Effect of weaning method on body weight,testicular growth,sexual behavior,age of puberty,and testosterone concentration of Beetal bucks

The current study evaluates the effects of early (8th week) and late (16th week of age) weaning of male goat kids on their body growth, testicular growth, sexual behavior, plasma testosterone concentration, and pubertal age. Early (n = 6) and late (n = 7) weaned Beetal bucks were weekly monitored from 18th to 38th week for their body weight, scrotal circumference, testicular volume, testicular echogenicity (via ultrasonography), sexual activities, and plasma testosterone concentration. In comparison to early-weaned, late-weaned bucks showed a marked increase (p < .05) in body weight (11.4 ± 0.8 vs. 13.7 ± 0.6kg), testicular volume (44.1 ± 7.2 vs. 79.8 ± 18.7cm³), scrotal circumference (10.7 ± 0.6 vs. 12.8 ± 0.7cm), and testicular echogenicity (28.3 ± 2.7 vs. 38.3 ± 2.1) from 18th, 28th, 21st, and 24th week onward, respectively. Sexual activities started earlier in late- than early-weaned bucks (22nd vs. 25th week, respectively). Moreover, the sexual behavior index was better (p < .05) after the 34th week in late than early-weaned bucks. The plasma concentration of testosterone (at 39 weeks of age) was relatively more and the onset of puberty was 2–3 weeks earlier (p < .05) in late than early-weaned bucks. In conclusion, age-based early weaning of male kids impairs their testicular growth, sexual behavior, and age at puberty compared to conventional weaning.     

Detection of Tomato yellow leaf curl virus in imported tomato fruit in northern Europe

Imported tomato fruits infected with Tomato yellow leaf curl virus (TYLCV) were identified on the market in northern Europe using paper‐based FTA Classic Cards (Whatman), polymerase chain reaction (PCR) and partial DNA sequence analysis. Trade tomatoes originating from southern Europe, Africa and the Middle East were sampled in Estonia and Sweden, and tested for infection with begomoviruses. Out of 100 batches analysed with five fruits sampled in each batch (58 batches from Estonia and 42 from Sweden), 20 batches were positive (16 from Estonia and four from Sweden). Rolling circle amplification (RCA) and full‐length genome sequence analysis of one isolate collected in Estonia and one isolate in Sweden, revealed highest nucleotide sequence identity at 99% to TYLCV‐IL for the Estonian isolate and at 97% to TYLCV‐Mld for the Swedish isolate. In this study, TYLCV was identified for the first time in imported tomato fruits on the market in northern Europe. FTA cards proved to be an effective means to collect, extract and store begomovirus DNA from tomato fruits and the subsequent molecular analysis.     

Current status and impact of mango malformation in Egypt

A survey was conducted in 1998 to determine the status and impact of mango malformation in Egypt. In the El Giza, Ismailîa and Sharkaia Governerates, disease incidence and severity ranged from 20 to 100% and from 5 to 60%, respectively. In contrast, 75 km to the south in the El Faiyûm Governerate, incidence and severity were lower, 3-5 and 0.1 to <1%, respectively. Based on these figures and recent production statistics, it is estimated that malformation causes losses in Egypt of at least E35 million/year. When malformation was managed in El Giza, Ismailîa and Sharkaia by removing affected vegetative and floral terminals, the mean disease incidence and severity were lower than in non-managed orchards (69 versus 29% and 29 versus 6%, respectively). Thirty-nine isolates of the pathogen, Fusarium mangiferae, recovered during the survey were sexually incompatible with the B, C and D mating populations of the Gibberella fujikuroi complex; 10 of these were also incompatible among themselves. Four vegetative compatibility groups (VCGs) were detected among 43 of the isolates from this and a previous survey. VCG was generally not correlated with farm, governerate or host cultivar, and in three instances, isolates from two different VCGs were recovered from the same tree. RAPD analyses divided isolates into two genetically distinct clusters: Group I contained isolates in VCGs 1, 2 and 4; Group II contained isolates in VCG 3. The VCG and RAPD data support the conclusion that isolates of the pathogen from the Nile Delta were probably responsible for the recent appearance of the disease in El Faiyûm.     

杏园梅下毛瘿螨Acalitus phloeocoptes(Nalepa)发生规律

【目的】研究新疆轮台县杏园芽瘿发生原因、分析梅下毛瘿螨的发生、转移、扩散规律,确定最佳防治时间。【方法】对杏芽瘿室内镜检,在田间定点、定时选取样株样枝记录危害症状、致瘿因子及田间时空动态;在新老枝条间粘贴胶带及树冠不同高度、方向、距离悬挂粘虫板的方法,记录致瘿因子的转移危害规律、传播的方式及传播距离。【结果】危害杏树芽苞,使其增生畸变成瘿瘤的是瘿螨,经鉴定系梅下毛瘿螨 Acalitus phloeocoptes (Nalepa)。在新疆轮台县该螨主要以成螨在瘿瘤芽苞幼嫩杏鳞叶片内越冬,占调查总数的95.91%;翌年3月下旬杏树开花中期,越冬成螨开始出蛰活动,4月上旬出蛰成螨开始大量产卵,4月下旬至5月上旬是梅下毛瘿螨的产卵高峰期,5月中下旬是成若螨高峰期,9月底随着气温下降,成螨为越冬做准备。梅下毛瘿螨5月上旬开始从芽苞内向外爬行转移,5月下旬是其转移高峰期。风是梅下毛瘿螨被动传播的主要媒介,帮助其远距离传播,传播距离最远可达15 m。在不同高度的粘虫板诱捕螨量存在差异:迎风面>背风面。【结论】杏芽瘿是由梅下毛瘿螨侵染引起,以成螨在瘿瘤芽苞内层越冬,在新疆轮台县3月底至9月下旬均有危害,一年发生10余代,其中4、5和6月危害较严重。5月下旬是其转移高峰期,这一阶段是化学防治的最佳时间。     

43个玉米品种在新疆吐鲁番旱区表现和抗旱类群划分

目的 基于形态指标和产量指标,将43份引进玉米品种划分为不同群体,并筛选出适合新疆旱区种植的玉米品种。方法 以43个玉米品种为材料,测定其在干旱胁迫下株高、穗位高、茎粗、单株穗数、穗长、穗粗、穗行数、穗粒重、百粒重、籽粒产量以及茎叶鲜重和茎叶干重等12项指标。运用相关分析、主成分分析、聚类分析、逐步判别分析和多元方差分析等方法综合评价多个玉米品种的抗旱性能。结果 12项数量性状间存在一定的相关性和信息的重叠,35对数量性状的相关系数达极显著水平,21对数量性状相关系数达到显著水平。前3个主成分代表了43个玉米品种的12项数量性状71.02%的信息,其贡献率分别为27.49%、27.41%和16.12%。其中,第一主成分是营养体生长状况,包括株高、穗位高、茎粗和茎叶重量;第二主成分是生殖生长状况,包括穗数、穗长、穗粒重、百粒重和产量;第三主成分是穗行数和穗粗。当类间距离为4.5时,43个玉米品种被聚为5大类。其中,第Ⅱ类属于高产品种,包含3个品种;第Ⅲ类属于中高产品种,包含7个品种;第Ⅳ类属于中产品种,包含10个品种;第V类属于中低产品种,包含19个品种;第Ⅰ类属于低产品种,包含4个品种。42个玉米品种被正确判别,判对概率为97.67%;1个玉米品种被误判,误判率为2.33%。结论 类群划分的结果准确可靠,选育的第Ⅱ类和第Ⅲ类玉米品种能够显著的增产,玉米育种在抗旱性方面进展明显。玉米正播模式引种,辽单145和辽单1211;复播玉米品种郑单958最佳。     

发酵饲料对京红蛋鸡产蛋后期生产性能、血清参数及脂代谢的影响

【目的】 研究饲粮中添加发酵饲料对京红蛋鸡产蛋后期生产性能、蛋品质、血清参数及脂代谢的影响。【方法】 选取480只54周龄的京红蛋鸡随机分为2组(对照组和试验组),每组4个重复,每个重复60只蛋鸡,对照组饲喂基础饲粮,试验组在基础饲粮的基础上添加30 g/kg发酵饲料。试验预试期为10 d,正试期为56 d。【结果】 (1)在生产性能方面,与对照组相比,试验组产蛋率显著升高4.56%(P<0.05)。(2)在蛋品质方面,与对照组相比,试验组的蛋壳强度极显著提高了17.18%(P<0.01);蛋黄比例极显著提高了7.48%(P<0.01);蛋白比例极显著降低了3.69%(P<0.01);蛋黄胆固醇含量极显著降低了24.90%(P<0.01)。(3)在血清生化指标和繁殖激素方面,试验组血清钙离子含量显著升高了11.99%(P<0.05);促卵泡素和促黄体素分别显著升高了24.55%(P<0.05)和12.88%(P<0.05)。(4)血清和肝脏总胆固醇含量分别显著降低18.86%(P<0.05)和18.54%(P<0.05),肝脏高密度脂蛋白极显著升高17.69%(P<0.01)。其余指标差异均不显著(P>0.05)。【结论】 在饲粮中添加30 g/kg的发酵饲料,对京红蛋鸡产蛋后期的生产性能以及蛋品质具有一定的改善作用。