四川省猪抗病营养研究国际领先

<正>近日,由四川农业大学牵头,浙江大学、新希望集团等产学研单位参加,历时15年协同创新的"猪抗病营养理论与技术"成果通过专家组鉴定。专家组一致认为,该成果整体研究达到国际先进水平,其中:猪抗病营养需求参数、营养与肠道发育和健康、营养与特异性疾病的互作规律等部分研究结果达国际领先水平。专家组认为该成果在三方面实现了重大突破:一是创新了猪抗病营养理论;二是创     

合理调节饲料营养 降低猪群疾病的发

适宜的营养能增强动物对疾病的抵抗力和抗应激能力,减少或消除疾病,维护动物正常的生理机能或生理状态,使动物生产性能充分发挥.因此,从营养的角度解决猪群健康问题具有重要意义.该文从饲料营养角度浅析养殖过程中如何预防和减少疾病的发生,以供大家参考和借鉴.     

猪的免疫营养及其免疫机能

免疫营养既能给动物提供营养,起到改善机体代谢和营养指标的作用,又能增强动物的免疫功能,提高动物的抗病力和免疫力,保证动物的健康生长。免疫系统是维护动物机体内新陈代谢平衡抵御病原侵害的重要防御系统。正常的生产条件下,绝大多数的免疫应激都与炎症反应有关。随着现代规模养猪面临的疾病挑战(包括免疫抑制病和营养代谢疾病等)形势越来越严峻,尤其对猪免疫营养需求的研究是越来越广泛。免疫营养的种类很多,文章就现代猪营养(包括氨基酸、脂肪类营养、维生素、微量元素、核苷酸和其他营养素等)及其免疫机能进行综述。     

猪的营养应激与肠道免疫应答

现代畜牧生产更趋向于高度密集和大规模,来提高生产效率.这种生产环境的变化会影响动物健康和加剧生长的应激.主要的应激源包括环境(空气质量和温度)、营养和感染.这些应激可以降低生长性能同时改变家畜全身和局部免疫系统的水平,包括胃肠道等.热应激会增加肠道的通透性、氧化应激和炎症反应;营养应激是由空腹、抗营养化合物、毒素作用,引起肠道紧密连接蛋白(TJ蛋白)的泄漏表达.禁食是能够抑制促炎性细胞因子,而脱氧雪腐镰刀菌烯醇能增加肠促炎性细胞因子在肠道中的淋巴细胞水平.疾病或病毒的感染如肠毒性大肠杆菌(ETEC)和病毒和猪流行性腹泻病毒可以导致肠上皮细胞屏障失效.另一方面,有研究添加乳酸杆菌或酿酒酵母可降低ETEC传染力.有研究指出,主要的应激源改变了肠道屏障的通透性和在猪粘膜系统中的促炎性细胞因子和趋化因子的基因和蛋白质的表达.但目前还不能解释,在应激条件下,猪肠道免疫系统的作用机制.在主要应激源下,肠道和全身免疫系统之间的相互作用有待进一步揭示.     

母仔猪群的健康管理——读《猪业科学》2021年第8期有感

仔猪、尤其是断奶仔猪,是养猪生产中极为重要的环节,其健康管理对于养猪场经济效益具有举足轻重的作用。第8期《猪业科学》杂志围绕“母仔猪群健康管理”这一主题,主要从应激的种类与危害、动物对应激反应的调节机理、抗应激的营养解决方案、断奶应激对仔猪的影响及缓解断奶应激的方法等内容展开论述与交流,在内容上逐层推进,由广及专,涵盖了应激的含义、分类、危害、动物抗应激机制与营养解决方案、仔猪断奶应激的危害及其解决方案,在使读者了解动物应激的基础知识与原理的基础上,促进读者更好地了解仔猪断奶应激的相关知识与防控思路,这对于断奶仔猪的健康管理具有十分重要的理论指导意义和临床应用价值。在饲料禁用抗生素后,一些细菌性疾病和寄生虫病等非病毒性疾病不容忽视,为此8期还提出了“禁抗后仔猪重要的细菌性腹泻与寄生虫性腹泻的防控措施”。这些内容,对于母健仔壮、稳产增效而言,无疑具有重要的生产指导价值。     

维生素作为免疫调节剂的作用

疾病和免疫学应激对畜禽生产性能造成很大的影响,有关疾病对动物生产性能影响的机制表明,提高饲料的营养水平是增强动物的免疫功能,抵抗疾病的重要措施。一些维生素(特别是那些具有抗氧化特性的维生素),因为它们在免疫和健康方面的特殊作用而受到重视。如果我们掌握了营养与免疫之间互作的机制,就可以从营养的角度来提     

生物发酵饲料在养猪增效降本中的作用

饲料营养包括生理营养、维持营养、生长营养、繁殖营养、免疫营养、抗病营养等,直接影响生产业绩和猪群健康,因此,营养管理在养猪增效降本中发挥重大作用.而生物发酵饲料是畜禽养殖中发挥防非、替抗、降本、增效综合功能的关键.大量理论研究与临床实践证明,优质生物发酵饲料在保黏膜、护肠道、抗应激、除毒素方面等发挥着重要的作用,能大大...     

猪肠道病毒感染的致病机理与营养调控研究进展

腹泻是养猪业面临的世界性难题,由猪肠道病毒感染导致的仔猪腹泻更是如此。营养与动物健康关系十分密切,营养干预已是防控肠道病毒感染的重要措施。营养干预的理论基础是弄清病毒的致病机制及营养对病毒及其感染与动物康复过程的调节作用。本文在简述猪主要肠道病毒特征基础上,重点围绕免疫、细胞命运和肠道微生物等方面总结了病毒的致病机制和营养调控作用研究进展,旨在为深入认识和研究营养与猪肠道病毒的关系,开发肠道保健和抗病营养技术提供参考。     

猪热应激的营养调控研究进展

猪在夏季高温环境下易发生热应激反应，影响其生长发育、免疫性能和肠道健康。近年来，国内外学者研究聚焦于调整日粮营养水平和添加功能性饲料添加剂等措施调节猪的热休克蛋白水平、抗氧化免疫性能和肠道健康，从而缓解猪的热应激。本文综述了热应激对猪的影响及其营养调控研究进展，以期为猪的热应激营养调控提供理论依据和数据参考。     

合理调节饲料营养 降低猪群疾病的发生

适宜的营养能增强动物对疾病的抵抗力和抗应激能力,减少或消除疾病,维护动物正常的生理机能或生理状态,使动物生产性能充分发挥。因此,从营养的角度解决猪群健康问题具有重要意义。该文从饲料营养角度浅析养殖过程中如何预防和减少疾病的发生,以供大家参考和借鉴。     

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