0-8周藏马鸡与环颈雉生长性能及消化性能的比较研究

比较了0~8周龄藏马鸡与环颈雉的生长及消化性能的差异。结果表明:采食NRC环颈雉饲养标准的全价日粮时,藏马鸡生长正常、体况良好其体重和生长速度显著高于环颈雉(P<0.05);藏马鸡对粗蛋白、粗纤维、0~4周龄酸性洗涤纤维和干物质的消化率、饲料转化率及表观能量代谢率与环颈雉无显著差异(P>0.05);藏马鸡对粗脂肪消化率低于环颈雉,对NDF和4~8周龄ADF的消化率则显著高于环颈雉(P<0.05)。     

外源复合酶对移地保护圈养马来熊日粮营养消化率的影响

利用外源复合酶对移地保护圈养的 9只马来熊日粮营养物质及能量消化率进行了测定 ,经单因子方差分析结果表明 ,在圈养马来熊日粮中添加一定量的外源复合酶 ,能提高马来熊对日粮营养物质的消化率 ,其中 ,添加 0 3%饲料量的酶能显著提高日粮粗蛋白的消化率(P <0 0 5) ;添加 0 5%的酶 ,能显著提高日粮粗纤维、粗蛋白质消化率 (P <0 0 5)。此研究结果可应用于马来熊的饲养中 ,提高其饲料报酬     

运用广义线性混合模型分析随机区组重复测量的试验资料

重复测量试验对同一受试对象进行多次测量,各时间点数据间存在自相关性,进行方差分析和均值比较时需要进行特殊处理。虽然此方法在农业等研究领域运用十分广泛,但目前有效地相关统计方法鲜见。为了建立操作简单、实用性强、结果可靠的统计分析方法,本研究采用SAS的广义线性混合模型(Generalized Linear Mixed Models,GLIMMIX),以随机区组重复测量试验资料为例,说明了协方差结构筛选、方差分析和均值比较的具体方法。结果表明,用传统的裂区设计、多变量统计等方法会造成资料信息浪费,统计功效降低,缺区无法处理等问题,甚至会导致错误的结论。GLIMMIX能很好地处理自相关问题,功能强大,结果可靠,使用简单,允许缺区,是进行重复测量试验资料方差分析和均值比较的理想方法。目前在国内将其运用到农学类试验数据的统计分析的相关报道鲜见,该文在本领域具有很强的实用性和创新性。     

低蛋白质饲粮中添加尿素对肉兔消化代谢的影响

本试验旨在研究低蛋白质饲粮中添加尿素对肉兔消化代谢的影响。采用单因子随机区组试验设计,选择 ９０只 ５０日龄体重相近的健康新西兰兔,随机分为 ３组,１个对照组和 ２个试验组,每组 １５个重复,每个重复 ２只。对照组饲喂粗蛋白质含量为 １１．１１％的基础饲粮,２个试验组分别饲喂在基础饲粮中以糊化淀粉缓释尿素的方式添加 １％、２％和 ３％尿素的试验饲粮。预试期为 １０ｄ,正试期为 ３０ｄ。正试期的第 １３～１８天收集试验兔排出的全部粪便和尿液。结果表明：与对照组相比,１％尿素组试验兔的有机物表观消化率、总能表观消化率及利用率、沉积氮、氮利用率和消化氮利用率显著或极显著升高（Ｐ＜０．０５或 Ｐ＜０．０１）,而 ２％尿素组试验兔的消化能、代谢能、沉积氮、氮利用率和消化氮利用率显著或极显著降低（Ｐ＜０．０５或 Ｐ＜０．０１）。对照组试验兔盲肠内容物脲酶活性和微生物蛋白浓度显著或极显著低于其余 ２组（Ｐ＜０．０５或 Ｐ＜０．０１）,而 ２％尿素组试验兔盲肠内容物氨氮和尿素氮浓度显著或极显著高于其余 ２组（Ｐ＜０．０５或 Ｐ＜０．０１）。由此得出,低蛋白质饲粮中添加 １％尿素可改善肉兔有机物、总能和氮的利用效率,提高盲肠内容物脲酶活性和微生物蛋白浓度;添加 ２％尿素则会降低肉兔氮的利用效率,提高盲肠内容物脲酶活性及微生物蛋白、氨氮和尿素氮浓度。     

家蚕对颗粒人工饲料的摄食性及若干物质添加效果的研究

研究结果表明 :家蚕对颗粒人工饲料的嗅觉反应和摄食反应与蒸煮切片饲料无明显差异 ,具有良好的适口性 ;饲料含水量和光照条件对摄食性有显著的影响 ;颗粒人工饲料中添加适量肌醇可提高小蚕的摄食性 ,促进生长发育 ,但添加VC、VB混合物和蔗糖 ,均无明显效果     

Dietary fiber in a low-protein diet during gestation affects nitrogen excretion in primiparous gilts,with possible influences from the gut microbiota

We investigated the effects of dietary fiber (DF) supplementation in normal or low crude protein (CP) diets on reproductive performance and nitrogen (N) utilization in primiparous gilts. In total, 77 Landrace × Yorkshire pregnant gilts were randomly allocated to four dietary treatments in a 2 × 2 factorial design. The groups comprised 1) equal intake of normal CP (12.82% and 0.61% total lysine), 2) low CP (LP) (10.53% and 0.61% total lysine), and 3) with or 4) without DF supplementation (cellulose, inulin, and pectin in a 34:10:1 ratio). A low-protein diet during gestation significantly reduced daily weight gain from days 91 to 110 of pregnancy (−162.5 g/d, P = 0.004). From N balance trials conducted at days 35 to 38, 65 to 68, and 95 to 98 of pregnancy, DF addition increased fecal N excretion at days 65 to 68 (+24.1%) and 95 to 98 (+13.8%) of pregnancy (P < 0.05) but reduced urinary N excretion (P < 0.05), resulting in greater N retention at each gestational stage. DF increased fecal microbial protein levels and excretion during gestation. An LP diet also reduced urinary N excretion at different gestational stages. An in vitro fermentation trial on culture media with nonprotein N urea and ammonium bicarbonate (NH₄HCO₃) as the only N sources revealed that microbiota derived from feces of gestating gilts fed the high DF diet exhibited a greater capacity to convert nonprotein N to microbial protein. Microbial fecal diversity, as measured by 16S rRNA sequencing, revealed significant changes from DF but not CP diets. Gilts fed an LP diet had a higher number of stillbirths (+0.83 per litter, P = 0.046) and a lower piglet birth weight (1.52 vs. 1.37 kg, P = 0.006), regardless of DF levels. Collectively, DF supplementation to gestation diets shifted N excretion from urine to feces in the form of microbial protein, suggesting that the microbiota had a putative role in controlling N utilization from DF. Additionally, a low-protein diet during gestation negatively affected the litter performance of gilts.     

Influence of Diet Type and Pretreatment Fasting on the Disposition Kinetics of Albendazole in Sheep

The influence of the quality and quantity of diets on the disposition kinetics of albendazole were studied in sheep in two different experiments. The plasma concentration profiles of albendazole sulphoxide and albendazole sulphone were measured following intraruminal administration of albendazole at 5.0 mg/kg body weight in weaner sheep offered three different diets: 100% green Sorghum spp., 100% dry mature Cenchrus ciliaris hay and a 50:50 mix of these two diets. The peak plasma concentrations and the availability of the albendazole metabolites, as measured by the area under the concentration–time curve, were significantly higher (p<0.01) in the animals offered exclusively dry fodder compared to other diets. Changing the diet from dry to green fodder resulted in a significantly lower systemic availability of the drug metabolites. It is suggested that a decreased transit time of the digesta in the bowel on the green diet, with its high water content, limited the systemic availability of the drug by reducing the time available for gastrointestinal absorption.An experiment on the influence of different levels of pretreatment fasting on the pharmacokinetics of albendazole revealed significantly higher (p<0.05) plasma concentrations of the anthelmintically active sulphoxide metabolite from 12 h onwards following administration of the drug in animals subjected to 24 h of pretreatment fasting compared to other groups with pretreatment fasting of 8, 12 or 18 h. The area under the concentration–time curve and the minimum residence time of the drug metabolites were significantly greater (p<0.05) in animals that had been fasted for 24 h. It is suggested that fasting induces a decrease in the flow of digesta through the gastrointestinal tract of ruminants and prolongs the duration of dissolution of the drug, resulting in enhancement of the absorption of albendazole and of the systemic availability of its metabolites.     

Artifactual changes in canine blood following storage, detected using the ADVIA 120 hematology analyzer

BACKGROUND: Artifactual changes in blood may occur as a consequence of delayed analysis and may complicate interpretation of CBC data. OBJECTIVE: The aim of this study was to characterize artifactual changes in canine blood, due to storage, using the ADVIA 120 hematology analyzer. METHODS: Blood samples were collected into EDTA from 5 clinically healthy dogs. Within 1 hour after blood sample collection and at 12, 24, 36 and 48 hours after storage of the samples at either 4 degrees C or room temperature (approximately 24 degrees C), a CBC was done using the ADVIA 120 and multispecies software. A linear mixed model was used to statistically evaluate significant differences in values over time, compared with initial values. RESULTS: The HCT and MCV were increased significantly after 12 hours of collection at both 4 degrees C and 24 degrees C, and continued to increase through 48 hours. The MCHC initially decreased significantly at 12-24 hours and then continued to decrease through 48 hours at both temperatures. Changes in HCT, MCV, and MCHC were greater at 24 degrees C than at 4 degrees C at all time points. A significant increase in MPV and a decrease in mean platelet component concentration were observed at all time points at 24 degrees C. Samples stored at 24 degrees C for 48 hours had significantly higher percentages of normocytic-hypochromic RBCs, and macrocytic-normochromic RBCs, and lower platelet and total WBC counts. CONCLUSIONS: Delayed analysis of canine blood samples produces artifactual changes in CBC results, mainly in RBC morphology and platelet parameters, that are readily detected using the ADVIA 120. Refrigeration of specimens, even after 24 hours of storage at room temperature, is recommended to improve the accuracy of CBC results for canine blood samples.     

克氏螯虾饲料中适宜的蛋白质含量和能量蛋白比研究

采用3×3因子试验法,设计了3种不同蛋白质水平(26%、29%、32%)及能最蛋白比水平(36、40、44 kl/g)的9种试验饲料,对体重(2.39±0.37)g的克氏螯虾(Procambarus clarkii)的适宜蛋白质含量及其蛋白能最比进行了研究,生长试验期42 d.结果表明,克氏螫虾幼虾配合饲料中适宜蛋白质含量为29.49%～32.24%,饲料的适宜能量蛋白比范嗣为34.67～37.46 kJ/g;当试验饲料蛋白质含量为31.86%,能量蛋白比为35.85 kJ/g时,试验虾获得最大增重率、最低的饲料系数、最高的蛋白质效率及最大的特定生长率.     

Effects of guanidinoacetic acid supplementation in all‐plant protein diets on growth,antioxidant capacity and muscle energy metabolism of bullfrog Rana (Lithobates) catesbeiana

Effects of guanidinoacetic acid (GAA) supplementation in all‐plant protein diets were evaluated on growth, antioxidant capacity and muscle energy metabolism of Rana (Lithobates) catesbeiana. Six diets were prepared: a basal fish meal diet (FM), an all soybean meal diet (SM) and four GAA‐supplemented diets by adding 0.2, 0.4, 0.6 and 0.8 g GAA/kg to the SM diet (GAA2, GAA4, GAA6 and GAA8 diets). Triplicate groups of bullfrog (45 ± 0.2 g) were fed the diets to apparent satiation for 8 weeks. Total substitution of FM with SM led to significantly (p < .05) reduced growth and feed utilization. Adding 0.4 g GAA/kg to the SM diet significantly improved growth performance, and the values were comparable to those of FM group. SM and GAA2 groups showed drastically lower serum total antioxidant capacity than FM, GAA4 and GAA6 groups. Also, SM and GAA2 groups showed significantly lower catalase activity than FM and GAA8 groups. A remarkable increase in serum malondialdehyde concentration was detected in SM and GAA2 groups. FM and GAA6 groups exhibited significantly higher serum creatinine concentration than other groups. Muscle creatine kinase activity and glycogen content were significantly decreased in SM group and application of 0.4–0.6 g GAA/kg significantly improved their values. GAA4 group showed significantly lower pyruvate kinase activity than FM and GAA6 groups. Also, GAA2 and GAA4 groups had significantly lower succinate dehydrogenase (SDH) activity than other treatments. These findings show that supplementing 0.4 g/kg GAA to SM‐based diets improves growth, antioxidant capacity and muscle energy metabolism.