温度和PE袋包装对皖金猕猴桃果实采后品质变化的影响

【目的】探究猕猴桃新品种皖金的采后贮藏特点,明晰其适宜的贮藏温度及包装膜袋厚度。【方法】试验分为两部分:首先将部分果实分别放入(0±0.5)℃、(1±0.5)℃、(2±0.5)℃,相对湿度(90±5)%冷库以及常温(CK1)下贮藏,定期取样测定相关指标,确定皖金适宜贮藏温度;在上述适宜贮温基础上,进一步优化贮藏条件,采用不同厚度(0.01、0.03、0.05 mm)的聚乙烯(polyethylene,PE)膜袋密封包装果实,未包装果实为对照(CK2),筛选膜袋厚度。【结果】(1±0.5)℃贮藏温度下,果实贮藏保鲜效果较好,与(2±0.5)℃处理相比延长了有效贮藏期,与(0±0.5)℃处理相比显著降低了冷害的发生;在(1±0.5)℃下,不同厚度的膜袋包装处理与对照相比均可减缓果实硬度下降,延长有效贮藏期,延缓果实冷害的发生。其中0.03 mm PE膜袋处理果实贮藏效果更优。【结论】在(1±0.5)℃贮藏条件下,0.03 mm PE膜袋处理对延长皖金猕猴桃果实的贮藏保鲜期、减缓冷害发生效果最佳。     

鸭场水质污染状况及防治措施——鸭场污染研究材料之二

鸭粪明显污染了鸭场附近的水质,增加了水中的细菌、大肠杆菌、氮、磷和COD量。鸭场附近水质污染程度要比参照点污染程度严重。封闭鸭场水质污染严重,而活水型鸭场对水系污染严重。防止此污染可采取如下措施:合理布局鸭场,减少鸭子入水时间,发展生态鸭和加强养鸭管理。     

Effect of semen extenders and storage time on quality of Muscovy duck (Cairina moschata) drake semen during the entire reproductive season

Avian semen dilution with appropriate extender allows to prolong the fertilizing ability of sperm stored in vitro. In the present study, the impact of extenders and time of storage on morphology of Muscovy duck (Cairina moschata) drake semen were examined. Semen was collected twice a week, using male stimulation by a female method, from 12 adults (29 weeks old) drakes kept individually in cages, under controlled environmental conditions. Freshly collected, pooled ejaculates were divided into three part: neat undiluted sample, and diluted 1:1 with Schramm (SCH) or Watanabe (W) extender and stored at 4°C. Morphological examination of all samples was conducted after dilution and then, after 3 and 6 hr of storage. The storage of undiluted semen caused decrease (p ≤ .01) in live morphologically normal sperm, from 79.73% in the freshly collected ejaculates to 55.75% and to 12.12% after 3 and 6 hr of storage, respectively (average calculated for the entire reproductive season). In the semen diluted with Schramm's extender the adequate values attained 86.84, 79.65 and 61.66%, and using Watanabe extender 84.77, 83.58 and 75.25%, respectively. The period of semen storage and the type of extender caused significant (p ≤ 0,05; p ≤ 0,01) changes in sperm morphology. The longer period of storage contributed to the decrease in number of morphologically normal sperm, whereas their content in Watanabe extender after 3 and 6 hr of storage was higher (p ≤ .01) than in semen diluted in Schramm extender.     

Reproductive season and male effect on quantitative and qualitative traits of individually collected Muscovy duck (Cairina moschata) semen

Males of Muscovy duck (Cairina moschata) are mainly used for mule duck production via artificial insemination of females originated from wild mallard duck (Anas platyrhynchos); therefore, the quantity and quality of drake semen play a crucial role. The assessment results of male reaction to sexual stimulation by dummy female and basic semen characteristic (ejaculate volume, sperm concentration and morphology) of 12 individually kept Muscovy drakes carried out during the entire reproductive season are described. The male and period of the reproductive season effect on scored semen traits are documented. In total, 792 individual semen collections and evaluations were performed. The average of positive reaction in the entire reproductive season varied from 90.6% in December and April to 50.0% in July, while for individual males, it varied between 97.1% and 29.0%. Throughout the season, the ejaculate volumes ranged from 0.05 to 2.45 ml, sperm concentration from 0.15 × 10⁹ ml⁻¹ to 4.44 × 10⁹ ml⁻¹, total number of live spermatozoa from 68.0% to 100% and live normal (properly formed, with any deformations) from 51.0% to 99.0%. Our study indicates the necessity of male breeders pre-selection before the onset of the reproductive season, and the need to leave an appropriate number of males to ensure adequate amount of semen for female insemination, especially when using Muscovy drakes (Cairina moschata) for interspecies crossing with Anas platyrhynchos ducks.     

550鱼营养补充料对水生环境及其微量元素含量的影响

试验于1990年在岳阳市南湖渔场进行.观察结果表明,添加4g550鱼营养补充料(浓度为16ppm)的试验组,其浮游生物数量最多,且生长繁殖快,浮游植物主要为绿藻门和硅藻门,浮游动物的优势种为秀体蚤;水体和浮游生物中微量元素含量也比其它浓度组高.水体中的微量元素含量随550鱼营养补充料的添加而递增.     

夏季不同复合添加剂对蛋鸭产蛋性能的影响

选用产蛋性能无差异的130 d商品蛋鸭280只,随机分成4组(对照组、抗热应激剂1、2、3组),每组70只,每组设7个重复,每重复10只,于2007年6月在湖北省荆州地区进行了夏季不同复合添加剂对圈养蛋鸭产蛋性能影响的研究.结果表明,平均气温为24～30 ℃、平均温湿指数(THI)为74～83时,圈养蛋鸭产蛋性能不受环境因素的影响(P＞0.05);夏季额外添加100 mg·kg-1的VC和100 mg·kg-1的VE、0.3%的KCl和0.5%的中草药,对130 d到180d的蛋鸭的产蛋性能有较好的效果(P＜0.01).     

气体循环系统酒精连续发酵

采用外循环反应器对酒精生产的新工艺流程进行了研究。在酒精发酵前,将反应器中培养液的酵母菌体浓度提高至70-80g/l,然后转入厌氧发酵。在发酵过程中,根据菌种的生理特性确定某一气体循环量,气体通过反应器带出酒精,通过冷凝和吸收装置收集起来,余下的气体返回到反应器中循环使用。本文对发酵过程中的进料量、出料量、进料糖浓度和残糖等因子进行了关联研究,得出相应最大的酒精生产强度为37g/l·h。     

奶畜散户生鲜乳抽样存在的问题与对策

奶畜散户在我国奶业发展中发挥过重要作用,并将在一定阶段存在的一类不小群体。对于在对他们近年来进行监管抽样中发现的散奶销售管理部门不明确、信息登记不规范、有些留样不符合要求、没有合适抽样工具、现场检测环境难达标、抽样中面临养殖户生物安全和抽样人员安全、市场拉羊挤奶销售无监管等问题,文章进行了详细分析,首次提出了对散户养殖及产品销售应由动物卫生监督部门进行管理,将市场拉羊挤奶者也列入散户行列,及针对上述其他问题提出了相应的对策,以期为做好散户抽样工作提供借鉴。     

菜用大豆贮藏保鲜工艺的研究与应用

菜用大豆(毛豆)含水量高,极易失水萎蔫或腐烂变质,选育适应市场需求,又宜于保鲜贮藏的品种,采用速冻冷藏的方式,开发、应用天然保鲜剂和生物技术,可提高菜用大豆的经济价值和拓宽国内外市场。     

不同基因型菜豆幼苗抗冷性鉴定

对收集到的32个不同基因型菜豆幼苗,以低温胁迫下的叶片冷害指数和电解质渗漏率为指标进行了抗冷性鉴定。聚类分析结果表明,可将其抗冷性划分为强、中、弱3个类群;冷害指数与电解质渗漏率之间存在明显的相关性,两者结合能够很好地鉴定菜豆幼苗的抗冷性。