Influence of supplementing diet with Oleic and Linoleic acid on the freezing ability and sex-sorting parameters of ram semen

In an effort to improve the cryosurvival of both non-sorted and sex-sorted ram spermatozoa the effect of supplementing the ram diet with Oleic and Linoleic acid, in the form of extra virgin olive oil and sunflower oil, respectively, was assessed. Rams (n = 4/group) were fed either (i) a standard maintenance diet (Control), (ii) maintenance diet + 5% (w/w) sunflower oil (Linoleic), or (iii) maintenance diet + 5% (w/w) extra virgin olive oil (Oleic) for a period of 6 weeks. The effect of these diets on the post-thaw (incubated 37 °C, 6 h) motility characteristics (as measured by CASA) of non-sorted, frozen-thawed ram spermatozoa were assessed every 2 weeks. The sex-sorted, frozen–thawed spermatozoa were assessed at the end of the 6 week trial period in the same manner. Linoleic and Oleic diets had a negative impact (P < 0.05) on the total sperm motility, viability and acrosome integrity after a 6 week period of dietary supplementation. Furthermore, the average path velocity and straight line velocity of spermatozoa from Oleic-fed rams was less when compared to samples originating from rams fed linoleic acid or the control diets after both 2 and 6 weeks post-diet modification. Curvilinear velocity of oleic spermatozoa 2 weeks post diet modification were inferior for Oleic—(P < 0.05) compared with Linoleic—but not control-fed rams. Spermatozoa from rams fed Oleic diets exhibited lower (P < 0.05) linearity than spermatozoa from rams fed Linoleic acid (2, 4 and 6 weeks) or the control diets (6 weeks). Diet did not significantly affect any motility characteristic or the viability/acrosome integrity of sex-sorted spermatozoa. Nutritional supplementation with the mono-unsaturated fatty acid, Oleic acid, or the polyunsaturated fatty acid, Linoleic acid, did not improve the cryosurvival of ram spermatozoa — whether or not it had been processed for sex-sorting by flow cytometry. However, these results provide insight into the relationship between nutrition and male reproductive characteristics and further research to elucidate the mechanisms by which diet manipulation affects sperm membranes and subsequent sperm quality is warranted.     

关于提高家蚕叶丝转化率的研究 Ⅴ.保幼激素类似物methoprene的增丝效果

用methoprene的250倍(5μg/ml)和500倍(2.5μg/ml)液对三、四、五龄,四、五龄及五龄的各龄初期雌蚕作体表涂布,并用硫堇作丝腺活体染色和摄食阻害剂皂角苷作添食试验证明,JHA对蚕体和丝腺的发育有延缓作用,但这种延缓作用只在五龄期有明显表现,处理区比对照区经过延长24—34小时,食下量、消化量和体重等在处理后暂时低于同时期的对照区,旋即回升并超过对照,最大体重是五龄500倍区重(4.98g/头),最后体重以五龄250倍区最大(4.513g/头)。JHA的生理效应,不像皂角苷只是起因于食下量减少,而是通过影响蚕体内分泌平衡所引起。JHA的处理能使茧重增加23—46％,茧层增加13—35％,但茧层率下降4—18％,从五龄积算食下量,消化量看处理区显著增加,而饲料效率对茧层低,对蛹体高,JHA浓度过高还出现畸形蛹和永久幼虫。     

非洲猪瘟常态下猪日粮设计的几点思考

自2019年以来,我国生猪养殖已进入非洲猪瘟常态化时代,除生物安全升级、养殖模式改变等外,日粮设计也至关重要。文章从减法原则、猪舍内环境、提高猪机体免疫力等方面讨论了非洲猪瘟常态化下日粮设计的基本原则与关键点,以期为非洲猪瘟常态下猪的日粮生产提供参考与依据。     

苜蓿干草在高产奶牛日粮中适宜添加量的研究

 36头 2～ 4胎的荷斯坦奶牛随机分为 3组 ,各组产奶量、体重、胎次、泌乳天数 (DIM)差异不显著。 3组奶牛日粮中苜蓿干草的添加量分别为 3kg(对照 )、6kg和 9kg,相应的日粮干物质 (DM)中粗蛋白含量分别为 16 .4 %、17.9%和 19.4 % ,组间中性洗涤纤维 (NDF)和产奶净能 (NEL)含量相同 ,分别为 37.8%和 6 .7MJ·kg-1DM。结果表明 ,在以苜蓿干草为主的奶牛日粮中提高粗蛋白含量能极显著提高产奶量 (P <0 .0 1) ,干物质采食量 (DMI)显著增加 (P <0 .0 5 ) ,乳脂率、乳蛋白率、乳糖以及干物质含量没有变化 ,乳脂量显著增加 (P <0 .0 5 ) ,乳蛋白量极显著增加(P <0 .0 1) ,体细胞数 (SCC)显著下降 (P <0 .0 5 )。在日粮NDF相同的条件下用苜蓿干草替代玉米青贮 ,不会降低乳脂率。在奶牛日粮中大量使用苜蓿干草并不增加日粮成本 ,可以大幅度提高经济效益 ,9kg组与对照相比纯增效益最高。苜蓿干草在高产奶牛日粮中的适宜添加量为 9kg。     

高食性重叠度对同域物种生境分离的影响——以马鹿和狍为例

2013年和2014年的1月份,在黑龙江穆棱东北红豆杉国家级自然保护区野外调查、采集东北马鹿(Cervus elaphus xanthopygus)与狍(Capreolus pygargus)的粪便,应用粪便显微组织学分析技术对马鹿、狍粪便组成成分对比分析,探讨同域分布的马鹿和狍的生境选择及食性的差异。结果表明:马鹿除采食东北红豆杉外,其余采食植物与狍的完全相同,二者食性重叠度高达84.8%。马鹿与狍采食植物多样性指数都较高,而营养生态位宽度则很低。在高食物重叠性的影响下,马鹿与狍对生境因子选择发生明显的分离。马鹿主要选择人为干扰距离大于1 km,海拔、食物丰富度、隐蔽度较高,阳坡,对于坡位要求并不十分严格的针阔混交林生境;而狍主要选择人为干扰距离小于1 km,海拔、食物丰富度、隐蔽度相对较低,阳坡,中坡位及上坡位的灌丛生境。     

垂柳锈病的研究

垂柳锈病近年来在内蒙古地区垂柳（ＳａｌｉｘｂａｂｙｌｏｎｉｃａＬ．）上发生严重。经接种试验结果和形态特征观察,该病是由鞘锈状栅锈菌（ＭｅｌａｍｐｓｏｒａｃｏｌｅｏｓｐｏｒｉｏｉｄｅｓＤｉｅｔ．）为害所致。病原菌的性孢子、锈孢子（０、Ⅰ）阶段发生在紫堇（ＣｏｒｙｄａｌｉｓｂｕｎｇｅａｎａＴｕｒｃｚ．）上,夏孢子、冬孢子（Ⅱ、Ⅲ）阶段发生在垂柳上。首次发现紫堇是垂柳锈病菌的转主寄主。采用２５％粉锈宁８００倍液对垂柳锈病的防治效果较好。用２．４—Ｄ丁酯１０００倍液防治转主寄主紫堇效果较为理想。     

PBL教学模式在营养与配餐课程中的应用

分析了在营养与配餐课程中应用PBL教学法的意义,比较了传统教学模式与PBL教学模式、一般课程教学与PBL教学各要素差异,以及不同教学方法的师生角色。探讨了PBL教学法在营养与配餐课程中的具体实施,并主张推广使用该教学方法。     

饱和链烷技术测定绵羊食性食量精确性研究

【目的】验证饱和链烷技术测定家畜食性和食量的精确性，确定绵羊粪便中链烷的回收率。【方法】于2004年秋季在中国科学院内蒙古草原生态系统定位研究站用不同放牧演替阶段的优势植物羊草（Leymus chinensis）、糙隐子草（Cleistogenes squarrosa）和冷蒿（Artemisia frigida）按一定比例混合组成日粮，饲喂9只2岁羯羊，每只羊投喂一粒QSM胶囊，试验期内每天记录绵羊实际牧草采食量、采食成分和排粪量，利用气相色谱分析牧草和粪样的链烷含量，应用链烷技术测定绵羊的排粪量、不同牧草采食比例和总干物质采食量，并与实际值进行比较。【结果】3种牧草链烷模式存在种间差异；绵羊粪便中链烷的回收率随链烷长度的增加而线性增加；绵羊排粪量测定值与实际值存在极显著的正相关（P < 0.01，r = 0.9994）；绵羊采食羊草、糙隐子草和冷蒿比例的测定值与实际值存在极显著(P < 0.01)正相关，相关系数分别为0.9913、0.9864和0.9999；绵羊干物质采食量用C33∶C32和C31∶C32比值测定的值分别比实际值低4％(±1.3％)和7％(±1.3％)，但差异不显著(P > 0.05)。【结论】饱和链烷技术可以精确测定典型草原绵羊的排粪量、食物组成和采食量。     

不同营养水平的小麦日粮添加木聚糖酶对肉仔鸡生长性能及胃肠组织形态的影响

研究了不同营养水平的小麦日粮添加木聚糖酶对肉仔鸡生长性能、胃肠道组织形态的影响。结果表明:(1)木聚糖酶提高了1～6周龄肉仔鸡平均日增重,未影响饲料转化率;(2)小麦+木聚糖酶日粮降低了肉鸡肌胃和腺胃的相对重量,不影响空肠、回肠、盲肠和胰腺的相对重量。总之,以肉仔鸡的日增重(尤其是1～21日龄期间)、消化器官和胃肠道的相对重量,维持了肠道的正常组织形态为指标,小麦+木聚糖酶日粮与玉米日粮相当。     

The diet and growth of larval and juvenile pikeperch (Stizostedion lucioperca (L.)): A comparative study of fishponds and a reservoir

Diet of larval and juvenile pikeperch (Stizostedion lucioperca) reared in ponds wasinvestigated and compared with the diet ofpikeperch from a reservoir. The standard lengthof first feeding pikeperch larvae in ponds was6.1 mm, on average, and although rotifers werepresent in the diet, their numericalcontribution can be considered asinsubstantial. Rotifers were soon replaced bynauplii of cyclopoid copepods, which werehighly positively selected and contributedlargely to the diet up to a larval length of 10 mm.Daphnia spp. were consumed from the onsetof exogenous feeding, but were not positivelyselected until 15 mm. Anothersmaller cladoceran Bosmina longirostriswas highly negatively selected and did notcontribute significantly to the diet. A clearpositive selection for larger relatively tosmaller prey and a preference for Daphniafrom a body length of 15 mm onwards could beobserved. In the reservoir, rotifers were notfound in the diet of pikeperch larvae even inthe smallest individuals. Dominant food itemswere nauplii and 1st copepodite instar ofEudiaptomus gracilis and Cyclopsspp. Cladocerans – Daphnia galeata andto a lesser extent Diaphanosomabrachyurum appeared in the pikeperch diet at alength of about 10 mm. A shift from copepods toDaphnia spp. and especiallyLeptodora kindtii could be recognised inpikeperch at a length of 20 mm. When comparing ourdata from nursing ponds with the data fromímov reservoir, similar trends in dietcomposition were observed.Growth of pikeperch was found significantlyfaster in nursing ponds than in the reservoir.Slow growth of reservoir pikeperch was probablyan artefact due to the prolonged spawningperiod in the reservoir. Larvae and juvenilesfrom later spawnings decreased the average sizeof the population over the studied period. Innursing ponds lowest average standard length atharvest was found in the pond with the highestnumbers of fish, and vice versa in the pondwith the lowest numbers the largest standardlength was recorded. This result corresponds tothe increased intracohort food competitionamong juvenile pikeperch with increasingstocking density.