复合有机铁对母猪繁殖性能及其抗氧化能力的影响

为研究复合有机铁对母猪繁殖性能、血液理化指标及抗氧化能力的影响,试验选用体重接近、胎次接近、预产期一致的健康“长×白”二元杂母猪30头,随机分为3组,每组10个重复,每个重复1头母猪,3个处理组分别在基础日粮中补充硫酸亚铁、甘氨酸亚铁、复合有机铁。结果显示:较硫酸亚铁组,复合有机铁组产程缩短23.57%、胎产健仔数增加14.00%、初生窝重增加14.14%(P < 0.05);母猪血红蛋白含量、红细胞数和红细胞压积分别提高19.88%、10.53%、8.33%(P < 0.05);母猪抗氧化酶活性和机体抗氧化能力提高47.33%(P < 0.05),丙二醛含量降低37.05%(P < 0.05)。综上所述,母猪日粮中额外补充复合有机铁源能提高母猪繁殖性能,改善血液理化指标,增强母猪抗氧化能力。     

Comparison of Metabolic Energy Content of Organic Cereal Grains for Chickens and Turkeys

Although there is an extensive database on the nutrient content of conventionally produced feedstuffs, there is very little published research on the nutrient content of feedstuffs that are organically grown. Industrial and organic crop production differ in both crop and soil management. There are data to suggest that these differences may result in differences in the nutrient content of organic grown feedstuffs. The purpose of this study was to determine the ME content of organically grown amaranth, buckwheat, white corn, yellow corn, and wheat samples obtained from the University of Minnesota's organic research farm. Both chickens and turkeys were used in the assays to compare the ME content for these 2 species. The TME_n content, on an as-fed basis, of amaranth, buckwheat, yellow corn, white corn, and wheat for chickens were found to be 3,146, 3,072, 3,603, 3,324, and 3,592 kcal/kg, respectively. The TME_n content of the same samples, on an as-fed basis, determined with turkeys were found to be 2,748, 2,227, 2,810, 2,757, and 2,959 kcal/kg, respectively. True ME content of the organically grown feed ingredients was found to be greater when chickens were used in the bioassay as compared with turkeys and differed significantly from published values for the same cereals grown using conventional means.     

返滴定法测定蜂胶中游离酸含量

建立测定蜂胶品中游离酸含量的方法.采用弱碱溶解蜂胶再酸化萃取的方法纯化样品,用返滴法测定,以水杨酸作为对照品检测样品中游离酸含量.结果测定了5个不同产地的蜂胶样品,游离酸含量在1.89～6.54%范围内,回收率为99.30%.本方法操作简单,重现性好,有助于蜂胶质量的鉴别.     

奶牛的有机锌应用效果研究进展

就有机锌对奶牛的营养作用效果、影响有机锌作用效果的因素进行综述。认为添加有机锌可提高奶牛的产奶性能、免疫机能、繁殖性能,改善体健康。同时影响有机锌作用效果的因素有:有机锌的产品质量、添加量和添加时期、饲料营养水平、参照物类型和评价指标等。     

Effects of dietary additives (potassium diformate/organic acids) as well as influences of grinding intensity (coarse/fine) of diets for weaned piglets experimentally infected with Salmonella Derby or Escherichia coli

The aim of this study was to examine whether and to what extent the addition of potassium diformate (pdf) or free organic acids (fpa) to the diet and the grinding intensity might affect the course of infection and the passage of orally applied Salmonella and Escherichia coli in pigs. Experiments were carried out using 80 reared piglets allotted to four groups. Pigs were fed pelleted diets ad libitum (except during a 15 h feed‐withholding‐period before infection). The control diet contained finely ground cereals (2 mm screen). To two test diets (also finely ground) 1.2% pdf, 0.9% organic acids (75% formic and 25% propionic acid, fpa) respectively were added. The fourth diet (without acids) was based on coarsely ground cereals (6‐mm screen). After experimental infection alternately with S. Derby or E. coli, the course of infection was examined (rectal swab technique). Pigs were sacrificed 4–5 h after a further oral application of ～10⁹–10¹⁰ CFU S. Derby or E. coli to determine the counts of Salmonella or E. coli in chyme (classical culture methods). Adding pdf or fpa to the diet led to reduced Salmonella shedding and resulted in significantly lower counts of Salmonella and E. coli in the stomach content indicating an improved efficacy of the stomach barrier. In the distal parts of the digestive tract, the effect was less obvious concerning counts of E. coli, whereas counts of Salmonella were reduced markedly as well. The diet based on coarsely ground cereals failed to demonstrate positive effects concerning infection and passage of orally applied bacteria as well, but this diet was also pelleted and showed unintentionally, comparable amounts of fine particles. Results obtained in this study allow the recommendation of using pdf or organic acids as additives when dietary measures against Salmonella or E. coli in pigs are required.     

The effect of genotype,choice feeding,and season on organically reared broilers fed diets devoid of synthetic methionine

In response to the impending ban on synthetic methionine in organic poultry diets, researchers have focused on finding alternative strategies to supply this amino acid. The objectives of this study were to assess performance and carcass characteristics of broilers fed diets devoid of synthetic methionine by using 1) a slow-growing and a fast-growing genotype, 2) choice-feeding management (supplying grain and a complementary premix in 2 separate feeders), and 3) pasture access and seasonal variation. Inclusion of fish meal and high percentages of soybean meal enabled the specific genotype methionine requirement to be met. All diets were certified organic. The experiment was conducted during the grower and finisher phases in 4 different seasons: late fall, spring, summer, and early fall. Pasture access was assessed either by housing broilers on the West Virginia University Organic farm and giving them outdoor access, or by housing broilers on the West Virginia University Animal Sciences farm and giving them no outdoor access. Fast-growing genotypes were superior in performance and carcass characteristics compared with slow-growing genotypes, and choice-feeding management did not improve performance or carcass characteristics. Pasture access tended to have no effect on slow-growing broilers and decreased the performance of fast-growing broilers. Performance was decreased in late fall, likely because of cold ambient temperatures.     

藏北高原退化高寒草甸土壤团聚体有机碳变化特征

采用湿筛法对藏北高原退化高寒草甸表层(0~10cm)、亚表层(10~20cm)土壤团聚体有机碳及其变化进行了研究。结果表明,高原冷湿环境中退化草地表层、亚表层SAOC的下降幅度随草地退化加剧均趋于显著提高,轻度、严重退化草地表层各粒级SAOC降幅均明显高于亚表层;草地退化缩小了不同土层间SAOC含量的差异,草地退化程度越高则表层、亚表层间SAOC含量的差异越小,退化草地大团聚体(0.25mm)SOC、微团聚体(0.25mm)SOC含量的土层分布亦呈相同趋势。轻度退化草地不同土层大团聚体SOC降幅均较高,严重退化草地不同土层微团聚体SOC降幅则较高;正常草地、轻度退化草地、严重退化草地表层大团聚体SOC/微团聚体SOC比值分别为0.95,0.87,1.55,亚表层分别为0.96,0.72,2.33,表明轻度、严重退化草地中大团聚体SOC含量随土层加深分别更趋下降、更趋提高。退化草地表层、亚表层SAOC贡献率在总体上亦均按2~0.25 mm,2 mm,0.25~0.053mm,0.053mm的顺序依次大幅降低,表明不同土层大团聚体SOC贡献率均较高。土壤团聚体与SAOC、SOC与SAOC间的关系受草地退化程度的影响。     

肉鸡对三碱基氯化铜、铜氨基酸螯合物、铜蛋白盐生物利用率研究

采用玉米—豆粕型饲粮研究肉公雏对三碱基氯化铜(TBCC)、铜氨基酸螯合物(CuAA)、铜蛋白盐(CuPro)或硫酸铜(CuSO4)的生物利用率。在基础饲粮(Cu14mg/kg,DM基础 ,实测值)上 ,TBCC、CuAA、CuPro、CuSO4 的铜添加水平依次为150mg/kg、300mg/kg、450mg/kg,试验3周。结果表明 ,铜源和铜水平对试鸡体重和饲料转化率的影响不显著。以CuSO4 为参比标准 ,铜添加水平或日粮铜摄入量为自变量 ,经对数转换后肝铜积累为因变量建立多元线性回归模型 ,按斜率法综合求测铜源生物利用率为 :CuSO4 100 % ;TBCC112.4 % ;CuAA127.7 %(P<0.01) ;CuPro99.3 %。结果表明TBCC或CuPro生物利用率与CuSO4同效 ,但CuAA生物利用率比CuSO4 高。该试验提供了评定肉鸡有机铜源生物利用率的实用方法。