藏鸡二元杂交组合生产性能及血液生理指标分析

研究旨在通过藏鸡杂交确定其对藏鸡生产性能的提高效果。以藏鸡纯系及其他2个地方鸡培育品系为素材,组成3个藏鸡二元杂交组合和2个纯系组合,测定5个组合13周龄公鸡屠宰性能、肉品质和血液生理指标及52周龄母鸡产蛋性能和40周龄蛋品质。结果显示:杂交组合活重大于藏鸡纯系,屠宰率高于C3纯系,52周龄产蛋率和入舍鸡产蛋数均高于藏鸡纯系,40周龄蛋重、蛋白高度、哈氏单位、蛋壳强度也高于藏鸡纯系,红细胞分布宽度等高于C3纯系。综合分析表明,含藏鸡血缘的杂交鸡性能与藏鸡纯系和C3纯系相比有一定优势,且血液生理指标优于C3纯系,研究结果为藏鸡杂交利用奠定基础。     

蛋鸡不同杂交组合主要经济性状的杂种优势的研究

通过对蛋鸡５个纯系和纯系间５个杂交组合的一个产蛋周期的生产性能测定，研究不同经济性状的杂种优势情况，以及不同杂交组合的杂种优势率。研究表明，极限性状受精率和孵化率在纯系水平较一般的情况下可以产生较大的杂种优势，而在纯系水平较高的情况下，由于受极限的限制，不可能表现明显的杂种优势；产蛋率和开产日龄的杂种优势率较高，料蛋比、成活率和７２周龄产蛋重的杂种优势略低一些，体重具有较强的杂种劣势，日耗料和蛋重的杂种优势（或劣势）率很低；遗传距离较远的品种（系）之间杂交产生杂种优势的可能性和程度较大，因此推荐用白来航和褐壳蛋鸡杂交生产商品蛋鸡。     

农华麻鸭配套效果分析

本研究对农华麻鸭MC、BGF2、GF2、GF1进行二系配套（MC♂×GF2♀（组合1）、BGF2♂×GF2♀（组合2）、BGF2♂×GF1♀（组合3））和三系配套（MC♂×（BGF2♂×GF2♀）♀（组合4）、（MC♂×GF2♀）♂×GF1♀（组合5）、BGF2♂×（MC♂×GF2♀）♀（组合6））实验，通过测定0～8周龄的体重及8周龄的屠宰性状、肉质性状和耗料增重比，计算各杂交组合在生长发育、屠宰性能上的杂种优势率。结果显示，与组合2和组合3相比，组合1的生长发育快、屠宰性能及肉质性能好、耗料增重比低。在三系配套中，组合4在0～8周龄体重显著高于组合5和组合6，组合4和组合6的屠宰性能、肉质性能优于组合5，但组合4的耗料增重比最小。杂种优势率分析表明，三系配套组合在生长性能和屠宰性能方面均体现更明显的杂种优势，其中，组合4在6～8周龄体重、宰前活重、腹脂率上均表现出明显正向的杂种优势，杂种优势率分别为6.16%、4.57%、2.42%、1.21%、10.44%,0～8周龄的耗料增重比为3.05。综合可知，组合4为最佳的杂交配套组合，该结果为优质麻羽肉鸭的配套系选育提供了理论依据。     

滨白蛋鸡不同品系的配合力测定及“滨白42”的品系配套(摘要)

以本院原种鸡场自1976年以来先后从国外引进和培育的D(1系)、E(2系)、S(3系)、N(4系)、B(5系)和C(6系)六个品系白壳蛋鸡为素材,通过连续四年的配合力测定,估计亲本品系的一般配合力和特殊配合力,为纯系选育和杂交组合配套提供理论根据;筛选优秀杂交组合,为商品鸡场提供高产配套杂交鸡。1979—1980年对滨白1、2、5、6四个品系按Griffing(1956)提出的完全双列杂交系统,配12个杂交组合,测定其主要经济性状的配合力效应值。结果产蛋量     

10个苜蓿杂交组合产量性状的杂种优势与配合力分析

通过早代测定和定向选择,可更快更准确的筛选优良杂交组合。本研究以10个苜蓿杂交组合及其13个亲本作为测验种,分析其3个主要产量性状的杂种优势表现及各性状的一般配合力和特殊配合力效应。结果表明:杂交组合5×Ⅴ、13×Ⅲ为牧草产量的强优势组合,其中分枝数和株高是影响苜蓿杂交组合牧草产量优势形成的主要性状;当亲本牧草产量性状的关键因子的一般配合力较高时,其组合的牧草产量获得强优势的概率较大,但同时也要考虑其特殊配合力的影响,在特殊配合力小的组合中也会有牧草产量优势强的组合。     

家蚕配合力效应及杂种优势研究

本文通过对中日系各3个品种15项性状的配合力效应分析和杂种优势测定,结果表明,性状间的一般配合力和特殊配合力存在明显差异,特殊配合力和杂种优势率最优的组合,其中系品种的一般配合力是最高的,而日系品种反而是最低的,说明一个组合的好坏,不能单从原种考虑,最终应从杂交组合本身优良与否来评定。     

北京油鸡杂交效果的研究

为培育优质北京油鸡配套系提供理论依据,试验采用北京油鸡纯系(Y系)与北京油鸡合成品系(G系)进行正反杂交,观测亲本及其杂交组合的体尺、外貌性状、生长性能、屠宰性能和肉质性状,并比较各性状的杂种优势。结果表明:Y系与G系的正反交组合不仅在生长性能、屠宰性能及相应的肉质性能上具有显著的杂种优势,而且杂交后代能够很好地保持北京油鸡的外貌特征;在正反交组合中,以Y系为父系、G系为母系的正交组合(YG)表现的更为优秀。说明北京油鸡在优质鸡育种和杂交利用上更适合做父系,以充分利用其优良的遗传品质。     

优质鲁西黄鸡杂交配套增重的优势分析

以鲁西黄鸡为基础，与狄高黄鸡、安卡黄鸡、隐性白鸡进行2系、3系杂交配套增重试验。试验目的是通过测定它们的一般配合力、特殊配合力、杂种优势值与杂种优势率，分析各种杂交配套生产的肉仔鸡增重规律，比较各种杂交配套组合的不同效果，从中选择最佳杂交配套生产，全面推向黄羽肉鸡市场。     

五龙鹅肝和腹脂生长的配合力分析

利用五龙鹅与四川白鹅、皖西白鹅、太湖鹅四个主要白鹅品种,设计包括纯繁在内的15个交配组合,测定了70日龄鹅肝脏重和腹脂重的一般配合力,特殊配合力,正反交效应,纯繁效应和母体效应.70日龄肝重最小二乘均数为五龙鹅63.0 g,四川白鹅82.9 g,皖西白鹅76.5 g,太湖鹅65.1 g.五龙鹅×皖白西鹅的杂交类型在肝重性状上具有2.3 g的特殊配合力,相应的杂种优势率为2.7%.腹脂重性状在六个杂交类型中都没有表现出正向的杂种优势.     

家蚕亲本遗传距离与杂种优势和特殊配合力的关系

采用Griffing交配设计,对56个家蚕杂交组合及其8个亲本进行比较试验,探索家蚕亲本遗传距离与F_1产量的杂种优势与组合特殊配合力的关系。结果表明:亲本遗传距离与杂种优势、遗传距离与特殊配合力均呈极显著的直线回归关系。杂种优势与特殊配合力之间高度一致。用双亲遗传距离在一定程度上能预测家蚕F_1产量的杂种优势和特殊配合力。用双亲平均值和遗传距离的二元回归法预测,效果比一元回归法更好。     

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.     

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.     

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.     

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 -