谷氨酰胺对肉仔鸡生长性能和盲肠沙门氏菌定植的影响

文章旨在研究谷氨酰胺对肉鸡生长性能和盲肠沙门氏菌水平的影响。试验1选择1日龄AA肉仔鸡234只,随机分为3组,每组3个重复,每个重复26只鸡,对照组饲喂玉米-豆粕型日粮,处理1组饲喂基础日粮(在3日龄感染3.6×10^6cfu沙门氏菌),处理2组饲喂基础日粮+10g/kg谷氨酰胺(在3日龄感染3.6×10^6cfu沙门氏菌)。试验2选择1日龄AA肉仔鸡312只,随机分为4组,每组3个重复,每个重复26只鸡,对照组和处理1组同试验1,处理3组同试验1的处理2组,但肉鸡感染7.5×10^6cfu沙门氏菌试验2处理2组饲喂基础日粮+10g/kg谷氨酰胺(不感染沙门氏菌)。两个试验均开展14d。试验1:日粮添加谷氨酰胺对肉鸡生长性能无显著影响(P>0.05)。试验2:处理2组较其他组显著提高了1~7d肉鸡的体重和日增重(P<0.05)。肉鸡感染沙门氏菌4或10d后,日粮添加谷氨酰胺对盲肠沙门氏菌含量无显著影响(P>0.05)。结论:日粮添加1%谷氨酰胺可以提高肉鸡生长性能,但并没有降低盲肠沙门氏菌水平,这说明日粮中添加1%谷氨酰胺不足以达到降低盲肠沙门氏菌的最佳水平。     

微生态制剂对肉鸡生长性能、免疫功能、肠道菌群及血清生化指标的影响

为研究微生态制剂对肉鸡生长性能、免疫功能、肠道菌群及血清生化指标的影响,试验选用1日龄AA肉仔鸡800只,随机分为5组,每组8个重复,每个重复20只。对照组肉鸡饲喂基础日粮,微生态制剂组在基础日粮中依次添加剂量0.1%、0.2%、0.4%、0.6%的微生态制剂,试验期42 d。结果显示:与对照组相比,日粮中添加0.2%、0.4%和0.6%的微生态制剂显著提高肉仔鸡末重(P<0.05),微生态制剂组肉鸡的平均日增重均显著高于对照组(P<0.05),日粮中添加0.2%、0.4%和0.6%的微生态制剂显著降低料重比(P<0.05);日粮中添加微生态制剂可以提高肉鸡血清IgG水平,且0.4%微生态制剂组显著高于对照组(P<0.05);与对照组相比,日粮中添加0.2%、0.4%和0.6%的微生态制剂可显著降低肉鸡肠道中大肠杆菌和沙门氏菌数量(P<0.05),且0.4%添加量组的效果显著优于其他添加量组(P<0.05);日粮中添加0.2%、0.4%和0.6%的微生态制剂可显著增加肉鸡肠道找那个乳酸杆菌和双歧杆菌数量(P<0.05);日粮中添加0.2%、0.4%和0.6%的微生态制剂可显著提高肉鸡血清总蛋白含量,降低血糖含量(P<0.05)。研究表明,在肉鸡日粮中添加微生态制剂能够提高肉鸡的生长性能,提高机体免疫力,改善肠道菌群结构,最适添加量为0.4%。     

玉米-杂粕型日粮中添加蛋氨酸对肉鸡生产性能的影响

本试验旨在研究在杂粕日粮中添加蛋氨酸对肉鸡生产性能的影响。试验选用12栋标准化肉鸡舍,每栋鸡舍内饲喂1日龄、体重相近的AA肉鸡6,000只。试验分为4个处理组,每个处理3个重复,每栋鸡舍为一个重复组,处理1为纯豆粕日粮组,处理2为杂粕日粮组,处理3和处理4组分别在杂粕日粮中添加0.1%和0.2%的DL-蛋氨酸。结果表明,饲喂杂粕日粮组肉鸡平均日采食量、料重比显著高于纯豆粕日粮组(P<0.05);在杂粕日粮中添加蛋氨酸,可显著降低日粮的日采食量和料重比(P<0.05),对日增重有所改善;杂粕0.2%蛋氨酸添加组与纯豆粕日粮组相比,日增重、日采食量差异不显著(P>0.05),料重比显著降低(P<0.05);杂粕中添加0.2%蛋氨酸比0.1%蛋氨酸组,料重比显著降低(P<0.05)。因此,在杂粕日粮中,合理地补充外源性氨基酸可改善日粮的营养水平,提高肉鸡生产性能。     

蛋氨酸铬对肉鸡生长、脏器指数及血液生化指标的影响

试验旨在研究日粮中添加蛋氨酸铬对肉鸡生长、脏器指数及血清生化指标的影响,为确定日粮中蛋氨酸铬的适宜添加量提供科学依据。试验选用1日龄AA肉鸡528只,设4个处理,每个处理4个重复,每个重复33只。对照组饲喂玉米-豆粕型基础日粮,其它处理组饲喂分别在基础日粮中添加蛋氨酸铬0.1 mg/kg(Ⅰ组)、0.2 mg/kg(Ⅱ组)、0.6 mg/kg(Ⅲ组)的日粮(以Cr3+计),试验期49 d。结果表明:蛋氨酸铬能显著降低饲料消耗(P<0.05),但对肉鸡各日龄段平均体重、料重比和成活率影响差异均不显著(P>0.05)。除能显著降低心脏相对重量(P<0.05)外,日粮中添加蛋氨酸铬对肉鸡其它脏器相对重量影响差异均不显著(P>0.05)。日粮中添加蛋氨酸铬对血液生化指标影响显著(P<0.05)。因此,日粮中补充蛋氨酸铬对肉鸡生产性能、脏器指数影响不明显;但对血液生化指标影响显著,建议日粮中蛋氨酸铬添加量以0.2 mg/kg为宜。     

植酸酶对肉鸡日粮养分表观利用率和表观代谢能的影响

试验在肉鸡玉米-豆粕型日粮中添加500U/kg植酸酶,研究植酸酶对肉鸡生长性能、养分利用率和骨骼指标的影响。选择1日龄AA肉仔鸡384只(公母鸡各192只)。按体重相近,性别各半的原则,随机分成4组,每组设6个重复,每个重复16只。Ⅰ组为不添加植酸酶的基础日粮组(对照组);Ⅱ、Ⅲ、Ⅳ组为日粮中添加500U/kg植酸酶分别替代0.09%、0.11%、0.13%的无机磷。试验分为试验前期(0～3周)和后期(4～6周)。结果表明:在肉鸡玉米-豆粕型日粮中添加植酸酶可提高日粮干物质、有机物、粗蛋白的利用率,但差异不显著(P>0.05);钙利用率提高了17.23%(前期)和22.86%(后期),差异达到显著水平(P<0.05);磷利用率提高了18.98%(前期)和20.73%(后期),差异显著(P<0.05)。肉鸡对饲料的能量利用率提高了1.94%(前期)和1.63%(后期),差异显著(P<0.05)。     

葎草水提物对肉鸡脂质代谢和抗氧化能力的影响

为探讨葎草水提物对肉鸡脂质代谢和抗氧化能力的影响,选用200只AA肉鸡随机分成4个处理组,每组5个重复,每个重复10只,对照组饲喂基础日粮,试验1组、试验2组、试验3组在基础日粮中分别添加0.2%、0.4%、0.6%葎草水提物。结果表明:与对照组相比,试验2、3组的血清总胆固醇、甘油三酯、低密度脂蛋白胆固醇均显著降低(P0.05),高密度脂蛋白胆固醇显著提高(P0.05);试验2、3组分别较对照组的血清总超氧化歧化酶、谷胱甘肽过氧化物酶、血清总抗氧化能力均显著提高(P0.05),丙二醛含量显著降低(P0.05),可见葎草水提物可以改善肉鸡脂质代谢相关生化指标,提高肉鸡的抗氧化能力,综合各项指标,在肉鸡饲料里添加0.4%葎草水提物效果较为理想。     

大蒜素对肉仔鸡生长性能、血液指标和屠体特性的影响

文章旨在评估日粮添加不同水平大蒜素作为促生长剂对肉仔鸡生长性能、血液指标和胴体品质的影响。试验选择1日龄白羽肉鸡252只,随机分为3组,每组84只(每组4个重复,每个重复21只)。试验采用玉米-豆粕型日粮,各组日粮中分别添加0%、2%和4%大蒜素,试验共进行42d,分析肉鸡生长性能和血液指标。结果:日粮添加2%大蒜素显著提高肉鸡采食量、体增重、末重及饲料转化率(P<0.05)。各组日粮对肉鸡的屠宰率无显著影响(P>0.05)。2%大蒜素组胸肌重量最高(P<0.05),而4%大蒜素组胸肌重最低(P<0.05)。大蒜素组对肉鸡法氏囊和胸腺重量的影响无显著差异(P>0.05)。2%和4%大蒜素组较对照组显著降低了脾脏重量(P<0.05)。日粮大蒜素添加水平对肉鸡血液淋巴细胞、单核细胞、嗜酸性粒细胞、嗜中性粒细胞占比、红细胞压积、红细胞数和白细胞数均无显著影响(P>0.05)。结论:肉鸡饲喂添加2%大蒜素日粮生长性能参数最好,而4%大蒜素组最低,因此,肉鸡日粮中大蒜素适宜添加水平为2%。     

黄粉虫副产物替代部分豆粕对肉鸡生长性能、表观消化率、屠宰性能的影响

本试验旨在研究黄粉虫副产物替代部分豆粕对肉鸡生长性能、表观消化率、屠宰性能的影响及在日粮中的最适添加量。试验选用刚出壳的健康艾维茵肉公鸡1200羽,随机分为4组,每组6个重复,每个重复50羽。对照组饲喂基础日粮;处理I组饲喂按2%添加黄粉虫副产物替代部分豆粕的基础日粮;处理II组饲喂按4%添加黄粉虫副产物替代部分豆粕的基础日粮;处理III组饲喂按6%添加黄粉虫副产物替代部分豆粕的基础日粮。试验期42d。试验结果表明:①与对照组相比,II组肉鸡在1～21日龄、22～42日龄、1～42日龄平均日增重显著提高(ADG)(P0.05),料比显著降低(P0.05);各组之间平均日采食量(ADFI)无显著差异(P0.05);各组之间成活率无显著差异(P0.05);②与对照组相比,II组、III组有提高粗蛋白、粗脂肪、粗纤维的趋势,但差异不显著(P0.05);③与对照组相比,添加2%、4%、6%黄粉虫粉副产物替代日粮中的豆粕对肉鸡屠宰性能没有显著提高(P0.05),但是有提高的趋势;因此在日粮中添加4%的黄粉虫副产物效果最好。     

日粮中添加辣木提取物对AA肉鸡生产性能、屠宰性能、肉品质及血清生化指标的影响

本试验旨在研究日粮中添加辣木提取物对AA肉鸡的生产性能、屠宰性能、肉品质、抗氧化性能及血清生化指标的影响,探讨辣木提取物作为饲料添加剂使用的有效性及最适添加量。试验选取1日龄AA肉鸡480只,随机分成5组,每组6个重复,每个重复16只鸡。对照组饲喂无抗生素基础日粮;抗生素组饲喂基础日粮+50mg/kg金霉素;3个辣木提取物试验组在基础日粮中分别添加0.25、0.50、1.00g/kg辣木提取物。试验期42d,分为1～21d和22～42d两个阶段。结果显示:①与对照组相比,抗生素组显著提高了42日龄肉鸡体重及各阶段平均日增重(ADG)(P<0.05)。添加0.25、0.50g/kg辣木提取物可显著提高42日龄肉鸡体重及1～42日龄ADG(P<0.05),其中添加0.50g/kg辣木提取物效果较好。各试验组平均日采食量(ADFI)和料重比(F/G)均无显著差异(P>0.05)。②各组肉鸡的屠宰性能与肉品质均无显著差异(P>0.05)。③与对照组相比,添加金霉素与0.50、1.00g/kg辣木提取物显著提高了肉鸡血清总抗氧化能力(T-AOC)(P<0.05),其中0.50g/kg辣木提取物组作用效果最佳;与抗生素组相比,添加辣木提取物显著降低了血清丙二醛(MDA)含量。④与对照组相比,添加金霉素与辣木提取物组对肉鸡血清生化指标均无显著影响(P>0.05)。⑤与对照组相比,添加0.25、0.50及1.00g/kg辣木提取物组肉鸡死淘率降低到1.04%、3.13%和2.08%。综上所述,肉鸡日粮中添加辣木提取物能够提高肉鸡的增重和抗氧化性能、降低肉鸡死淘率,其中添加0.50g/kg辣木提取物的效果最佳。     

吡啶甲酸铬对肉鸡生长性能、脂肪沉积及脂代谢相关酶活的影响

文章旨在评估日粮添加不同水平的吡啶甲酸铬对肉鸡生长性能、脂肪沉积及脂代谢相关酶活的影响。试验将396只平均初始体重为（54.27±0.35）g的商品肉仔鸡随机分为3组,每组6个重复,每个重复22只。对照组饲喂铬水平为0.15 mg/kg的基础日粮,处理组分别饲喂基础日粮+0.2和0.4 mg/kg铬（以吡啶甲酸铬形式）。试验分为1～21 d和22～42 d两个阶段。结果：对照组与0.2和0.4 mg/kg铬组肉鸡42 d体重无显著差异（P＞0.05）,但0.2 mg/kg铬组42 d肉鸡的体重较0.4 mg/kg铬组显著提高了0.75%（P＜0.05）。对照组和0.2 mg/kg铬组肉鸡腿肌相对重量较0.4 mg/kg铬组分别显著提高4.86%和4.30%（P＜0.05）,但肝脏相对重量分别显著降低17.17%和17.60%（P＜0.05）。与对照组相比,0.4 mg/kg铬组肉鸡皮下脂肪相对重量显著降低9.24%（P＜0.05）。对照组脂肪酸合酶和脂蛋白脂肪酶活性显著高于0.4 mg/kg铬组（P＜0.05）,而对照组肝脏羧化酶活性和血清胆固醇浓度最高（P＜0.05）。0.4 mg/kg铬组肉鸡血清高密度脂蛋白浓度显著高于对照组（P＜0.05）。结论：在本研究条件下,日粮添加0.2～0.4 mg/kg铬（吡啶甲酸铬形式）可以通过降低肝脏脂肪合成相关酶活性降低脂肪沉积,但0.4 mg/kg铬降低了肉鸡体重。 [关键词]吡啶甲酸铬|肉鸡|生长性能|脂肪沉积|酶活     

Intracloacal Salmonella typhimurium infection of broiler chickens: reduction of colonization with anaerobic organisms and dietary lactose

The combined effect of treatments with dietary lactose plus anaerobic organisms on cecal colonization of broiler chicks by Salmonella typhimurium was evaluated. Chickens treated with a combination of anaerobic organisms and 7% dietary lactose were resistant to cecal colonization by S. typhimurium. The number of recoverable S. typhimurium cells per gram of cecal contents taken on days 10 and 15 after infection was significantly reduced. Treatment with anaerobes without the addition of lactose did not effectively control cecal colonization. Intracloacal inoculations with bacterial concentrations that varied by 10,000-fold resulted in roughly similar levels of colonization. The treatments resulted in reduced cecal pH and elevated levels of undissociated volatile fatty acids. Statistically significant correlations (P less than 0.01) were observed between the S. typhimurium concentrations in cecal material and the concentrations of undissociated fatty acids (r = -0.79, and between the bacterial counts and pH (r = 0.72).     

Effects of soybean oligosaccharide,stachyose, and raffinose on growth performance and cecal microbiota in broiler chickens

This study was conducted to examine the effects of soybean oligosaccharide, stachyose, and raffinose on growth performance and cecal microbiota in broiler chickens. Three-hundred 1-day-old Arbor Acres broiler chickens were randomly assigned to five dietary treatments: a basal diet (control diet); diets supplemented with soybean oligosaccharide, stachyose, or raffinose at levels of 0.6% total sugar content; and diet with soybean meals (positive control). Results showed that feed-to-gain ratio (F/G) was improved (p < 0.05) in broiler chickens that received stachyose, but not raffinose, while addition of soybean oligosaccharide to the diet significantly (p < 0.05) resulted in decreases in the average daily feed intake (ADFI) and average daily gain (ADG). Supplementation with soybean oligosaccharide, stachyose, or raffinose had a positive effect (p < 0.05) on the nutrient digestibility, but not on the blood immune parameters (p > 0.05). The results of the gene sequencing indicated that, at the family level, Ruminococcaceae, Lachnospiraceae, and Lactobacillaceae were comparatively present in all the treatments but the cecal microbial composition was changed after dietary addition of different oligosaccharides. Our study had led to a greater understanding of prebiotic effects of these oligosaccharides on growth and intestinal health.     

Biological control of Salmonella typhimurium in young chickens

The effect of dietary lactose and anaerobic cultures of cecal microflora of mature chickens on the colonization of young broiler chickens by Salmonella typhimurium was evaluated. Newly hatched chicks were given either no treatment (controls), anaerobic cecal cultures, lactose (2.5%) in the drinking water, or both anaerobic cultures and lactose. Chicks were challenged per os at 3 days of age with either 10(6) or 10(8) S. typhimurium resistant to nalidixic acid and novobiocin. On day 10, the cecal contents of the chicks were examined for S. typhimurium, pH, short-chained volatile fatty acids (VFAs), undissociated VFAs, and lactic acid. Chicks given either lactose alone or cecal anaerobes alone had significantly (P less than 0.05) fewer S. typhimurium recovered from their ceca than the controls. Chicks given the combination of dietary lactose and cecal anaerobes had significantly fewer S. typhimurium recovered from their ceca than the chicks given dietary lactose or cecal anaerobes alone. Chicks given lactose had significant (P less than 0.05) increases in the lactic acid concentration of their cecal contents. Increased lactic acid concentrations were directly correlated to decreased cecal pH values and caused a reduction in the total concentration of VFAs but a significant (P less than 0.05) increase in the undissociated form of some VFAs.     

Effect of dietary lactose on cecal pH, bacteriostatic volatile fatty acids, and Salmonella typhimurium colonization of broiler chicks

One-day-old broiler chicks were inoculated with volatile fatty acid producing cecal flora from adult chickens. The chicks were divided into four groups and provided 1) no lactose, 2) 2.5% lactose in water, 3) 5% lactose in feed, or 4) 10% lactose in feed, until 10 days of age. All groups were challenged at 3 days of age with 10(6) or 10(8) S. typhimurium. At 10 days, the number of Salmonella in the ceca of the chicks challenged with 10(6) Salmonella was significantly decreased (P less than 0.01) in the groups provided lactose as compared with the controls. A significant decrease (P less than 0.01) in Salmonella numbers occurred in the chicks challenged with 10(8) Salmonella and provided 10% lactose. Providing 2.5% lactose or 5% lactose failed to inhibit Salmonella growth in chicks challenged with 10(8) Salmonella. The pH of the ceca of the groups provided lactose decreased significantly (P less than 0.05) and was accompanied by significant increases (P less than 0.01) in the concentrations of bacteriostatic acetic and propionic acids. Results showed that providing dietary lactose to broiler chicks and inoculation with normal cecal flora decreased cecal pH, increased the concentrations of bacteriostatic volatile fatty acids, and inhibited Salmonella colonization.     

Dietary supplementation of phenyllactic acid on growth performance,immune response,cecal microbial population,and meat quality attributes of broiler chickens

A total of 750 one-day-old male broiler chicks were randomly fed 5 dietary treatments with 5 replicate pens per treatment. The 5 dietary treatments fed for 42 d were a corn-soybean meal basal diet without antibiotic (control); a mixture of 10 ppm of avilamycin + 60 ppm of salinomycin as antibiotic growth promoters (AGP); 0.1% phenyllactic acid (PLA); 0.2% PLA; and 0.4% PLA. The BW gain and FE were significantly improved in AGP and PLA groups compared with control group. The white blood cells and heterophil counts were significantly higher in the PLA-supplemented groups compared with AGP and control groups, but the heterophil-to-lymphocyte ratio was lower in the control group than other groups. The plasma IgY concentration was significantly increased in birds fed PLA-supplemented diets, but the plasma IgA and IgM concentrations were not different among the treatment groups. In addition, the antibody titer against Newcastle disease virus was significantly higher in PLA-treated compared with control and AGP-treated groups. Neither PLA nor AGP treatments affected the cecal aerobes andSalmonella content; however, cecalLactobacillus population increased in chickens fed 0.1% PLA, and total coliform bacteria population significantly decreased in chickens fed various levels of PLA and AGP. Dietary supplementation of PLA did not affect the pH, lightness, and redness of breast meat, but the water-holding capacity and shear force value increased and the yellowness decreased significantly when birds were fed PLA. It was concluded that dietary supplementation of 0.1 and 0.2% PLA improves BW gain and FE of broiler chickens. In addition, PLA supplementation increases the immune characteristics and the number of lactic acid bacteria, decreases the number of coliform bacteria, and improves the meat quality attributes of broiler chickens. Thus, dietary PLA could be a viable alternative to antibiotics in broiler diets.     

Evaluation of curcumin and copper acetate against Salmonella Typhimurium infection,intestinal permeability,and cecal microbiota composition in broiler chickens

Background: Interest in the use of natural feed additives as an alternative to antimicrobials in the poultry industry has increased in recent years because of the risk of bacterial resistance. One of the most studied groups are polyphenolic compounds, given their advantages over other types of additives and their easy potentiation of effects when complexes are formed with metal ions. Therefore, the objective of the present study was to evaluate the impact of dietary supplementation of copper acetate(CA), curcumin(CR), and their combination(CA-CR)against Salmonella Typhimurium colonization, intestinal permeability, and cecal microbiota composition in broiler chickens through a laboratory Salmonella infection model. S. Typhimurium recovery was determined on day 10 post-challenge by isolating Salmonella in homogenates of the right cecal tonsil(12 chickens per group) on Xylose Lysine Tergitol-4(XLT-4) with novobiocin and nalidixic acid. Intestinal integrity was indirectly determined by the fluorometric measurement of fluorescein isothiocyanate dextran(FITC-d) in serum samples from blood obtained on d 10 post-S. Typhimurium challenge. Finally, microbiota analysis was performed using the content of the left caecal tonsil of 5 chickens per group by sequencing V4 region of 16 S rRNA gene.Results: The results showed that in two independent studies, all experimental treatments were able to significantly reduce the S. Typhimurium colonization in cecal tonsils(CT, P 0.0001) compared to the positive control(PC)group. However, only CA-CR was the most effective treatment in reducing S. Typhimurium counts in both independent studies. Furthermore, the serum fluorescein isothiocyanate dextran(FITC-d) concentration in chickens treated with CR was significantly lower when compared to PC(P = 0.0084), which is related to a decrease in intestinal permeability and therefore intestinal integrity. The effect of dietary treatments in reducing Salmonella was further supported by the analysis of 16 S rRNA gene sequences using Linear discriminant analysis effect size(LEfSe)since Salmonella was significantly enriched in PC group(LDA score 2.0 and P 0.05) compared to other groups. In addition, Coprobacillus, Eubacterium, and Clostridium were significantly higher in the PC group compared to other treatment groups. On the contrary, Fecalibacterium and Enterococcus in CR, unknown genus of Erysipelotrichaceae at CA-CR, and unknown genus of Lachnospiraceae at CA were significantly more abundant respectively.Conclusions: CR treatment was the most effective treatment to reduce S. Typhimurium intestinal colonization and maintain better intestinal homeostasis which might be achieved through modulation of cecal microbiota.     

壳聚糖对肉仔鸡生长性能及血清生化指标的影响

试验选用1日龄AA雄性肉仔鸡270只,随机分到5个日粮处理组,进行为期42d的饲养试验。5种日粮是在基础日粮中加入0、50、100、150mg/kg的壳聚糖和50mg/kg的金霉素。结果表明:日粮中添加100mg/kg壳聚糖在提高日增重趋势的同时,提高了饲料转化效率,效果优于金霉素。在血清生化指标方面,100mg/kg壳聚糖组相比对照组降低了血清中TC、TG含量(P<0.05),提高了TPI、GF-1和GH含量(P<0.05),而对葡萄糖和尿酸含量无影响(P>0.05)。初步确定壳聚糖在肉鸡日粮中的适宜添加量为100mg/kg。壳聚糖的促生长作用可能与提高了血清中GH和IGF-1的分泌有关。     

Effect of dietary supplementation with alpha-galactosidase preparation and stachyose on growth performance, nutrient digestibility and intestinal bacterial populations of piglets.

Two experiments were conducted to investigate the effect of dietary supplementation with alpha-galactosidase preparation and stachyose on growth performance, nutrient digestibility and intestinal bacterial populations of piglets. In Experiment I 72 crossbred piglets were allotted to three treatments, i.e. 1) control (basal) diet, 2) alpha-Gal1 and 3) alpha-Gal5, the basal diet supplemented with 0.01% and 0.05% alpha-galactosidase preparation (alpha-Gal), respectively. Average daily gain, average daily feed intake and feed conversion ratio were not influenced by alpha-Gal supplementation. In Experiment II 72 crossbred weanling piglets were randomly assigned to four treatments with a complete factorial design, i.e. 1) basal diet, 2) basal diet with 0.01% alpha-Gal supplementation, 3) basal diet with 1% stachyose supplementation and 4) basal diet with 1% stachyose and 0.01% alpha-Gal supplementation. Average daily gain and feed conversion ratio were influenced by alpha-Gal and stachyose supplementation. The ileal digestibility of stachyose, raffinose, gross energy and crude protein was improved significantly by alpha-Gal supplementation. The microbial populations in the intestine were modified by both alpha-Gal and stachyose supplementation. The data suggested that stachyose supplementation had an adverse effect on the growth performance of piglets and alpha-Gal supplementation could ameliorate it, especially in younger pigs.     

Effect of dietary lactose on Salmonella colonization of market-age broiler chickens

The effect of providing lactose in feed and inoculation with volatile fatty acid-producing anaerobic cultures (AC) of cecal flora on Salmonella typhimurium colonization was evaluated in broilers. One-day-old chicks were divided into four groups and provided 1) no lactose, no AC; 2) AC, no lactose; 3) AC and lactose on days 1-10; or 4) AC and lactose on days 1-40. All groups were challenged per os with 10(6) Salmonella on day 3 and with 10(8) Salmonella on day 33. Salmonella growth in the cecal contents was significantly decreased (P less than 0.01) on day 10 in the chicks provided lactose from day 1-10. However, after the removal of lactose from the diet, the chicks were susceptible to Salmonella colonization. The number of Salmonella in the ceca was significantly reduced (P less than 0.05) in the chicks provided lactose throughout the 40-day growing period. Dietary lactose decreased the pH of the cecal contents and was accompanied by marked increases in the concentrations of undissociated bacteriostatic volatile fatty acids in the cecal contents.     

Effect of carbohydrates on Salmonella typhimurium colonization in broiler chickens

The effect of carbohydrates in the drinking water of broiler chickens on Salmonella typhimurium colonization was evaluated. Results indicate that mannose and lactose (2.5%) significantly (P less than 0.05) reduced intestinal colonization of S. typhimurium by at least one-half, as compared with dextrose, maltose, and sucrose. Lactose and mannose also significantly reduced (P less than 0.01) the mean log10 number of S. typhimurium in the cecal contents. Although mannose was the most effective sugar at blocking colonization, lactose may be more practical because it is effective and costs much less than mannose. Provision of carbohydrates in the drinking water had no significant effect on weight gain.