Genotype and treatment biases in estimation of carcass lean of swine.

Carcasses of 181 barrows, representing five genotypes, 1) H x HD, 2) SYN, 3) HD x L[YD], 4) L x YD, and 5) Y x L (H = Hampshire, D = Duroc, SYN = synthetic terminal sire line, L = Landrace, and Y = Yorkshire), and two levels of ractopamine (RAC) treatment (0 and 20 ppm) were completely dissected and the data were used to examine genotype and treatment (RAC) biases in estimation of fat-standardized lean weight and to evaluate accuracies and precisions realized by use of equations based on variables derived from different technologies. Independent variables used to establish regression equations represented technologies of direct carcass measurements, optical probe data, TOBEC (total body electrical conductivity) readings, and dissected (DHMLN) and fat-standardized (FSHMLN) ham lean. Genotype bias existed when any equation from a single technology was used and was minimized by combining FSHMLN with one TOBEC reading, carcass length, and the probe measurement of 10th rib fat depth. Large RAC biases appeared when equations from direct carcass measurements or optical probe data were used and were minimized by an equation using either DHMLN or FSHMLN. A practical equation with relatively high R2 value and small genotype and RAC biases were developed by combining TOBEC readings with direct carcass measurements of 10th rib fat depth and warm carcass weight.     

Risk factors for Salmonella enterica subsp. enterica infection in senegalese broiler-chicken flocks

Our objective was to assess the association of managerial practices, general hygiene and Salmonella infection in Senegalese broiler flocks. Seventy broilers farms were studied from January 2000 to December 2001 around Dakar. A questionnaire was submitted to the farmers and samples of fresh broiler droppings were taken. A 28.6% of the flocks were infected by Salmonella (mainly Hadar and Brancaster serovars). Salmonella infection of the previous flock (OR=6.82) and of day-old chicks (OR=3.73), frequent poultry farmers’ visits (OR=5.38) and keeping sick birds inside the farm (OR=5.32) increased the risk of Salmonella infection. But, using antibiotics on day-old chicks (OR=0.17) and a detergent for cleaning (OR=0.16) decreased the risk.     

Pharmacokinetics of oxytetracycline in hemolymph from the Chinese mitten crab, Eriocheir sinensis

Feng, Q., Wu, G. H., Liang, T. M., Ji, H. Y., Jiang, X. J., Gu, W., Wang, W. Pharmacokinetics of oxytetracycline in hemolymph from the Chinese mitten crab, Eriocheir sinensis. J. vet. Pharmacol. Therap. 34 , 51–57. The purpose of this study was to investigate the hemolymph kinetics and depuration time of oxytetracycline following intramuscular administration at doses of 2, 8 and 40 mg/kg body weight, respectively. The concentration of OTC in hemolymph was assayed using solid phase extraction and high performance liquid chromatography. The elimination half‐life of the terminal part of the elimination phase (t_1/2β) ranged from 87.9 to 114.3 h. The total body clearance (CL_b) was 0.0430 L/kg/h at the lower dose, 0.0123 L/kg/h at the medium dose and 0.0013 L/kg/h at the higher dose. The apparent volume of the central compartment (V_c) was found to be 1.383, 0.699 and 0.143 L/kg respectively. The depuration time for each dose was 13.6, 29.6 and 57.6 days, respectively. Results from the present study suggest that the 40 mg/kg dose might have the best therapeutic efficacy following intramuscular administration.     

植物甾醇和甾烷醇降胆固醇作用机理研究进展

本文介绍了植物甾醇和甾烷醇的性质、来源、代谢及其降胆固醇作用和作用机理.     

预防兽医资源库的构建与学生实践能力的培养

预防兽医资源库的构建,建立了以六门课程为主干,以文献资料、互动网站为依托,以素材库、课件库、网络课程案例库、试题库为内容,形成综合性教学体系。视频图像的引入,增强了学生对实践教学的预知和理解能力,大大地提高了实践教学的效果,同时增加了实践教学的容量,培养了学生的实践能力。     

苏丹红和饲料着色剂的区别

本文主要从苏丹红和饲料着色剂的化学结构、作用机理及毒性等方面说明饲料着色剂与苏丹红的天壤之别。     

在广东省饲料行业协会第四次会员代表大会上的讲话

广东省饲料行业协会第四次会员代表大会的召开,是广东省饲料界的一件喜庆事,也是我们全饲料行业的一件喜庆事。我谨代表全国畜牧总站、中国饲料工业协会表示热烈的祝贺!热烈祝贺通过选举产生的广东省饲料行业协会新一届领导集体!热烈祝贺广东省饲料工业取得的巨大成就!热烈祝贺广东省饲料工业协会取得的出色业绩!热烈祝贺广东饲料行业对养殖业增产增效、对农民增收、对农业和农村经济建设和社会主义新农村建设做出的突出贡献!     

复方中草药免疫增强剂对鸡堆型艾美耳球虫早熟株免疫的影响研究

选用两个中草药方剂,采用1.5%、2.0%两个添加水平,在相同方法、相同攻虫强度下,比较其抗鸡堆型艾美耳球虫的效果。结果表明:方剂一在2.0%的添加水平时效果显著,抗球虫指数高达196.04,其E-玫瑰花环形成率也显著提高,具有明显的免疫促进作用。     

Differential expression of peroxisome proliferator-activated receptors alpha and gamma gene in various chicken tissues

The peroxisome proliferator-activated receptors (PPARs) are the members of superfamily of nuclear hormone receptors. A great number of studies in rodent and human have shown that PPARs were involved in the lipids metabolism. The goal of the current study was to investigate the expression pattern of PPAR genes in various tissues of chicken. The tissue samples (heart, liver, spleen, lung, kidney, stomach, intestine, brain, breast muscle and adipose) were collected from six Arber Acres broilers (8 weeks old, male and female birds are half and half). Semi-quantitative RT-PCR and Northern blot were used to characterize the expression of PPAR-alpha and PPAR-gamma genes in the above tissues. By semi-quantitative RT-PCR, the results showed the expression level of PPAR-alpha gene was higher in brain, lung, kidney, heart and intestine, medium in stomach, liver and adipose than in spleen, and it did not express in breast muscle. The expression level of PPAR-gamma gene was higher in adipose, medium in brain and kidney than in spleen, heart, lung, stomach and intestine, but it did not express in liver and breast muscle. Northern blot results showed that PPAR-alpha gene expressed in heart, liver, kidney and stomach, and the intensity of hybridization signal was the stronger in liver and kidney than in other tissues, however, PPAR-gamma gene only expressed in adipose and kidney tissues. The results of this study showed the profile of PPAR gene expression in the chicken was similar to that in rodent, human and pig. However the expression profile of chicken also have its own specific trait, i.e. compared with mammals, PPAR-alpha gene can not be detected in skeletal muscle and PPAR-gamma gene can be stronger expressed in kidney tissues. This work will provide some basic data for the PPAR genes expression and lipids metabolism of birds.     

高温条件下湿度对肉用仔鸡干物质和能量采食量及代谢率的影响

分别用4～5周龄艾维茵肉用仔鸡216只和6～7周龄180只分两阶段进行了试验,第1阶段同在32℃气温下设置30％,60％,90％相对湿度,第2阶段,同在30℃气温下设置30％,60％,90％相对湿度,分别测定对干物质及能量的采食量和表观代谢率.每个处理设6个重复,每阶段试验期为2周.结果表明,高温条件下,相对湿度显著影响4～5周龄肉仔鸡的干物质采食量和能量采食量(P<0．05),而对6～7周龄肉鸡无显著影响;高温条件下6～7周龄高湿组的干物质代谢率和能量代谢率较高(P<0．05),而4～5周龄阶段这一差异不显著