Effects of selenium source and level on growth performance,antioxidative ability and meat quality of broilers

This experiment was conducted to investigate the effects of selenium(Se) source and level on growth performance, carcass traits, antioxidative ability and meat quality of broilers. A total of 320 one-d-old Arbor Acres commercial broilers were randomly assigned to 1 of 5 treatments with 8 replicates in a completely randomized design involving a 2×2 factorial arrangement of treatments plus one Se-unsupplemented basal diet control for 42 d. The two Se sources were sodium selenite and Se yeast, and the two supplemental Se levels were 0.20 and 0.40 mg Se kg–1. The results showed that broilers fed the Se-supplemented diets had higher(P0.05) average daily gain and average daily feed intake from 22 to 42 d of age, eviscerated yield and abdominal fat percentages, Se concentrations and glutathione peroxidase(GSH-Px) activities in breast and thigh muscles on d 42, and lower(P0.05) feed/gain from 1 to 21 and 22 to 42 d of age, mortality from 22 to 42 d of age and malondialdehyde(MDA) concentration in thigh muscle on d 42 than those fed the control diet. Broilers fed the diets supplemented with Se yeast had higher(P0.05) p H value and lower(P0.05) shear force in thigh muscle than those fed the diets supplemented with sodium selenite. Additionally, broilers fed the diets supplemented with 0.40 mg Se kg–1 had lower(P0.05) shear force in thigh muscle and higher(P0.05) GSH-Px activities in breast and thigh muscles than those fed the diets supplemented with 0.20 mg Se kg–1. Furthermore, broilers fed the diet supplemented with Se yeast at 0.40 mg Se kg–1 had higher(P0.05) Se concentrations in breast and thigh muscles than those fed the diet supplemented with Se yeast at 0.20 mg Se kg–1, but no differences(P0.05) were observed in these indices of broilers fed the diets supplemented with sodium selenite between 0.20 and 0.40 mg Se kg–1. The results from the present study indicated that supplemental Se could increase the growth performance, muscle Se concentration and antioxidative ability of broilers; and the Se from Se yeast was more effective than the Se from sodium selenite in improving meat quality of broilers.     

Effect of dietary supplementation with flavonoid from Scutellaria baicalensis Georgi on growth performance,meat quality and antioxidative ability of broilers

An experiment was conducted to investigate the effect of dietary supplementation with flavonoid from Scutellaria baicalensis Georgi(SBGFN) as SBGFN-zinc(SBGFN-Zn) on growth performance, meat quality, immune responses and antioxidation of broilers. A total of 450 one-d-old Arbor Acres male broilers were randomly allocated to 5 treatments with 6 replicates of 15 birds per replicate for each treatment in a completely randomized design. Birds were fed a SBGFN-unsupplemented cornsoybean meal basal diet(control) or the basal diet supplemented with 60, 120, 180 or 240 mg SBGFN kg~(–1) from SBGFN-Zn for 42 d. Dietary SBGFN supplementation affected(P0.03) drip loss in thigh muscle, total superoxide dismutase(T-SOD) and glutathione peroxidase(GSH-Px) activity in liver of broilers at 42 d of age. Chicks fed the diets supplemented with 120, 180 and 240 mg SBGFN kg~(–1) had lower(P0.03) drip loss of thigh muscle than those fed the control diet. Chicks fed the diet supplemented with 180 mg SBGFN kg~(–1) had higher(P0.03) liver T-SOD and GSH-Px activity than those fed the diets supplemented with 0, 60 and 120 mg SBGFN kg~(–1). The results from the present study indicate that dietary supplementation with 180 mg SBGFN kg~(–1) as SBGFN-Zn improved both meat quality and antioxidative ability of broilers.     

角鲨烯对1~21日龄白羽肉鸡生长性能、抗氧化能力 和免疫功能的影响

为了研究SQ对1～21日龄白羽肉鸡生长性能、抗氧化能力和免疫功能的影响,选取体重为（38.38±0.25） g的 1日龄雄性AA⁺白羽肉鸡360只,将雏鸡随机分为3组,每组6个重复,每个重复20只,分别饲喂基础日粮,基础日粮+175 mg·kg^-1角鲨烯（squalene,SQ）和基础日粮+350 mg·kg^-1 SQ,试验期为21 d。结果表明：（1）饲粮中添加175和350 mg·kg^-1 SQ均能显著提高肉鸡平均日增重,并显著降低料重比（P＜0.05）,同时提高肉鸡血清中超氧化物歧化酶（superoxide dismutase,SOD）、谷胱甘肽过氧化物酶（glutathione peroxidase,GSH-Px）、过氧化氢酶（catalase,CAT）活性及总抗氧化力（total antioxidant capacity,T-AOC）（P＜0.05）,显著降低血清丙二醛（malonyldialdehyde,MDA）含量（P＜0.05）,且350 mg·kg^-1SQ 添加量在改善肉鸡血清过氧化氢酶活性和总抗氧化力方面,效果显著优于175 mg·kg^-1（P＜0.05）。（2）饲粮中添加175和350 mg·kg^-1 SQ均能显著提高肉鸡血清中高密度脂蛋白、补体C3和C4水平（P＜0.05）,显著降低血清中低密度脂蛋白水平（P＜0.05）,且350 mg·kg^-1 SQ 添加量在降低血清低密度脂蛋白和提高补体C3和C4水平方面效果显著优于175 mg·kg^-1（P＜0.05）。（3）饲粮中添加175和350 mg·kg^-1 SQ均能显著提高肉鸡免疫器官指数（P＜0.05）。综上所述,饲粮中添加 SQ能有效改善1~21日龄白羽肉鸡生长性能、抗氧化能力和免疫功能,其中350 mg·kg^-1 SQ在改善肉鸡血清过氧化氢酶、总抗氧化力、补体C3和C4方面更具优势。     

舍内不同氨气浓度对肉鸡抗氧化性能及肉品质的影响

【目的】探讨鸡舍内不同氨气浓度对肉鸡抗氧化性能和肉质性状的影响。【方法】采用单因素完全随机设计,将400只21日龄健康艾拔益加（AA）肉公鸡,随机分在4个呼吸代谢舱中,每个舱为1个处理,每个处理设4个重复,每个重复25只鸡。4个处理组分别为：对照组氨气浓度控制在＜3 mg·kg-1,试验组氨气浓度分别控制在(25±3)、(50±3)和(75±3) mg·kg-1。呼吸代谢舱采用全自动化控制养殖环境条件。试验期为21 d,21-31 d为试验前期,32-42 d为试验后期。肉鸡采用网上平养,自由采食和饮水。分别在32 d和42 d屠宰取样,测定肉鸡血液、肌肉、肝脏的抗氧化性能以及肉质性状。【结果】1）抗氧化性能：在21-31日龄阶段,随着鸡舍氨气浓度的升高,肉鸡血清超氧化物歧化酶（superoxide dismutase,SOD）活性呈二次曲线增加（P＜0.05）,总抗氧化能力（total antioxidation capacity,T-AOC）活性和丙二醛（malondialdehyde,MDA）含量呈线性增加（P＜0.05）;胸肌过氧化氢酶（catalase,CAT）活性和MDA含量具有呈线性增加的趋势（0.05＜P＜0.10）,而T-AOC活性呈线性降低（P＜0.05）;腿肌T-AOC活性有呈线性增加的趋势（0.05＜P＜0.10）,75 mg·kg^-1氨气处理组SOD活性显著高于对照组（P＜0.05）;肉鸡肝脏CAT活性具有线性降低的趋势（0.05＜P＜0.10）,MDA含量呈现线性增加（P＜0.05）。在32-42日龄阶段,随着鸡舍氨气浓度的升高,肉鸡血清谷胱甘肽过氧化物酶（glutathione peroxidase,GSH-Px）活性呈二次曲线降低（P＜0.05）,CAT活性呈线性降低（P＜0.05）,50 mg·kg^-1氨气处理组SOD活性显著低于对照组（P＜0.05）;胸肌CAT活性呈线性增加（P＜0.05）,T-AOC活性呈二次曲线降低（P＜0.05）;腿肌GSH-Px活性呈二次曲线增加（P＜0.05）,75 mg·kg^-1 氨气处理组腿肌SOD活性显著高于其他各组（P＜0.05）;肝脏T-AOC活性具有呈二次曲线增加的趋势（0.05＜P＜0.10）,GSH-Px活性呈线性降低（P＜0.05）。（2）肉质性状：在21-31日龄阶段,随着氨气浓度的升高,肉鸡胸肌剪切力和肉色b*值呈线性降低（P＜0.05）,L*值呈线性升高（P＜0.05）;腿肌肉色L*值呈线性降低（P＜0.05）,肉色a*值和宰后24 h的pH值呈二次曲线增加（P＜0.05）,b*值具有线性降低的趋势（0.05＜P＜0.10）。在32-42日龄阶段,随着氨气浓度的升高,肉鸡胸肌剪切力和肉色a*值呈线性降低（P＜0.05）,b*值与屠宰后24 h肉质pH值均呈线性升高（P＜0.05）,50 mg·kg^-1氨气处理组胸肌肉色L*值显著高于其他各组（P＜0.05）;宰后45 min腿肌pH具有呈二次曲线增加的趋势（0.05＜P＜0.10）。【结论】鸡舍高浓度氨气可降低肉鸡的抗氧化能力,影响鸡肉品质,且随氨气浓度的升高而逐渐增强,具有时间累加效应。     

新型复合氨基酸络合铁对肉鸡生产性能、血液指标和组织铁含量的影响

为探究肉鸡日粮中添加以两种氨基酸螯合成的新型复合氨基酸络合铁添加剂对肉鸡生长性能、器官指数、血液指标、组织抗氧化性能和铁含量的影响,选用960只1日龄爱拔益加(AA)肉鸡公雏,随机分为6个处理,每个处理8个重复,每个重复20只雏鸡。试验处理组分别在玉米-豆粕基础日粮中添加0、20、40、80及120mg/kg的新型复合氨基酸络合铁(ZprFe)和80mg/kg硫酸亚铁(FeSO_4)。结果表明:1)肉鸡日粮中添加ZprFe对肉鸡平均日采食量、平均日增重、料重比均无显著差异(P0.05)。2)日粮中添加ZprFe显著提高了肉鸡42日龄肝脏和脾脏指数(P0.05),且随着日粮中铁水平的添加呈线性和二次增加(P0.05)。3)添加ZprFe显著提高21日龄和42日龄血清铁含量(P0.05);显著降低21日龄血清总铁结合力(P0.05),但对42日龄血清总铁结合力无显著影响(P0.05)。添加ZprFe显著提高21日龄血清含锰超氧化物歧化酶(Mn-SOD)活性和42日龄血清含铜与锌超氧化物歧化酶CuZn-SOD活性(P0.05)。4)添加ZprFe对肝脏总超氧化物歧化酶(T-SOD)和总抗氧化能力(T-AOC)无显著影响(P0.05),但可显著提高胸肌T-SOD活性和T-AOC能力(P0.05)。添加ZprFe对肝脏铁含量影响显著,随着日粮中铁水平含量的增高,肝脏铁含量呈显著线性增加(P0.05)。综上,日粮中添加新型复合氨基酸络合铁ZprFe有利于肉鸡器官生长发育,提高肉鸡抗氧化性能和组织铁沉积,推荐在本研究条件下AA肉鸡日粮中添加ZprFe的适宜添加范围为40～80mg/kg,为实际生产提供理论依据。     

21～42日龄肉鸡能量和蛋白质需要量的研究

以商品代艾维茵肉鸡为供试动物,设置3个日粮代谢能(ME)水平,分别为12.55、12.97和13.38 MJ/kg;4个粗蛋白(CP)水平,分别为18.5%、19.0%、19.5%和20.0%.采用3×4因子设计进行饲养试验, 研究日粮ME和CP水平对22～42日龄肉鸡生产性能、胴体性能以及肉品质的影响.结果表明:(1)日粮ME水平对22～42日龄肉鸡的日均采食量、平均日增体质量、料重比和21日体质量影响极显著(P<0.01);日粮CP水平对22～42日龄肉鸡的日均采食量影响不显著(P>0.05),但对平均日增体质量、42日体质量和料重比影响极显著(P<0.01).日粮ME和CP的互作对22～42日龄肉鸡料重比影响极显著(P<0.01);较高的日粮ME水平和CP水平可获得理想的生产性能;(2)日粮ME水平对22～42日龄肉鸡半净膛率、腿肌率和腹脂率影响极显著(P<0.01),对屠宰率影响显著(P<0.05),对全净膛率和胸肌率影响都不显著(P>0.05);日粮CP水平与22～42日龄肉鸡的胸肌率呈正相关,对其他胴体性能指标影响不显著(P>0.05);(3)随日粮ME水平增加,腿肌的红度(a*)先降低后增加,但对胸肌红度(a*)影响不显著(P>0.05);胸肌和腿肌的黄色度值(b*)都与日粮ME和CP水平呈正相关;日粮ME水平对胸肌的亮度(L*)影响不显著(P>0.05);(4)胸肌的PH值与日粮ME水平呈负相关,腿肌的pH值随日粮CP水平的升高呈先上升后下降趋势;腿肌的持水率与日粮ME水平呈正相关.通过本试验并结合生产实际认为: 22～42日龄肉鸡适宜的ME水平为12.97MJ/kg,CP水平为19.0%～20.0%之间.     

α-半乳糖苷酶对肉鸡生产性能和养分代谢率的影响

为研究在玉米-豆粕型基础日粮中添加不同水平的α-半乳糖苷酶制剂对AA肉鸡生产性能和养分代谢率的影响。饲养试验选用1日龄AA肉仔鸡360只,随机分为5个处理,在基础日粮中分别添加0、0.05、0.10、0.15、0.20g/kgα-半乳糖苷酶制剂,每个处理6个重复,每个重复12只鸡,试验期6周,测定21d和42d的平均日增体质量、日采食量和料重比。结果表明:0.10、0.15、0.20g/kgα-半乳糖苷酶组显著提高21、42日龄日增体质量,增幅为2.56%～4.54%(P<0.05),降低42日龄的料重比,降幅为1.91%～4.59%(P<0.05);排空强饲代谢试验结果表明:在玉米-豆粕型日粮中添加α-半乳糖苷酶,提高了表观代谢能及真代谢能能值,增幅为0.31～0.34MJ/kg(P<0.05),改善了其他营养物质的利用率。综合分析,以0.1～0.2g/kgα-半乳糖苷酶添加水平效果较好。     

Effectiveness of dietary xylo-oligosaccharides for broilers fed a conventional corn-soybean meal diet

An experiment was conducted to investigate the effect of dietary supplementation of xylo-oligosaccharides(XOS) on growth performance, meat quality, immune functions, duodenal morphology and intestinal microbial populations of broilers fed a conventional corn-soybean meal basal diet. A total of 450 1-day-old commercial Arbor Acres male broiler chicks were randomly allocated by bodyweight to 1 of 5 treatments with 6 replicate cages(15 broilers per cage) for each of 5 treatments in a completely randomized design. Chicks were fed the basal corn-soybean meal diets supplemented with 0, 25, 50, 75, or 100 mg of XOS kg–1 of diet, respectively, for an experimental duration of 42 days. The results showed that supplementation of XOS affected feed conversion rate(feed/gain, F/G) during days 22–42 and 1–42(P0.03), drip loss in thigh muscle(P=0.02), and duodenal crypt depth(P=0.005) on day 42, but had no effect(P0.05) on all other measured indices. The chicks fed the diet supplemented with 100 mg of XOS kg–1 had the lowest(P0.05) F/G and drip loss in thigh muscle. The drip loss in thigh muscle decreased linearly(P=0.003) as the supplemented XOS increased. Duodenal crypt depth decreased(P0.05) at the supplemental level of 75 mg of XOS kg–1. The results indicate that dietary supplementations of 75 and 100 mg of XOS kg–1 are beneficial to broilers fed a conventional corn-soybean meal diet.     

饲粮中添加不同剂量Vc对0～21日龄肉仔鸡腹水综合征的影响研究

试验采用2×3因子设计,研究正常和T3诱导2种条件下,3个不同梯度饲粮Vc水平对肉鸡生产性能、血液生化指标、机体氧化和抗氧化功能、腹水综合征(AS)发病率及死亡率的影响。180只1日龄AA肉鸡随机分配到6个处理,每处理3重复,试验期为21 d。结果表明:①T3诱导肉鸡AS可显著或极显著降低肉鸡0~21日龄平均增重(P<0.01),血液、肝脏、肺脏总抗氧化能力(T-AOC,P<0.05);显著或极显著增加血液乳酸(Lac)浓度(P<0.01)、乳酸脱氢酶(LDH)活性(P<0.05)、心脏指数(P<0.01)、肺脏Vc含量(P<0.05),血液、肝脏和肺脏丙二醛(MDA)极显著增加(P<0.01);②饲粮Vc可极显著降低肉鸡血液Lac的浓度、LDH活性及MDA的含量(P<0.01),可显著增加肺脏T-AOC(P<0.05),降低肝脏MDA(P<0.05),1000 mg/kg Vc对肉鸡生产性能、机体抗氧化功能的改善作用比500 mg/kg Vc好;③饲料Vc对AS肉鸡的料肉比、心脏指数和血液T-AOC有显著的影响(P<0.05)。从本结果可看出,为增进0~21日龄正常和腹水肉鸡机体健康,预防肉鸡AS发生,其饲粮Vc的适宜添加量为1000 mg/kg。     

Effect of dietary calcium or phosphorus deficiency on bone development and related calcium or phosphorus metabolic utilization parameters of broilers from 22 to 42 days of age

This experiment was conducted to investigate the effect of dietary calcium (Ca) or phosphorus (P) deficiency on bone development and related Ca or P metabolic utilization parameters of broilers from 22 to 42 days of age based on our previous study, which indicated that dietary Ca or P deficiency impaired the bone development by regulating related Ca or P metabolic utilization parameters of broilers from 1 to 21 days of age. A total of 504 one-day-old Arbor Acres male broilers were randomly assigned to 1 of 4 treatments with 7 replicates in a completely randomized design, and fed the normal control and Ca- or P-deficient diets from 1 to 21 days of age. At 22 days of age, the broilers were further fed the normal control diet (0.90% Ca+0.35% non-phytate P (NPP)), the P-deficient diet (0.90% Ca+0.18% NPP), the Ca-deficient diet (0.30% Ca+0.35% NPP) or the Ca and P-deficient diet (0.30% Ca+0.18% NPP), respectively. The results showed that dietary Ca or P deficiency decreased (P<0.05) tibia bone mineral density (BMD), bone breaking strength (BBS), ash content, tibia ash Ca content and serum P content on days 28 and 42, but increased (P<0.05) tibia alkaline phosphatase (ALP) activity of broilers on day 42 compared with the control group. Furthermore, the broilers fed the P-deficient diet had the lowest (P<0.05) tibia BMD, BBS, ash content, serum P content and the highest (P<0.05) serum Ca content on day 28 compared with those fed the Ca-deficient or Ca and P-deficient diets. The results from the present study indicated that the bone development and related Ca or P metabolic utilization parameters of broilers were the most sensitive to dietary P deficiency, followed by dietary Ca deficiency or Ca and P-deficiency; dietary Ca or P deficiency impaired the bone development possibly by regulating serum Ca and P contents as well as tibia Ca content and ALP activity of broilers from 22 to 42 days of age.     

壳聚糖对肉仔鸡肉品质的影响

试验旨在探讨壳聚糖对鸡肉品质的影响.试验选用了体重相近的健康的1日龄AA肉仔鸡(公)120只,随机分成5组,每组设4个重复,每个重复6只鸡.在各组基础饲料中分别添加0、50、100、150mg·kg-1的壳聚糖,第5组在基础日粮中添加6mg·kg-1黄霉素,试验期42d.结果表明,肉仔鸡日粮中添加不同水平的壳聚糖,鸡肉...     

鸡源复合益生菌对肉仔鸡免疫球蛋白及Toll样受体通路的影响

目的 探究益生菌对肉仔鸡血清免疫球蛋白与肠道Toll样受体通路的影响。方法 选择90只1日龄白羽肉杂鸡,随机分为3组,即对照组、益生菌低剂量组和益生菌高剂量组。其中对照组饲喂基础日粮,益生菌低剂量组在每千克基础日粮中添加复合益生菌10⁹ cfu,益生菌高剂量组在每千克基础日粮中添加复合益生菌2×10⁹ cfu。第21天,每组随机选取10只鸡放血致死,并立即采集样本,进行ELISA、免疫组化、qPCR及Western blot检测。结果 在第21天,益生菌低剂量组和益生菌高剂量组鸡的料肉比分别比对照组降低9%和12% (P<0.05),血清IgG含量分别升高28%和40% (P<0.01),血清IgM含量分别升高44%和58% (P<0.01)。益生菌低剂量组TLR4蛋白表达和mRNA相对表达量比对照组分别升高33%和28%,AP-1蛋白表达和mRNA相对表达量分别比对照组升高106%和67% (P<0.01);益生菌高剂量组TLR4蛋白表达及mRNA相对表达量比对照组分别升高106%和69%,AP-1蛋白表达及mRNA相对表达量比对照组分别升高163%和98% (P<0.01)。结论 饲喂益生菌可降低肉仔鸡料肉比,提高血清中IgG、IgM的含量,并且通过调节Toll样受体通路蛋白表达可以提高机体免疫力。     

Effects of Dietary Isoflavone Supplementation on Meat Quality and Oxidative Stability During Storage in Lingnan Yellow Broilers

To investigate the effects of a synthetic isoflavone （SI） on meat quality and oxidative stability, 1 500 43-d-old Lingnan yellow male broilers were randomly assigned to five dietary treatments： diets supplemented with 0, 10, 20, 40, or 80 mg SI kg-1, fed ad libitum for a period of 3 wk. After refrigerated storage, a＊ value of the meat increased with dietary SI supplementation using 10 and 40 mg kg-1 level （P〈0.05）, L＊ value decreased （P〈0.05）, and 40 mg kg-j increased the pH （P〈0.05）. Supplementation with SI, at all levels, increased water holding capacity （P〈0.05） and decreased lactic acid content of meat （P〈0.05）. The concentration of malondialdehyde at 72 h decreased linearly （P=0.005） and quadratically （P=0.004） with increasing levels of SI. Dietary SI at 20 and 40 mg kg-1 levels enhanced total superoxide dismutase activity in meat （P〈0.05）. Meat pH quadratically decreased as the storage time increased （P〈0.05）, with the highest value at 24 h （P〈0.05）. Lactic acid and malondialdehyde concentrations of meat increased over time, with value at 96 h being far higher than at earlier times （P〈0.05）. Supplemental SI linearly and quadratically increased the mRNA abundance ofglutathione peroxidase （GPX） （P=0.001 and P=0.002） and catalase （CAT） （P=0.003 and P=0.006） in breast muscle. The results from this study indicate that dietary supplementation with SI can improve meat quality during refrigerated storage by decreasing lipid peroxidation and enhancing oxidative stability and, for male broilers from 43 to 63 d of age, the optimal level of SI was 40 mg kg-1.     

The toxicological effect of dietary excess of saccharicterpenin,the extract of camellia seed meal,in piglets

Recently, saccharicterpenin extracted from Camellia oleifera seed meal has become a widely used feed supplement in animal husbandry. In order to assess its safety, this study was designed to investigate the toxicity and histopathological effects of saccharicterpenin on piglets. One hundred-fifty weaned pigs((Yorkshire×Landrace)×Duroc), 75 males and 75 females with body weight(BW) of(7.35±0.29) kg, were randomly allotted to groups receiving diets supplemented with 0, 500, 1 000, 2 500 or 5 000 mg kg~(–1) saccharicterpenin for 70 d. The diet with 500 mg kg~(–1) saccharicterpenin supplementation improved liver glutathione peroxidase(GSH-Px) activity, and the diet with 1 000 mg kg~(–1) saccharicterpenin supplementation improved liver glutathione S-transferase(GSH-S) activity in piglets on d 70(P0.05). At 2 500 mg kg~(–1), saccharicterpenin in the diets reduced average daily feed intake(ADFI) and average daily gain(ADG) of piglets from d 1 to 35, damaged the cardiac tissue and liver on d 35, and decreased white blood cell counts(WBC), activities of catalase(CAT) and GSH-Px, and concentrations of glucose(GLU) and urea nitrogen(BUN) in the blood of piglets on d 70(P0.05). In addition, diets with 5 000 mg kg~(–1) saccharicterpenin supplementation reduced ADFI, ADG and increased diarrhea rates of piglets from d 36 to 70, and decreased hemoglobin(HGB) concentration and activity of CAT in the blood of piglets on d 70(P0.05). Moreover, at a rate of 5 000 mg kg~(–1), saccharicterpenin supplementation increased pancreas index on d 35 and hepatic index on d 70, and damaged cardiac tissue, liver and spleen during the whole experimental period(P0.05). These results suggested that dietary 500 mg kg~(–1) saccharicterpenin supplementation had beneficial effects on piglets, but excessive supplementation(2 500 or 5 000 mg kg~(–1)) of saccharicterpenin in the diets could lead to growth retardation, hematological abnormalities and organ injuries.     

复合蛋白酶和甘露寡糖对肉鸡消化道的影响及其互作效应研究

试验选用1日龄、平均体质量为(37.6±0.42)g的爱拨益加肉雏鸡112羽以研究蛋白酶和甘露寡糖对肉鸡消化道的影响及其互作效应。随机将试验鸡只分为4个组,每组4个重复,每个重复7羽鸡。试验分两个阶段,即前期(1～21 d)和后期(22～42 d)。试验组曰粮在玉米.豆粕日粮的基础上分别添加125 g/t的蛋白酶、1 000g/t的甘露寡糖及125 g/t的蛋白酶+1 000 g/t的甘露寡糖。结果表明:与对照组相比,日粮中添加125 g/t的蛋白酶对21日龄肉鸡腺胃和肌胃相对重有降低的趋势(P>0.05),但显著提高了42日龄肉鸡的腺胃相对重(P<0.05)和日增重(P<0.01),对小肠(十二指肠、空肠、回肠)相对重略有提高(P>0.05);日粮添加1 000 g/t的甘露寡糖对肉鸡腺胃和肌胃的相对重也有降低的趋势(P>0.05),而对21日龄和42日龄肉鸡小肠相对重也略有提高(P>0.05),从全期以及整个生长期(1～42日龄)来看日增重并无显著提高作用(P>0.05)。随着日龄的增加3个试验组日增重有增加的趋势(P>0.05)。日粮添加125 g/t的蛋白酶+1 000 g/t的甘露寡糖对21日龄和42日龄肉鸡腺胃、肌胃、日增重和小肠相对重均没有明显的互作效应。     

五味子CO_2超临界提取物对肉仔鸡免疫功能的影响

文章通过以五味子CO2超临界提取物作为添加剂,研究其对肉鸡免疫功能的影响。试验选用1日龄的健康艾维茵肉仔鸡200只,随机分为5个处理组,空白组饲喂基础日粮,试验组分别在基础日粮中添加黄霉素5mg·kg-1、五味子CO2超临界提取物0.1%、0.15%、0.3%。于21、42、56日龄进行五味子提取物的免疫功能调控试验。结果表明,日粮中添加五味子提取物可显著提高肉仔鸡后期的胸腺指数,在日粮中添加0.3%五味子提取物可显著提高肉仔鸡血清NDV-HI抗体效价和血清溶菌酶含量,并可显著提高肉仔鸡血清IgM含量和肉仔鸡外周淋巴细胞转化率。结果显示,五味子能够增强肉鸡的免疫功能。     

棉籽低聚糖对肉仔鸡生长性能和抗氧化能力的影响

选用1日龄艾维茵肉仔鸡360只,雌雄各半,随机分为6个处理,每个处理6个重复,每个重复10只鸡。试验组在基础日粮中分别添加0.05%,0.1%,0.2%,0.3%的棉籽低聚糖和0.1%氟哌酸,观察对肉仔鸡生长性能和抗氧化能力的影响。结果表明：添加0.1%棉籽低聚糖和抗生素可显著提高肉仔鸡1～42 d增重（P〈0.01）,添加0.3%棉籽低聚糖可显著提高肉仔鸡1～21 d,1～42 d增重（P〈0.01）。添加0.1%,0.2%,0.3%棉籽低聚糖可显著提高23日龄肉仔鸡血浆总抗氧化能力（P〈0.05）。添加0.05%棉籽低聚糖可显著提高42日龄肉仔鸡血浆总超氧化物岐化酶（T-SOD）的活力（P〈0.05）,显著降低血浆丙二醛（MDH）含量（P〈0.05）。添加0.2%棉籽低聚糖和抗生素的处理组可显著提高肉仔鸡42日龄血浆过氧化氢酶（CAT）的活力（P〈0.01）。     

大蒜素对肉鸡生产性能和免疫机能的影响

选择1日龄爱拔益加(AA)商品肉鸡135只,随机分成3组(A、B、C),每组设3个重复,每个重复15只.A组为空白对照组,饲喂基础日粮;B组为在基础日粮中添加50 mg/kg洛克沙生和750 mg/kg 10％金霉素;C组在基础日粮中添加200 mg/kg大蒜素,研究大蒜素对肉鸡生产性能和免疫机能的影响.结果表明,与A组相比,大蒜素组在21、42日龄都能显著提高肉鸡的体重、日增重和成活率,显著降低21日龄料重比(P＜0.05),但42日龄料重比降低不明显,采食量在42日龄明显增加(P＜0.01);与B组相比.21日龄大蒜素组也能显著提高肉鸡体重(P＜0.01)、日增重(P＜0.05),降低料重比(P＞0.05),在42日龄大蒜素组也使肉鸡体重、日增重增加,料重比下降(P＞0.05);与A组相比,日粮中添加大蒜素后肉鸡胸腺指数和新城疫抗体效价显著提高(P＜0.05),但法氏囊指数和脾脏指数有所下降(P＞0.05);与B组相比,胸腺指数和新城疫抗体效价也有所增加(P＞0.05).这说明大蒜素具有促进肉鸡生长和提高免疫功能的效果.     

外源蛋白酶对肉鸡饲粮体外干物质消化率和酶水解物能值的影响

【目的】研究外源蛋白酶对肉鸡饲粮体外干物质消化率(DMD)和酶水解物能值(EHGE)的影响,并使用仿生法获取饲粮中外源蛋白酶的最适添加量,为饲用酶制剂效价快速评价方法的建立提供理论参考。【方法】试验采用单因素完全随机设计,对照组分别为肉鸡前期和后期基础饲粮(粗蛋白质水平分别为:24.29%和21.72%,干物质基础),试验组分别在肉鸡前期和后期基础饲粮中添加0、15 000、75 000和150 000 PROT·kg-1的外源蛋白酶,试验共8种饲粮样品,每种饲粮样品设5个重复,每个重复1根仿生消化管,使用单胃动物仿生消化系统(SDS-Ⅱ)分别模拟饲粮在鸡的胃和胃—肠道的消化过程,测试并计算饲粮样品的DMD、体外能量消化率(GED)和EHGE,分别建立DMD和EHGE与蛋白酶添加量(protease supplementation,PS)的回归方程,并分析DMD和EHGE与PS的相关关系。【结果】随着外源蛋白酶添加剂量的增加,肉鸡前期和后期基础饲粮全消化道DMD、GED和EHGE也随之增加(P0.01)。随着在肉鸡后期基础饲粮中外源蛋白酶添加剂量的增加,胃消化阶段的DMD和GED随之降低(P0.01)。而在肉鸡前期基础饲粮中添加外源蛋白酶,对胃消化阶段的DMD、GED和EHGE影响不显著(P0.05)。肉鸡前期基础饲粮全消化道DMD(%)和PS(g·kg~(-1))的关系为:DMD(%)=2.56 PS-0.82 PS×PS+73.90(R~2=0.82,RSD=0.42,P0.001);EHGE(MJ·kg~(-1))和PS(g·kg~(-1))的关系为:EHGE(MJ·kg~(-1))=0.75 PS-0.30 PS×PS+15.02(R~2=0.89,RSD=0.07,P0.001);当外源蛋白酶添加剂量为112 500 PROT·kg~(-1)时,肉鸡前期基础饲粮全消化道EHGE达到最大值。肉鸡后期基础饲粮全消化道DMD(%)和PS(g·kg~(-1))的关系为:DMD(%)=3.56PS-1.46 PS×PS+75.20(R ~2=0.70,RSD=0.60,P0.001);EHGE(MJ·kg~(-1))和PS(g·kg~(-1))的关系为:EHGE(MJ·kg~(-1))=0.61 PS-0.30 PS×PS+15.67(R~2=0.79,RSD=0.06,P0.001),当外源蛋白酶添加剂量为91 800 PROT·kg~(-1)时,肉鸡后期基础饲粮全消化道的EHGE达到最大值。【结论】玉米-豆粕基础饲粮中添加外源蛋白酶,可显著提高肉鸡基础饲粮体外全消化道DMD、GED和EHGE。但外源蛋白酶的添加剂量对不同消化道阶段和不同营养指标消化率的影响并不呈单纯一致的剂量反应规律。本试验条件下,肉鸡前期和后期基础饲粮中分别添加112 500和91 800PROT·kg~(-1)的蛋白酶时EHGE提升效果最好。     

Regulation of bone phosphorus retention and bone development possibly by BMP and MAPK signaling pathways in broilers

The bone morphogenetic protein (BMP) and mitogen-activated protein kinase (MAPK) signaling pathways play an important role in regulation of bone formation and development, however, it remains unclear that the effect of dietary different levels of non-phytate phosphorus (NPP) on these signaling pathways and their correlations with bone phosphorus (P) retention and bone development in broilers. Therefore, this experiment was conducted to investigate the effect of dietary P supplementation on BMP and MAPK signaling pathways and their correlations with bone P retention and bone development in broilers. A total of 800 one-day-old Arbor Acres male broilers were randomly allotted to 1 of 5 treatments with 8 replicates in a completely randomized design. The 5 treatments of dietary NPP levels were 0.15, 0.25, 0.35, 0.45 and 0.55% or 0.15, 0.22, 0.29, 0.36 and 0.43% for broilers from 1 to 21 days of age or 22 to 42 days of age, respectively. The results showed that extracellular signal-regulated kinase 1 (ERK1) mRNA expression in the tibia of broilers on days 14 and 28, phosphorylated-ERK1 (p-ERK1) on day 14, and BMP2 protein expression on days 28 and 42 decreased linearly (P<0.04), while c-Jun N-terminal kinase 1 (JNK1) mRNA expression on day 42 increased linearly (P<0.02) with the increase of dietary NPP level. At 14 days of age, total P accumulation in tibia ash (TP_TA), bone mineral concentration (BMC), bone mineral density (BMD), bone breaking strength (BBS) and tibia ash were negatively correlated (r=–0.726 to –0.359, P<0.05) with ERK1 and JNK1 mRNA as well as p-ERK1; tibia alkaline phosphatase (ALP) and bone gal protein (BGP) were positively correlated (r=0.405 to 0.665, P<0.01) with ERK1 mRNA and p-ERK1. At 28 days of age, TP_TA, BMC, BMD, BBS and tibia ash were negatively correlated (r=–0.518 to –0.370, P<0.05) with ERK1 mRNA and BMP2 protein, while tibia ALP was positively correlated (r=0.382 to 0.648, P<0.05) with them. The results indicated that TP_TA, BMC, BMD, BBS or tibia ash had negative correlations, while tibia ALP and BGP had positive correlations with ERK1 and JNK1 mRNAs, BMP2 protein and p-ERK1, suggesting that bone P retention and bone development might be regulated by BMP and MAPK signaling pathways in broiler chickens.