The Application of Copper Waterline on Laying Performance and Gut Health of Aged Laying Hens

The effect of the application of copper waterline on the performance and gut health of aged laying hens was evaluated in this study. Forty-eight 70-week-old laying hens were divided into two groups (three replicates of eight hens each): control and copper (Cu) groups provided with normal polyvinyl chloride (PVC) waterline or Cu waterline. The laying performance was measured during the four-week period of the experiment. The intestinal antioxidant status and the microbiota diversity of the cecal content were determined. Moreover, a bacteriostasis test on Escherichia coli and Salmonella enteritidis was conducted after inoculation in waterline and hens, respectively. The water Cu²⁺ content was increased by Cu waterline compared to the control (P<0.05). Cu waterline had no detectable effect on most production performances, however, it increased the egg weight (P<0.05). Cu waterline increased the Cu level in the eggshell. Cu level in excreta increased with time, especially in the final two weeks, however, there was no significant change in fecal Cu excretion. The lipid peroxidation product malondialdehyde content in ileum decreased (P<0.01), while the activities of CuZn-superoxide dismutase (SOD) of ileum and glutathione peroxidase (GSH-PX) activity of jejunum and ileum increased after Cu treatment. The relative abundance and richness of cecal microbiota increased after Cu treatment (P<0.05). Cu waterline changed the microbial composition, including the increased proportion of Methanocorpusculum, Paludibacter, and decreased proportion of Fucobacterium, Anaerobiospirillum, and Campylobacter. The colonization of E. coli and S. enteritidis in Cu waterline was suppressed by Cu treatment, indicating that Cu waterline had potential antibacterial properties. The result suggests that Cu waterline could inhibit the colonization of pathogenic microorganisms such as E. coli and Salmonella and facilitate the enrichment of cecal microbiota diversity.     

Use of machine-learning algorithms to aid in the early detection of leptospirosis in dogs

Leptospirosis is a life-threatening, zoonotic disease with various clinical presentations, including renal injury, hepatic injury, pancreatitis, and pulmonary hemorrhage. With prompt recognition of the disease and treatment, 90% of infected dogs have a positive outcome. Therefore, rapid, early diagnosis of leptospirosis is crucial. Testing for Leptospira-specific serum antibodies using the microscopic agglutination test (MAT) lacks sensitivity early in the disease process, and diagnosis can take >2 wk because of the need to demonstrate a rise in titer. We applied machine-learning algorithms to clinical variables from the first day of hospitalization to create machine-learning prediction models (MLMs). The models incorporated patient signalment, clinicopathologic data (CBC, serum chemistry profile, and urinalysis = blood work [BW] model), with or without a MAT titer obtained at patient intake (=BW + MAT model). The models were trained with data from 91 dogs with confirmed leptospirosis and 322 dogs without leptospirosis. Once trained, the models were tested with a cohort of dogs not included in the model training (9 leptospirosis-positive and 44 leptospirosis-negative dogs), and performance was assessed. Both models predicted leptospirosis in the test set with 100% sensitivity (95% CI: 70.1–100%). Specificity was 90.9% (95% CI: 78.8–96.4%) and 93.2% (95% CI: 81.8–97.7%) for the BW and BW + MAT models, respectively. Our MLMs outperformed traditional acute serologic screening and can provide accurate early screening for the probable diagnosis of leptospirosis in dogs.     

雕鸮与黄腿渔鸮羽毛扫描电镜观察

选取雕鸮与黄腿渔鸮的面盘羽、体羽、飞羽、尾羽4类羽毛进行扫描电镜观察,测量记录羽毛的腹齿数、羽小钩数、纤毛数,绒羽节直径、节间距等数据,并利用SPSS22.0进行数据分析,为鉴别鸟种提供重要依据,对于案件定性、侦破、辨别至关重要。结果表明：雕鸮与黄腿渔鸮飞羽和尾羽除羽小钩数外其他测量性状,以及体羽所有测量性状均存在极显著差异;体羽基部绒羽结构的基节长度和绒羽节直径存在极显著差异。因此,利用面盘羽、体羽、飞羽和尾羽的微观结构差异可以区分雕鸮与黄腿渔鸮。     

硼对甘蓝型双低春油菜产量和品质的影响

旨在阐明硼对甘蓝型双低春油菜产量和品质形成的影响机理,明确甘蓝型双低春油菜产量和品质形成与施硼量的关系。试验以甘蓝型双低春油菜"青油14"为供试材料,采用单因素五水平随机区组设计,研究了不同施硼量对甘蓝型双低春油菜产量和品质形成的影响。结果表明:甘蓝型双低春油菜单株角果数与施硼量之间呈显著线性关系,而每角果粒数则与施硼量呈二次曲线关系,适量施硼可以协调每株角果数与每角果粒数的关系,有利于提高产量。籽粒产量与每角果粒数呈极显著正相关性(r=0.982 8**),与单株一次有效分枝数和千粒重也呈一定的正相关性,而与单株角果数则呈一定的负相关性。适量施用硼肥,可明显提高甘蓝型双低春油菜的籽粒产量和产油量,增加籽粒粗脂肪和粗蛋白质含量,而降低硫苷含量,进而改善品质。籽粒产量、产油量与施硼量之间均呈二次曲线关系,施硼量分别为17.84 kg/hm2和19.42 kg/hm2时,籽粒产量和产油量分别达到理论最大值3 154.18 kg/hm2和1 344.61kg/hm2,施硼过量,籽粒产量、产油量均下降。粗脂肪含量与施硼量之间呈单峰曲线关系,粗脂肪含量达到最大值(45.3%)时的施硼量为24.62 kg/hm2。硫苷含量与施硼量则呈开口向上的二次曲线关系,施硼量为19.42 kg/hm2时,硫苷含量为10.29 mg/g(≤30 mg/g)。试验综合考虑甘蓝型双低春油菜的籽粒产量、产油量及籽粒综合品质,提出适宜的施硼量(含硼11%)以19.42 kg/hm2为宜。     

苯甲·丙环唑300克/升乳油防治水稻纹枯病药效评价

试验结果表明,苯甲.丙环唑300克/升乳油对水稻纹枯病有较好的防治效果,防治效果可达72.84~84.68%。推荐使用剂量78.75~90g/hm2,施药间隔期为7d,施药3次。     

基于RAPD技术分析花椰菜种质资源遗传多样性

【研究目的】为了解花椰菜种质资源的遗传多样性和亲缘关系,为花椰菜育种提供理论基础,本研究采用RAPD技术对37份花椰菜种质资源的遗传多样性进行了分析;【结果】从80条随机引物中筛选出6条随机引物,6条引物扩增获得的总谱带数为38条,多态性谱带数为13条,多态性谱带比例为34.2%,利用随机引物S17对花椰菜的遗传多样性进行分析,发现当遗传距离为0.41时,可将花椰菜种质资源分为4类;【结论】花椰菜的遗传多样性与地理种质资源的地理来源及生育期关系不大,部分不同地区的品种相互交织在一起,这可能是由于地区间的品种互引造成的,有些品种地理近源但亲缘关系较远,有些品种地理远源但亲缘较近。     

海南槟榔园昆虫病原线虫对红脉穗螟的致病力

红脉穗螟Tirathaba rufivena Walker是槟榔上的重要害虫。本研究采用大蜡螟诱捕法,对海南省主要槟榔产区槟榔园中采集到的土样进行昆虫病原线虫的诱捕,并评估了目标线虫对红脉穗螟的致病力。在采集的150份土样中共有12个土样经检测发现含有昆虫病原线虫,检出率为8%。其中,屯昌、定安和万宁三个市县采集的土样中检出的带线虫比率相对较高,分别为12.90%、11.76%和10.00%,而海口和保亭土样中未检出昆虫病原线虫。在室内以大蜡螟为试虫测试线虫的致病力,结果表明诱捕的12个线虫种群均对大蜡螟幼虫具有一定的致病力,但致病力的大小存在较大差异（120 h校正死亡率21.11%～72.22%）。选取致病力较高的Tc05、Wn01和Wn09样本测试对红脉穗螟3龄幼虫的致病作用,结果显示在600 IJs/mL线虫液处理后24 h,Wn01种群对寄主的校正死亡率达到86.67%,半致死浓度LC₅₀为283.70 IJs/mL;Tc05和Wn09对红脉穗螟的致病力相近,校正死亡率分别为61.67%和65.00%,LC₅₀分别为504.75 IJs/mL和502.70 IJs/mL。研究表明,Wn01,Tc05和Wn09线虫种群对红脉穗螟幼虫具有一定的控制潜力。     

不同营养条件下马铃薯锌素吸收分配规律的研究

在内蒙古土默川地区,以紫花白为材料,在不同栽培施肥条件下,采用二年多点田间试验与化学分析、生物统计相结合的方法,对马铃薯锌素吸收分配规律进行了研究.结果表明,在有效锌含量较高的土壤上,马铃薯全株锌含量从苗期57.0mg kg-1下降到收获期28.4mg kg-1.各器官全生育期平均含量依次为茎49.8 mg kg-1,叶44.3mg kg-1,块茎27.3 mg kg-1.随着生育期的推进,全株和茎、叶中锌素吸收量变化可用一元三次式模拟,块茎吸收量变化可用Logistic方程定量地表达.全株锌素最快吸收期出现在块茎形成期,最快吸收速率出现在出苗后50d.块茎锌素最快吸收期是块茎增长期,最快吸收速率出现在出苗后70d.出苗后50d前后是喷施锌肥的关键时期.随着生长中心由茎叶向块茎的转移,锌在块茎中的分布逐步上升,收获期锌的运转率63%.每生产1 000kg薯块需吸收锌5.3g～12.9g,马铃薯锌的消耗系数在0.002 1～0.005 2.