猪低蛋白氨基酸平衡日粮配制的关键技术

低蛋白氨基酸平衡日粮是利用猪的理想蛋白模式、采用可消化氨基酸和净能体系等配合日粮技术发展而来的。与传统日粮相比，猪低蛋白氨基酸平衡日粮具有节约蛋白质饲料原料、减少氮排放、改善肠道健康和提高饲料消化利用率等优势。本文将综合阐述猪低蛋白氨基酸平衡日粮配制的关键技术，包括蛋白质的水平、必需氨基酸的组成、非必需氨基酸的添加、氨基酸的平衡以及净能体系的应用等问题，为低蛋白氨基酸平衡日粮的运用提供参考。     

肥育猪日粮中应用完整蛋白质与晶体氨基酸的效果

以降低背膘厚度为目的的基因选择可使生猪胴体背膘厚度明显下降。瘦肉生长模型表明,肥育猪采食玉米-豆粕型日粮以达到最佳瘦肉增重和生长性状时,摄入的能量已经过量。研究结果表明,肥育猪摄入过多脂肪,会导致胴体背膘厚度增加0.25cm。当肥育猪饲喂添加晶体氨基酸的低蛋白质日粮时,会比采食完整蛋白质日粮的肥育猪更肥。脂肪增加的原因还不清楚,估计与低蛋白质日粮中净能含量增加有关。添加晶体氨基酸的低蛋白质日粮能降低肥育猪血浆尿素氮的水平,表明肥育猪对过量的氨基酸脱氨基供能的需要降低。同时,这些肥育猪的胰腺重量降低,说明胰腺活性…     

低蛋白日粮在生长育肥猪上的研究进展

低蛋白日粮在玉米-豆柏型日粮的基础上,以可消化氨基酸和净能体系、理想蛋白质模型为基础发展而来,具有节约蛋白原料、提高能量利用率、降低氮排放量以及提高经济效益等优势。猪的饲料成本占总成本的70%~75%,生长育肥猪所耗饲料占总耗料的2/3,低蛋白日粮的合理使用能对畜牧行业产生巨大的经济效益,故本文针对低蛋白日粮在生长育肥猪上的应用效果进行了综述。     

猪鸡需要原蛋白质—肽

早在60年代饲料生产者就于猪、鸡日粮中添加合成氨基酸以改善日粮氨基酸平衡.这样除可提高动物生产性能外,还可减少日粮蛋白饲料用量,降低饲料生产成本.由于发酵技术改进,合成氨基酸的生产费用大为降低.但是,原蛋白质能为单体氨基酸替代的量是有限的.试验表明,畜禽饲喂低蛋白质并补充合成氨基酸的日粮并不能获得最佳生长性能和饲料效率;而要达到这两个目的,日粮必须要有最低数量的原蛋白质.试验表明降低猪、鸡日粮的粗蛋白质水平而代之以合成氨基酸时,生长速度和饲料效率均下降.给3～6周龄的肉鸡,喂用粗蛋白质16%、补充氨基酸     

养猪实践中低蛋白日粮配制的若干技术问题

低蛋白日粮具有节约蛋白质饲料资源和减少环境污染的作用.在实际生产中以理想蛋白质模式的可消化氨基酸含量为基础,应用净能体系,以添加合成氨基酸来补充和平衡日粮氨基酸,同时添加其他添加剂,方能设计出安全、科学、合理的猪低蛋白日粮.     

早期断奶仔猪蛋白质及矿物质的营养需要

早期断奶仔猪消化道酶系发育尚未健全，胃内pH值升高，易发腹泻，低蛋白氨基酸平衡日粮可显著降低仔猪断奶后腹泻和提高仔猪的生长速度，第一限制性氨基酸，赖氨酸在日粮中的含量以1．65－1．80％为最佳，日粮中的蛋白质原料以动物性蛋白质为主，添加饲用酸化剂，脂肪，酶制剂和抑菌促生长剂都能提高全猪对蛋白质的消化率和减少腹泻发生，日粮中钙水平控制在0．58％－0．80％之，高铜日粮能提高猪的日增重和饲料效率，高锌和含砷制剂日粮能促进仔猪食欲，减少腹泻发生。     

猪低蛋白质低氮排放日粮研究进展

猪低蛋白质日粮的研究始于20世纪70年代,氨基酸平衡是其理论基础.随着理想蛋白质概念的发展和理想蛋白质氨基酸模式的建立,加之氨基酸工业化生产的实现,推动了低蛋白质日粮的研究和应用.近年来,蛋白质资源的短缺、玉米加工燃料乙醇以及低碳、低氮经济的提出,低蛋白质日粮受到人们的广泛重视,其理论和技术得到了更加深入的研究.我国是一个蛋白质资源特别紧缺的国家.2009年,我国大豆进口量已达5200多万t,是我国大豆生产总量的3倍,是美国大豆总产量的63%.研究和应用猪的低蛋白质日粮对缓解我国饲料蛋白自知资源短缺有非常重要的显示意义.依据氨基酸平衡理论,从日粮蛋白质水平与猪的生长性能和胴体品质的关系、低蛋白质日粮中合成氨基酸的利用、日粮蛋白质水平与氮排放、净能体系在低蛋白日粮中的应用等各个方面对猪低蛋白日粮的研究进展进行总结,供读者在配制低蛋白日粮时参考.     

猪和家禽需要完整蛋白质—肽的营养

30多年来,饲料生产者一直给家禽和猪的日粮添加合成氨基酸。合成氨基酸改善了饲料中氨基酸的平衡。合成氨基酸除提高动物生长性能外,还通过降低日粮的蛋白质比例减少饲料生产成本。然而,随着生产合成氨基酸发酵技术的进步,合成氨基酸的价格日趋降低。但是,单一氨基酸可代替的完整蛋白质(intact protein)的数量则有限。当家禽和猪喂补充大量合成氨基酸的低蛋白质日粮时,就很难获得最佳生长速度和饲料报酬。显然,动物为了达到最佳生长性能必需摄入最低限量的完整蛋白质即肽。当给家禽和猪饲喂蛋白质含量略低但补充     

不同净能水平的低蛋白质日粮对猪生长性能和养分消化率的影响

低蛋白质日粮是指将日粮蛋白质水平按NRC推荐标准降低2～4个百分点,通过添加合成氨基酸,降低蛋白质原料用量来满足动物对氨基酸的需求。本试验采用低蛋白质日粮饲喂生长猪以探讨低蛋白质饲粮的使用效果。     

低蛋白日粮对育肥猪生产性能和血清指标的影响

正在满足氨基酸需要量的条件下,日粮蛋白水平降低2.9个百分点,对育肥后期猪生长性能无显著影响;且低蛋白日粮降低了配方成本,提高了育肥猪增重,这些都提示低蛋白日粮可以提高猪场经济效益。由于蛋白质饲料资源短缺的问题日益突出,如何通过降低饲料蛋白水平、提高蛋白利用率来节约蛋白质资源是目前动物营养领域的研究热点。有研究表明,将育肥猪日粮的蛋白水平降低2~4个百分点并补充合成氨基酸,对猪生产性能没有影响,还可降低养殖成本,提高经济效益。但目前低蛋白日粮在育肥猪上的应用研究大部分只针对生产性能,对机体内营     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.     

Micronutrient Content of Certain Tropical Conventional and Unconventional Feed Resources of Southern India

The ash, silica and certain important micronutrients were estimated in conventional and unconventional feed and fodder resources available in Southern India. Commonly used dry roughages, such as paddy straw, ragi straw, maize kadbi/stalk, jowar kadbi/stalk, bajra stalk and wheat straw, were high in ash (9.9% +/- 0.77%) and silica (6.4% +/- 0.65%) and low in most of the other micronutrients, except iron, with paddy straw containing most silica (>9%). Cultivated non-leguminous (maize, jowar) and improved green crops (hybrid napier, guinea, green panic, NB-21, CO-1) were also high in ash (10.5% +/- 0.60% and 12.5% +/- 0.51%) but were moderate sources of P, Mg and Cu and good sources of Zn (98 +/- 13.8 ppm and 55 +/- 6.7 ppm). Leguminous green fodders (stylosanthus, lucerne, cow pea, soyabean) were excellent sources of Ca (1.9% +/- 0.16%), Mg (0.40% +/- 0.05%), Cu (30 +/- 5.2 ppm), Zn (121 +/- 14.7 ppm) and Fe (1234 +/- 166 ppm) and moderate sources of P. Mixed local grasses and weeds were high in silica (6.9% +/- 1.00%) but were good sources of Cu, Zn and Fe. Cereal grains (maize, wheat, rice, ragi) were low in ash (2.9% +/- 0.33%) and were relatively poor sources of Ca (0.22% +/- 0.03%), Mg (0.19% +/- 0.03%) and Cu (13 +/- 3.1 ppm). Pulses were low to medium sources of most minerals and good sources of Fe (1230 +/- 293 ppm). Oil seed cake/extractions (groundnut cake, cotton seed cake, soyabean meal, sunflower cake, safflower cake) and cereal by-products (rice polish, rice bran, wheat bran) were excellent sources of P (1.1% +/- 0.47% and 2.3% +/- 0.19%) and good sources of Zn (65 +/- 3.9 ppm and 66 +/- 10.7 ppm) and Fe (938 +/- 130 ppm and 662 +/- 126 ppm). Among the unconventional feeds screened, orange peel, sunflower heads, meat meal, rubber seed cake, spirulina algae and sea weeds contained plentiful Ca, Zn and Fe: tree leaves/top feeds (mulberry, erythrina, glyricidia, banana, subabul, groundnut haulms) were excellent sources of Ca (1.5% +/- 0.13%), Zn (120 +/- 22.9 ppm) and Fe (1033 +/- 133 ppm) but relatively poor sources of P. Soyabean husk, cocoa seed husk, rubber seed cake and meat meal were moderate to good sources of P (1.0% and 0.33%). The high Zn and Fe values of most feeds/fodders were probably due to soil contamination. This account of the micronutrient content of feed/fodder resources should help in strategic supplementation intended to alleviate local deficiencies.     

Bovine Mastitis in Selected Areas of Southern Ethiopia

A study on bovine mastitis, designed to determine the causal agents, prevalence of infection and impact of risk factors in three cattle breeds, was conducted in selected areas of southern Ethiopia. A total of 307 lactating and non-lactating cows, of which 162 were indigenous Zebu, 85 Jersey and 60 Holstein-Friesian, were examined by clinical examination and the California mastitis (CMT) test. Of these, 40.4% were positive by CMT and bacteriology for clinical or subclinical mastitis, with prevalence rates of 37.1% and 62.9%, respectively. Out of 1133 quarters examined, 212 (18.7%) were found to be infected, 83 (39.2%) clinically and 129 (60.8%) subclinically. The prevalence of mastitis was significantly higher in Holstein-Friesian than in indigenous Zebu, in non-lactating cows than in lactating cows, in the early lactation stage than in the mid-lactation stage, in cows with lesions and/or tick infestation on skin of udder and/or teats than in cows without this factor, and in the wet season than in the dry season. Mastitis increased with parity number (R = 0.9). Of 248 CMT and clinically positive udder quarter samples analysed microbiologically, 212 were culturally positive for known mastitis pathogens and 36 were negative. Of the 199 positive samples, Staphylococcus accounted for 39.2%, Streptococcus for 23.6%, coliforms for 14.1%, Micrococcus and Bacillus species for 8.0% each and Actinomyces or Arcanobacterium (Corynebacterium) for 7.0%. It was concluded that there was a high prevalence of clinical and subclinical mastitis, mainly caused by Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli, in this study area.     

不同日粮氮水平对山羊氮代谢和微生物蛋白质合成的影响

本试验旨在探讨不同日粮氮水平对内蒙古白绒山羊氮代谢和微生物蛋白质合成(MCP)的影响,以达到提高氮利用率,减少环境污染和饲料资源的浪费。试验选用9只体况良好、体重为(43.83±2.95)kg,装有瘤胃瘘管的内蒙古白绒山羊,按体重随机分为3组,每组3只。日粮分为低氮7.5%、中氮10.5%、高氮13.5%3个氮水平。试验使用常规试验方法分析测定粪尿血液等生化指标,通过全收尿法和尿嘌呤衍生物法估测MCP。结果表明:随着氮水平增加,氨氮(NH3-N)浓度、氮摄入量、尿氮排出、尿中尿素氮(UUN)和MCP显著增加(P0.05),干物质采食量(DMI)显著降低(P0.01);沉积氮占总摄入氮的比例在中氮组最高,MCP在高氮组最高。综上所述,适当降低日粮氮水平可减少粪尿氮排放,提高反刍动物氮利用率。     

Microsporidial keratopathy in two dogs

A microsporidial keratopathy is described in two dogs. Both dogs presented with a unilateral stromal keratopathy characterized by multifocal coalescing opacities, and the diagnosis was made on histopathologic examination of keratectomy specimens. Transmission electron microscopy (TEM) on formalin‐fixed, paraffin‐embedded corneal tissue was performed in one dog, and the morphologic features were consistent with Nosema species infection. Both dogs were initially diagnosed and treated by superficial keratectomy. One dog received additional antifungal medication and underwent a penetrating keratoplasty following local recurrence two years later. No other systemic lesions attributable to the microsporidial infection were identified clinically. The clinical and diagnostic pathology findings, treatment, and follow‐up are discussed.