Inheritance of myotonic discharges in American quarter horses and the relationship to hyperkalemic periodic paralysis.

Electromyography (EMG) was used to detect myotonic discharges in Quarter Horse breeding stock and to follow the results of mating horses with hyperkalemic periodic paralysis (HPP). The studies were performed on two brood mare farms. A total of six breeding stock showed myotonic discharges and 15 were nonmyotonic. Myotonic discharges were seen in five of six horses belonging to the blood line previously implicated as being predisposed to HPP. Two of these horses had shown clinical signs of HPP. Only one of 15 breeding horses unrelated to the HPP predisposed blood line showed myotonic discharges. When both parents were non-myotonic on EMG than the F1 generation (n = 6) were also nonmyotonic. When a stallion with HPP and myotonic discharges was mated to eight nonmyotonic mares over a six year period half the animals of the F1 generation (n = 25) showed myotonic discharges. When both parents showed myotonic discharges four F1 offspring were myotonic and two were nonmyotonic on EMG testing. There was no evidence of sex linkage. The results are consistent with an autosomal dominant mode of inheritance. Hyperkalemic periodic paralysis and myotonic discharges on EMG may be different manifestations of the same underlying defect.     

Studies on mutlispecific resistance of gastrointestinal nematodes to benzimidazoles on dairy-goat farms

Multispecific resistance to benzimidazoles was studied in three selected farms. These farms had bred dairy goats for more than 15 years. The helminths were introduced with the goats at the establishment of the farms which afterwards remained isolated. Nematode resistance could then be related to their own management practices. Faecal egg count tests and egg hatch assays were performed to assess intensity of resistance. The generic (infective larvae in faecal cultures) and specific richness (adult worms) were assessed. The resistant species were Trichostrongylus colubriformis, Teladorsagia circumcincta, Haemonchus contortus and Oesophagostomum venulosum. Faecal egg count reduction tests and egg-hatch assays did not match exactly. Faecal larval counts after treatments gave a distorted picture of multispecific resistance: Haemonchus and Oesophagostomum were very largely over represented. The number of species found in the three farms was relatively low compared with other reports in goat farms of the area. This reduction of diversity might also be due in part to characteristics of breeding management and history (use of permanent pasture and introduction of goats at the establishment of farm).     

采用现代食品加工技术开发蛋白质食物资源

本文分析了现阶段我国人民的食物结构以及食品加工在开发蛋白质食物开源中的地位和作用，并从五个方面进行了论述。     

金属热防护系统多层隔热材料的传热分析及参数优化

采用能量平衡方程和离散坐标法近似地建立了金属热防护系统多层隔热材料的一维稳态传热的数学模型，并利用遗传算法和纤维隔热材料的有效导热系数试验数据求解传热反问题，从而得到了模型中的纤维隔热材料的辐射衰减系数、反照率和隔热屏表面辐射发射系数。最后，由实验测得了多层隔热材料的有效导热系数，验证了采用优化参数后，多层隔热材料的传热模型的正确性。     

不同处理稻草混合青贮料对奶牛生产性能的影响

本试验采用稻草分别与玉米秸杆、象草混合青贮,同时添加纤维素复合酶制剂和乳酸菌制剂,研究稻草的最佳青贮模式以及5种不同处理的稻草混合青贮料对奶牛生产性能的影响。结果表明,稻草与玉米秸杆混合青贮(同时添加纤维素复合酶制剂)料可使奶牛产奶量显著高于其他青贮组合(P<0.05),但对乳成分无显著影响(P>0.05),其他组之间的产奶量和乳成分差异不显著(P>0.05)。     

低聚糖对雏鸡大肠粪便NH3-N含量及肠道菌群的影响

试验选取1日龄罗曼蛋公雏250只，随机分为5组，试验组饲料或饮水中分别添加海藻糖(500mg／kg)、海藻胶(600mg／kg)、大豆寡糖(500mg／kg)、圆葱寡糖(500mg/d)。结果表明，四种低聚糖均可促进肠道乳酸菌及双歧杆菌的生长繁殖，对魏氏梭菌的生长呈现抑制作用。海藻糖、海藻胶对降低大肠粪便NH3—N含量效果不显著(P＞0．05)，而大豆寡糖效果显著(P＜0．05)，圆葱寡糖效果极显著(P＜0.01)。     

波尔山羊杂交后代体尺、体重与肉用性能的相关性研究

本文利用 SPSS数据处理软件 (10 .0版 )统计分析了 2 3只 (约 8～ 9月龄 )波尔山羊与唐山奶山羊杂交后代公羊的体尺、体重和肉用性能。结果表明 :(1)波尔山羊与唐山奶山羊杂交 F1 代体尺、体重与肉用性能指标的变异程度大于 F2 代 ,其中宰前重、胴体重、净肉重和胸宽四项指标变异程度在 F1 和 F2 代中都很大 ;(2 )杂交 F1 代、F2 代各项指标 t检验结果 ,除胸宽外其余指标差异显著或极显著 ;(3 )波尔山羊杂交后代中胸宽与各项指标间相关不显著 ,宰前重、胴体重、净肉重与体尺指标相关显著或不显著。     

新的β-二氢沉香呋喃倍半萜多元酯和生物碱的HR-FABMS研究

利用高分辨快原子轰击质谱(HR-FABMS),以(甘油 氯化钠)为基质测定了9个新的β-二氢沉香呋喃倍半萜多酯和生物碱的HR-FABMS。结果表明,所有该类化合物均可以精确地获得[M Na] ,[M H] ,[M H-H2O] 等特征离子的质量和元素组成,从而方便地获得原有该类化合物的分子量和分子式。     

Verification by polymerase chain reaction of vertical transmission of Theileria sergenti in cows

To evaluate the transplacental transfer of Theileria sergenti infection in cattle, we used DNA probes to detect T. sergenti in 6 pregnant cows and their calves. All the animals were monitored by parasitologic, serologic, and polymerase chain reaction (PCR) assays for a predicted 875-base-pair (bp) DNA product and a 684-bp amplicon detected by nested PCR in the blood and spleens of aborted fetuses. An open reading frame (ORF) starting at nucleotide 170 and terminating at position 1021 was shown to code for a polypeptide of 283 amino acid residues. All 6 dams and 5 calves were positive for T. sergenti in all tests. One calf was positive only with nested PCR. We conclude that transplacental transmission of T. sergenti is a significant problem. The relevance of the data in the programmed introduction of new (especially pregnant) animals into established clean herds needs serious consideration with regard to control of theileriosis and other tickborne diseases.