Evaluation in broilers of the probiotic properties of Pichia pastoris and a recombinant P. pastoris containing the Clostridium perfringens alpha toxin gene

The probiotic properties of Pichia pastoris and of a recombinant P. pastoris containing the Clostridium perfringens alpha toxin gene were evaluated in broilers. One-day-old chicks randomly divided in four groups were fed with commercial feed devoid of antibacterials. The control group (1) received plain food, while the other groups were supplemented with either P. pastoris (2), the recombinant P. pastoris (3) or Bacillus cereus var. Toyoi (4). At day 49, live weights, feed efficiency and seroconversions were higher (P<0.05) in the supplemented groups than in the control groups. Group 3 showed the best results, while group 2 had lower weight gain than groups 3 and 4 although food conversion was better than in group 4. Seroconversions were not different (P>0.05) among the supplemented groups. Adverse reactions were not observed in histopathologic evaluation. We concluded that P. pastoris and the recombinant P. pastoris could be used as probiotics in broilers.     

中草药和益生素对肉仔鸡生产性能影响的研究

试验旨在研究中草药、益生素及其合剂对肉仔鸡生产性能的影响。选择3500只1日龄罗斯308肉仔鸡随机分为7组,每组设5个重复,每个重复100只鸡,对照组饲喂基础日粮,试验1、2、3、4、5组分别在基础日粮的基础上添加0.5%的药方1、药方2、益生素、中草药益生素合剂药方3、中草药益生素合剂药方4组;抗生素组为基础日粮中添加500 mg/kg杆菌肽锌。结果表明,中草药益生素合剂药方3组的体重、料重比、死淘率与对照组相比差异显著(P＜0.05),与抗生素组相比差异不显著(P＞0.05),优于其它处理组。因此,药方3促生长抗病效果较好,可以替代抗生素。     

Administration of probiotics influences F4 (K88)-positive enterotoxigenic Escherichia coli attachment and intestinal cytokine expression in weaned pigs

ABSTRACT: This study evaluated the effect of the probiotics Pediococcus acidilactici and Saccharomyces cerevisiae boulardii on the intestinal colonization of O149 enterotoxigenic Escherichia coli harbouring the F4 (K88) fimbriae (ETEC F4) and on the expression of ileal cytokines in weaned pigs. At birth, different litters of pigs were randomly assigned to one of the following treatments: 1) control without antibiotics or probiotics (CTRL); 2) reference group in which chlortetracycline and tiamulin were added to weanling feed (ATB); 3) P. acidilactici; 4) S. cerevisiae boulardii; or 5) P. acidilactici + S. cerevisiae boulardii. Probiotics were administered daily (1 × 109 CFU per pig) during the lactation period and after weaning (day 21). At 28 days of age, all pigs were orally challenged with an ETEC F4 strain, and a necropsy was performed 24 h later. Intestinal segments were collected to evaluate bacterial colonization in the small intestine and ileal cytokine expressions. Attachment of ETEC F4 to the intestinal mucosa was significantly reduced in pigs treated with P. acidilactici or S. cerevisiae boulardii in comparison with the ATB group (P = 0.01 and P = 0.03, respectively). In addition, proinflammatory cytokines, such as IL-6, were upregulated in ETEC F4 challenged pigs treated with P. acidilactici alone or in combination with S. cerevisiae boulardii compared with the CTRL group. In conclusion, the administration of P. acidilactici or S. cerevisiae boulardii was effective in reducing ETEC F4 attachment to the ileal mucosa, whereas the presence of P. acidilactici was required to modulate the expression of intestinal inflammatory cytokines in pigs challenged with ETEC F4.     

非淀粉多糖酶和益生素对肉仔鸡生长性能及养分表观代谢率的影响

本研究旨在探讨在饲粮中添加非淀粉多糖酶和益生素对肉仔鸡生长性能和养分表观代谢率的影响。选用1日龄健康AA+肉仔鸡,采用单因素完全随机化试验设计,试验共设3个处理组,每个处理5个重复,每个重复40只。对照组饲喂基础饲粮,试验1组饲喂基础饲粮+400 mg/kg非淀粉多糖酶,试验2组饲喂基础饲粮+100 mg/kg益生素,试验期6周。结果表明:益生素与对照组相比能显著提高1～42日龄肉仔鸡的日采食量5.26%(P<0.05),分别降低1～21日龄6.43%(P<0.05)和1～42日龄料重比4.57%(P<0.05)。非淀粉多糖酶和益生素能显著提高钙的表观代谢率6.83%(P<0.05)和11.86%(P<0.05),以及磷的表观代谢率11.45%(P<0.05)和16.10%(P<0.05)。由此得出,添加非淀粉多糖酶和益生素对肉鸡生长性能和表观养分代谢率作用有所提高,益生素组好于非淀粉多糖组。     

苯甲酸和精油对肉鸡生长性能、抗氧化状态和肠道微生物群的影响

本研究开展了3个饲养试验,旨在探讨苯甲酸和精油单独或联合使用对肉鸡生长性能、肠道微生物含量及肝脏抗氧化性能的影响。试验1和2均选择1日龄肉鸡450只,分为3组,每组5个重复,每个重复30只。对照组均饲喂相同的基础日粮,试验1处理组肉鸡分别饲喂基础日粮添加1.5和3 g/kg苯甲酸,试验2处理组肉鸡分别饲喂日粮添加2和4 mg/kg精油。试验3选择1日龄肉鸡300只,分为2组,每组5个重复,每个重复30只,对照组饲喂基础日粮,处理组饲喂基础日粮添加1.5 g/kg苯甲酸和4 mg/kg精油。3个试验均开展42 d。结果：试验1,1.5 g/kg苯甲酸组较对照组和3 g/kg苯甲酸组显著提了21和42 d肉鸡的体重及1～21 d、22～42 d、1～42 d日增重（P＜0.05）,同时1.5 g/kg苯甲酸组各阶段肉鸡料重比最低（P＜0.05）。与对照组相比,苯甲酸处理组显著提高了盲肠乳酸菌含量（P＜0.05）,显著降低了盲肠大肠杆菌数量（P＜0.05）。试验2,基础日粮添加4 mg/kg植物精油组42 d肉鸡体重和日增重、盲肠乳酸菌含量（P＜0.05）,料重比和盲肠大肠杆菌数量最低（P＜0.05）。同时,植物精油组较对照组显著提高了肝脏谷胱甘肽过氧化物酶（GSH-Px）和谷胱甘肽-S转移酶（GST）活性（P＜0.05）,显著降低了肝脏丙二醛含量（P＜0.05）。试验3,处理组较对照组显著降低了嗉囊大肠杆菌数量（P＜0.05）。处理组肝脏谷胱甘肽过氧化物酶（GSH-Px）和和谷胱甘肽-S转移酶（GST）活性显著高于对照组（P＜0.05）,但丙二醛含量显著降低（P＜0.05）。结论：日粮添加1.5 g/kg苯甲酸或4 mg/kg精油可以改善肉鸡生长性能,降低肠道有害微生物含量,而苯甲酸与精油无论是单独添加还是联合使用均可以提高肉鸡肝脏的抗氧化状态。 [关键词]苯甲酸|精油|肉鸡|生长性能|抗氧化|微生物     

日粮中添加柑桔皮粉对黄杂肉用仔鸡生产性能的影响

将32日龄黄杂肉用仔鸡240只随机分成4组,每组60只雏鸡。第1组为对照组,第2～4组为试验组,分别饲喂在基础日粮的基础上添加了3．5％,3．0％,2．5％柑桔皮粉的日粮,试验期35天。结果表明,在日粮中添加3．5％的柑桔皮粉组鸡效果最佳,料重比3．09-1,比对照组鸡降低11．71个百分点,饲料转化率提高了13．27％,只均增重0．9345kg比对照组鸡（0．8365kg）提高11．72％（P〈0．05）。经济效益比对照组鸡提高27．35％,增重耗料成本降低了0．55元／kg。     

Growth response, blood characteristics and copper accumulation in organs of broilers fed on diets supplemented with organic and inorganic dietary copper sources

1. A 56-d experiment was conducted to study the comparative influence of organic and inorganic dietary copper (Cu) sources on growth, blood characteristics and copper accumulation in organs of broilers. 2. A total of 480 Arbor-Acre unsexed broilers were fed on diets containing copper sulphate (CuSO(4)) or copper proteinate (Cu Pro) at concentrations of 50, 100 or 150 mg/kg of Cu supplementation. The birds were given a broiler starter diet from 1-28 d and a broiler finisher diet from 29-56 d which contained 30·8 mg/kg and 41·1 mg/kg basal copper concentration respectively. Growth performance, blood characteristics and Cu accumulation in organs of the broilers were measured. 3. At 28 d, Cu Pro-fed birds had improved feed conversion ratio compared with CuSO(4). At 56 d, birds fed on Cu Pro diets had significantly greater body weight than CuSO(4)-fed birds. Birds fed on CuSO(4) supplemented diets had significantly better feed conversion efficiency. Feed consumptions for the two Cu sources were not significantly different. At no stage did the concentration of added Cu affect the productive traits measured. 4. Cu Pro supplementation increased haemoglobin concentration but reduced plasma triglyceride and plasma cholesterol. Plasma cholesterol decreased as Cu concentration increased. 5. There was a greater accumulation of Cu in the blood, heart, lung, liver and bone of broilers fed on Cu Pro than in those receiving CuSO(4). The liver Cu concentration increased as dietary Cu concentration increased. 6. Cu Pro was more effective in promoting growth and reducing blood cholesterol, and was more bio-available in the organs of broilers.     

Effects of chitosan on growth performance and energy and protein utilisation in broiler chickens

1. Two experiments were conducted to investigate the effects of dietary chitosan on growth performance, energy availability and protein retention in broilers. 2. Experiment 1 was a 42-d growth assay, in which 294 1-d-old male broilers were given one of 7 dietary treatments. A control feed was supplemented with 5 levels of chitosan (0.2, 0.5, 1.0, 3.0 and 5.0 g/kg) or 50 mg/kg chlortetracycline (CTC). 3. Increasing chitosan inclusion gave a nonlinear increase (P< 0.001) in feed conversion efficiency (FCE). Optimal growth and feed conversion were obtained with 0.5-1.0 g/kg chitosan. 4. In experiment 2, 42 1-d-old male broilers (6/treatment) were individually housed but fed on the same diets as in experiment 1. Excreta were collected from d 19-21 and d 40-42. 5. The addition of 0.5-1.0 g/kg chitosan increased nitrogen retention compared with the control group (P< 0.01), while apparent metabolisable energy in the diets was not altered.     

Intestinal morphology, brush border and digesta enzyme activities of broilers fed on a diet containing Cu2+-loaded montmorillonite

1. A total of 320 1-d-old Arbor Acres broiler chicks were used to investigate the effect of Cu(2+)-loaded montmorillonite (CM) on the growth performance, intestinal morphology and activities of brush border enzyme in the intestinal mucosa and digestive enzyme in the intestinal digesta of broilers. 2. The chicks were assigned randomly into 4 groups with 80 chicks per treatment. The 4 dietary treatments were: basal diet only (control group), basal diet + 2 g montmorillonite/kg, basal diet + 1 g CM/kg, and basal diet + 2 g CM/kg. The chicks were raised in cages and feed and water were provided ad libitum for a period of 42 d. 3. The addition of CM to the diet of broilers significantly increased body weight and feed efficiency. Similarly, birds receiving montmorillonite had higher feed efficiency than the control after 42 d of feeding. 4. Data on villus height and crypt depth for duodenum, jejunum and ileum indicated that treating the diet of broilers with either CM or montmorillonite improved the mucosal morphology of the small intestine. 5. The presence of CM in the diet of broilers significantly increased the activities of maltase, aminopeptidase N and alkaline phosphatase in small intestinal mucosa. However, the activities of protease, trypsin, chymotrypsin, amylase and lipase in small intestinal digesta of broilers fed on the CM-supplemented diet were slightly higher than control values.     

益生菌剂、异麦芽寡糖对肉仔鸡生产性能的影响

本试验研究在玉米-豆粕型基础日粮中添加益生菌剂、异麦芽寡糖对肉仔鸡生产性能的影响.结果表明与空白对照组相比,益生菌剂、异麦芽寡糖显著提高了肉仔鸡的体增重,改善了饲料效率(P＜0.05)益生菌组,日增重提高了3.1%,饲料效率提高了6.63%;异麦芽寡糖组,日增重提高了4.4%,饲料效率提高了1.1%.益生菌剂和异麦芽寡糖联合应用,日增重提高了4.9%,饲料效率提高了4.42%(P＜0.05),且效果优于畜禽常用抗生素-金霉素,是比较理想的抗生素替代品,益生菌剂和异麦芽寡糖的联合应用效果优于单独使用,但与单独使用的效果差异不显著(P＞0.05).     

复合芽孢杆菌制剂对肉鸡福利的影响

试验旨在探讨饲喂或鸡舍喷洒复合芽孢杆菌制剂对肉鸡福利状况的影响。选取健康、体重相近的1日龄AA肉鸡300只,随机分在3个处理中,每个处理4个重复,每个重复25只鸡,网上平养。处理1为对照组,饲喂玉米一豆粕基础日粮;处理2为饲喂组,在基础日粮中添加复合芽孢杆菌制剂200mg／kg;处理3为喷洒组,在鸡舍空气中喷洒复合芽孢杆菌喷剂。41日龄时对各处理肉鸡的福利状况进行评估。结果表明,饲喂组和喷洒组肉鸡试验期没有出现死亡,而对照组的死亡率为3％,各组间肉鸡死亡率差异不显著（P〉0．05）;肉鸡羽毛清洁度与步态评分结果优劣次序为：喷洒组〉饲喂组〉对照组;饲喂或喷洒芽孢杆菌的肉鸡脚垫评分都优于对照组;从跗关节损伤度来看,各处理组评分结果优劣程度为：对照组优于喷洒组,喷洒组优于饲喂组。试验结果显示,在AA肉鸡日粮中添加复合芽孢杆菌制剂或在鸡舍中喷洒复合芽孢杆菌制剂可以在一定程度上改善肉鸡的福利状况。     

布拉氏酵母对哺乳期犊牛生长性能、营养物质消化率和血清生化指标的影响

试验旨在研究布拉氏酵母菌对哺乳犊牛的生长性能、营养物质表观消化率和血清生化指标的影响.选择48头初生体重(38.16 ±3.73)kg且健康状况良好的中国荷斯坦犊牛,随机分为4组,每组12头,公母对半.各处理组饲粮中分别添加0(对照)、1(I组)、3(Ⅱ组)、5(Ⅲ组)g/(天?头)的布拉氏酵母,整个试验共42 d.结...     

日粮中添加微生态制剂对樱桃谷鸭生产性能的影响

试验旨在研究日粮添加不同水平微生态制剂对樱桃谷鸭生产性能的影响,确定最佳添加水平。选用1日龄樱桃谷鸭750只,随机分成5个组(试验Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ组,Ⅴ组为对照组),每组设3个重复,每个重复50只。分别在基础日粮中添加500、1000、1500、2000和0 mg/kg微生态制剂,饲养至42日龄。结果表明,添加1000和1500 mg/kg的微生态制剂促生长效果显著高于对照组(P<0.05);添加1000 mg/kg微生态制剂的肉鸭全程料重比最佳;添加500 mg/kg的微生态制剂组对肉鸭增重不明显;添加2000 mg/kg的微生态制剂组优于对照组和500 mg/kg添加组,但差异不显著(P>0.05)。因此,日粮微生态制剂能促进樱桃谷肉鸭的增重、降低料重比,从而提高其生长性能、产肉性能及养殖效益,1000 mg/kg微生态制剂能取得最佳料重比和经济效益,1500 mg/kg微生态制剂能取得最佳产肉性能,由此可知,添加1000 mg/kg微生态制剂为最佳添加水平。     

复合微生态制剂对肉鸡生产性能、肠道菌群、抗氧化指标和免疫功能的影响

本试验旨在探讨复合微生态制剂对肉鸡生产性能、肠道菌群、抗氧化指标和免疫功能的影响。将 ２４０只 １日龄雌性健康肉鸡随机分为 ４组,每组 ３个重复,每个重复 ２０只。试验预试期 ５ｄ,Ⅰ组为对照组,饲喂基础饲粮;Ⅱ、Ⅲ、Ⅳ组为试验组,在饲喂基础饲粮同时,分别定时在饮水中添加复合微生态制剂 Ａ及其佐剂 Ｂ,其中复合微生态制剂 Ａ的添加水平为饲粮的２．０‰,６日龄时开始添加,每周 ２次,每次饮用量为周采食量 ２．０‰的 １／２;复合微生态制剂佐剂Ｂ在 ７、１４和 ２１日龄免疫后分别连续使用 ３ｄ,每天 １次,每次饮用量为日采食量的 ０．５‰、１．０‰和 ２．０‰。正试期为 ３７ｄ。测定各组生产性能、肠道菌群数量、抗氧化指标和免疫指标。结果表明：１）在每个试验阶段,Ⅱ组肉鸡平均日增重均显著高于对照组（Ｐ＜０．０５）,料重比均显著低于对照组（Ｐ＜０．０５）,且除 ７～１４日龄和 １５～２１日龄料重比外,Ⅱ组肉鸡平均日增重最高,料重比最低,与其他组差异显著（Ｐ＜０．０５）。２）１４日龄和 ２８日龄时,Ⅱ组和Ⅲ组肉鸡盲肠乳酸菌数量均显著高于对照组（Ｐ＜０．０５）;１４日龄时,Ⅱ组和Ⅲ组肉鸡盲肠大肠杆菌数量均显著低于对照组（Ｐ＜０．０５）,２８日龄时,仅Ⅱ组肉鸡盲肠大肠杆菌数量显著低于对照组（Ｐ＜０．０５）。３）２１、２８和 ３５日龄时,Ⅱ组和Ⅲ组肉鸡血浆总抗氧化能力均显著高于对照组（Ｐ＜０．０５）,２组之间差异不显著（Ｐ＞０．０５）。４）１４日龄和 ４２日龄时,Ⅳ组肉鸡的脾脏指数最高,均显著高于对照组（Ｐ＜０．０５）;１４、２８和 ４２日龄时,Ⅲ组肉鸡的法氏囊指数均较高,显著高于对照组（Ｐ＜０．０５）。由此可知,２．０‰复合微生态制剂 Ａ和 ０．５‰复合微生态制剂佐剂 Ｂ能够提高肉鸡生产性能,改善其肠道微生态环境,提高其抗氧化能力。同时,复合微生态制剂及其佐剂的添加可在一定程度上增强肉鸡免疫功能。     

Effects of Probiotics Interaction on Growth Performance,Intestinal Digestion and Absorption,and Sugar Transporter GLUT2 in Broilers

The aim of this study was to investigate the effects of probiotic interaction on growth performance, intestinal nutrient digestion and absorption, and related sugar transporters in broiler. Two hundred 1-day-old male Arbor Acres broilers were selected, and then randomly divided into 4 groups with 5 replicates per group and 10 for each replicate. Lactobacillus casei, Lactobacillus acidophilus and Bifidobacterium lactis were mixed in proportion, and then fermented in milk. The chicks in the control group received normal drinking water, the chicks in probiotic group Ⅰ (mixed ratio of 2:1:1), group Ⅱ (mixed ratio of 1:2:1), and group III (mixed ratio of 1:1:2) received drinking water supplemented with 1% compound probiotics. All chickens were fed with normal diet for 42 days, every 21 days as a stage. The results showed that: 1) Compared to control group, the ADG(P<0.05) and feed conversion ratio (P>0.05) of broilers in all probiotic groups were improved. Furthermore, the production performance of broilers in probiotic group Ⅰ was higher than those of probiotic group Ⅱ and Ⅲ. 2) Compared to control group, specific activities of amylase, lipase, trypsin in jejunum of probiotic groups increased significantly (P<0.05). 3) In all probiotic groups, the intestinal villus height increased significantly (P<0.05), crypt depth decreased significantly (P<0.05), and the expression of glucose transporter 2 (GLUT2), particularly in probiotic group Ⅰ and Ⅲ, was significantly upregulated (P<0.05). In conclusion, probiotics interaction can enhance digestive enzyme activity, improve the structure of digestive tract, upregulate the expression of nutrient transporter, improve the nutrient digestibility and energy absorption efficiency, and further improve production performance of broiler. When the mixing ratio of L. casei, L. acidophilus and B. lactis was 2:1:1, the compound probiotics had a better effect on broilers.     

益生菌互作对肉鸡生长性能、肠道消化吸收及糖转运蛋白GLUT2影响的研究

旨在研究益生菌互作对肉鸡生长性能、肠道养分消化吸收及相关糖转运蛋白的影响。本研究中,200只1日龄雄性爱拔益加肉雏鸡被随机分为4组,每组5个重复,每个重复10只。将干酪乳杆菌、嗜酸乳杆菌和双歧杆菌分别按比例混合后于牛乳中发酵。对照组正常饮水（control组）,益生菌Ⅰ组（混合比例为2：1：1）、Ⅱ组（混合比例为1：2：1）、Ⅲ组（混合比例为1：1：2）补充1%复合菌乳制品于饮用水中,各组皆饲喂基础日粮。整个试验饲养周期为42 d,每21 d为一个阶段。结果表明：1）与对照组相比,益生菌互作组均可显著提高肉鸡平均日增重（P<0.05）,改善饲料利用率（P>0.05）,在所有益生菌互作组中,益生菌Ⅰ组的肉鸡生长性能最好;2）益生菌互作显著刺激了空肠淀粉酶、脂肪酶、胰蛋白酶的特异性活性（P<0.05）;3）益生菌互作组均显著提高了小肠绒毛高度（P<0.05）,降低了隐窝深度（P<0.05）,上调了GLUT2 mRNA的表达（P<0.05）,其中,以益生菌Ⅰ、Ⅲ组作用最佳。综上所述,益生菌互作能够增强消化酶活性、改善消化道结构、上调营养转运蛋白表达,提高养分的消化率及能量吸收有效性,从而提高肉鸡的生产性能;且当干酪乳杆菌、嗜酸乳杆菌和双歧杆菌的混合配比为2：1：1时,复合益生菌制剂对肉鸡的作用效果较佳。     

Foot ash can replace tibia ash as a quantification method for bone mineralization in broilers at 21 and 42 days of age

Prior research indicated that foot ash determinations were as robust as tibia bone ash determinations in reflecting the degree of bone mineralization in chicks at 14 d of age. In the current research, the relative effectiveness of the 2 procedures was evaluated in 21- and 42-day-old broilers while also evaluating a new dietary phytase supplement. In experiment 1, broilers were fed until 21 d of age a negative control diet with 0.24% available phosphorus, a positive control diet with 0.48% available phosphorus, or the negative control diet supplemented with 300, 500, 1,000, or 2,500 phytase units/kg diet. In experiment 2, broilers were fed until 42 d of age negative control diets having 0.275, 0.250, and 0.225 percent available dietary phosphorus in the starter, grower, and finisher periods, respectively, positive control diets having 0.475, 0.450, and 0.425 percent available dietary phosphorus in the starter, grower, and finisher periods, respectively, or the negative control diets supplemented with 500, 1,000, or 2,500 phytase units/kg diet. At 21 and 42 d of age, broilers fed diets supplemented with the 2 highest doses of phytase had foot and tibia ash values equal to those fed the positive control diet and higher than those fed the negative control diet. At 42 d of age, feed conversion and total breast meat yield values for the broilers fed the highest dose of phytase were superior to the values of the birds fed the positive control diet or the diet containing the lowest dose of phytase. The results indicate that adding levels of this new dietary phytase beyond what is necessary for normal bone mineralization enhances feed conversion and that dried foot and tibia bone ash determinations are both reliable in detecting differences in bone mineralization in 21- and 42-day-old broilers.     

Growth response of broilers to spray-dried plasma in pelleted or expanded feed processed at high temperature

A series of 4 experiments evaluated effects of mash conditioning temperature from a pellet mill or expander on performance of broilers fed pelleted diets containing spray-dried plasma (SDP). All experiments utilized Ross x Ross 308 male broilers randomly assigned to their respective treatments (6 or 10 broilers/pen and 8 or 10 pens/treatment). Treatments in Exp. 1 consisted of a control (0% SDP), SDP coated postpelleting, or SDP blended into the meal prepelleting. Experiment 2 and 3 included the same 3 treatments as in Exp. 1 but with additional treatments of SDP blended into the meal and conditioned at 90 or 95 degrees C before pelleting. In Exp. 4, treatments consisted of a control (0% SDP) or SDP blended into the meal and pelleted (85 degrees C conditioning temperature) or expanded (149 degrees C final effective temperature) and then pelleted. Corn-soybean meal-based diets were formulated to be equal in lysine and ME in all experiments. Pelleted diets were conditioned for 15 s at 85 degrees C, and expanded diets were conditioned at 95 degrees C, 29.7 MJ/t, 13.95 kg/cm2 cone pressure, exit temperature of 149 degrees C, and then pelleted through a 4 x 32-mm die. In Exp. 1, ADG and feed intake were improved (P < 0.05) for broilers fed SDP from d 1 to 28 of age, with greater BW at d 42. In Exp. 2, both in early (d 1 to 28 of age) phases, and overall (d 1 to 42 of age), broilers fed SDP had improved (P < 0.05) gain and efficiency. In Exp. 3, ADG, feed intake, efficiency of gain, and BW were improved (P < 0.01) for broilers fed SDP from d 1 to 21 of age, regardless of conditioning temperature. In Exp. 4, broilers fed SDP had improved (P < 0.05) gain, BW, and feed intake regardless of processing method. Overall, the results of all of the experiments demonstrated that pellet conditioning temperature from 85 to 95 degrees C and expander temperatures to 149 degrees C did not impair the positive growth effects of SDP in pelleted or expanded broiler feed.     

磷源对福美双诱导的肉鸡胫骨软骨发育不良及骨骼钙、磷代谢的影响

本试验旨在研究磷酸一二钙(MDCP)和磷酸氢钙(DCP)对福美双诱导的肉鸡胫骨软骨发育不良(TD)及骨骼钙、磷代谢的影响。选取1日龄科宝(Cobb)肉雏鸡120只,试验1～21 d采用2因子设计,按磷源的不同分为2个处理(磷源DCP和MDCP),每个处理60只鸡;试验22～42 d采用2×2因子设计,将每种磷源按福美双的添加水平不同再分为2个处理(福美双水平为0和100 mg/kg),每个处理3个重复,每个重复10只鸡。福美双组在基础饲粮中添加100mg/kg福美双,于22～28 d饲喂,然后换喂对应不含福美双饲粮。结果表明:1)MDCP组肉鸡第35天TD评分相对DCP组有降低的趋势(P=0.09),但磷源对肉鸡第28和42天TD评分影响差异不显著(P>0.05)。福美双显著升高了肉鸡第28、35和42天TD评分(P<0.05)。2)福美双和磷源对肉鸡第35天胫骨灰分、钙和磷含量交互效应显著(P<0.05)。福美双诱导条件下,MDCP组肉鸡第35天胫骨灰分、钙、磷含量显著高于DCP组(P<0.05)。3)DCP组第35天血清甲状旁腺素含量高于MDCP组(P=0.12)。由此可见,相对DCP,MDCP对福美双诱导的TD发生有一定减缓作用,且与肉鸡骨骼钙、磷代谢密切相关。2种磷源对肉鸡最终TD评分影响差异不显著。     

微生态制剂对应激雄性肉仔鸡生长性能和肠道健康的影响

本试验旨在研究应激对肉仔雄鸡生长性能和肠道健康的影响,以及微生态制剂的可能缓解作用。试验采用对肉仔雄鸡注射糖皮质激素(地塞米松)的应激模型,选取1日龄爱拔益加(AA)肉仔雄鸡176只,按照2×2析因进行试验设计,分为应激+微生态制剂组[皮下注射2 mg/kg BW地塞米松,饮用微生态制剂0.02 g/(只·d)]、应激组(注射2 mg/kg BW地塞米松)、微生态制剂组[注射2 mg/kg BW生理盐水,饮用微生态制剂0.02 g/(只·d)]、空白组(注射2 mg/kg BW生理盐水)4个组,每组4个重复,每个重复11只鸡。微生态制剂组和应激+微生态制剂组在肉鸡11~14日龄和25~28日龄饮水中添加用冷却沸水溶解的微生态制剂,应激组和空白组饮用相同体积不含微生态制剂的冷却沸水。应激组和应激+微生态制剂组在肉鸡12~14日龄和26~28日龄皮下注射地塞米松磷酸钠,微生态制剂组和空白组注射相同剂量的生理盐水。试验期35 d。结果表明:应激导致肉仔雄鸡35日龄的平均体重、平均日增重和欧洲效益指数显著降低(P0.05),料重比和死淘率显著提高(P0.05),15日龄和29日龄的免疫器官指数和空肠绒毛高度显著降低(P0.05);微生态制剂使肉仔雄鸡29日龄的胰脂肪酶活性和空肠绒毛高度显著提高(P0.05),隐窝深度显著降低(P0.05)。在绒毛高度/隐窝深度指标上,应激和微生态制剂有显著的交互作用(P0.05)。结果提示:应激能破坏肉仔雄鸡肠道微环境,降低肉仔雄鸡生长性能,抑制免疫器官正常发育;微生态制剂能显著缓解应激对肠道绒毛的损伤,但未发现微生态制剂对生长性能的显著作用。