用MTDFREML方法估计大白猪遗传参数

本研究应用ＭＴＤＦＲＥＭＬ方法对３４１窝大白猪选育群和１４７０头测定猪繁殖性状、生长性状、体型性状等进行遗传力和遗传相关估计,窝总产仔数和活产仔数遗传力分别是０．１１和０．１３。１６５日龄校正体重的遗传力是０．３１。校正背膘厚遗传力０．３８～０．５０。窝总产仔数与校正体重的遗传相关为－０．０２。窝总产仔数与肩部、腰部、荐部及三点平均膘厚的校正背膘厚的遗传相关是－０．３４～－０．６６。活产仔数与校正背膘厚的遗传相关是－０．０８～－０．１１。     

基于系谱和基因组信息估计荷斯坦青年母牛体重性状遗传参数

旨在设计利用不同信息来源的模型估计荷斯坦后备牛不同月龄体重性状的遗传参数。本研究于2014—2020年测定并收集了7 122头荷斯坦牛32 338条0～12月龄体重数据,分别利用系谱信息(linear mixed model with pedigree relationship matrix, LM＿A)和系谱-基因组信息构建亲缘关系矩阵(linear mixed model with genotype-pedigree joint relationship matrix, LM＿H),基于母体效应动物模型估计初生重,基于是否考虑初生重作为协变量的单性状动物模型估计2～12月龄各月龄体重遗传力,并利用双性状动物模型估计初生重与其它月龄体重的遗传相关。结果显示,对于初生重,根据赤池信息量准则(Akaike information criterion, AIC),LM＿H方法的拟合程度显著优于LM＿A方法,但两种方法估计的遗传参数相差不大：直接遗传力分别为0.30和0.32,母体遗传力分别为0.08和0.09,个体直接遗传效应和母体遗传效应遗传相关系数分别为-0.65和-0.64;对于2～...     

猪乳头数的参数估计及翻乳头遗传方式的判定

太原花猪总乳头数和先天有效乳头数分别为１４．７２和１３．３４个。山西黑猪分别为１４．３３和１３．６３个。乳头数具有显著的母体效应及性别和品种差异，且品种和性别间存在显著互作。按阈性状估计遗传力可以消除某些系统误差。山西黑猪翻乳头的出现范围大致是０￣６个，多出现在２￣５对乳头。翻乳头呈常染色体隐性遗传，其隐性基因频率为０．４５，外显率为８．４１％。由于其不完全外显，可能呈主基因遗传。     

BLUP法在种兔选择上的应用

采用最佳线性无偏预测（ＢＬＵＰ）技术，配合公畜模型，对种兔的育种值进行了估测，同时也估测了长毛兔主要经济性状的遗传力及性状间的表型相关和遗传相关。结果表明，以体重的遗传力为最大（０．４４５），其次为胸围（０．４１１），繁殖性状的遗传力较小，产仔数和泌乳力的遗传力分别为０．１３１和０．１２１；体重、体长、胸围与剪毛量的遗传相关较大，分别为０．４１７、０．２９５和０．３５５，而与粗毛率的遗传相关较小，分别为０．１１５、０．０５１和０．２１４。     

非遗传因素对高山美利奴羊早期生长性状及其遗传力估计的影响

本研究利用ASReml软件分析了不同非遗传因素组合对20 057只高山美利奴羊早期生长性状及其遗传力估计的影响。结果表明:血统、性别、出生类型、出生年份、配种月份、初生月份、群别以及某些非遗传因素间的互作效应对高山美利奴羊早期生长性状均有极显著影响(P0.001)。研究发现,高山美利奴羊早期生长性状遗传参数估计过程中有无考虑非遗传因素间的互作效应对其结果影响较大,未考虑固定效应间互作效应时所估计各性状的直接遗传力均高于考虑了固定效应间互作效应所估计出的各性状直接遗传力;考虑了固定效应间互作效应后所估计的母体效应遗传力略高于未考虑固定效应间互作效应时所估计的母体效应遗传力。本研究结果不仅为优化高山美利奴羊早期生长性状遗传评估模型提供科学依据,更为该品种的早期科学选种及后期选育提高奠定了基础。     

湖北红鸡几个重要性状的遗传分析

用ｈａｒｖｅｙ软件中的ｍｏｄｅｌ４对湖北红鸡Ⅰ、Ⅲ系的三、四世代资料进行遗传分析。开产日龄、开产体重、４０周龄产蛋数、４０周龄蛋重的遗传力分别为：０．２６，０．４２，０．２１和０．５２。４０周龄产蛋数与开产日龄、开产体重、４０周龄蛋重的遗传相关分别为：－０．６４７～－０．７２７，０．００７～０．１４７和０．４３１～－０．４４９。     

绵羊生长性状母本效应方差组分、遗传参数估计的研究

本文利用公畜母畜模型和公畜外祖父模型估计了初生重、断奶重的直接加性遗传方差、母本遗传方差和遗传参数,得出初生重的直接加性遗传效应、母本遗传效应和总的加性遗传效应的遗传力分别为:0.164、0.101、0.103;断奶重相应的各遗传力为:0.076、0.108、0.081。初生重和断奶重二性状加性遗传效应和母本遗传效应间的遗传相关为:-0.57和-0.36。     

不同模型对贵州半细毛羊的遗传参数估计比较

采用平均信息与期望最大结合约束似然法用不同混合动物模型估计贵州半细毛羊的生长性状遗传参数,并采用赤池信息量准则(AIC)指数对不同模型进行比较。各模型中均包含固定效应、随机效应和残差效应。不同模型对随机效应做了不同的考虑:模型1中随机效应包括个体加性遗传效应、模型2中包括个体加性遗传效应、母体遗传效应;模型3中包括个体加性遗传效应、永久环境效应。各模型估计的初生重遗传力为:0.208 9⁰.380 2;断奶重遗传力为:0.253 60.380 2;断奶重遗传力为:0.253 6⁰.292 6;周岁重遗传力范围:0.224 60.292 6;周岁重遗传力范围:0.224 6⁰.344 2;成年体重遗传力范围:0.221 20.344 2;成年体重遗传力范围:0.221 2⁰.399 6;模型间比较结果表明:对于初生重和断奶重,模型2估计效果最优;对于周岁重和成年重,模型1估计效果最优。生长性状中初生重、断奶重受母体遗传效应影响显著;周岁重和成年重受母体效应影响不显著。     

不同动物模型对贵州黑山羊生长性状遗传参数的估计

为计算贵州黑山羊生长性状的遗传参数,试验建立了三种不同混合模型,运用平均信息-期望最大约束似然法(EM-AI REML)对贵州黑山羊初生重、3月龄体重、12月龄体重和24月龄体重的遗传力进行估计,最后使用赤池信息法则(AIC)对各模型进行验证。结果表明:不同的模型对遗传力的估计存在差异,当模型中只设加性效应为随机效应时,模型对贵州黑山羊12月龄体重和24月龄体重的遗传力估计最准确;当设加性效应和母体遗传效应为随机效应时,模型对初生重和3月龄体重的遗传力估计最准确。说明贵州黑山羊初生重、3月龄体重受母体遗传效应的影响较大,而12月龄体重和24月龄体重受母体遗传效应影响较小;贵州黑山羊的生长性状属于中等遗传力性状。     

长白猪肥育、胴体及肉质性状的遗传参数估测

该文资料取自1992－1999年杭州市种猪试验场所进行的长白猪SⅣ系选育工作中的5个世代肥育试验和146头猪的屠宰测定记录，采用公畜模型REML等方法估测了长白猪肥育、胴体及肉质性状的遗传参数。结果表明：平均日增重、达90kg日龄、饲料转化率等3个肥育性状的遗传力较高，分别为0．40、0．68、0．48。多数胴体性状的遗传力中等，少数性状较高，范围在0．20－0．70之间。 肉质性状的遗传力中等 ,范围在0．25－0．42之间，肌肉干物质含量的遗传力达0．88。平均日增重与饲料转化率及背腰厚的遗传相关分别为－0．24、－0．74；平均日增重与胴体瘦肉率的遗传相关达0．97；背腰厚与pH1及系水力的遗传相关分别为－0．38、－0．14。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein