杂交选育抗应激系育肥猪生产性能的测定

本试验通过分别设置应激群×应激群（对照）、应激群♂×抗应激系♀、抗应激系×抗应激系、皮特兰♂×抗应激系♀4个杂交组合,在相同的营养水平和饲养管理条件下,对各组合的肥育性能,胴体品质进行系统测定和统计分析。结果表明,皮特兰作为父本生产商品猪的经济效益最好。     

猪RYR_1基因的PCR-RFLP分析和氟烷基因利用的研究

采用ＰＣＲ－ＲＦＬＰ分析技术，以血液或猪毛提取ＤＮＡ为模板，建立了快速和简便的从分子水平上鉴别ＲＹＲ１基因型的方法，其准确率为１００％。不同品种（系）初步配套杂交结果显示：皮特兰×抗应激猪的胴体品质优于杜洛克×抗应激猪（Ｐ＜０．０５或Ｐ＜０．０１），而肉质优于皮特兰×应激群猪（Ｐ＜０．０１），并提出了氟烷基因的利用策略     

“953”巨型高产长毛兔新品系培育研究(Ⅰ)——杂交组合的筛选与杂种效应分析

以西平本地长毛兔、德系安哥拉兔和浙江产高产长毛兔群为亲本，进行品系（群）间杂交创新，为选育“９５３”巨型高产长毛兔提供基础群。结果表明，本地兔♀×德系兔♂、本地兔♀×浙江兔♂和德系兔♀×浙江兔♂３个杂交组合比较优秀，每一杂交组合的杂种与其父本级进杂交三代，其后代在体尺、体重、产毛量和繁殖性能等方面均有不同程度提高，而且不同组合的杂交效果表现出一定的互补性，上述３个杂交组合的级进三     

美系和台系杜洛克公猪与长大母猪杂交试验

本试验选用美系和台系杜洛克作终端父本与长大母猪杂交,对其繁殖性能、生长肥育性状、胴体性状指标进行测定。试验结果表明,繁殖性能方面,美系♂×长大♀组合(美系杂)好于台系♂×长大♀组合(台系杂),窝均产仔总数、窝均产活仔数、初生窝重分别高1.04头、1.09头、1.33 kg;生长育肥性状方面,美系杂在30~100kg阶段的日增重比台系杂高52 g,差异显著(P0.05),饲料转化率则是美系杂略优于台系杂,在30~100 kg阶段的耗料增重比分别为2.86︰1和2.94︰1;胴体性状方面,台系杂胴体的瘦肉率比美系杂胴体的瘦肉率高3.05%。说明2个品系的杜洛克公猪各有优势,因根据需要选择最佳的杂交组合。     

皮特兰、杜洛克猪正反杂交效果分析

此试验在相同饲养条件下对皮特兰、杜洛克纯繁及其正反杂交的繁殖性能,后代的肥育性能和胴体品质进行比较。结果表明,这些品种组合的产仔数、断奶个体重及后代的日增重都较高,且二元杂高于亲本,具有中等杂优率,其中皮杜组合各项指标表现最优。     

荣昌猪瘦肉型品系肥育性能研究

本研究对荣昌猪瘦肉型品系０至５世代共２４６头同胞肥育试验猪进行了肥育性能测定。结果表明，通过六个世代的选育，荣昌猪瘦肉型品系具有优良的胴体品质及较快的生长速度，并保持了原种荣昌猪肉质优良的遗传特性，胴体瘦肉率、肩腰荐三点均膘、后腿比例、胴体长分别由０世代的５１．７３％、２．６３ｃｍ、３１．３９％、８４．７５ｃｍ提高（降）至５世代的５５．００％、２．０６ｃｍ、３２．３９％、８７．２５ｃｍ，分别提高（降低）了６．３％、２１．７％、３．２％、２．９％；２０～９０ｋｇ日增重、每增重１ｋｇ耗料、达９０ｋｇ体重日龄分别由０世代的４５０．０ｇ、４．１７ｋｇ、２３４．９天提高（降）至５世代的５９８．８ｇ、３．３９ｋｇ、１８９．５天．分别提高（降低）了３３．５％、１９．３％、１９．３％。     

二花脸猪四元杂交组合与杜长大三元杂交组合比较试验报告

以中国优良地方猪种——二花脸猪为母本，用新美系杜洛克、德系抗应激皮特兰、加系双肌臀大白猪和新丹系长白猪等西方瘦肉型猪种作为父本进行“土四元”配套杂交组合试验，并与杜长大“洋三元”杂交组合进行比较。结果表明，除生长性能外，二花脸猪“土四元”杂交组合在繁殖性能和肉质特性方面有突出表现，甚至优于杜长大，尤其是以长大杜二组合的杂交效果较为理想。     

含黔东花猪血缘不同杂交组合繁殖性能测定

为提高贵州地方良种黔东花猪的繁殖性能,试验选取高繁品种太湖猪为父本,黔东花猪为母本,进行杂交,得到F1（♀）后分别与皮特兰（♂）、杜洛克（♂）杂交,获取不同组合F2,再以巴克夏为终端父本,测定不同组合F2（♀）繁殖性能。结果表明,黔东花猪、太湖猪、皮特兰杂交组合所得的母本在乳头数、初情期、初配日龄、初产及经产母猪产仔数、断奶后发情间隔期等指标均优于黔东花猪、太湖猪和杜洛克组合,是一种具有较高繁殖性能的黑猪母本材料,但在仔猪初生重、生长速度方面低于黔东花猪、太湖猪和杜洛克组合。     

南方农村条件下PIC300配套系公猪杂交效果研究

选择PIC300配套系公猪分别与普杂母猪、洋二元母猪、新荣昌Ⅰ系母猪进行杂交,在南方农村条件下,分别测定3个杂交组合的繁殖性能及其后代的生长肥育性能、胴体品质和肉质。结果表明,3个杂交组合各项性能优良,证明PIC300配套系公猪是南方农村条件下进行经济杂交的优良父本。     

定远猪及其一代杂种猪胴体,肌肉品质的比较研究

本试验将定远猪分别与长白、大约克和杜洛克杂交，对所产Ｆ１代肉猪作胴体性状和肌肉品质分析比较，结果发现，（１）要交Ｆ１代猪眼肌面积增大，眼肌重增加，前者分别比定远猪对照组提高０．９１￣９．３４ｃｍ＾２，后者分别比对照组高２０－４７％，达到显著水平；（２）各杂交系胴体瘦肉量增国极显著（１．９２￣３．１７ｋｇ，Ｐ〈０．０１），其肉详细交对照组提高７．８５￣９．５３个百分点；（３）杂交Ｆ１代猪皮重均明显减     

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