31–1.0 in broiler chicken. Breast muscle content was significantly lower in smaller Aseel chickens. Aseel chicken had stronger and heavier backs and shanks. Abdominal fat percentage was significantly lower in Aseel (0.73–0.78%).

6. The study concluded that the firm texture of Aseel meat was due to the high collagen content and interlocking connective tissue between the muscle fibres. The texture and acceptability of Aseel meat was higher. Aseel cocks had strong legs, lean meat and less abdominal fat, making them a high-value meat bird in addition to their aggressive fighting ability.

     

The Effects of n-3 Fatty Acid Supplementation on Bleeding Time, Plasma Fatty Acid Composition, and In Vitro Platelet Aggregation in Cats

Dietary supplementation with fish and fish oils rich in the n-3 fatty acids eicosapentaenoic acid ( EPA ) and docosahexaenoic acid (DHA) has been shown to alter eicosanoid metabolism and impair platelet function in several species. As an initial step in evaluating the antithrombotic effect of these n-3 fatty acids in cats, purified EPA and DHA were administered daily to 8 clinically normal cats for 2 months. Platelet function was evaluated biweekly by determining mucosal bleeding time and in vitro platelet aggregation parameters. Plasma fatty acid profiles were obtained before fish oil supplementation and at the termination of the study. In spite of significant increases ( P < .0001) in the plasma concentrations of EPA and DHA after n-3 fatty acid supplementation, there were no significant changes in platelet aggregation or bleeding times. Although it is tempting, based on extrapolation of data from other species, to recommend dietary supplementation with fish oil for cats prone to arterial thromboembolism, these results indicate that administration of large doses of purified EPA and DHA once daily does not inhibit platelet function in normal cats and is unlikely to prevent thrombosis in cats with cardiovascular disease. Additional studies are recommended to ascertain whether more frequent administration of these purified n-3 fatty acids or continual feeding of diets high in n-3 fatty acid content will impair platelet function.     

Effects of full-fat rice bran inclusion in diets on growth performance and meat quality of Sichuan goose

1. This trial was conducted to study the effect of full-fat rice bran inclusion in diets on growth performance, carcass and meat quality and fatty acid composition in Sichuan goose.

2. A total of 204 Sichuan white male geese (28-d-old, 984 ± 15 g) were used in the 42-d assay. Full-fat rice bran inclusion in diets was 0%, 6%, 12% and 18%, respectively.

3. On d 70, two geese from each pen were randomly selected and killed for measuring the carcass and meat quality and the meat fatty acid composition.

4. The results showed that full-fat rice bran inclusion had no effect on average daily gain during 28–56 d, but rice bran inclusion at 18% increased average daily gain during 57–70 d. In addition, the full-fat rice bran supplementation decreased the subcutaneous fat yield, and the inclusion of full-fat rice bran in amounts of 12% and 18% decreased the half-eviscerated carcass yield, eviscerated carcass yield and crude fat content in goose meat. Moreover, full-fat rice bran supplementation had no effect on the content of total saturated fatty acid (SFA), but decreased the content of total monounsaturated fatty acid (MUFA). The inclusion of full-fat rice bran in amounts of 12–18% increased the content of total polyunsaturated fatty acid (PUFA) and total n-6 in goose meat and in the amount of 18% increased n-3 fatty acids content in goose meat.

5. The results indicated that the rice bran inclusion had a positive effect in geese by stimulating growth performance and improving meat quality and fatty acid composition of goose meat.

     

Effects of saturated and unsaturated fats with vitamin E supplementation on the antioxidant status of broiler chicken tissues

The influence of fish oil (highly unsaturated) and beef tallow (highly saturated) with vitamin E (100 IU/kg) supplementation on the antioxidant status of broiler chicken cockerels was investigated. Chicks were fed a control diet with no added fat, 40 g/kg each of fish oil and beef tallow diets, respectively, from 11 to 42 days of age. Tocopherol concentration and the rate of lipid peroxidation, thiobarbituric acid reactive substance (TBARS) in liver, fatty acid composition of the liver lipids, blood serum total antioxidant status (TAS), and reduced glutathione (GSH) content were determined. Vitamin E supplementation of the diet increased liver alpha-tocopherol content in chicks regardless of the type of dietary fat. Fish oil diet resulted in higher liver TBARS value while beef tallow diet showed lower values compared to the control diet. Vitamin E supplementation reduced liver TBARS as well as serum GSH, and raised serum TAS for all diets. Serum GSH was the same for vitamin E supplemented diets regardless of the fat supplement. Fish oil diets resulted in a significant increase in hepatic lipid n-3 PUFA content. A significant positive correlation was found between liver TBARS and n-3 PUFA content. No relationships were established, however, between liver TBARS and n-6 PUFA or saturated fatty acids. The results suggest that feeding oils rich in n-3 PUFA increases tissue concentration of these fatty acids, consequently increasing tissue lipid peroxidation and reducing the antioxidative status of broiler chickens. Supplementing high levels of vitamin E with such oils may increase tissue oxidative stability. Serum TAS or GSH may be used as a measure of antioxidative status in chickens.     

日粮中添加亚麻籽油对鸡蛋脂肪酸组成和风味的影响

试验旨在研究日粮中添加亚麻籽油对蛋鸡生产性能、蛋品质、蛋黄脂肪酸组成及鸡蛋风味的影响。选取40周龄海兰灰商品代蛋鸡288只,随机分为4组,每组8个重复,每个重复9只鸡。设计分别添加0、0.5%、1.0%和3.0%亚麻籽油的4种等能等氮日粮。预试期1周,正试期4周。结果显示：①日粮中添加0.5%、1.0%、3.0%亚麻籽油对产蛋鸡生产性能、蛋品质均无显著影响（P>0.05）;②亚麻籽油可显著提高蛋黄中α-亚麻酸（ALA）、二十碳五烯酸（EPA）、二十二碳六烯酸（DHA）及总n-3多不饱和脂肪酸（PUFA）含量,且其随亚麻籽油添加水平增加呈线性和二次变化（P<0.05）;③3.0%亚麻籽油组显著降低了蛋黄气味及滋味评分,同时显著增强了蛋黄鱼腥气味及滋味评分（P<0.05）,而蛋黄总体接受度显著降低（P<0.05）,且其均随亚麻籽油添加水平增加呈线性和二次变化（P<0.05）;④鸡蛋蛋黄总n-3 PUFA含量与鱼腥气味、滋味间具有显著相关性（P<0.05）,且鸡蛋蛋黄接受度随n-3 PUFA含量增加而降低（R²=0.801）。综上所述,日粮添加亚麻籽油可提高蛋黄总n-3 PUFA含量,但添加量过高时对鸡蛋风味产生不良影响导致总体接受度下降;蛋黄总n-3 PUFA含量不高于21.26 mg/g时,可接受度评分大于5分,鸡蛋感官品质在可接受范围内。     

Improving the nutritional quality and shelf life of broiler meat by feeding diets supplemented with fermented pomegranate (Punica granatum L.) by-products

1. Four experimental diets containing 0, 0.5, 1.0 and 2.0% fermented pomegranate by-products (FPB) were supplied to 320d-old broilers to evaluate the effects of FPB on growth performance, nutritional composition, fatty acid profile and oxidative stability of meat.

2. Dietary supplementation of FPB linearly increased the weight gain and feed intake of broilers with linear reduction in feed conversion ratio.

3. The crude protein, iron, magnesium, and sodium content were linearly higher, whereas cholesterol was linearly lower in the breast meat of FPB-supplemented broilers. In thigh meat, linearly lower ether extract and cholesterol with higher moisture was noted in response to increasing levels of FPB.

4. The proportion of saturated fatty acids was both linearly and quadratically lower in breast and thigh meat, whereas those of monounsaturated fatty acids of breast (linear and quadratic) and n-3 fatty acids of breast and thigh (linear) meat was higher in the FPB-supplemented broilers. The n-6/n-3 ratio of breast meat was linearly lower in response to FPB supplementation. The hypocholesterolaemic to hypercholesterolaemic ratio of thigh meat was higher in the FPB-supplemented groups.

5. The thiobarbituric acid reactive substances and pH value were lower in the breast and thigh meat of FPB-supplemented broilers.

6. Thus, additive supplementation of the diet with up to 2% FPB improved the nutritional quality, fatty acid profile and shelf life of broiler meat.     

日粮中脂肪酸对羊牛猪肉中长链多不饱和脂肪酸和共轭亚油酸的影响

随着消费者健康意识的提高,越来越多的研究关注提高家养动物肉产品中多不饱和脂肪酸(PUFA)含量,尤其是n-3长链脂肪酸和共轭亚油酸(CLA)在羊、牛、猪肉肌内脂中的含量。研究结果表明通过添加鱼油或鱼粉能提高动物肉中n-3长链脂肪酸含量。富含亚麻油酸(LNA)的日粮能提高肉中LNA、二十碳五烯酸(EPA)和二十二碳五烯酸(DPA)水平,但大部分对肌肉中二十二碳六烯酸(DHA)水平没有影响。然而,在日粮中添加鱼油或鱼粉大部分能提高动物肌肉中DHA含量。大部分研究中提高n-3脂肪酸含量的同时n-6脂肪酸含量下降,这主要归因于试验组日粮中n-6脂肪酸降低。这样刚好可以使肉中两者比例更合理,但对多不饱和脂肪酸与饱和脂肪酸比例没什么影响。饲喂反刍动物富含n-3脂肪酸日粮(亚麻籽或加草料)、鱼油或富含LA的浓缩料可提高肌肉中c9t11CLA含量。牛肉、羊肉中c9t11CLA在总脂中含量介于0.2~1.0 g/100 g,不随营养因素提高到更高。相对应的,在单胃动物日粮中添加混合CLA油则显著提高CLA含量。     

Effect of dietary high-oleic acid sunflower seed, palm oil and vitamin E supplementation on broiler performance, fatty acid composition and oxidation susceptibility of meat

1. A study was conducted to evaluate the effect of inclusion of two fat sources: high-oleic acid sunflower seed (HOASS; 0, 50, 100, 150 and 200 g/kg diet) and palm oil (PO), and dietary supplementation of vitamin E (alpha-tocopheryl acetate, 200 mg/kg diet) on performance, fatty acid composition and susceptibility to oxidation of white and dark chicken meat during refrigerated storage. Female chicks (3 to 6 weeks) were given one of 5 diets containing 90 g/kg of added fat with increasing monounsaturated fatty acid (MUFA) content, adjusted by progressively replacing PO by HOASS. 2. Body weight gain and gain:food ratio of birds were depressed in diets containing the highest proportions of HOASS (150 and 200 g/kg). Relative abdominal fat was reduced in birds fed diets including HOASS, except in the diet containing 100 g HOASS/kg. The inclusion of alpha-tocopheryl acetate improved body weight gain and gain:food ratio. 3. According to the fatty acid profile of the diets, saturated and polyunsaturated fatty acid (SFA and PUFA, respectively) contents were significantly reduced and MUFA content was significantly increased in white and dark chicken meats when the saturated oil, PO, was replaced progressively by HOASS in the diet. The inclusion of alpha-tocopheryl acetate increased PUFA content in both meats. 4. After 4 and 7 d of refrigerated storage, white and dark meat samples obtained from birds fed on diets containing HOASS had significantly lower thiobarbituric acid reacting substance (TBARS) values than those derived from the PO diet. The addition of alpha-tocopheryl acetate significantly reduced the lipid oxidation in white and dark meat. 5. Overall, the results showed that increasing MUFA content of chicken meat by replacing dietary PO with HOASS (up to 100 g/kg) did not adversely affect broiler performance and reduced the susceptibility of meat to oxidation during refrigerated storage. Dietary alpha-tocopherol supplementation improved chicken performance and was effective in protecting lipid meat from oxidation.     

Comparison of effects of dietary olive oil,tallow and vitamin E on the quality of broiler meat and meat products

1. The effect of dietary fat and vitamin E supplementation on quality attributes (drip loss, oxidative stability, sensory quality) in chicken meat and meat products was investigated. Broiler chicks were fed on diets containing tallow (60 g/kg) or olive oil (60 g/kg) at a basal (30 mg/kg diet) or supplemental (200 mg/kg diet) concentration of alpha-tocopheryl acetate for 8 weeks. The alpha-tocopherol content and fatty acid composition of breast and thigh meat was determined. Drip loss was determined in breast fillets. Lipid oxidation (thiobarbituric acid-reacting substances/TBARS) and sensory quality (warmed-over flavour development/WOF) were assessed in minced thigh meat during storage. 2. Dietary olive oil increased the ratio of monounsaturated to saturated fatty acids (MUFA/SFA) in the diets. In breast and thigh, this resulted in approximately a two-fold increase in the MUFA/SFA ratio. Supplemental alpha-tocopherol increased the alpha-tocopherol content of muscles. 3. Dietary fat did not influence drip loss in thawed breast fillets during refrigerated storage, but supplemental alpha-tocopherol reduced drip loss. 4. TBARS and WOF development in minced thigh meat patties were also reduced by supplemental alpha-tocopherol following frozen storage, or cooking and refrigerated storage. Storage stability was not adversely affected by dietary fat. 5. Overall, the results showed that increasing the monounsaturated profile of chicken meat lipids did not adversely affect quality characteristics. Dietary alpha-tocopherol supplementation was a more important factor in the determination of broiler meat quality.     

Fatty Acid Taste Receptor GPR120 Activation by Arachidonic Acid,Eicosapentaenoic Acid,and Docosahexaenoic Acid in Chickens

It has been reported that the supplementation of chicken diet with polyunsaturated fatty acids (PUFAs) such as arachidonic acid (AA), eicosapentaenoic acid (EPA), or docosahexaenoic acid (DHA) affects the qualities of eggs and meat. Previous studies have shown that a functional fatty acid taste receptor, G protein-coupled receptor 120 (GPR120), is broadly expressed in chicken oral and gastrointestinal tissues, and chickens have a gustatory perception of oleic acid, which is a chicken GPR120 agonist. The aim of this study was to elucidate the role of chicken GPR120 in response to PUFAs in chicken diets. Ca²⁺ imaging analyses revealed that chicken GPR120 was activated by AA, EPA, and DHA in a concentration-dependent manner. These results suggest that chickens can detect PUFAs via GPR120 in the oral and gastrointestinal tissues, implying that chickens have a gustatory perception of PUFAs.     

Effects of dietary glutamine and gamma-aminobutyric acid on meat colour,pH, composition,and water-holding characteristic in broilers under cyclic heat stress

1. An experiment was conducted to evaluate the effects of dietary glutamine (Gln, 0 and 5?g/kg) and gamma-aminobutyric acid (GABA, 0 and 100?mg/kg) on raw breast meat colour, pH, composition and water-holding characteristic of broilers under cyclic heat stress (HS).

2. A total of 360 21-d-old Arbor Acres male chicks were randomly assigned to 5 treatment groups (6 replicates of 12 birds per cage). The positive control (PC) broilers were kept in a thermoneutral chamber (22–24°C) and fed on the basal diet. The other 4 groups were kept in a cyclic HS chamber (30–34°C) for 9?h (from 09:00 to 18:00).

3. A significant increase was observed in breast meat lightness at 28, 35 and 42?d; and pH values at 28, 35 and 42?d; while a significant decrease was observed in breast meat cooking loss (CL) and contents of moisture, crude protein (CP), crude fat (CF) and crude ash (CA) due to HS.

4. The supplementation with 0·5?g?Gln/kg decreased lightness at 28, 35 and 42?d; while increasing redness at 28?d, yellowness at 35?d, contents of CP, CF and CA, thawing loss (TL) and drip loss (DL). The addition of 100?mg?GABA/kg decreased lightness at 28 and 35?d, pH value at 28, 35 and 42?d, and TL; while increasing redness at 28?d, 35 and 42?d, contents of moisture, CP and CF.

5. The lightness, redness, and pH value; contents of moisture, CP, CF and CA; and TL, DL and CL of breast meat of broilers fed with the mixture of Gln and GABA under cyclic HS were similar to those of the broilers in the PC group.

6. Significant interactions were found between Gln and GABA for yellowness at 28 and 35?d; pH at 28, 35 and 42?d; moisture content, CP content, water-holding capacity and TL.

7. These results demonstrated that dietary Gln and GABA offer a potential nutritional strategy to prevent cyclic HS-related depression in broiler meat chemical composition and quality.     

Effect of synbiotic supplementation and dietary fat sources on broiler performance,serum lipids,muscle fatty acid profile and meat quality

1. A 42-d trial was conducted to investigate the effect of adding a synbiotic supplement to diets containing two different types of fat on performance, blood lipids and fatty acid (FA) composition and oxidative stability of breast and thigh meat in broilers.

2. A total of 800 one-d-old male broiler chickens were randomly assigned into 1 of 8 treatments with 4 replicates of 25 birds per treatment. The experiment consisted of a 4 × 2 factorial arrangement of treatments including 4 concentrations of synbiotic (0, 0.5, 1 or 1.5 g/kg diet) and 2 types of fat [sunflower oil (SO) or canola oil (CO)] at an inclusion rate of 50 g/kg diet.

3. Dietary fat type did not affect body weight gain (BWG) or feed conversion ratio (FCR) during the overall experimental period (0–42 d). However, fat type modified serum lipid profile and FA composition and 2-thiobarbituric acid-reactive substances (TBARS) content in breast and thigh meat.

4. The addition of synbiotic to the diet linearly improved overall BWG and FCR and also decreased serum cholesterol and low-density lipoprotein cholesterol concentrations. The TBARS value in thigh meat after 30 d of storage at 4°C was linearly decreased as the synbiotic inclusion concentrations in the diets increased. Dietary synbiotic also decreased the proportion of monounsaturated fatty acids and increased n-6 polyunsaturated fatty acid (PUFA) concentration in thigh meat, whereas the FA profile of breast meat was not affected by synbiotic supplementation. Moreover, the PUFA/SFA ratio in the breast meat was linearly increased when synbiotic was included in the CO-containing diets.

5. In conclusion, the addition of synbiotic to broiler diets had a positive effect on growth performance, blood lipid profile and meat quality. The results also support the use of synbiotic to increase the capacity of canola oil for enhancing PUFA/SFA ratio of breast meat in broilers.

     

Effects of fermented corni fructus and fermented kelp on growth performance,meat quality,and emission of ammonia and hydrogen sulphide from broiler chicken droppings

1. Corni fructus is the fruit of Cornus officinalis, a dogwood species. This study was conducted to prepare fermented corni fructus preparation (FCFP) and fermented kelp (FK) from corni fructus and by-products of Laminaria japonica fermented with Bacillus subtilis and Aspergillus oryzae.

2. The effects of dietary FCFP and FK as replacer of oxytetracycline (OTC) on growth performance, meat composition, meat oxidative stability, and emissions of ammonia (NH₃) and hydrogen sulphide (H₂S) from broiler chicken droppings were investigated.

3. A total of 140 d-old broiler chicks were randomly allotted to 4 dietary treatments including control, OTC (0.05 g/kg), FCFP (5 g/kg), and FK (5 g/kg).

4. Overall, inclusion of FCFP resulted in lower weight gain and feed intake during the overall experimental period. Broilers fed FCFP diets tended to have lower crude fat and higher crude ash content in the carcasses.

5. In the fresh state, the malondialdehyde (MDA) value of broiler meat was lower in the FK supplemented group. At one week, meat from broilers fed antibiotic and FK diets had lower MDA values, whereas at 2 weeks broiler meat from all dietary treatment groups had lower MDA values than the control.

6. Dietary supplementation with FK significantly reduced faecal NH₃ emissions throughout the experimental period, whereas dietary OTC and FCFP supplementation increased NH₃ emissions at 2 and 4 weeks. There were no significant effects of dietary treatments on H₂S emissions throughout the experimental period, except during week one, when FCFP supplementation reduced the emission.

7. In conclusion, dietary supplementation with 5 g/kg FK improved the oxidative stability of broiler meat and reduce faecal NH₃ emissions without affecting growth performance.     

桑叶粉对肉鸡生长性能和屠宰性能及肉质的影响

本试验旨在研究桑叶粉对肉鸡生长性能、屠宰性能及肉质的影响。选择35日龄的广西青脚麻公鸡172只,随机分为4组,分别饲以桑叶粉添加量为0(对照组)、5%、8%和11%的饲粮。结果表明:8%、11%桑叶粉组的饲料增重比相对于对照组显著提高(P<0.05);5%桑叶粉组的肉鸡腹脂率显著降低(P<0.05);与对照组相比,桑叶粉组的肌内脂肪(IMF)含量显著降低(P<0.05);11%桑叶粉组的不饱和脂肪酸(UFA)、ω-3脂肪酸含量显著提高(P<0.05),饱和脂肪酸(SFA)含量显著降低(P<0.05);桑叶粉组的矫正肌苷酸含量有上升趋势,但差异不显著(P>0.05)。综上,桑叶粉的添加具有降低腹脂率、IMF和提高UFA、ω-3脂肪酸含量的效果,但使肉鸡的饲料利用率降低。     

性别和营养水平对福建河田鸡风味前体物质含量的影响

研究了不同性别和日粮能量、蛋白水平对河田鸡胸肌肉中风味前体化合物含量的影响。结果表明：性别对腹脂率、氨基酸（Asp、Thr、Ser、Pro、Cys除外）以及肌内脂肪（IMF）及其饱和脂肪酸（SFA）、单不饱和脂肪酸（MUFA）、多不饱和脂肪酸（PUFA）含量有显著影响（P〈0．05），而对肌苷酸（IMP）含量无显著影响（P〉0．05）；公鸡的总氨基酸（TAA）、肌苷酸、肌内脂肪中的SFA、MUFA含量略高于母鸡，母鸡的肌内脂肪及其PUFA含量明显高于公鸡。能量水平对肌苷酸、肌内脂肪及其SFA、MUFA、PUFA以及总氨基酸含量有显著影响（P〈0．05）；当鸡采食高能日粮时，肌内脂肪中的SFA、MUFA含量会显著升高（P〈0．05），而IMP、IMF、PUFA含量会显著下降（P＜0．05），TAA没有显著变化。蛋白水平对肌内脂肪及其MUFA、PUFA含量以及总氨基酸含量有显著影响（P〈0．05）。当采食高蛋白日粮时，肌内脂肪及SFA、MUFA显著降低，而其PUFA会显著增加（P〈0．05）。风味品尝结果表明，公鸡的香味、鲜味都显著高于母鸡，而嫩度低于母鸡；随着能量和蛋白水平的增加，鲜味和嫩度都显著下降（P〈0．05）。从肉品的总可接受性来看，性别对总可接受性没有显著影响（P〉0．05），低营养水平时的总可接受性大于高营养水平（P〈0．05）。