青海天峻县高原型藏羊毛纤维物理性能分析

通过对青海天峻县高原型藏羊毛纤维物理性能分析。结果表明纤维类型重量百分比:无髓毛、有髓毛和干死毛含量:周岁羊平均分别占48.87%,43.23%,15.38%,无干死毛羊只占15.11%;成年羊平均分别占40.85%,44.40%,17.52%,无干死毛羊只占14.41%。羊毛纤维细度:无髓毛、有髓毛和干死毛细度,周岁羊平均分别为21.06μm,38.85μm,68.31μm,成年羊平均分别为22.44μm,38.67μm,79.29μm。毛辫长、底绒长、毛纤维手排平均长度:周岁羊平均分别为274.13mm,82.72mm,70.05mm;成年羊平均分别为275.30mm,90.70mm,73.21mm。净毛率和色度(Wht、YT):周岁羊平均分别为72.37%,68.68,30.60;成年羊平均分别为73.55%,69.11,30.16。天峻县高原型藏羊具有良好的毛辫长度和底绒长度,而且底绒细度细,粗毛、绒毛比例适中,干死毛含量少,净毛率高,色度好的特点,是纺织地毯、长毛绒和提花毯的优质原料。     

Effect of dietary non-starch polysaccharide solubility and inclusion level on gut health and the risk of post weaning enteric disorders in newly weaned piglets

The objective of this experiment was to investigate the effect of non-starch polysaccharide (NSP) solubility and inclusion rate on gut health and development, performance and risk of post weaning enteric disorders (PWED) using NSP sources known not to affect digesta viscosity. The experiment consisted of a 2 × 3 factorial combination of NSP type (sNSP vs insoluble NSP (iNSP); inulin vs purified cellulose) and inclusion level (50 vs 100 vs 150 g/kg). Piglets were weaned at 28 days (day 0) and fed ad libitum until slaughter on day 14. There were no incidences of PWED. NSP solubility had little effect on performance, but sNSP diets resulted in lower caecal and colonic pH and higher colonic Lactobacilli to coliform ratio compared to iNSP diets. Increasing NSP levels significantly reduced caecal and colonic pH but decreased empty body weight percentage (P = 0.067). These results suggest that gut health may benefit most from diets containing appropriate sources of predominantly sNSP rather than iNSP. The optimal level of such sNSP will likely depend upon the level of risk of PWED in order to balance the trade off between maximising performance and improving gut health. Effects of NSP feeding under a higher infectious pressure remains to be assessed.     

Effects of dietary tryptophan and stocking density on the performance,meat quality,and metabolic status of broilers

Background

Highly automated cage-rearing systems are becoming increasingly popular in China. However, a high stocking density can cause oxidative stress and decrease broiler performance. The tryptophan (TRP) derivative 5-hydroxytryptophan (5-HT) has been shown to preserve membrane fluidity in birds suffering from oxidative stress. Therefore, this experiment was conducted to determine the effects of dietary TRP supplementation on performance, breast meat quality and oxidative stress in broilers reared in cages with a high or low stocking density.

Methods

Female Arbor Acres broilers (25-d-old, n = 144) were randomly allocated to 1 of 4 treatments. The birds were fed a diet based on corn, soybean meal, cottonseed meal and corn gluten meal containing either 0.18 or 0.27% TRP and were housed with stocking densities of 11 or 15.4 birds/m² in a 2 × 2 factorial experiment. Broiler performance was evaluated from d 25 to 42. Eight birds from each treatment were slaughtered on d 42 and plasma and breast muscle samples were collected to measure biochemical indices.

Results

A higher stocking density tended to be associated with reduced weight gain (P < 0.10), and significantly increased plasma glutamic-pyruvic transaminase (GPT) activity (P < 0.001). Increased dietary TRP significantly reduced the activities of lactic dehydrogenase and GPT while increasing total cholesterol in the plasma (P < 0.01), reducing drip loss of breast muscle (P < 0.10) and improving feed efficiency (P < 0.10).

Conclusions

An increase in dietary TRP, 1.5-fold higher than the standard supplementation level, can alleviate oxidative stress as well as improve welfare and feed efficiency in broilers reared in cages with a high stocking density.     

用HPLC法测定动物肌肉中的磺胺类药物

七种动物肌肉组织中残留的磺胺间甲氧嘧啶(SMM)、磺胺地索辛(SDM)、磺胺二甲氧嘧啶(SM2)、磺胺甲恶唑(SMZ)、磺胺喹恶啉(SQ)经乙腈提取,正己烷分配,再经碱性氧化铝SPE柱净化后,用高效液相色谱-紫外检测法测定。该方法的最低检测限为2μg/kg,最低检出限为10μg/kg,回收率为60％-110％,批内变异系数小于15％,批间变异系数小于20％。     

无角美利奴亲本母羊生产性能与血液生化指标的相关性

对８７只无角美利奴亲本母羊的生产性能及其血液生化指标进行了测试分析，试验结果表明，毛长，毛密，体重与其血清无机磷，血清钙磷乘积，血清总蛋白，血清白蛋白、胆固醇、黄疽指数呈极显著正相关；与血清钠、胡萝卜素，ａ２球蛋白呈显著正相关；而与血清磨香草酚浊度呈极显著负相关；与硫酸锌浊度、血清谷草转氨酶活力呈显著负相关；与其年龄呈显著负相关。     

UPLC-MS/MS法检测稻米及土壤中扑草净除草剂的残留量

建立检测稻米及土壤中扑草净的UPLC-MS/MS方法。稻米和土壤样品经乙腈和混合液提取,甲醇/二氯甲烷溶解,PSA固相萃取柱净化,氮气吹干后经UPLC-MS/MS测定,外标法定量。建立了水稻及土壤中提取扑草净残留量的液相色谱-质谱/质谱测定方法。扑草净在稻米及土壤中的最低检测质量分数分别为0.01mg/kg;最小检出量5×10~11g;稻米添加回收率为82.7%~105.3%,土壤中添加回收率为79.6%~103.3%;稻米的RSD为2.6%~3.6%,土壤的RSD为3.2%~5.2%。建立方法准确、快速、灵敏度高,能够满足扑草净残留量分析的要求。     

种植密度与施肥对巨菌草农艺性状和生产性能的影响

以巨菌草为试验草种,通过研究种植密度与施肥对其农艺性状和生产性能的影响,探明高产栽培技术,为其大面积推广应用提供科学依据。结果表明,随种植密度增大,巨菌草分蘖数、茎粗减小,株高、鲜草产量先升后降,适宜的种植密度为株行距80 cm×60 cm （20 833丛·hm^-2）;以有机肥或废菌料作基肥,适宜施肥量为3 000 kg·hm^-2;在基肥基础上进行尿素或复合肥追肥,适宜追肥量为750 kg·hm^-2。     

放牧强度对南方人工草地和绵羊生产性能的影响(简报)

放牧强度对草地生存环境和家畜生产性能关系密切^[1]。我国对放牧强度的研究集中于北方^[2],南方草地建设比较晚,尤其是南方人工草地相关研究比较少。本试验旨在探讨南方人工草地不同放牧强度与草地植物产量和放牧家畜生产性能之间的关系,为确定合理的载牧量提供参考依据。     

环保促进剂TBzTD对硫化天然胶乳胶膜的硫化性能及力学性能的影响

目前胶乳工业中常用的硫化促进剂如TMTD（秋兰姆类）、ZDC（二硫代氨基甲酸盐类）等,均会在胶乳制品硫化过程中产生强致癌N-亚硝胺,对人类健康产生严重影响。采用硫磺硫化体系,考察未产生有毒N-亚硝胺的促进剂四苄基二硫化秋兰姆（TBzTD）对天然胶乳配合胶膜的硫化性能及其硫化胶膜力学性能的影响。同时也考察氧化锌（ZnO）及硫化温度对天然胶乳配合胶膜的硫化性能及硫化胶膜力学性能的影响。结果表明：随TBzTD,ZDC及ZnO用量的增加和硫化温度的提高,天然胶乳配合胶膜的硫化速度显著提高;当用量为0.5~1.5份时,随TBzTD用量的增加,天然胶乳硫化胶膜的定伸应力、拉伸强度及撕裂强度均先增大后减小;随着硫化温度（90~110 ℃）的提高,以ZDC作为促进剂的硫化胶膜的力学性能先提高后降低,而以TBzTD为促进剂的硫化胶膜的力学性能则逐渐提高。     

生态公益林效益发挥的保障机制

文章具体阐述了生态公益林的多重效益和对生态公益林保护建设的生态补偿机制进行了探讨。