Failure of young goats to acquire resistance to Haemonchus contortus

Two experiments were carried out to investigate the acquisition by goats of resistance to Haemonchus contortus. In Experiment 1, five Saanen wethers reared worm-free and averaging 51/2 months of age at the start of the experiment, were dosed with 200 H. contortus infective larvae three times per week for 10 weeks (approximately 23 infective larvae/kg mean initial liveweight/week) and then given anthelmintic treatment. Each goat and an equal number of worm-free controls were then challenged with 10,000 infective larvae. Post mortem worm counts were carried out 30 days later. In Experiment 2, eight worm-free Saanen wethers, 14 months old at the start of the experiment, were dosed with 825 infective larvae per week for 14 weeks (approximately 23 infective larvae/kg mean initial liveweight/week) except for one week when only 300 larvae were given and one week when no larvae were given. After anthelmintic treatment, each received, together with seven worm-free control animals, a challenge dose of 15,000 infective larvae. Post-mortem worm counts were carried out 28 days later. There were no significant dii- ferences in post-mortem worm counts between previously infected and uninfected groups in either experiment. In both experiments, serum pepsinogen values rose significantly as a result of infection but there was no significant (p>0.5) correlation between worm counts and pepsinogen values on the day of slaughter.     

通过雏鸡MDV攻毒试验选择抗马立克氏病亲本

对F0、F1、F2亲本经继代No.614血型基因选择后繁殖的F2、F3雏鸡,10日龄以马立克氏病强毒（MDV）攻击至60日龄的死亡率,其父母亲对No.614抗血清呈阳性反应的试验组显著低于其父母亲对此抗血清呈阴性反应的对照组。试验组25个家系中,有14个家系的F2雏鸡死亡率显著低于对照组;F3雏鸡有21个家系的死亡率低于对照组,其中8个家系具有统计意义。肿瘤发生率,以肾脏和腺胃最高,肺脏和神经组织最低。综合血型抗原检测和MDV攻毒结果,从试验组25个家系中选留强MDV抗性家系留种繁殖,继代选育。     

UHT乳在货架期内理化性质的变化研究

本文研究了UHT全脂乳在37℃温度下,酸度、黏度、蛋白水解度和酒精稳定性的变化情况,并得出UHT乳在37℃温度下的货架期。     

Genetic parameters estimates for ewes’ behavioural reactivity towards their litter after lambing

In livestock, improving maternal reactivity towards the litter is an important issue in breeding strategies to promote production and animal welfare. As of yet, no studies have investigated the within-breed genetic variation of maternal reactivity in sheep. The objective of this study was to estimate the genetic parameters of maternal reactivity traits. A total of 1,095 primiparous and 1,441 multiparous Romane ewes were phenotyped 24 hr postlambing using a behavioural test (arena test, AT) over a 10-year experimental period. The test consisted of three successive phases evaluating the ewe's attraction to her litter, reactivity to separation from her litter, and reactivity to a conflict between attraction to her litter and avoidance of a motionless human. The ewes were reared exclusively on rangelands (South of France) and lambed outdoors in the spring. High-pitched bleating and low-pitched bleating in the AT were mostly highly heritable (0.39‒0.46). Heritabilities were moderate for proximity to the litter in the presence of a human (0.27) and low for locomotion and vigilance in the AT (0.09‒0.15). The measurements of a given behaviour in the three phases of the AT were highly genetically correlated. Few genetic correlations were found between the different behavioural traits in the AT, the highest correlations being between high-pitched bleating and low-pitched bleating (−0.43 to −0.77). In conclusion, our findings demonstrate moderate-to-high heritability for maternal reactivity traits. These traits could be included in genetic selection schemes to enhance maternal attachment provided there is no unfavourable link with other production traits.     

Postprandial venous ammonia concentrations in the diagnosis of hepatobiliary disease in dogs

A postprandial ammonia tolerance test (PPATT) was performed on normal dogs and dogs with signs that suggested they may have liver disease. All dogs underwent transcolonic scintigraphy, liver biopsy, or both and were assigned to extrahepatic disease, primary hepatocellular, and congenital portosystemic vascular anomalies (PSVA) groups. Each dog was fed a chicken and rice diet providing 25% of its estimated daily metabolizable energy requirement (MER) as an ammonia challenge. This is practical in patients with liver disease because ammonium chloride administration often causes vomiting or ammonia toxicity. Venous ammonia concentrations were measured before feeding and every 2 hours after feeding for 8 hours. No difference in mean ammonia concentrations between dogs with extrahepatic disease and control dogs was found. Therefore, the specificity of the PPATT was 100%. Dogs with hepatocellular disease showed no change in mean ammonia concentration at any time point, before or after feeding, but sensitivity was greatest when venous ammonia was measured 6 hours after feeding (sensitivity before feeding, 28%, and after feeding, 36%). Among dogs with congenital PSVA, mean ammonia concentrations were higher than the reference range at all time points before and after feeding, and peak mean ammonia concentration occurred 6 hours after feeding. In this group, the sensitivity of the PPATT was 81% before feeding and 91% 6 hours after feeding. This study demonstrates that the measurement of venous ammonia concentration is a useful test to detect congenital PSVA, and the sensitivity of the test may be improved by sampling 6 hours after feeding. The PPATT has poor sensitivity in detecting primary hepatocellular disease.     

德西黄三元杂交幼牛产肉性能研究

本文对甘肃省武威市凉州区新华乡的6头德西黄三元杂交牛11-12月龄育肥牛的产肉性能进行测定。其结果：育肥期末体重、日增重、屠宰率、净肉率、胴体产肉率、肉骨比、眼肌面积分别是322.67kg、1101.85g、55.33%、45.09％、81.47％、5.09、75.9cm^2。表明该三元杂交组合的肉用性能良好，比二元杂交的西黄有明显提高。     

Prevalence of clinical findings at examinations of young Swedish warmblood riding horses

Background

Soundness of an individual horse is important for animal welfare and owner economy. However, knowledge of health status in normal horse populations is limited due to lack of systematic health recordings. The aim of the investigation was to study the prevalence of veterinary clinical findings in 4-5-year-old Swedish warmblood riding horses, and their influence on overall health scores, where associations to future longevity has been indicated.

Results

The prevalence of clinical findings in 8,281 horses examined during 1983–2005 was studied according to a standardised protocol and related to overall health scores in linear statistical models. Effects of sex, age, examination event and changes over time were included. In total, 49% of the horses had clinical findings of medical health (MED), 42% in hooves (HOOF) and 74% of palpatory orthopaedic health (PALP). However, only 6%, 3% and 24% had moderate or severe findings, of MED, HOOF and PALP, respectively. Flexion test reactions were reported in 21% of the horses (5% moderate/severe), heavily influencing the overall score (H2). One fifth of these horses also had findings of unprovoked lameness while 83% had PALP findings (44% with moderate/severe findings). Acute clinical signs, i.e. heat or soreness, had a large influence on the H2 score but were rare, whereas more common clinical findings had smaller effects on overall health. Large variations in recorded health results were observed among events. A decrease in findings has occurred since 1983, in particular for PALP findings.

Conclusions

Results of occurrence and relevance of evaluated clinical findings could be used for advice on preventive actions to keep horses sound, and possibly for benchmarking, and genetic evaluation of health traits. The distinct effect of event on recorded clinical findings emphasises that further harmonisation of veterinary examinations are desirable.     

川东鸭茅的生产试验研究

在影响川东鸭茅种子产量的诸多因素中，播种量和行距是主要因素之一。本试验采用的行距是30、60、90cm，10m^2小区的播种量分别为10、15、20g，进行2因子9处理3重复的生产试验。结果表明，组合A2B3的种子产量最高，达799g／10m^2,极显著高于其它组合。因此，建议种植川东鸭茅采用行距90cm、播种量0．67kg／667m^2。     

猪伪狂犬病油乳剂灭活疫苗的制备及安全性与免疫性试验

用本室分离鉴定的猪伪狂犬病毒鄂A经毒株接种仓鼠肾细胞（BHK－21）,制备病毒抗原液，毒价不低于10^-6TCID50/0.1ml。经一定浓度的甲醛溶液灭活后与油相佐剂乳化研制成油乳剂灭活油疫苗4批。本研究对该制品的安全性、免疫性进行了测定。对18g左右小白鼠接种0.3ml，初生仔猪、断奶仔猪及妊娠母猪加倍剂量注射，均未出现不良反应，安全性良好。对母猪的繁殖性能不产生影响。后备母猪及妊娠母清中和抗体指数于免疫后21d达到316以上，间隔35d加强免疫一次后，中和抗体指数可达1000以上。断奶仔猪及初生仔猪免疫后对强毒的攻击，保护率分别为100％及90.62％。