肉种鸡能量限饲对胚胎期血清脂类代谢相关指标影响

文章对产蛋期AA肉种鸡进行能量限饲,旨在探讨其对胚胎期血清脂类代谢相关指标影响。选用20周龄肉种母鸡400羽,随机分为4组,每组5个重复,每个重复20羽。当产蛋率达到5%时开始正式试验,对照组饲喂基础日粮,试验组日粮能量水平分别为基础日粮能量80%、70%、50%,对照组和试验组均限饲且饲喂量相同,于产蛋期(37~39周龄)进行人工授精并按肉种鸡分组收集种蛋(每组150枚)后孵化,分别于13、15、17、19和21胚龄采集血清样品。结果表明,①肉种鸡能量限饲显著提高了15胚龄各试验组及17、19、21胚龄80%能量组血清CHO含量(P<0.05)、13胚龄80%能量组TG含量(P<0.05)。②肉种鸡能量限饲显著降低了13、15、19胚龄各试验组血清GLU含量(P<0.05)和17胚龄各试验组血清LDL含量(P<0.05)。③肉种鸡能量限饲显著提高了15胚龄70%和80%能量组及17胚龄80%能量组血清T3含量(P<0.05)、15胚龄80%能量组及21胚龄70%和80%能量组血清T4含量(P<0.05),显著降低了17胚龄50%能量组血清T3含量(P<0.05)及13胚龄70%能量组血清T4含量(P<0.05)。④肉种鸡能量限饲显著降低了13胚龄70%、80%能量组及21胚龄80%能量组血清LEP含量(P<0.05),13胚龄80%能量组血清INS含量(P<0.05),17、19、21胚龄试验组血清GH含量(P<0.05)。以上结果显示,肉种鸡能量限饲对胚胎期血脂代谢指标影响存在着母体效应,表现为对血清CHO、TG含量提升作用和对血清GLU、LDL、LEP、INS、GH含量降低作用。     

多效唑调节杂交水稻制种父本花期利弊探讨

目前在杂交水稻制种生产上,应用 15%多效唑调节发育偏快的父本较为普遍.但因施用技术不当,效果差异很大,甚至导致制种减产或失收.分析、探讨了其使用的利弊.     

豇豆胰蛋白酶抑制剂(CpTI)抗虫转基因新疆杨的获得

利用根癌农杆菌介导法将广谱抗虫基因豇豆胰蛋白酶抑制剂(CpTI)基因导入新疆杨(Populus a1-ba var．pyramidalis)，经筛选获得了大量转基因植株。对转基因植株经PCR鉴定、PCR-Southern和点杂交分子检测结果证实CpTI基因已整合进杨树基因组中。部分转基因植株的饲虫实验表明，饲喂转基因杨树叶片可明显抑制杨尺蠖幼虫生长发育。     

封育对人工针叶林林下植物多样性恢复的影响

该文以河北省木兰林管局较强封育、较弱封育和非封育等3种封育强度的人工油松林和人工华北落叶松林林下植被为研究对象,对其物种丰富度、群落结构特征、物种多样性指数、群落相似度等4个方面进行了比较。结果表明:不同封育强度下人工针叶林林下草本植被差距较大,较强封育区油松林和落叶松林比非封育区的物种数分别多33种和21种,高度大2.49倍和3.28倍,盖度值大52.21%和54.87%;而木本植物的密度、盖度差距等不明显。各封育强度下植被反映物种多样性的Simpson指数值差异并不显著,部分Shannon-Wiener指数差异显著。随着封育强度的变弱,相同树种各标准地间的林下物种组成差异增大。油松林和落叶松林林下植物在较强封育下物种种类和群落结构相似程度不大,但在非封育的极强干扰胁迫下,两个不同的建群种林下植物种类和群落结构表现出较为接近的特征。外界的严重干扰影响人工针叶林林下植被,人为干扰一旦停止,针叶林林下植被的恢复较快。限制人、畜对林下植被的干扰,加强封育,可有效恢复和增加林下植被的物种多样性。这说明人工林群落加强封育、减小干扰直接影响着群落的生物多样性的高低及其生态效益。     

Ocular surface physiology and aqueous tear secretion in cats of diverse cephalic conformations

Objective

To describe normative ocular surface and aqueous tear testing data for cats of various cephalic conformation.

Animals studied

Fifty-three healthy adult cats (11 British Shorthair, 11 Burmese, 10 Devon Rex, 10 Scottish Fold, and 11 Sphynx).

Procedures

Blink rate, corneal tactile sensation (CTS), and Schirmer tear test with or without topical anesthesia (STT-1, STT-2) and with nasolacrimal stimulation (NL-STT1, NL-STT2) were assessed. Palpebral fissure length (PFL) and skull morphology were measured, and cephalic index (CI) and craniofacial ratio (CFR) calculated.

Results

Mean ± SD test results were as follows: blink rate (5.0 ± 2.3 blinks/min), CTS (3.2 ± 0.7 cm), STT-1 (11.2 ± 4.3 mm/min), STT-2 (6.7 ± 3.6 mm/min), NL-STT1 (13.4 ± 5.7 mm/min), NL-STT2 (13.5 ± 5.2 mm/min), and PFL (2.0 ± 0.2 cm). Corneal sensitivity did not differ significantly among breeds (p = .152) but was negatively correlated with body weight (r = −.32, p = .019). STT-1 significantly differed among breeds (p < .001) and was lowest in Sphynx cats (8.7 ± 4.3 mm/min). A positive correlation was detected between STT-1 values at 30 and 60 s (r = .98; p < .001). The nasolacrimal reflex significantly increased STT in anesthetized and unanesthetized eyes (approximately +100% and +20%, respectively; p ≤ .002). STT-1 tended to be higher in intact versus neutered cats (p = .062). Age did not impact any test result (p ≥ .085).

Conclusions

Normative data described here serve as a baseline for future studies assessing ocular surface disease in multiple feline breeds. Unlike dogs, brachycephalic cats did not have lower CTS or STT-1 than non-brachycephalic cats.     

赴加拿大森林航空消防吊桶培训考察报告

为进一步增强森林航空消防直接灭火特别是吊桶灭火的能力,受加拿大SEI责任有限公司的邀请和局领导的安排,我们组成森林航空消防吊桶技术培训考察团于2006年10月16～29日赴加拿大进行了培训和考察。     

赴西北林业考察报告

考察西北林业建设及林业产业发展,吸取生态公益型林场的经营管理经验。     

茄子嫁接栽培技术关键

利用嫁接技术,选择抗病的茄子砧木,再嫁接本地适销对路的茄子品种,即增加产量,又增强抗逆性,会产生很好的经济效益,具有很高的开发价值.     

Apparent Digestible Energy and Nutrient Digestibility Coefficients of Diet Ingredients for Pacu Piaractus brachypomus

The digestible energy and apparent nutrient digestibility coefficients of common diet ingredients were determined for pacu Piaractus brachypomus (370.21 ± 17.56 g). Fish were fed with pelleted practical diets to apparent satiation and the feces were collected by siphoning. The digestibility value for each ingredient was determined by comparison of the digestibility of a test diet with a reference diet (24.5% crude protein and 1% chromic oxide). The digestible energy values of soybean meal (SBM), fish meal (FM), corn (CN), and wheat bran (WB) were 2382. 3826, 3353, and 1784 kcal/kg, respectively. The apparent dry matter digestibility coefficients were 83.72, 90.14, 89.13, and 82.05% for SBM, FM, CN, and WB, respectively. The apparent crude protein digestibility coefficients were 75.88, 90.49, 85.06, and 61.62% for SBM. FM, CN, and WB, respectively. The apparent lipid digestibility coefficients were 63.03, 77.00, 83.01, and 82.45% for SBM, FM, CN, and WB, respectively. The digestibility of protein, lipid, and energy from SBM were somewhat low compared to values for other warmwater omnivorous fishes, but similar to values reported for pacu-caranha P. mesopotamicus. Otherwise, the nutrient and energy availability of the ingredients to P. brachypomus was similar to that of other fish. This information will be useful in formulating nutritious, economical diets for pacus.