文昌鸡产蛋性能及蛋品质研究

本文就文昌鸡产蛋规律、种蛋品质进行研究.结果表明:文昌鸡开产后第7周前产蛋率快速上升,到开产后第7周或第8周,产蛋率到达最高峰,60%以上的产蛋率能维持15～18周,经过产蛋高峰期后,产蛋率缓慢下降,期间略有波动,说明文昌鸡的产蛋性能良好;文昌鸡55周龄蛋品质性状蛋重(EW)、蛋壳重(SW)、蛋壳厚度(ST)、蛋壳强度(SS)、哈氏单位(HU)、蛋形指数(SI)、蛋黄重(YW)、蛋黄颜色(YC)的测定结果平均值分别为49.00g、6.34 g、320.69μm、4.01 kg/cm2.70.02、1.31、16.45 g、6.13.     

花粉主要营养成分与保健功能

6 眼病与蜂花粉 眼视力一般随老年人年龄增加而下降。研究发现，眼疾与B族维生素和维生素c密切相关。另外，白内障是老年人致盲的主要原因。尽管目前原因尚不十分了解，但与老年人晶状抗氧能力减弱和脂类过氧化增强有关。     

土壤脲酶活性两种测定方法的比较

利用比色法和扩散法对金强河地区和甘肃农业大学校园内的土壤脲酶活性进行了分析。结果表明：比色法和扩散法测定的土壤脲酶活性平均值分别为（0．531±0．207）mg／g和（0．446±0．204）mg／g,两种测定方法的结果和变异系数差异均不显著（P〉0．05）。但从试验操作方面考虑,扩散法操作比较简单、所用药品种类少、时间短,是一种比较可行的土壤脲酶活性测定方法。     

冷季型草坪草在环渤海旱碱区的适应性评价

针对环渤海低平原区较复杂的环境条件、恶劣的立地条件及目前草坪建植中存在的引种盲目、失败率高、寿命短等问题，通过对引进的4个草种37个品种的生育期、抗逆性、坪用价值等进行综合评价，结果表明：高羊茅为最适合的草种，草地早熟禾较适合，多年生黑麦草不适宜单播，可和高羊茅以适当的比例混播，紫羊茅不适宜在该区种植。筛选出最优良的高羊茅品种为皇后、贝克，草地早熟禾为亨特、普通、兰神、奖品。     

鸡传染性法氏囊病毒VP2蛋白B细胞抗原表位预测

以鸡传染性法氏囊病毒VP2蛋白的基因组序列为基础,采用Garnier-Robson方法、Chou-Fasman方法和Karplus-Schultz方法预测VP2蛋白质的二级结构;用Kyte-Doolittle方案预测蛋白质的亲水性;用Emini方案预测蛋白质的表面可能性;用Jameson-Wolf方案预测氨基酸的抗原性指数。综合分析,预测VP2蛋白的抗原表位。通过以上几种方法预测IBDV病毒VP2蛋白的B细胞表位位于VP2蛋白N端3-10、30-45、77-84、150-157、197-206、211-222、278-288、298-303、315-325、376-381、386-394、403-411、415-425区段。     

温度及预处理对苏丹草种子萌发的影响

本实验采用15～30℃和20～30℃2种变温,7℃、10℃、15℃和20℃4种恒温,以及0℃、5℃和10℃3种低温和硝酸钾预处理等技术,测定了苏丹草种子的萌发特性。结果表明:苏丹草种子室内最适萌发温度为20～30℃变温;预处理可破除种子休眠率达71.43～100％,并能提高幼苗的长度和简化活力指数,其中,以10℃低温预处理6天效果最好。建议苏丹草种了早春播种应以地温达15℃以上为宜。     

辽西地区野兔危害情况调查

通过走访、问卷调查和样地调查,对辽西地区野兔危害情况进行了初步调查,并对调查数据进行了统计分析。结果表明：辽西地区野兔主要危害杏树,其次是刺槐、杨树和梨树等;野兔对不同林龄杏树危害差异显著。其中,对3林龄以下杏树危害严重,3林龄以上危害较轻;野兔对不同地区杏树危害程度差异显著,主要表现在对海拔较高降雨较少的地区危害程度较海拔低降雨相对多的地区高。     

Immune responses of orange-spotted grouper,Epinephelus coioides,against virus-like particles of betanodavirus produced in Escherichia coli

Betanodaviruses are the causative agents of viral nervous necrosis (VNN), a serious disease of cultured marine fish worldwide. Virus-like particles (VLPs) are one of the good novel vaccine candidates to control this disease. Until now, betanodavirus vaccine studies mainly focused on the humoral immune response and mortality after virus challenge. However, little is known about the activation of genes responsible for cellular and innate immunity by vaccines. In the present study, VLPs of orange-spotted grouper nervous necrosis virus (OGNNV) were produced in prokaryotes and their ability to enter Asian sea bass cells was the same as native virus, suggesting that they possess a similar structure to OGNNV. VLPs immunogenicity was then determined by intramuscularly vaccinating Epinephelus coioides at different concentrations (1.5 or 15 μg g^?1 fish body weight, FBW) and immunizing frequencies (administration once, twice and thrice). A single vaccination with the dosage of 1.5 μg g^?1 FBW is enough to provoke high titer antibodies (average 3 fold higher than that of negative control) with strong neutralizing antibody titer as early as 1 week post immunization. Furthermore, quantitative PCR analysis revealed that eleven genes associated with humoral, cellular and innate immunities were up-regulated in the liver, spleen and head kidney at 12 h post immunization, correlating with the early antibody response. In conclusion, we demonstrated that VLP vaccination induced humoral immune responses and activated genes associated with cellular and innate immunity against betanodavirus infection in orange-spotted grouper.     

Leucine markedly regulates pancreatic exocrine secretion in goats

Four goats (30.1 ± 1.3 kg) with common bile duct re‐entrant catheter and duodenal catheter were used to evaluate the effects of duodenal leucine infusion on pancreatic exocrine secretion and plasma parameters with two 4 × 4 Latin square design experiments. In the long‐term infusion experiment, goats were fed twice daily [700 g/day, dry matter (DM) basis] at 8:00 and 18:00 hours and were duodenally infused with 0, 3, 6, 9 g/day leucine for 14 days. Pancreatic juice and jugular blood samples were collected over 1‐h intervals for 6 h daily from d 11 to 14 days to encompass a 24‐h day. In the short‐term experiment, goats were infused leucine for 10 h continuously at the same infusion rate with Experiment 1 after feed deprivation for 24 h repeated every 10 days. Pancreatic juice and blood samples were collected at 0, 1, 2, 4, 6, 8 and 10 h of infusion. The results showed that the long‐term leucine infusion did not affect pancreatic juice secretion, protein output, trypsin and lipase secretion and plasma insulin concentration, but linearly increased α‐amylase secretion. No changes in pancreatic protein and lipase secretion were observed in the short‐term infusion. Pancreatic juice and α‐amylase secretion responded quadratically, with the greatest values observed in the 3 and 6 g/day leucine respectively. Trypsin secretion linearly decreased, while plasma insulin concentration increased linearly with increased leucine infusion. The results demonstrated that duodenal leucine infusion dose and time dependently regulated pancreatic enzyme secretion not associated with the change in plasma insulin concentration.     

Identification of lactic acid bacteria in the feces of dairy cows fed whole crop maize silage to assess the survival of silage bacteria in the gut

In order to assess the survival of lactic acid bacteria (LAB) in whole crop maize silage in the gut of dairy cows, one representative silage sample and three different feces samples were collected from dairy cows on three dairy farms in Hua Bei, China and three dairy farms in Kyushu, Japan. The composition of the bacterial community was examined by denaturing gradient gel electrophoresis and quantitative polymerase chain reaction. Lactobacillus acetotolerans was detected in all bunker‐made maize silage samples, regardless of the dairy farm or sampling region from which they were sourced. A total of eight LAB species were detected in the maize silage samples, of which three (L. acetotolerans, L. pontis and L. casei) appeared to survive digestion. The populations of L. acetotolerans in silage and feces were 10^6–7 and 10^3–4 copies/g, respectively, indicating that, even for the LAB species showing potential survival in the gut, competition in this niche may be harsh and the population may substantially decrease during the digestion process. It may be difficult for silage LAB to survive in the gut of silage‐fed dairy cows, because marked decrease in population can take place during the digestion process, even for surviving species.