鲁烟白猪与杜洛克杂交商品猪肥育性能、胴体品质及肉质研究

研究测定了鲁烟白猪及鲁烟白猪与鲁育杜洛克、一般杜洛克杂交商品猪的生长肥育性能、胴体性能及肉品质。结果表明,生长肥育性能以鲁育杜洛克X鲁烟白猪组合最高,与一般杜洛克X鲁烟白猪和鲁烟白猪X鲁烟白猪组合相比,平均日增重分别提高3．80％（P〉0．05）、6．55％（P〈0．05）,料重比分别降低0.35％（P〉0．05）、3．75％（P〉0．05）。3个组合的肥育猪胴体性能和肉质性状差异显著。其中,鲁育杜洛克×鲁烟白猪组合的瘦肉率最高、背膘最薄,与一般杜洛克×鲁烟白猪和鲁烟白猪×鲁烟白猪组合相比,瘦肉率分别提高1．87％（P〉0．05）、4．75％（P〈0．05）,背膘厚分别降低5.32％（P〉0．05）和13．98％（P〈0．05）;肉色评分以鲁育杜洛克×鲁烟白猪最高,但组合间差异不显著;大理石纹评分和肌内脂肪都以一般杜洛克×鲁烟白猪组合最高,分别比鲁育杜洛克×鲁烟白猪和鲁烟白猪×鲁烟白猪提高21．09％（P〈0．05）、24．67％（P〈0．05）和29.39％（19〉0．05）、69．54％（P〈0．05）。背最长肌17种氨基酸含量组合间差异显著。氨基酸总量、鲜味氨基酸含量、必需氨基酸含量也都以鲁育杜洛克×鲁烟白猪组合最高,分别比一般杜洛克×鲁烟白猪和鲁烟白猪X鲁烟白猪提高5．16％（P〈0．05）和5．11％（P〈0．05）、4．46％（P〈0．05）和4．68％（P〈0．05）、4．81％（P〈0．05）和4．66％（P〈0．05）。4种脂肪酸含量组合间差异不显著．     

IGF—I基因第3外显子多态性对山西白猪生长性状的影响

胰岛素样生长因子I（IGF—I）是动物生长发育和代谢的主要调节因子，是生长激素启动生长活性的主要介导者。采用PCR—SSCP技术检测了山西白猪群体IGF-I基因第3外显子的多态性，共检测到3个等位基因A、B、C，形成了AA、AB、AC、BB、BC和CC6种基因型。A等位基因的频率较高，为0．549，等位基因B和C的频率较低，分别为0．173和0．278．就基因型频率的分布来看，纯合子AA型、杂合子AB和AC型频率较高，分别为0．230、0．204和0．434，其他类型频率较低，均低于10％。利用最小二乘法分析了突变位点对山西白猪初生重、断奶重、6月龄体重和体高、体长、胸围、背膘厚等性状的影响。结果表明，该突变位点对6月龄猪的体高有显著影响（P〈0．05），BC型个体的6月龄体高显著低于其他类型个体（P〈0．05），而对其他性状的影响不显著（P〉0．05）。     

大白猪育种核心群氟烷基因PCR—RFLP检测及其净化

采用PCR—RFLP技术,对正邦集团大白猪原始基础群及其育种核心群0、1世代共538头个体,以及红星衣场大白猪原始基础群和育种核心群0世代共249头个体进行氟烷基因（Hal）基因型检测,并对阳性个体予以清除使其净化。基因继代选择结果显示,正邦原始基础群及核心群0、1世代群体Hal^n基因频率分别为9．48％、2．22％、0;红星原始基础群及核心群0世代群体Hal^n基因频率分别为1．08％、0,呈现世代递减并实现净化,进而培育出大白猪抗应激品系。研究表明,PCR—RFLP技术可准确诊断猪氟烷基因,在种猪选育过程中及时淘汰携带氟烷基因的个体,提高猪种质量。     

郏县红牛CLPG基因的SNP及对生长发育性状的影响

利用PCR-SSCP检测了113头郏县红牛CLPG基因的SNP，发现了AA、AB、AC 3种基因型，测序结果显示AA型在第150和419碱基处分别表现为C和T，为野生型；AB型在第419处发生碱基T→C突变；AC型在第150处发生碱基C→T突变。多态信息含量为0．226，属低度多态。分析了不同基因型与部分生长发育性状的相关性，结果显示，AA、AC基因型个体在体重、体长指标上显著（P〈0．05）或极显著（P〈0．01）大于AB型个体；在管围指标上，AA基因型个体优于AB基因型个体，差异显著（P〈0．05）；在坐骨端宽指标上，AA与AB基因型个体之间差异显著（P〈0．05），AB与AC基因型个体间差异极显著（P〈0．01）。     

不同周龄菜籽鹅和北方白鹅17项血清生化指标的比较研究

分别测定了4、8、12周龄时菜籽鹅（莱菌鹅♂×籽鹅♀）和北方白鹅（东北白鹅♂×籽鹅♀）17种血清生化指标的正常值，并进行比较分析。结果表明，2品种鹅各时期血清生化指标存在不同程度的差异，4周龄莱籽鹩葡萄糖（Glu）含量显著高于北方白鹅（P〈0．05）；8、12周龄2品种鹅丙氨酸氨基转移酶（ALT）存在极显著差异（P〈0．01），12周龄菜籽鹅磷（P）含量极显著高于北方白鹅（P〈0．01），而北方白鹅甘油三酯（TO）含量显著高于莱籽鹅（P〈0．05）；2品种鹅钙（Ca）、乳酸脱氢酶（LDH—L）及碱性磷酸酶（ALP）都有随周龄增加而减少的趋势，其中Ca含量各时期差异极显著（P〈0．01）；而TG、蛋白胆固醇（HDLC）、天门冬氨酸氨基转移酶（AST）和肌酐含量都随周龄显著升高（P〈0．05），ALP、镁（Mg）、γ-谷氨酸酰基转移酶（7GT）、LDHL含量趋于稳定（P〉0．05）。     

北京油鸡AMPD1基因多态性及其与肌苷酸含量关系的研究

根据人和大鼠的腺苷-磷酸脱氨酶1（AMPD1）基因序列设计引物，采用PCR-RF-SSCP技术检测了130只北京油鸡AMPD1基因多态性，并分析了AMPD1的不同基因型与北京油鸡肌苷酸含量的关系。结果表明：在北京油鸡中检测到AMPD1基因的A、B、C3个等位基因，基因频率分别为0．1808、0．6615、0．1577；产生AA、AB、AC、BB、BC、CC6种基因型，基因型频率分别为0．0769、0．1769、0．0308、0．4615、0．2231、0．0308。最小二乘分析表明基因型AC、BB所对应的肌苷酸含量最小二乘均值显著高于基因型AA所对应的最小二乘均值（P〈0．05），肌苷酸含量在AMPD1其余基因型之间没有显著差异（P〉0．05）。     

猪IGF2基因G3072A位点多态性及其与大白猪初生重和早期生长的关系

本研究采用PCR-SSCP技术对猪胰岛素样生长因子2（IGF2）基因G3072A位点在大白、长白和杜洛克猪群体的单核苷酸多态性（SNP）进行了检测，对其与大白猪初生重和早期生长的关系进行了分析。结果表明，在所分析的大白、长白和杜洛克猪群体的511个体中，IGF2基因在该位点均呈现多态性，大白、长白和杜洛克猪群体AA、AB和BB基因型均有分布，且大白和长白猪群体均显著偏离Hardy-Weinberg平衡（P〈0．01），而杜洛克猪群未偏离Hardy-Weinberg平衡（P〉0．05）。测序结果显示，等位基因A和B分别对应于核苷酸A和G，在A等位基因中，有（AG）二核苷酸的插入。关联分析表明，在大白猪群中，AA、AB和BB基因型个体的初生重差异显著（P〈0．05），AA和AB基因型个体的21、28和70日龄体重以及从出生～21日龄、21～28日龄、28～70日龄的日增重差异不显著（P〉0．1）。     

猪FSHβ基因多态性及其与产仔性能的相关性分析

以518头母猪（含杜洛克、长白、大白）为研究对象,以FSHβ基因为候选基因,采用PCR产物直接电泳法检测FSHβ基因位点的多态性。检出3种基因型,分剐为AA、AB、BB基因型。将基因座不同基因型与总产仔数和产活仔数进行关联分析,结果表明．FSHβ基因在杜洛克、长白猪、大白猪中主要以胎基因型形式存在,曰基因频率分别为96．67％、73．36％和86．01％．但对产仔数影响不显著（P〉0．05）。不同基因型的猪头胎产仔数差异不显著（P〉0．05）,不同基因型对总产仔数的影响差异不显著（P〉0．05）。总体而言,FSHβ基因在该位点的多态性与这3个猪种的头胎产仔数、总产仔数均无显著联系。     

京海黄鸡MC4R基因多态性及其与生长性能的关联分析

研究以140只京海黄鸡为试验材料，以MC4R为候选基因，采用PCR-SSCP和DNA测序技术分析了MC4R基因在京海黄鸡群体中的多态性。结果表明：MC4R基因编辑区第662bp处有G→C碱基的点突变，在京海黄鸡中检测到AA、AB、BB3种基因型，A等位基因的频率为0．929．B等位基因的频率为0．071。经过基因型与生长性能的关联分析得知：不同基因型与京海黄鸡4、8、12周龄体重差异显著（P〈0．05），与16周龄体重差异极显著（P〈0．01）。由此推测，MC4R基因可能对于鸡生长性能具有很大的影响或与控制生长性能的主基因连锁。     

猪PGC1基因多态性与胴体性状的相关性分析

通过PCR-RFLP方法,检测外来品种大约克猪和江苏地方品种梅山猪、二花脸猪、姜曲海猪以及培育品种苏钟猪共144头,结果表明PGC1基因第8外显子序列经AulⅠ酶切后存在AA、AT和TT3种基因型,其中大约克猪中AA基因型占优势,A等位基因频率为0．7,而江苏地方品种猪中,TT占绝对优势。分析PGC1基因型与胴体性状相关性发现,AA基因型猪的左胴重、右胴重和脂肪重均高于TT基因型猪,差异达到显著水平（P〈0．05）。倒数第三、四腰椎间背膘厚AA基因型显著高于TT基因型猪,差异达到极显著水平（P〈0．01）,AT基因型与TT基因型差异达到显著水平（P〈0．05）。     

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.     

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.     

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     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

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

Tropical Animal Health and Production -