巴克夏与广东小耳花猪杂交效果分析

为进一步开发利用广东小耳花猪肉品质优良的种质特性,本研究选用广东小耳花猪和巴克夏猪进行杂交,测定其杂交后代巴花猪(巴克夏猪♂×广东小耳花猪♀)的生长性能、胴体性状和肉品质。结果表明:巴×花杂交组合的总产仔数达到11.47头;巴花猪的初生均重达到850 g,育肥阶段日增重达到667 g,育肥阶段耗料增重比为3.35;120 kg体重屠宰,肌内脂肪含量为4.27%,瘦肉率为43.12%,肉色评分为5.58分,背膘厚度为47.42 mm,剪切力为37.35 N。综合来看,巴花猪在生长、胴体等多项性能方面均优于广东小耳花猪,体现出了父本生长速度快、胴体瘦肉率高的特性,同时其肌内脂肪含量高,胴体瘦肉率偏低,也表现出母本肌肉细嫩、大理石纹丰富、胴体瘦肉率低的特性,是一种可推广的生产优质猪肉的杂交模式。     

Hedgehog信号通路介导猪肌内脂肪分化调控的研究进展

肌内脂肪直接影响猪肉的风味,肌内脂肪含量过低造成猪肉风味变差。肌内脂肪含量性状与瘦肉率性状之间呈负相关,单靠遗传育种同时解决猪的瘦肉率和肌内脂肪含量问题已经遇到瓶颈。本文主要综述hedgehog信号途径在胚胎发育期如何调控间充质干细胞成脂分化,在提高猪的瘦肉率的同时增加肌内脂肪含量,为我国瘦肉型猪的培育和猪肉品质调控研究提供新的思路。     

提高瘦肉型猪瘦肉率的途径

瘦肉型猪是指屠宰后胴体膘薄、瘦肉率高的品种猪。这些品种猪是经过长时间的精心培育并在一定的饲养条件下,保持稳定的瘦肉生产能力的优良猪种。这类猪生长瘦肉的能力强,胴体瘦肉多,脂肪少,瘦肉占胴体重的60％以上。由于瘦肉型猪产肉多,经济效益高,是当前和今后饲养商品猪的发展方向。做繁殖用的瘦肉型公猪和母猪,称为瘦肉型种猪。用瘦肉型种公猪与瘦肉率低的本地土种或地方优良品种杂交,可以提高杂种后代的瘦肉率。     

商品瘦肉型猪三元杂交生产配套技术（一）

一、什么叫瘦肉型猪 瘦肉型猪是指屠宰后胴体膘薄、瘦肉率高的品种猪。这些品种猪是经过长时间的精心培育并在一定的饲养条件下,保持稳定的瘦肉生产能力的优良猪种。这类猪生长瘦肉的能力强,胴体瘦肉多,脂肪少,瘦肉占胴体重的60％以上。由于瘦肉型猪产肉多,经济效益高,是当前和今后饲养商品猪的发展方向。做繁殖用的瘦肉型公猪和母猪,称为瘦肉型种猪。用瘦肉型种公猪与瘦肉率低的本地土种或地方优良品种杂交,可以提高杂     

日粮中添加能量和脂肪对猪脂肪酸含量、瘦肉率和脂肪生成的影响

试验采用40头去势大白公猪,研究日粮脂肪来源(日粮中含有5%的牛羊油或豆油)对猪脂肪酸含量、瘦肉率和脂肪生成的影响是否依赖于日粮可消化的能量浓度(8.8MJDE/kg、14.0MJDE/kg)。试验猪分为4组,体重27-105kg定量饲喂(170g×BW0.569/d)。测背膘、网膜脂、背最长肌中肌间脂肪组织脂肪酸含量和成脂酶活性。试验结果表明,猪生长性能和胴体品质受日粮能量水平影响(p<0.01)与脂肪来源无关。在低能量组胴体脂肪沉积少、成脂酶活性降低(p<0.01)。在日粮能量水平范围内,采食含豆油的     

互助猪及其杂交猪的肉质比较

对互助猪、杜洛克猪和以互助猪为母本,用国内外6个不同品种猪为第一和第二父本的8个杂交组合猪的肉质测定结果:互助猪肉质优良,肌肉干物质、脂肪含量明显高于各杂交组和杜洛克猪(P<0.01),嫩度接近80％,背脂和板油的融点低,肌肉颜色、大理石纹也优于其它各组合;各杂交组猪的眼肌面积比互助猪提高47.8—133.8％(P<0.01),以杜苏互和杜长互为最高,分别增加133.8％、115.4％,瘦肉率比互助猪提高5.0—10.1％,以杜苏互和长苏互较高,分别增加10.1％和9.3％;肌肉pH值以杜苏互、长苏互、杜长互和汉巴互较佳,均比亲本杜洛克猪有明显提高(P<0.05)。由此看出,互助猪虽然眼肌面积小,瘦肉率低,但其与瘦肉型品种的杂交后代,眼肌面积和瘦肉率都有较大提高。就肉质比较而言,杜苏互和长苏互是较好的瘦肉型杂交组合。     

软膘猪的预防

软膘猪是指酮体脂肪较软,特别是在颈部、奶脯等部位蓄积大量软脂的商品肉猪。 软膘猪主要是由于猪采食了大量合不饱和脂肪酸多的饲料致使猪胴体脂肪中不饱和脂肪酸含量增加而引起的。在生产中应采取如下措施进行有效地预防。 一、选用瘦肉型猪种,或利用瘦肉型猪种与地方品种进行杂交来生产商品肉猪。猪沉积脂肪的能力和胴体脂肪的含量主要受遗传因素的影响,国外引进的和我国培育的瘦肉型品种沉积脂肪能力低,体脂含量少,瘦肉率高,不易形成软膘猪。而我国的地方品种则相反,饲养不当极易形成软膘猪。用瘦肉型猪种与地方品种杂交,后代体…     

影响猪胴体品质的一些饲料因素

猪的胴体品质大体上包括胴体瘦内率及胴体肉、脂的质量。随着人们生活水平的提高及外向型养猪业的发展．市场对用作品质的要求不断提高．并逐渐由原来单纯追求高瘦肉率转为瘦肉率与肉脂质量并重。胴体品质受遗传、饲料、性别、生长阶段、疾病等因素的影响,其中饲料对胴体品质具有重要的影响。本文介绍一些影响猪胴体品质的饲料因素。     

乐平花猪种质特性研究

乐平花猪是江西省地方优良猪种，属我国华中型猪种。１９８３～１９８８年江西农业大学组织多学科协作对乐平花猪的繁殖性能、生长发育、肥育性能、胴体品质和肉质、生理生化常值、杂交利用等主要生物特性进行测定与研究。结果表明，乐平花猪体型较大，生长速度较快、性早熟。幼公猪８０日龄时曲精细管内出现精子，幼母猪１２０日龄时排出卵子。产仔数较多，经产母猪产仔数１１～１２头。在中等营养水平下肥育，日增重４７０多ｇ，胴体瘦肉率４０％左右，胴体脂多，皮的比例较大。肉质好，肌肉脂肪含量高，肉色鲜红，肌纤维细嫩，肌肉系水力强，熟食肉的感官品质好。此外，发现乐平花猪血清转铁蛋白的ＢＢ型和ＡＢ型瘦肉率显著高于ＡＡ型。测定了后备猪生理生化常值。初步研究了乐平花猪杂交优势表现，认为是一个较好的杂交母本。     

新引皮特兰猪的品种特性及其种用资源价值

为了发展瘦肉型猪，引进胴体瘦肉率高达80%左右的皮特兰猪进行试验。研究结果表明，其杂种后代外部特征遗传力强。瘦肉率特性遗传力高。较当地对照提高10个百分点以上，且肉品质较好。     

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.     

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 -