山麻鸭品系配套杂交效果研究

利用经过专门化品系选育的山麻鸭I系（S1S1）、山麻鸭II系（S2S2）、山麻鸭III系（S3S3）、金定鸭（JJ）、莆田黑鸭（PP）和闽农白鸭（FF）为育种素材,通过杂交配合力测定,筛选产蛋量高、饲料转化率高的三系杂交的山麻鸭配套系。结果表明,筛选出三个最佳三系杂交配套组合F（PS2）、P（S1F）和F（S1P）,其500日龄产蛋数分别为345.4±1.2枚、339.2±2.0枚和331.1±1.3枚,总产蛋重分别为25.12±0.08kg、24.26±0.06kg和24.13±0.17kg,料蛋比分别为2.60、2.68和2.67,较亲本山麻鸭S1S1系500日龄产蛋数300.2枚、总产蛋重19.9kg、料蛋比2.91分别提高了10.3%-15.1%、21%-26.1%和15.1%-18.7%。     

不同品系大白猪生产性能对比分析

对大白猪丹系、法系、美系3个品系初产母猪窝均总产仔数、校正达100 kg体重日龄和背膘厚及胴体组成进行研究,结果表明:1)窝均总产仔数,丹系、法系、美系依次分别为(14.93±3.859)头、(12.36±3.139)头和(10.38±2.756)头,品系间差异均极显著(P0.01)。2)校正达100 kg体重日龄,丹系、法系、美系公猪分别为(165.78±12.127)d、(160.93±10.115)d和(165.21±10.724)d,其中丹系与法系、美系与法系之间差异极显著(P0.01);母猪分别为(173.35±11.263)d、(169.03±11.968)d和(170.13±10.108)d,其中丹系与法系和丹系与美系之间差异极显著(P0.01)。3)校正达100 kg体重背膘厚,公猪分别为(8.72±1.377)mm、(8.30±1.562)mm和(9.66±1.550)mm,品系间差异均极显著(P0.01);母猪分别为(9.39±1.507)mm、(8.68±1.486)mm和(9.98±1.978)mm,品系间差异均极显著(P0.01)。4)胴体瘦肉率,丹系、法系、美系分别为(69.07±1.876)%、(72.28±2.778)%和(65.87±1.437)%,法系和美系之间差异极显著(P0.01)。5)眼肌面积,丹系、法系、美系分别为(44.89±3.522)cm~2、(50.77±1.516)cm~2和(40.09±3.626)cm~2,其中丹系与法系之间差异显著(P0.05),法系与美系之间差异极显著(P0.01)。     

湘沙猪配套系专门化品系胴体品质、肉质性状和必需氨基酸评分的比较与分析

为了比较湘沙猪配套系3个专门化品系(XS3系、XS2系和XS1系)胴体品质、肉质性状、必需氨基酸评分等方面差异,试验分别选择6头、6头、5头体重为90 kg、95 kg、115 kg左右的健康XS3系、XS2系、XS1系,按品系分为3组,进行屠宰测定,比较分析相关指标。结果表明:1)XS3系的3点平均背膘厚、脂率显著高于XS1系、XS2系(P<0.05),胴体斜长、瘦肉率、3点平均皮厚、皮率3组间均差异显著(P<0.05),XS3系的眼肌面积、后腿比例、骨率显著低于XS2系、XS1系(P<0.05);2)XS2系的背最长肌pH 1 h、b*1 h显著高于XS1系、XS3系(P<0.05),XS1系的背最长肌pH 24 h显著低于XS2系、XS3系(P<0.05),XS3系的L^*1 h显著高于XS1(P<0.05),XS2系的a^*1 h显著高于XS1系(P<0.05),XS3系、XS2系的肉色等级、大理石纹显著高于XS1系(P<0.05);3)XS2系的水分含量显著高于XS3系(P<0.05),XS3系的粗脂肪含量显著高于XS2系和XS1系(P<0.05);4)3组的必需氨基酸得分均差异不大。说明湘沙猪配套系3个专门化品系,在胴体品质上以XS1系最优,XS2系居中,XS3系次之;在肉质性状上XS3系最优、XS2系居中、XS1系次之;必需氨基酸评分无明显区别。     

扬翔华系三元杂商品猪肉质性能的比较研究

试验旨在比较扬翔华系杜洛克的三元杂商品猪与美系杜洛克的三元杂商品猪在肉质性状的差异,为评估和培育新品系提供参考。试验选取广西扬翔股份有限公司健康状况良好的杜洛克三元杂商品猪共325头,其中美系杜洛克的三元杂商品猪247头,扬翔华系杜洛克的三元杂商品猪78头,按相同饲养标准饲养至体重120±15 kg时进行屠宰测定,测定指标包括肉色、pH、肌内脂肪含量等肉质性状。研究结果表明,两个品系三元杂商品猪肉pH、肉色评分及鲜肉水分含量的变异系数均小于10%。此外,扬翔华系杜洛克三元杂商品猪的肌内脂肪含量显著高于美系杜洛克三元杂商品猪(P 0.05),因此,具有较好的肉质口感和风味,而在其他肉质性状间差异不大。性状间相关性分析表明,杜洛克三元杂商品猪的肌内脂肪含量均与大理石纹评分呈显著正相关(r 0.56,p 0.01),与水分含量呈显著负相关(r 0.34,p 0.05)。     

湖羊肉用系选育初报

根据湖羊品种特征及肉用系要求,组建0世代肉用系选育核心群。经过三个世代封闭纯繁选育,初步形成了以第2胎为主、由4个公羊家系、27只公羊和92只基础母羊组成的肉用系纯繁选育核心群。核心群公羊平均同胞数为2.29±0.46只,初生和6月龄体重分别为3.61±0.70 kg和36.09±3.18 kg;母羊平均同胞数为2.23±0.54只,初生和6月龄体重分别为3.06±0.55 kg和31.14±2.37 kg;选育群第2胎后代公、母羊平均初生体重分别由第一世代的2.83±0.51 kg和2.82±0.40 kg,增加到第三世代的2.98±0.58 kg和3.12±0.74 kg;三个世代公、母羊初生体重平均选育进展分别为80 g和150 g,母羊6月龄平均体重由第一世代的29.89±1.60 kg,增加到第三世代的33.02±2.49 kg,三个世代平均选育进展为1.57 kg。     

华农温氏Ⅰ号猪配套系的选育与应用

本项目采用配套系育种理念,利用数量遗传方法结合分子标记技术,培育出由4个专门化品系组成的华农温氏配套系猪Ⅰ号。以四系配套生产的HN401肉猪肌肉发达,生长快、瘦肉率高、肉质优良、综合经济效益好;达100kg体重日龄154d,活体背膘厚13.4mm,饲料转化率2.49∶1;100kg体重胴体瘦肉率67.2%,变异系数在10%以下。该配套系肉猪可以在规模化养猪生产中广泛应用。     

快速和中等生长速度猪种的日粮维生素B需求

本研究利用来自2个猪品系的10组（每组5头同窝仔猪）试验猪,测定5种B族维生素（核黄素、烟酸、泛酸、维生素B12和叶酸）的日粮水平对体重9～28kg的高和中等瘦肉系仔猪生长的影响。所有试验仔猪均采用单只圈养,并进行早期隔离断奶,以便能够使其发挥出瘦肉生长潜力。基因日粮所提供的5种测试维生素生物的总体和估测生物可利用率分别相当于体重5～10kg仔猪的NRC（1998）估测需求量的100%和70%。当体重为9±0.9kg时,给每窝内的各头仔猪分别喂给添加了生物可利用率相当于NRC（1998）需求量的0%、100%、200%、300%或400%的5种测试维生素的基础日粮。结果表明,与中等瘦肉系猪相比,高瘦肉系猪消耗的饲料少（P〈0.05）、体重增长快（P〈0.02）和饲料利用率高（P〈0.01）。当日粮B族维生素添加水平提高时,两个瘦肉品系的试验猪生长速度和生长效率均得到提高（P〈0.01）。然而,高瘦肉系试验猪获得最佳增重/耗料比所需的日粮B族维生素水平（为NRC需求量的470%以上）显著高于中等瘦肉率试验猪（270%）（P〈0.03）。根据这些研究结果,表明现代猪种对5种B族维生素中的1种或多种维生素的需求量要高于目前NRC（1998）的估测值,尤其是高瘦肉系的猪种。对这些维生素较高的需求与较高的日粮能量摄入量或较高的机体能量沉积量无关,但很可能是由于主要的代谢通路发生改变所致。     

扬翔华系杜洛克猪专门化品系生长性状选育

扬翔华系杜洛克是以美系杜洛克和丹系杜洛克为育种素材,通过多个世代持续选育而成的一个瘦肉型猪专门化品系。该研究以扬翔华系杜洛克7个不同世代后备猪为对象,针对其生长性状的选育结果进行分析。结果表明,扬翔华系杜洛克后备公、母猪从第5世代开始,后面3个世代生长速度均显著优于前面各世代(P 0.05),且第7世代后备公、母猪校正115 kg体重日龄分别达到了166.28 d和171.36 d,均显著快于0世代(P 0.05)。后备公、母猪在校正115 kg体重日龄方面的平均世代改良比例分别达到了1.76%和1.72%。在校正115 kg体重背膘厚方面,扬翔华系杜洛克后备公、母猪平均世代改良比例分别达到了1.77%和2.44%。扬翔华系杜洛克在校正115 kg体重日龄及校正115 kg体重背膘厚方面取得较大遗传改良。扬翔华系杜洛克公、母猪达115 kg体重日龄平均每个世代减少2.69 d和2.49 d,115 kg体重背膘厚平均每个世代降低0.15 mm和0.20 mm。文章主要总结了扬翔华系杜洛克猪专门化品系生长性状选育的阶段性成果,为后续研究选育奠定了基础。     

家兔的合成配套系建系法及配套系

在家兔的育种过程中,品系繁育是重要的繁育方式。通常品系繁育有三种方法：系祖建系法、群体建系法（群体继代选育建系法）和合成配套系建系法。后者又称专门化品系建系法。这种育种方式是将家兔的全部选育性状划分为几个“性状组”,然后培育几个品系（通常３～４个,以...     

湘沙猪配套系选育及展望

湘沙猪配套系以地方良种沙子岭猪和引进品种巴克夏、大白猪为育种素材,经过5个世代的持续选育,分别育成XS1系(终端父本)、XS2系(母系父本)、XS3系(母系母本)3个专门化品系。各专门化品系主要经济技术指标达到或超过育种目标,遗传稳定。XS1系初产总仔数10.7头,产活仔数10.3头;经产总产仔数11.8头,产活仔数11.4头;公猪达100 kg日龄165.4 d,背膘厚9.9 mm;母猪达100 kg日龄166.5 d,背膘厚10.8 mm。XS2系初产总仔数10.0头,产活仔数9.5头;经产总产仔数10.2头,产活仔数9.8头;公猪达100 kg日龄168.8 d,背膘厚12.5 mm;母猪达100 kg日龄169.7 d,背膘厚13.5 mm。XS3系初产总仔数10.2头,产活仔数9.4头;经产总产仔数11.1头,产活仔数10.3头;公猪达50 kg日龄193.9 d,背膘厚15.6 mm;母猪达50 kg日龄185.7 d,背膘厚17.9 mm。配套系父母代总产仔数12.4头,产活仔数11.9头。配套系商品猪30~100 kg期间平均日增重832.44 g,料重比3.16;100.6 kg屠宰,屠宰率73.0%,胴体瘦肉率58.2%,系水力93.26%,肌内脂肪含量2.9%,肉质优良,市场前景广阔。     

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