Growth performance,nutrient digestibility and immune response of broiler chicks fed diets supplemented with a culture of Lactobacillus bulgaricus

BACKGROUND: Probiotics are being developed for use in animal feed to enhance production performance and prevention of gastrointestinal infections. The ban on using antibiotics as growth promoters, antibiotic resistance and the inherent problems of developing new vaccines make a compelling case for developing alternatives for in‐feed antibiotics. The alternatives of choice have to be considered under the environmental conditions of the animal. Among the probiotics in use today, Lactobacillus has been shown to play a vital role in disease prevention, immune enhancement, improved growth and carcass yield in poultry. The present study investigates the effect of Lactobacillus bulgaricus (LB)‐based probiotic on the growth performance, nutrient digestibility and immune response of broilers under tropical environmental conditions. RESULTS: Broilers fed LB diets consumed more feed (P < 0.05) and had greater body weight gain than the control group. Feed/gain ratio improved significantly (P < 0.05) with the 20, 40 and 60 mg kg^?1 LB diets compared with the control or 80 mg kg^?1 LB diet. The apparent digestibilities of nitrogen and fat increased with LB supplementation. However, there was no significant difference (P > 0.05) in fibre digestibility. White blood cell count increased significantly in broilers fed higher levels (>40 mg kg^?1) of LB compared with the control group. Antibody production measured as antibody titre against Newcastle disease vaccine showed a curvilinear response over the range of LB concentrations examined. CONCLUSION: The results indicate that LB addition to broiler chick diets significantly improved growth performance, increased nutrient digestibility and stimulated humoral immune response. Copyright © 2008 Society of Chemical Industry     

The influence of dietary hazelnut kernel oil on the performance and fatty acid composition of broilers

A total of 360 one‐day‐old broilers (Ross 308) were allocated to three treatment groups with four replicates each of 30 chicks to evaluate the effects of the dietary hazelnut kernel oil (HKO) inclusion on the performance and the composition of fatty acid of meat in broilers. Treatments were diets with (1) soybean oil (SO), (2) HKO, or (3) HKO + SO (in equal amount, HKSO) added to the basal diets. There were no significant differences in weight gain, feed per gain, dressing percentage, abdominal fat weight, and mortality among the different dietary oil sources. Dietary HKO decreased (P < 0.01) linoleic and linolenic acids contents and the ratio of SFA:MUFA (saturated fatty acids:unsaturated fatty acids) of breast meats in broiler, and increased oleic acid content compared to SO. The result indicates that meat from broiler chickens fed diets containing HKO, singly or combined with SO could be an important source of oleic acid for human diets. Copyright © 2007 Society of Chemical Industry     

超高效合相色谱(UPC^(2))技术快速测定植物油中的维生素A和维生素E北大核心CSCD

为了使植物油中脂溶性维生素E异构体得到更好的分离,建立一种超高效合相色谱(UPC^(2))快速分离和测定植物油中维生素A和维生素E的方法。样品经异丙醇溶解,过0.22μm有机相滤膜后直接进样分析。分析条件为HSS C_(18)SB色谱柱(3.0 mm×100 mm, 1.8μm),CO_(18)和0.2%甲酸甲醇溶液为流动相,梯度洗脱,流速1.0 mL/min,柱温50℃,检测波长290 nm。结果表明:维生素A和维生素E在测定范围内呈现良好的线性关系,相关系数均在0.999 5及以上,样品回收率为82.00%~106.82%,RSD在0.94%~3.57%之间,日内精密度与日间精密度的RSD分别为1.94%~3.51%与3.74%~5.13%,并采用已建立的方法对26份植物油样品中的维生素A和维生素E含量进行测定,表明植物油中维生素E含量最高,其中以α-生育酚和γ-生育酚为主,β-生育酚含量较低。该方法简单高效、灵敏度高、重复性好,可用于植物油中脂溶性维生素A和维生素E的分离检测。     

不同剂型维生素E对肉鸡生产性能、血清生化指标和抗氧化能力的影响

研究比较维生素E(VE)和微囊化VE(MVE)对肉鸡生产性能、血清生化指标和抗氧化能力的影响。试验选用1日龄AA肉仔鸡360只,随机分成3组,每组6个重复,每个重复20只。对照组(CON组)饲喂基础日粮(不添加VE),试验组分别在基础日粮中添加20 IU/kg普通VE(VE组)和20 IU/kg微囊化VE(MVE组)。试验期为42 d,分别于肉鸡21 d和42 d时,测定生产性能,并采取血样,测定血清生化指标和抗氧化指标。结果表明：(1)与CON组相比,VE和MVE组对肉鸡21 d的生产性能均无显著影响(P > 0.05),但MVE组肉鸡22~42 d和1~42 d的平均日增重均显著提高(P < 0.05)。(2)与CON组相比,VE和MVE组显著降低了肉鸡21 d和42 d血清的尿素氮水平(P < 0.05),且血清肌酐水平在21 d时有下降趋势(P = 0.09),血清碱性磷酸酶含量在42 d时有升高趋势(P = 0.09)。(3)21 d时,MVE组血清总蛋白和球蛋白显著高于CON组(P < 0.05),VE组无显著差异(P > 0.05);42 d时,与CON组相比,MVE组血清总蛋白和白蛋白显著提高(P < 0.05),VE组无显著差异(P > 0.05)。(4)与CON组相比,日粮中添加MVE显著提高了血清T-SOD和GSH-Px活性(P < 0.05),VE组无显著差异(P > 0.05)。结论：日粮添加微囊化VE能够改善肉鸡的生产性能,提高肉鸡体内的蛋白质合成与代谢功能,并能够提高肉鸡的血清抗氧化能力。     

Altering the ratio of dietary palmitic,stearic, and oleic acids in diets with or without whole cottonseed affects nutrient digestibility,energy partitioning,and production responses of dairy cows

The objective of this study was to evaluate the effects of varying the ratio of dietary palmitic (C16:0), stearic (C18:0), and oleic (cis-9 C18:1) acids in basal diets containing soyhulls or whole cottonseed on nutrient digestibility, energy partitioning, and production response of lactating dairy cows. Twenty-four mid-lactation multiparous Holstein cows were used in a split-plot Latin square design. Cows were allocated to a main plot receiving either a basal diet with soyhulls (SH, n = 12) or a basal diet with whole cottonseed (CS, n = 12) that was fed throughout the experiment. Within each plot a 4 × 4 Latin square arrangement of treatments was used in 4 consecutive 21-d periods. Treatments were (1) control (CON; no supplemental fat), (2) high C16:0 supplement [PA; fatty acid (FA) supplement blend provided ～80% C16:0], (3) C16:0 and C18:0 supplement (PA+SA; FA supplement blend provided ～40% C16:0 + ～40% C18:0), and (4) C16:0 and cis-9 C18:1 supplement (PA+OA; FA supplement blend provided ～45% C16:0 + ～35% cis-9 C18:1). Interactions between basal diets and FA treatments were observed for dry matter intake (DMI) and milk yield. Among the SH diets, PA and PA+SA increased DMI compared with CON and PA+OA treatments, whereas in the CS diets PA+OA decreased DMI compared with CON. The PA, PA+SA, and PA+OA treatments increased milk yield compared with CON in the SH diets. The CS diets increased milk fat yield compared with the SH diets due to the greater yield of de novo and preformed milk FA. The PA treatment increased milk fat yield compared with CON, PA+SA, and PA+OA due to the greater yield of mixed-source (16-carbon) milk FA. The PA treatment increased 3.5% fat-corrected milk compared with CON and tended to increase it compared with PA+SA and PA+OA. The CS diets increased body weight (BW) change compared with the SH diets. Additionally, PA+OA tended to increase BW change compared with CON and PA and increased it in comparison with PA+SA. The PA and PA+OA treatments increased dry matter and neutral detergent fiber digestibility compared with PA+SA and tended to increase them compared with CON. The PA+SA treatment reduced 16-carbon, 18-carbon, and total FA digestibility compared with the other treatments. The CS diets increased energy partitioning toward body reserves compared with the SH diets. The PA treatment increased energy partitioning toward milk compared with CON and PA+OA and tended to increase it compared with PA+SA. In contrast, PA+OA increased energy partitioned to body reserves compared with PA and PA+SA and tended to increase it compared with CON. In conclusion, milk yield responses to different combinations of FA were affected by the addition of whole cottonseed in the diet. Among the combinations of C16:0, C18:0, and cis-9 C18:1 evaluated, fat supplements with more C16:0 increased energy output in milk, whereas fat supplements with more cis-9 C18:1 increased energy storage in BW. The combination of C16:0 and C18:0 reduced nutrient digestibility, which most likely explains the lower performance observed compared with other treatments.     

Vitamin E levels,thiobarbituric acid test and sensory evaluation of breast muscles from broilers fed α‐tocopheryl acetate‐ and β‐carotene‐supplemented diets

The objective of this study was to investigate the effect of dietary α‐tocopheryl acetate and β‐carotene supplementation on lipid oxidation of breast meat from broilers fed lard as the fat source. Supplementation of broilers with 100 mg kg^?1 α‐tocopheryl acetate increased the vitamin E levels in raw breast samples significantly (p < 0.05), whereas the presence of 1.5 mg kg^?1 dietary β‐carotene tended to decrease vitamin E deposition. The presence of vitamin E delayed lipid oxidation significantly, but thiobarbituric acid values of samples from broilers fed the β‐carotene‐supplemented diet did not differ from those of control samples. Vitamin E reduced sensory meat rancidity, whilst vitamin E, β‐carotene and their combination modified meat texture. The results show the effectiveness of dietary α‐tocopheryl acetate supplementation in protecting broiler meat against lipid oxidation. Copyright © 2004 Society of Chemical Industry