提升犊牛日增重的方法研究

犊牛阶段的生长状况对牛只的生产性能具有重要影响,为提高牧场效益,牧场越来越追求犊牛阶段生长的最大化。通过饲喂代乳粉达到犊牛断奶前1.0 kg日增重,对牛只生产性能的提升具有重要意义。本文主要介绍增加犊牛日增重对牛只生产性能的积极影响,同时根据荷兰Schils的试验对代乳粉的选择和饲喂流程提出建议,以期对牧场合理使用代乳粉,实现犊牛阶段生长最大化提供参考。     

土壤硒富集空间分布特征及影响因素研究

以揭阳市土壤为对象,系统采集了表层土壤样(0～20 cm)1 330个和深层土壤样(150～200 cm)331个,并利用相关性分析、回归分析、方差分析及GIS空间分析技术等方法对土壤硒的含量分布、富集特征及影响因素进行了系统的分析。结果表明,揭阳市表层土壤Se含量处于0.02～2.01 mg/kg之间,几何平均值为0.48 mg/kg,是中国土壤Se平均含量的1.66倍。揭阳市土壤总体呈足硒及富硒特征,不存在硒过剩,极少区域土壤呈硒缺乏特征,表层与深层土壤表现基本一致,富硒土壤主要分布于普宁市、惠来县及北部边缘。表层土壤中Se富集面积达到52.03%,但在空间上分布零散,这可能与母质、土壤类型等因素有关。强富集区域集中分布于花岗岩与粉砂岩为母质的土壤区,而大部分由第四纪冲积物形成的土壤无富集。方差分析表明:不同母质、土壤类型及土地利用方式对土壤Se的含量及富集水平均造成不同程度的影响,其中影响揭阳市表层土壤Se含量的主要因素为成土母质。除此之外,土壤理化性质及海拔也是影响揭阳市表层土壤Se富集的重要因素。回归分析表明表层土壤Se与pH值呈极显著的负相关,并且分别与有机碳、Fe_2O_3及Al_2O_3呈极显著线性正相关。     

广东清远市一次局地暴雨过程分析

利用探空观测资料以及FY-2D气象卫星云图、多普勒天气雷达回波等非常规气象观测资料,采取天气学诊断分析方法,对2009年7月26日出现在广东清远市一次局地突发性暴雨过程进行了诊断分析。结果表明,副热带高压边缘的不稳定气流及南支槽前的上升运动是此次局地暴雨过程的天气尺度系统和大尺度环流背景;暴雨发生前大气不稳定能量不断积累,为中尺度系统形成创造了有利的环境条件;地形与降水有着密切的关系,中小尺度地形使近地面上升气流增强,造成了对流云团在该地不断生成和发展。     

发酵秸秆饲喂生长育肥猪的效果

通过对发酵玉米、发酵高粱秸和发酵麦秸3种秸秆进行发酵处理,添加于饲料中确定其对生长育肥猪的效果。选用48头健康生长状况相似的杜花F1杂种猪,将其随机分为4组,每组12头。第1组作为对照组,饲喂基础日粮;第2、3、4组作为试验组,分别饲喂添加了发酵玉米秸、发酵高粱秸和发酵麦秸的饲料。根据生长育肥猪的采食量、饮水、日常活动、粪便及日增重的效果探讨发酵秸秆的饲喂效果。结果表明,发酵玉米秸喂猪较好,其增重速度与对照组无明显差异。而发酵高粱秸和发酵麦秸效果较差,日增重分别比对照组低11.32%(P0.05)和12.28%(P0.05),每1kg增重耗料分别高于对照组12.20%和13.24%。     

纳米铜、灵芝孢子粉与大豆异黄酮对1~30日龄清远麻鸡生长、免疫及抗氧化性能的影响

本研究对比分析了饲粮中添加纳米铜、灵芝孢子粉与大豆异黄酮对育雏阶段清远麻鸡生长性能、免疫功能及抗氧化性能的影响，旨在为肉鸡生产中添加剂的开发及应用提供参考。采用单因素随机分组设计，选用1 200只1日龄清远麻鸡母鸡分成4组，对照组（CON）饲喂基础饲粮，3个处理组（NC、GLS及SI）分别在基础饲粮中添加2 500 mg/kg纳米铜、600 mg/kg灵芝孢子粉和300 mg/kg大豆异黄酮预混剂。每个处理10个重复，每个重复30只鸡，试验期30天。试验结束后，采集试验鸡血浆、空肠黏膜样品，测定血液抗氧化相关生化指标及肠道免疫因子。结果表明：与对照组相比，①饲粮添加纳米铜、灵芝孢子粉与大豆异黄酮对清远麻鸡肉仔鸡的生长性能均无显著影响（P>0.05）。②灵芝孢子粉显著提高了30日龄清远麻鸡的胸腺比例（P<0.05）。③纳米铜显著提高了清远麻鸡的空肠绒毛隐窝比（P<0.05）。④纳米铜、灵芝孢子粉与大豆异黄酮均显著增加了清远麻鸡血浆和空肠中总超氧化物歧化酶（T-SOD）活性（P<0.05）；纳米铜显著增加了血浆谷胱甘肽过氧化氢酶（GSH-Px）活性（P<0.05）、降低了空肠黏膜丙二醛（MDA）含量（P<0.05）；大豆异黄酮显著降低血浆与空肠MDA含量（P<0.05）。⑤纳米铜组清远麻鸡空肠中免疫球蛋白A（IgA）含量显著增加（P<0.05），灵芝孢子粉组清远麻鸡血浆中肿瘤坏死因子-α（TNF-α）、空肠中干扰素-γ（IFN-γ）含量显著降低（P<0.05）。在本试验条件下，纳米铜、灵芝孢子粉与大豆异黄酮对清远麻鸡肉仔鸡生长性能没有显著影响，但均可改善抗氧化性能指标；纳米铜可提高空肠绒毛隐窝比，纳米铜与灵芝孢子粉可调节免疫因子分泌。其中纳米铜对抗氧化性能的调节作用最优，灵芝孢子粉对免疫功能调节作用最优。     

Effects of Citrus Extract on Plasma Biochemical Indexes,Hormone Levels and Antioxidant Function of Broilers after Transport Stress

In order to study the effects of citrus extract on the plasma biochemical indexes,hormone level and antioxidant function of broilers after transport stress,a total of 360 twenty-eight-day-old fast-growing Yellow feather broilers were randomly divided into two groups (6 replicates per group,30 per replicate).The control group was fed basic diet without antibiotics,the experimental group was fed basic diet supplemented with 10 mg/kg citrus extract.At 63 days,six chickens were selected from each replicate for transport stress test for 0,2,and 4 h,respectively,and plasma sampling were conducted after transportation.The results showed that:① For glucose,cholesterol and urea nitrogen,there was a significant interaction between food treatment and transportation time (P<0.05).Compared with the control group,the contents of urea nitrogen and cholesterol in the plasma of broilers in the experimental group were significantly lower than that in the control group,and the content of glucose in the plasma of broilers in the experimental group was significantly higher than that in the control group (P<0.05).Transport stress significantly affected the content of urea nitrogen,cholesterol and glucose in the plasma of broilers in the control group,after transportation,the content of urea nitrogen and cholesterol increased significantly,while the content of glucose decreased significantly (P<0.05).② For corticosterone,triiodothyronine and thyroxine,there was significant interaction between food treatment and transport time (P<0.05).Compared with the control group,the content of corticosterone in the plasma of broilers in the experimental group was significantly lower than that in the control group,while the content of triiodothyronine and thyroxine in the experimental group was significantly higher than that in the control group (P<0.05).Transport stress significantly affected the content of corticosterone,triiodothyronine and thyroxine in the plasma of the control group,after transportation,the content of corticosterone in the plasma of the broiler significantly increased,while the content of triiodothyronine and thyroxine significantly decreased (P<0.05).③ For glutathione peroxidase,there was a significant interaction between food treatment and transportation time (P<0.05).Compared with the control group,the glutathione peroxidase activity in the plasma of broilers in the experimental group was significantly higher than that in the control group (P<0.05);Transport stress significantly affected the activity of glutathione peroxidase in the plasma of broilers in the control group.With the prolongation of transport time,the activity of glutathione peroxidase in the plasma of broilers decreased significantly (P<0.05).Therefore,transportation stress affected the metabolism level,hormone secretion and antioxidant function of Yellow feather broiler.Adding citrus extract to the diet could improve the metabolism level,regulate hormone secretion and improve antioxidant capacity,and alleviate the impact of transportation stress on Yellow feather broiler.     

中草药防治肉鸡腹水综合症的研究进展

肉鸡腹水症是遍布世界各地的一种代谢性疾病,发病率及死亡率高,对肉鸡养殖业造成了严重损失.通过查阅文献资料的方式汇总了近年用中草药防治肉鸡腹水症的研究资料,阐述了肉鸡腹水症病因及用中草药防治的研究进展,旨在探讨中草药防治本病的作用机理,为采取有效防治措施提供理论依据.     

越北腹露蝗胚胎发育的研究

从采自粤北地区后保存在广州室内的不同卵块中每隔一定时间取出卵粒,一部分固定染色后用立体解剖显微镜观察、研究其发育阶段,一部分测定其含水量．结果表明,越北腹露蝗卵胚胎发育可分为10个阶段．卵从产后到胚胎发育萌动前,含水量、鲜质量较稳定,含水量（W）保持在47％-48％,鲜质量保持在7．27—7．30mg,胚胎刚开始萌动时,含水量（W）迅速上升到60％～62％,其鲜质量迅速上升到9．17—9．19mg,随着胚胎发育含水量逐渐增加,在胚胎发育完全接近孵化时,含水量达到82％～83％,其鲜质量为13．48～13．51mg,卵的平均生物量则随胚胎发育而减少．越北腹露蝗产下滞育卵,在室温（20～25℃）下卵的滞育期长达6个月左右,胚胎发育历期仅为23．26d．     

Study on Slaughter Performance and Meat Quality of Guangxi Partridge Chickens

In order to develop product and improve breeding for Guangxi partridge chickens,the slaughter performance,amino acids,inosine acid and fatty acids contents in muscle were measured and evaluated for Guangxi partridge chickens at 120 days old,which were raised at same nutrition level and management. Carcass traits and meat characteristics were evaluated. The results were showed that the dressing percentage and eviscerated yield percentage of cocks and hens were 90.15%,92.57% and 69.12%, 68.08%,respectively. The total amino acids in the breast and leg muscles of cocks and hens were 20.37,18.40 and 21.30, 18.44 g/100 g,respectively. The ratio of essential amino acids to total amino acids in breast and leg muscles of cocks and hens were 39.32%,42.33% and 42.72%, 43.06%,respectively,and essential amino acid index (EAAI) were 84.33,88.82 and 90.44, 90.77,respectively. The content of delicious,sweet,branched chain amino acids and inosinic acid in breast muscle were 0.85 g/100 g,0.42 g/100 g,0.56 g/100 g and 1.55 mg/g higher than that in leg muscle,respectively,and the content of sweet amino acids in hens was 0.40 g/100 g more than that in cocks. The first limiting amino acid was Met+Cys in muscle of Guangxi partridge chickens. Oleic acid and linoleic acid were mainly components of unsaturated fatty acids in muscle,palmitic acid and stearic acid were mainly components of saturated fatty acids in muscle. The relative content of polyunsaturated fatty acids and essential fatty acids in leg muscle were higher than that in breast muscle, and their contents in hens were more than that in cocks. All these showed that the Guangxi partridge chickens had good meat production,flavor and high nutrition value,meanwhile the nutritional values in hens were superior than that in cocks.     

便携式茶鲜叶品质光谱检测装置研制

品质监测对茶鲜叶适时采摘和茶叶加工品控具有重要意义。该研究基于可见/近红外光谱技术，研发了便携式茶鲜叶品质无损检测装置。该装置分为主机和手柄2部分，主机大小约240 mm×250 mm×240 mm，包括光谱仪、光源、可充电锂电池、稳压板和散热风扇；手柄大小约130 mm×100 mm×30 mm，包括光纤探头、金属灯杯、白参考板和外触发按钮。基于该设备，采集了茶鲜叶500～900 nm范围内可见/近红外漫反射光谱，对比了归一化（Normalize，NOR）、一阶导数（First Derivative，FD）、标准正态变量变换（Standard Normal Variable Transformation，SNV）和概率商归一化（Probabilistic Quotient Normalization，PQNOR）等不同光谱预处理方法对茶叶光谱的处理结果，建立了茶鲜叶干物质含量、水浸出物含量、茶多酚含量的偏最小二乘定量预测模型。结果表明，PQNOR预处理后建立的偏最小二乘预测模型精度最好，干物质、水浸出物和茶多酚含量预测模型在验证集的相关系数分别为0.905、0.896和0.747，均方根误差分别为0.856%、0.559%和0.549%。在茶园对装置的精度进行了现场测试，单片茶鲜叶检测时间约为1 s，干物质、水浸出物和茶多酚含量预测值与测量值的均方根误差分别为0.903%、0.634%和0.551%。该装置可以实现茶鲜叶光谱原位采集和干物质含量、水浸出物、茶多酚的定量分析，对及时掌握茶树生长情况、辅助决策采茶方案和保障茶叶品质具有重要作用。