Effect of L‐theanine on meat quality,muscle amino acid profiles,and antioxidant status of broilers

This study investigated the effect of L ‐theanine on carcass traits, meat quality, muscle antioxidant capacity, and amino acid (AA) profiles of broilers. Three hundred 1‐day‐old Ross 308 male broilers were randomly allotted to five groups with six replicates. Birds were fed the basal diet or basal diet with 300, 600, 900, or 1,500 mg/kg L ‐theanine for 42 consecutive days. The results showed that L ‐theanine quadratically increased dressing percentage, eviscerated percentage, and leg muscle yield (p < .05). Meanwhile, drip loss, cooking loss, shear force, L*_24h, and muscle lactate content decreased quadratically in response to dietary L ‐theanine supplementation (p < .05), while pH_24h and muscle glycogen content were quadratically improved by L ‐theanine (p < .05). Notably, the contents of muscle malondialdehyde and protein carbonyl, and the activities of muscle total antioxidant capacity, catalase, and glutathione peroxidase decreased quadratically in response to dietary L ‐theanine supplementation (p < .05), suggesting that the oxidative stress level of muscle was decreased quadratically. Moreover, L ‐theanine quadratically increased the concentrations of most of muscle essential AA, nonessential AA, and flavor AA (p < .05). In conclusion, L ‐theanine can be used as a valuable feed additive to modulate carcass traits, meat quality, muscle antioxidant status, and AA profiles of boilers, and its optimum addition level is 600 mg/kg based on the present study.     

红车轴草异黄酮对肉鸡生产性能及肉品质的影响

为了研究红车轴草（Trifolium pratense）异黄酮对肉鸡生长、屠宰性能及肉品质的影响,将180羽1日龄AA肉仔鸡分成3组,即对照组、试验Ⅰ组、试验Ⅱ组,分别饲喂基础日粮、基础日粮+红车轴草异黄酮(10 mg/kg)、基础日粮+红车轴草异黄酮(20 mg/kg)。结果显示,红车轴草异黄酮可以提高肉鸡的日增体质量（P<0.05）和屠宰性能（P>0.05）,降低血清中甘油三酯、总胆固醇和腹脂率（P<0.05）,减少了储存第6天肉中丙二醛含量（P<0.05）,降低了肉品滴水损失和剪切力（P>0.05）。表明红车轴草异黄酮能够提高肉鸡生长性能和屠宰性能,改善肉品品质,添加20 mg/kg时肉鸡日增长速度最快。     

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.     

The effect of vitamin E on growth performance and meat quality in broilers given diets containing distillers’ dried grain with solubles (DDGS)

1. The objective of the present study was to investigate the effect of vitamin E (VE, α-tocopherol acetate) on growth performance and meat quality of broilers fed on diets containing maize distillers’ dried grains with solubles (DDGS).

2. A total of 360 one-d-old broilers were randomly assigned to 6 groups. Each group comprised 6 replicates of 10 broilers. Broilers were allocated to 1 of 6 diets and fed for 49?d in a 3?×?2 factorial design. The dietary treatments included three concentrations of DDGS (0, 10 or 20%) and two concentrations of VE (0 or 200?mg/kg).

3. Diets containing 20% DDGS decreased the growth phase and average daily feed intake, demonstrating that small amounts of DDGS affected feed intake in broilers and that an excess of DDGS was not conducive to feed intake.

4. Different dietary concentrations of DDGS did not significantly improve colour, drip loss, cooking loss, or shear force. Supplementation with 200?mg/kg VE significantly reduced cooking loss and shear force and improved colour.

5. In conclusion, supplementation with DDGS at 10% and/or α-tocopherol acetate at 200?mg/kg had positive effects on growth performance and meat quality in broilers.     

L-组氨酸对肉鸡生长性能、肌肉品质、血浆抗氧化能力和肌肉咪唑二肽含量的影响

本试验旨在研究饲粮添加L-组氨酸对肉鸡生长性能、肌肉品质、血浆抗氧化能力和肌肉咪唑二肽含量的影响。选取体重相近、健康的1日龄爱拔益加(AA)肉仔鸡公雏300只,随机分为5组,每组6个重复,每个重复10只鸡。对照组饲喂基础饲粮,试验组饲喂在基础饲粮中分别添加250、500、1 000、2 000 mg/kg L-组氨酸的试验饲粮。试验期42 d。结果表明:1)L-组氨酸降低了肉鸡生长后期(22~42日龄)的料重比,250和2 000 mg/kg添加组显著低于对照组(P0.05)。2)L-组氨酸对肌肉全净膛率、胸肌率、腿肌率、腹脂率、滴水损失、剪切力和pH无显著影响(P0.05)。3)L-组氨酸线性提高了42日龄血浆总抗氧化能力及谷胱甘肽过氧化物酶、总超氧化物歧化酶的活性(P0.05)。4)L-组氨酸增加了42日龄肌肉中肌肽和鹅肌肽含量,500、1 000和2 000 mg/kg添加组肌肽含量分别较对照组升高了40.58%、42.75%、33.70%(P0.05),1 000 mg/kg添加组鹅肌肽含量较对照组增加了37.80%(P0.05);对肌肉中肌肽和鹅肌肽含量进行二次曲线方程拟合表明,L-组氨酸添加量为1 276 mg/kg时,肌肉咪唑二肽含量最高。可见,饲粮添加L-组氨酸可提高肉鸡的饲料转化率,改善血浆抗氧化能力,增加肌肉中咪唑二肽含量。本试验条件下,饲粮添加1 000~2 000 mg/kg L-组氨酸较佳。从增加肌肉咪唑二肽含量考虑,饲粮L-组氨酸适宜添加量为1 276 mg/kg     

苜蓿多糖对不同性别肉仔鸡生长性能、屠宰性能、肉品质及抗氧化性能的影响

本试验旨在研究苜蓿多糖对不同性别肉仔鸡生长性能、屠宰性能、肉品质及抗氧化性能的影响。选取468只1日龄爱拔益加(AA)肉仔鸡,随机分为3组,每组12个重复(公母各6个重复),每个重复13只鸡。组1为对照组,饲喂基础饲粮,组2、组3分别在基础饲粮中添加1 000和2 000 mg/kg苜蓿多糖,试验期42 d。结果表明:与对照组相比,1)饲粮中添加1 000和2 000 mg/kg苜蓿多糖对公鸡和母鸡的平均体重、平均日采食量、平均日增重、料重比、屠宰率、腿肌率和腹脂率均无显著影响(P0.05),但显著提高了母鸡全净膛率和胸肌率(P0.05),且添加2 000 mg/kg苜蓿多糖显著提高了公鸡胸肌率(P0.05)。2)1 000 mg/kg苜蓿多糖组(即组2)公鸡胸肌p H45 min显著提高(P0.05),公鸡和母鸡胸肌滴水损失率和公鸡胸肌蒸煮损失率显著降低(P0.05);2 000 mg/kg苜蓿多糖组(即组3)公鸡和母鸡胸肌滴水损失率和公鸡胸肌蒸煮损失率显著降低(P0.05)。1 000 mg/kg苜蓿多糖组公鸡和母鸡腿肌滴水损失率和母鸡腿肌剪切力显著降低(P0.05),母鸡腿肌p H24 h显著提高(P0.05);2 000 mg/kg苜蓿多糖组母鸡腿肌滴水损失率和剪切力显著降低(P0.05)。3)1 000和2 000 mg/kg苜蓿多糖组21日龄公鸡血清总抗氧化能力(T-AOC)显著提高(P0.05),2 000 mg/kg苜蓿多糖组35和42日龄母鸡血清T-AOC显著提高(P0.05),2 000 mg/kg苜蓿多糖组28日龄公鸡和母鸡血清谷胱甘肽过氧化物酶(GSH-Px)活性显著提高(P0.05),1 000和2 000 mg/kg苜蓿多糖组21和35日龄母鸡血清总超氧化物歧化酶(T-SOD)活性显著提高(P0.05),但饲粮中添加1 000和2 000 mg/kg苜蓿多糖对公鸡和母鸡血清中丙二醛(MDA)含量无显著影响(P0.05);此外,饲粮中添加1 000和2 000 mg/kg苜蓿多糖对公鸡和母鸡肝脏和胸肌中T-AOC、GSH-Px和T-SOD活性及MDA含量均无显著影响(P0.05)。综上,饲粮中添加苜蓿多糖对公鸡和母鸡的生长性能无显著影响,但能够改善公鸡和母鸡的屠宰性能、肉品质和血清抗氧化性能,且苜蓿多糖的适宜添加量为1 000mg/kg。     

Resveratrol beneficially affects meat quality of heat‐stressed broilers which is associated with changes in muscle antioxidant status

This study was conducted to evaluate the effect of dietary resveratrol (Res) supplementation on serum parameters, meat quality and muscle antioxidant status of broilers under heat stress (HS). A total of 270 21‐day‐old male Cobb broilers were randomly assigned to three treatment groups with six replicates of 15 birds each. The three treatment groups were as follows: the control group, in which birds were reared at 22 ± 1°C, and the HS and HS + Res (400 mg/kg) groups, in which birds were reared at 33 ± 1°C for 10 h (08.00–18.00 h) and 22 ± 1°C for the rest of the time. Compared with birds in the control group, birds in the HS group exhibited increased serum corticosterone (CORT) and triacylglycerol contents, L*, drip loss and muscle malondialdehyde content, and decreased serum glucose content, pH_24 h, muscle total antioxidant capacity (T‐AOC), catalase (CAT) and glutathione peroxidase (GSH‐PX) activities (P < 0.05). Compared with birds in the HS group, birds in HS + Res group exhibited increased serum glucose content, a*, pH_24 h, muscle T‐AOC and CAT activities, and decreased serum CORT and triacylglycerol contents, L*_24 h, drip loss and muscle malondialdehyde content (P < 0.05). In conclusion, Res beneficially protects against HS‐impaired meat quality of broilers through regulating muscle antioxidant status.     

Effects of guanidinoacetic acid on growth performance,creatine metabolism and plasma amino acid profile in broilers

The objective of this study was to assess the effects of guanidinoacetic acid (GAA) on growth performance, creatine deposition and blood amino acid (AA) profile on broiler chickens. In Exp. 1, a total of 540 one‐day‐old Arbor Acres male broilers (average initial body weight, 45.23 ± 0.35 g) were divided randomly into five treatments with six replicates of 18 chicks each. Broilers were fed corn–soybean meal‐basal diets supplemented with 0, 600, 800, 1,000 or 1,200 mg/kg GAA for 42 days respectively. Results showed that dietary GAA inclusion increased average daily gain (ADG) and improved gain‐to‐feed ratio (G:F) from 1 to 42 days (p < 0.01). However, average daily feed intake was unaffected by dietary supplementation of GAA. As GAA inclusion increased, the contents of creatine in plasma and kidney were increased (linear, p < 0.01), while the contents of GAA and creatine in liver were decreased (linear, p < 0.01). Similarly, GAA supplementation was inversely related to concentrations of most essential AA in plasma. In Exp. 2, a total of 432 one‐day‐old Arbor Acres male broilers (average initial body weight, 39.78 ± 0.58 g) were divided randomly into four treatments with six replicates of 18 chicks each. Birds were fed a corn–soybean meal‐basal diet supplemented with 0, 200, 400 or 600 mg/kg GAA for 42 days respectively. Dietary inclusion of 600 mg/kg GAA significantly increased ADG and G:F of broilers (p < 0.05). In conclusion, dietary supplementation of 600–1,200 mg/kg GAA can effectively improve the growth performance in broiler chickens by affecting creatine metabolism and utilization efficiency of essential AA, and 600 mg/kg GAA is the minimum dose for improving performance.     

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.     

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 dietary astaxanthin rich yeast,Phaffia rhodozyma,on meat quality of broiler chickens

We evaluated effects of dietary supplementation with astaxanthin (Ax)‐rich yeast, Phaffia rhodozyma (Xanthophyllomyces dendrorhous), on broiler chicken meat quality. Fourteen‐day‐old female Ross broilers were divided into three groups: control group, Ax‐free diet; Ax 10 group, 10 mg/kg Ax diet; and Ax 20 group, 20 mg/kg Ax diet for 28 days. At 42 days old, chickens were slaughtered, and then growth performance, meat quality and sensory attributes were analyzed. Compared with the control, a* values increased significantly after slaughter and 48 h postmortem for Ax 20 samples (P < 0.05) and for b* values in Ax 20 and Ax 10 groups (P < 0.05). Cooking loss decreased in the Ax 20 group (P < 0.05). After 120 h aging, contents of several free amino acids and total free amino acid content of Ax 20 group were significantly higher than the control (P < 0.05). In sensory evaluation, meat texture attributes improved significantly in the Ax 20 group (P < 0.01). No significant changes occurred in flavor attribute scores of meat soup from the Ax 20 group compared with the control even though most assessors preferred meat soup from the Ax 20 group. Overall, Ax‐rich yeast in the diet improves broiler chicken meat quality.     

Stability of abdominal fat and meat of broilers: Effect of duration of feeding antioxidants 1

1. The α‐tocopherol (AT) content of abdominal fat and fat stability increased as a function of the duration of α‐tocopheryl acetate (ATA) feeding in broilers fed on diets containing either 40 g acidulated soyabean‐oil soapstock (ASS) or tallow/kg. A linear relationship was observed between AT content of the adipose tissue and its stability with both types of fat supplements.

2. The stabilities of carcass fat and meat of 9‐week‐old broilers fed on diets containing ASS with 300 mg ethoxyquin (EQ)/kg or diets containing tallow with 20 mg ATA/kg from weeks 5 to 9 were comparable with those obtained by feeding these antioxidants and fats throughout the growth period.

3. ATA added to a diet containing ASS, and EQ, added to a diet containing tallow did not improve meat stability despite such an effect on adipose tissue when fed for 9 weeks. The results emphasise the importance of using the dietary antioxidant appropriate to the fat supplement to improve carcass stability.     

Potential application of Fe-methionine as a feed supplement on improving the quality of broilers breast meat

A total of 250 one-day-old Ross 308 male chicks were used to investigate the effects of Fe-methionine (Fe-met) and iron sulfate (FeSO₄.7H₂O) on performance, mineral concentration, meat quality, and oxidative stability of breast. The feeding experiment was performed with five dietary groups including group I (basal diet [BD] + 80 mg/kg FeSO₄), group II (BD + 60 mg/kg FeSO₄ + 20 mg/kg Fe-met), group III (BD + 40 mg/kg FeSO₄ + 40 mg/kg Fe-met), group IV (BD + 20 mg/kg FeSO₄ + 60 mg/kg Fe-met), and group V (BD + 80 mg/kg Fe-met). The results showed that Fe and Cu content in the breast muscle increased by dietary supplementation of organic and inorganic iron from II to V groups. Dietary groups of II, IV, and V increased L* value and b* value of breast meat. Additionally, redness of breast meat enhanced linearly and quadratically by dietary supplementation of 80 mg/kg Fe as FeSO₄. In addition, dietary supplementation Fe from II to V groups led to a significant increase in pHu at 24-h postmortem while it was negatively correlated with L* value of breast muscle. This study demonstrates that replacing FeSO₄ with Fe-Met could improve breast meat yield of broilers. Although 80 mg of Fe-Met improved the iron content of meat, it showed detrimental effects on the lipid oxidation of breast meat.     

Effects of epigallocatechin gallate on lipid metabolism and its underlying molecular mechanism in broiler chickens

The objective of this study was to investigate the effects of epigallocatechin gallate (EGCG) on fat metabolism and to establish the molecular mechanism of these effects in broilers. Seventy‐two 28‐day‐old male Ross 308 broiler chickens were divided into three groups with different levels of EGCG supplementation for 4 weeks: normal control (NC) group, L‐EGCG (a low‐level supplement of EGCG, 40 mg/kg body weight daily) and H‐EGCG (a high‐level supplement of EGCG, 80 mg/kg body weight daily). After 4 weeks of oral administration, EGCG significantly reduced the level of abdominal fat deposition in broilers. The serum triglycerides and low‐density lipoprotein cholesterol of chickens in H‐EGCG group were also significantly decreased compared with the NC group, and the high‐density lipoprotein cholesterol was notably increased at the same time. Moreover, the vital role of the liver and abdominal adipose tissue in lipid metabolism of poultry animals was examined through gene expression and enzyme activities related to fat anabolism and catabolism in these organs. Our data show that EGCG supplementation for 2 weeks significantly downregulated the expression of fatty acid synthesis and fat deposition‐related genes, and upregulated the expression of genes involved in fatty acid β‐oxidation and lipolysis genes. Simultaneously, the activities of hepatic fatty acid synthesis enzymes (fatty acid synthase and acetyl CoA carboxylase) were significantly decreased, and the activity of carnitine palmitoyl transferase‐1 was notably elevated. The results suggest that EGCG could alleviate fat deposition in broilers through inhibiting fat anabolism and stimulating lipid catabolism in broilers.     

饲粮维生素E水平对43～63日龄黄羽肉鸡肉品质和抗氧化功能的影响

本试验旨在研究饲粮维生素E水平对43 ～ 63日龄黄羽肉鸡肉品质和抗氧化功能的影响.选用1 440只43日龄岭南黄羽肉公鸡,采用单因子随机分组试验设计,共设6个处理,每个处理6个重复,每个重复40只鸡.试验采用玉米淀粉-豆粕型基础饲粮,各处理饲粮营养水平除维生素E水平不同外,其他均相同.空白对照组饲喂未添加维生素E的基础饲粮,其余各处理饲粮中分别添加5、10、20、40、80 mg/kg维生素E.试验期21 d,试鸡地面平养,自由采食颗粒料和自由饮水.结果表明:1)饲粮中维生素E添加水平对试鸡生长性能和胴体品质无显著性影响(P＞0.05).2)胸肌肉色的L*、a*、b *值和肌肉嫩度也未受饲粮维生素E添加水平显著影响(P＞0.05).添加各水平维生素E均显著提高了宰后45 min胸肌pH(P ＜0.05),添加5、10、40、80 mg/kg维生素E均显著提高了宰后24 h胸肌pH(P ＜0.05).添加20、40 mg/kg维生素E显著降低了宰后45 min胸肌滴水损失,添加5、10、40、80 mg/kg维生素E显著降低了宰后48 h胸肌滴水损失(P＜0.05).3)饲粮中添加不同水平维生素E对试鸡血清中丙二醛(MDA)含量和总超氧化物歧化酶(T-SOD)活性无显著性影响(P＞0.05),添加10、20 mg/kg维生素E使试鸡血清中谷胱甘肽过氧化物酶(GSH-Px)活性分别比对照组提高了27.51％、30.57％(P＜0.05).添加各水平维生素E均使试鸡肝脏中GSH-Px活性显著提高(P＜0.05),添加20、40、80 mg/kg维生素E均显著降低了肝脏中MDA含量(P＜0.05),显著提高了肝脏中α-生育酚含量和肌肉中T-SOD活性(P＜0.05).以上试验结果提示,饲粮中添加维生素E可提高43～63日龄黄羽肉鸡机体抗氧化功能,改善肉品质,且添加20 mg/kg效果较好.     

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.     

洋葱提取物对肉鸡生长性能、血清生化指标及肉品质的影响

文章旨在探讨日粮添加洋葱提取物对肉鸡生长性能、血清生化及肉品质的影响。试验选择平均体重接近的1日龄肉仔鸡512只,随机分为4组,每组4个重复,每个重复32只。对照组饲喂基础日粮,T1组肉鸡饲喂基础日粮+60?mg/kg抗菌肽,T2组和T3组肉鸡分别饲喂基础日粮+200、400?mg/kg洋葱提取物,试验共进行35?d。结果：T1～T3组肉鸡35?d体重较对照组分别显著提高2.08%、1.00%和0.84%（P＜0.05）,而T1和T2组肉鸡1～35?d料重比较对照组分别显著降低1.55%和1.55%（P＜0.05）。与对照组相比,处理组血清甘油三酯浓度分别显著降低19.18%、20.10%和18.60%（P＜0.05）,同时T2和T3组肉鸡血清胆固醇含量较对照组分别显著降低24.84%和23.16%（P＜0.05）。T2和T3组肉鸡腹脂相对重量较对照组分别显著降低12.50%和10.53%（P＜0.05）,而对照组肌肉蒸煮损失较处理组分别显著提高9.75%、10.96%和10.12%（P＜0.05）。结论：日粮添加洋葱提取物对肉鸡生长性能的影响与抗菌肽的效果相似,同时洋葱提取物可改善肉鸡脂肪代谢,降低腹脂水平和肌肉蒸煮损失。在本研究条件下,日粮中适宜的洋葱提取物添加水平为200?mg/kg。 [关键词]洋葱提取物|肉鸡|生长性能|肉品质|血清生化     

Influence of dietary vitamin E supplementation on "heavy" pig carcass characteristics, meat quality, and vitamin E status.

Crossbred "heavy" pigs (average weight 120 kg, slaughter weight above 160 kg) were supplemented with all-rac-alpha-tocopheryl acetate during the last 60 d of late finishing at doses of 25 (control), 50, 100, 200, or 300 mg/kg of diet. At the end of this period, the pigs were slaughtered. Carcass characteristics and the meat quality of pork chops from longissimus muscle (LM) at the last lumbar vertebra were evaluated on eight barrows from each dosage group. Alpha-tocopherol levels were determined in plasma during supplementation and in LM muscle after slaughter. Thiobarbituric acid reactive substances (TBARS) and drip loss were also evaluated in meat. Plasma alpha-tocopherol levels increased (P < .005) during supplementation in treated animals compared to controls, with a peak at 40 d. Alpha-tocopherol levels were higher (P < .05) in LM from pigs treated with 300 mg/kg than in controls (8.4 vs 5.6 microg/g). Dressing percentages correlated (P < .05) with the ratio of plasma alpha-tocopherol levels to the sum of cholesterol and triglycerides. Inhibition of TBARS during storage was related (P < .005) to vitamin E supplementation level, but drip losses in chops were not related to supplementation levels. We concluded that dietary vitamin E supplementation to heavy pigs during the last 60 d of finishing improves dressing percentage, reduces lipid oxidation, and increases the alpha-tocopherol concentration of tissues.     

甜菜碱对黄羽肉鸡屠宰性能和肌肉品质的影响

试验旨在研究甜菜碱对黄羽肉鸡屠宰性能和肌肉品质的影响。选用400只1日龄雌性黄羽肉鸡,随机分成5组,每组8个重复,每个重复10只鸡。对照组饲喂基础饲粮,试验组在基础饲粮中分别添加125、250、500、1 000 mg/kg甜菜碱。试验期74 d。结果表明：1)饲粮中添加甜菜碱可显著降低皮下脂肪厚度和肌间脂肪宽度(线性,P<0.05),对屠宰率、全净膛率无显著影响(P>0.05)。2)饲粮中添加甜菜碱可显著降低胸肌24和48 h滴水损失(线性与二次,P<0.05),且各试验组的胸肌24和48 h滴水损失显著低于对照组(P<0.05)。饲粮中添加甜菜碱可显著提高胸肌中不易流动水的峰面积比(线性,P<0.05),显著降低胸肌中不易流动水的出峰时间、自由水的出峰时间、结合水的峰面积和结合水的峰面积比(线性,P <0.05),且500、1 000 mg/kg甜菜碱添加组胸肌中自由水的出峰时间显著低于对照组(P<0.05)。3)饲粮中添加甜菜碱可显著提高胸肌粗脂肪含量(线性,P<0.05),且1 000 mg/kg甜菜碱添加组胸肌中粗脂肪含量显著高...