断喙对肉鸭啄羽及其生产性能的影响

选择200只1日龄樱桃谷肉鸭,随机分成试验和对照两组,每组100只。试验组于14日龄断喙,对照组正常饲养,观察肉鸭在饲养过程中啄羽情况,测量试验鸭增重、料肉比、死亡率等指标,结果表明肉鸭断喙能有效防止啄羽,提高生产性能,减少死亡率,试验组比对照组每只多增重175g,料肉比低0.3,死亡率降低6%,经济效益显著。     

A preliminary in vivo study on the potential application of e-tracking in poultry using ink printed 2D barcodes

A preliminary study on the potential application of electronic tracking in poultry in vivo has been conducted. The experimental procedure for this study was based on previous in vitro findings (Fröschle et al., 2009) as part of the same research programme. The study consisted of two phases whereby an initial experiment using inkjet printing of 10 × 10 DataMatrix barcodes onto the beaks of broiler chickens in a live commercial setting has been carried out. Results demonstrated very poor percentage of readability after a short period of time. Barcodes deteriorated very rapidly and this was attributed to the physical effects on the barcodes of the actions of the chickens in a commercial environment, together with the inability of the ink to bond to the hard keratinous surface of the beak. In a subsequent part of the study, a number of commercially available ink types were screened, using a predetermined abrasion testing procedure, for their ability to bond to the beak and provide a readable barcode on the beaks following some predetermined graduated physical abrasion.     

印度洋西北海域鸢乌贼角质颚长度分析

根据2004~2005年我国鱿钓渔船对印度洋西北海域鸢乌贼资源调查期间采集的103个鸢乌贼角质颚和60枚耳石样本,分析了角质颚长度特征,并与鸢乌贼胴长、体重和日龄建立了关系。结果显示,角质颚长度与胴长呈极显著的线性相关,与体重呈极显著的指数相关;角质颚各部长度随着鸢乌贼日龄增加逐步增大,上、下颚头盖和脊突生长较快,喙部和翼部生长较慢;上颚头盖和脊突较下颚头盖和脊突生长快;上颚翼部呈幂函数生长,上、下颚其余各部均呈线性生长。     

Failure of acid secretion during infection of the ovine abomasum by the nematode parasite Teladorsagia circumcincta

Elevation of the abomasal pH of ruminants is a well known consequence of nematode parasitism. Many have argued that the nematodes seek to increase pH to promote their survival. Indeed, there is limited evidence that substances released by the parasites are capable of directly influencing parietal cell activity. In one experimental series, excretions/secretions (ES) of Teladorsagia circumcincta reduced the apparent activity of rabbit gastric glands. Worm ES were shown to contain ammonia, probably accounting for the observed activity, and the effects of ES/ammonia are almost certainly an in-vitro phenomenon only. An alternative hypothesis contends that the loss of acid secretion arises as a consequence of the profound host response elicited by the presence of the parasites. Invariably, presence of parasites is accompanied by an inflammatory response in which eosinophils are conspicuous. Recent research has shown that exudates from inflamed tissues were also inhibitory to gastric gland activity and that during infection, expression of the pro-inflammatory cytokine interleukin 1-beta, the most potent known inhibitor of acid secretion by parietal cells, was increased. Further, the elevation of abomasal pH may prove to have adverse effects on the ability of the parasites to maintain their position within the abomasum.     

西非沿岸乌贼角质颚形态及生长特征

乌贼(Sepia officinalis)是生活在大西洋西岸的重要头足类之一,研究乌贼角质颚形态及生长特征有利于对其的开发利用。本研究根据2015年在毛里塔尼亚附近海域生产期间所获得的乌贼渔获样本,对乌贼角质颚的各项形态参数进行描述,探究不同胴长和不同性腺成熟阶段角质颚生长情况的差异,并估算乌贼个体的大小。通过对乌贼上、下颚各长度指标的比值比较发现,乌贼角质颚下颚的长度比值波动较大,较不稳定。t检验表明,将各项形态参数除以胴长消除样本规格影响差异后,乌贼雌性个体在角质颚的各项形态参数上均极显著大于雄性(P0.01);方差分析及多重比较(LSD法)表明,随着胴长的增加,乌贼的各个角质颚的形态参数也极显著增加(P0.01)。在性腺成熟期Ⅱ~Ⅳ中,乌贼角质颚的形态参数随着性腺成熟度的增加而显著增加(P0.05),但性腺成熟度为Ⅴ期的个体的角质颚形态参数却显著小于前面几期(P0.05)。主成分分析显示,第一主成分的负载绝对值最高的指标为上头盖长(Upper hood length,UHL)和下脊突长(Lower crest length,LCL);第二主成分下喙长(Lower rostrum length,LRL)和下喙宽(Lower rostrum width,LRW),利用主成分分析得到的前2个主成分可以对乌贼的胴长进行估算。研究表明,同一种类不同性别的乌贼个体角质颚形态参数及其比值存在特异性,研究结果为西非沿岸乌贼类分类及生态研究提供基础资料。