Effect of dietary defatted diatom biomass on egg production and quality of laying hens

Background： This study was to determine if feeding laying hens with defatted diatom microalgal biomass （DFA） from biofuel production affected their egg production and health status. Methods： Five replicates of 5 individually caged ISA Babcock White leghorn hens were fed 4 diets, including a corn-soybean meal control diet, a diet containing 7.5% DFA substituting for soybean meal, and diets containing 7.5% or 15% DFA substituting for corn and soybean meal. Body weights, feed intake, feed conversion ratio （FCR）, rate of egg production, egg size, egg mass, and several characteristics of eggs were determined at 4 and 8 wk. Venous blood was sampled at 4 and 8 wk for measurement of 5 biomarkers of health. Results： The15% DFA diet decreased （P 〈 0.05） feed intake, egg production, and plasma uric acid concentrations as compared with the control diet, but increased （P 〈 0.05） egg albumen weight and height compared with the 7.5% DFA diets. The two levels of DFA produced dose-dependent （P 〈 0.05） changes in three color measures of egg yolk, without affecting four hen plasma biochemical indicators of health. Conclusions： Feeding laying hens with 7.5% DFA in the corn-soybean meal diet for 8 wk had no adverse effect on their health, egg production, or egg quality, but 15% inclusion reduced feed intake, egg production, and efficiency of feed utilization.     

湖北省蛋鸭产业现代化经营及其可持续发展

蛋鸭养殖作为一项投资少、门槛低、见效快、产出高的产业,一直是农民现金收入的重要途径之一,在全国水禽产业中占据重要地位。湖北省蛋鸭产业发展在全国水禽养殖区域中占有重要的份额和地位,且湖北在蛋鸭养殖方面拥有突出的资源环境和区位优势,具有独特性、典型性和代表性。因此,研究湖北蛋鸭产业现代化经营及其可持续发展对解决湖北农民增收问题、农村劳动力就业问题、壮大农产品加工业、调整产业结构等都具有重要作用。本文根据国家水禽产业体系经济研究团队对湖北省的实地调查情况,介绍了湖北省蛋鸭产业现代化经营的发展现状,分析了湖北蛋鸭产业现代化经营中存在的利弊,提出了针对性的建议,阐释了未来湖北蛋鸭产业实现现代化经营的着力点及对策。     

饲粮中添加碳酸氢钠对蛋鸡肠道内容物pH、消化蛋白酶活性及菌群的影响

【目的】研究蛋鸡饲粮中添加不同水平的碳酸氢钠对肠道内容物pH、消化蛋白酶活性和肠道菌群的影响,以探讨饲粮中添加碳酸氢钠对蛋鸡消化机能的影响。【方法】选取21周龄海兰褐壳蛋鸡450只,随机分为5组,每组6个重复,每重复15只鸡;对照组饲喂基础饲粮,试验组分别饲喂添加0.1%,0.5%,2.5%,5%NaHCO3的试验饲粮,试验期133d。试验期末采集各组肌胃、十二指肠、空肠、回肠、盲肠食糜及粪便,测定各段食糜和粪便的pH、肌胃食糜的胃蛋白酶活性、十二指肠食糜的胰蛋白酶和糜蛋白酶活性以及回肠和盲肠食糜中菌群的变性梯度凝胶电泳(DGGE)指纹图谱,并计算回肠、盲肠食糜的多样性指数和相似性指数。【结果】1)饲粮中添加0.1%和0.5%的碳酸氢钠对蛋鸡肠道各段pH无显著影响,而饲粮中添加2.5%和5%的碳酸氢钠可显著提高蛋鸡肌胃、十二指肠和空肠内容物以及粪便的pH(P0.05)。2)饲粮中添加2.5%和5%的碳酸氢钠可显著降低肌胃中胃蛋白酶、十二指肠中胰蛋白酶和糜蛋白酶活性(P0.05)。3)饲粮中添加碳酸氢钠可改变蛋鸡回肠和盲肠的微生物多样性指数。【结论】饲粮中添加高剂量的碳酸氢钠(2.5%和5%)显著影响蛋鸡消化道内环境,降低蛋鸡的蛋白消化机能。     

传统框剪结构的改造与应用

本文叙述了框剪结构中方案阶段的重要性。在这一阶段应将问题涉及的各个方面考虑周到,对方案构思严谨,以便为后阶段各个环节打下良好基础。     

孕酮处理对蛋鸡蛋壳钙化过程中CaBP-d28k基因表达的影响

实验旨在研究孕酮对蛋鸡CaBP-d28k基因表达的影响。对产蛋高峰期蛋鸡进行孕酮和孕酮受体拮抗剂(RU-486)处理,利用实时荧光定量PCR技术(QRT-PCR),测定在蛋壳形成过程中输卵管子宫部钙结合蛋白(CaBP-d28k)、孕酮受体(PGR)的表达量;同时对血液中钙离子和孕酮浓度变化进行测定。结果表明:孕酮处理后,血液中钙离子浓度显著降低(P<0.05),输卵管子宫部CaBP-d28k表达量也显著降低(P<0.05);孕酮受体拮抗剂处理后,血液中钙离子浓度显著升高(P<0.05),输卵管子宫部CaBP-d28k表达量极显著升高(P<0.01)。结果提示,在蛋壳钙化过程中,孕酮对CaBP-d28k表达和钙离子转运起负调控作用。     

The Potential for Plants to Trap Emissions from Farms with Laying Hens: 2. Ammonia and Dust

The potential for plants to trap NH₃ and dust [particulate matter (PM)] discharged from a layer house through the exhaust fans was evaluated at The Pennsylvania State University Poultry Education and Research Center in August 2006. Poultry and livestock NH₃ emissions are a concern for air quality, surface deposition, and animal and human health. Particulate matter is a human health concern as well and is regulated by the United States Environmental Protection Agency in nonattainment areas. A vegetative buffer comprising 5 tree species was planted in pot-in-pot containers in 5 rows downwind from 4 henhouse fans, with 1 control row of plants upwind from the fans. When measured with a photoacoustic NH₃ detector at fan elevation (1.5 m), NH₃ concentrations decreased sharply (P ≤ 0.0001) with greater distance, from 71.1 ppm at 0 m (at the fan) to 2.1 ppm at 5.5 m (between rows 2 and 3), 0.3 ppm at 10 m (after row 5), and 0.1 ppm at 50 m (control). This trend was also observed with colorimetric dosi-tubes and a photoacoustic detector at 0.3- and 3.0-m elevations. Significantly lower NH₃ concentrations were recorded at both the 0.3- and 3.0-m elevations in the presence of the trees compared with when the trees were removed from their pot-in-pot containers, suggesting that a portion of the atmospheric NH₃ was being trapped by the plants. This was further supported by greater foliar N concentrations in plants when measured downwind from the fans (P ≤ 0.0001). Dust concentrations sampled downwind from the fans were greatest at 2.5 m and decreased linearly to 50 m (P ≤ 0.0001). Plant PM_2.5, PM₁₀, and total PM washed from the foliage showed the same significant linear trend with greater distance from the fans. Plants also showed unique species differences in their capacity to trap and hold NH₃ and PM that can be applied in practical recommendations. These findings indicated vegetative buffers are capable of trapping NH₃ and PM fan emissions from poultry facilities.     

粗酶制剂在大麦日粮中对产蛋鸡的影响

就粗酶制剂在大麦日粮中对产蛋鸡产蛋性能的影响进行了两次试验。按０．１％比例的酶制剂添加于含大麦２８．５％和５０％的日粮中，分别饲喂３３０和２４２日龄的产蛋鸡。结果添加酶制剂对鸡产蛋率无明显提高，而对每个蛋重和鸡蛋质量有所改善，同时使产蛋鸡外周血液中促甲状腺激素和生长激素显著提高，而使甲状腺素显著降低。