鸡舍真菌气溶胶潜在危害的定量评估

本文采用6级Andersen生物空气采样器和常用真菌计数培养基,在鸡舍入口处收集气溶胶真菌,经培养和纯化鉴定出78种真菌,其中包括黄曲霉、烟曲霉、黑曲霉及镰刀菌等在内的50余种真菌.研究表明鸡舍入口处空气真菌污染程度与鸡舍内没有显著差异.早晨气溶胶真菌浓度明显低于中午(P=0.07)和晚间(P=0.05)的浓度,且夏秋季节浓度相对较高,峰值在7月份.鸡舍内气溶胶真菌的年平均浓度为2.3×103 CFU/m3.黄曲霉、烟曲霉、黑曲霉在鸡舍空气中的浓度相对较高,分别超过真菌气溶胶组成平均浓度77.7 CFU/m3、63CFU/m3、57.1 CFU/m3,而镰刀菌是常见的空气真菌,其总平均浓度为74.6 CFU/m3,比平均值高出45.3 CFU/m3.平均CMD值分别为3.1μm;GSD分别为2.1.每分钟可沉积到支气管和直接侵入肺泡的活性真菌量分别是居室的3.4倍和3.3倍.本研究探讨了真菌气溶胶不同时间和季节的变化规律,并从其组成、浓度及粒子大小定量评估采样点鸡舍真菌气溶胶的危害,为有效控制禽类真菌病的流行提供科学依据和预警资料.     

鸡舍气溶胶真菌的种类及浓度动态

为评估鸡舍空气的卫生质量,用Andersen-6级采样器采集鸡舍空气样本,计算各级培养基的菌落总数,分析真菌气溶胶颗粒大小和浓度,用ITS基因序列分析结合形态学的方法对分离菌株进行鉴定。结果显示:鸡舍气溶胶真菌浓度与季节、养殖模式、日龄和品种有关,其气溶胶真菌浓度在夏季、秋季、冬季和春季由高到低依次为(1.78±0.26)×103,(1.43±0.2 2)×103,(1.31±0.31)×103,(1.06±0.22)×103 CFU/m3。在不同的养殖模式中,地下最高,为(1.50±0.36)×103 CFU/m3;半封闭最低,为(0.98±0.25)×103 CFU/m3;封闭介于两者之间,为(1.04±0.14)×103 CFU/m3。肉鸡舍(3.12±0.48)×103 CFU/m3明显高于蛋鸡舍(0.98±0.11)×103 CFU/m3,并随日龄的增加而提高。在真菌气溶胶颗粒中,C-F级(0.65~4.70μm)颗粒占88%。获得26 703菌落,分离出153个菌株,鉴定出13个属,25种真菌;优势菌属为曲霉菌属(37株)和青霉菌属(44株),占菌落总数的52.93%(81/153);优势菌种为芽枝状枝孢菌(16株)、黑曲霉(15株)、草酸青霉(12株)、黄曲霉(10株)和链格孢(10株)。分离烟曲霉和热带念珠菌2种常见致病菌。这对鸡舍气溶胶真菌浓度、种类和颗粒大小有了一个全面的认识,为评估环境质量奠定基础,对环境卫生控制有指导意义。     

笼养肉鸡舍内空气微生物气溶胶的研究

为评估笼养鸡舍环境卫生质量及推断微生物气溶胶对饲养人员及肉鸡可能造成的危害,本试验采用FA-1型六级筛孔撞击式空气微生物采样器分别对3个笼养肉鸡场鸡舍环境中气载需氧菌、气载大肠杆菌、气载金黄色葡萄球菌、气载真菌气溶胶的含量进行检测,并对其气溶胶粒子分布情况进行分析。结果表明:鸡舍环境中气载需氧菌浓度可达21.4×10~3 CFU/m~3,气载大肠杆菌浓度可达0.71×10~3 CFU/m~3,气载金黄色葡萄球菌浓度均值可达2.52×10~3 CFU/m~3,气载真菌浓度可达7.28×10~3 CFU/m~3;鸡舍内环境气载需氧菌在FA-1型六级筛孔撞击式空气微生物采样器第1层级分布比例显著高于其他层级(P0.05),气载大肠杆菌在第4层级分布比例显著高于其他层级(P0.05),气载金黄色葡萄球菌在第5层级分布比例显著高于其他层级(P0.05),气载真菌在第4层级分布比例显著高于其他层级(P0.05)。     

养殖环境真菌气溶胶的研究

用Andersen-6级采样器、虎红氯霉素琼脂(RBC)在养殖环境采样,培养后分级计数,按形态学鉴定,并进行空气动力学分析.结果共捕获活性真菌粒子7.77×103CFU.鸡、猪、兔、牛舍气溶胶真菌浓度分别为2.39×103CFU/m3、2.51×103CFU/m3、1.76×103CFU/m3和1.66×103CFU/m3;平均CMD值分别为3.02μm、3.52 μm、3.29 μm和3.39 μm;GSD分别为2.03、1.71、1.70和1.69.养殖环境中每分钟可沉积到支气管、直接侵入肺泡和极细粒子的活性真菌量分别是居室的3.4倍、1.4倍和1.9倍;鉴定出21个属,各采样点优势菌群主要有曲霉属、青霉属、链格孢属、枝孢霉属、镰刀菌属等.表明所测养殖环境活性真菌粒子浓度高于原野或居室环境,且其浓度可以通过采用开放式或半开放式结构、合理降低饲养密度及调整舍内温湿度等人为措施来控制;真菌粒子比细菌更易进入呼吸道深部;养殖环境优势真菌属与真菌感染及毒素中毒密切相关.     

养殖环境真菌气溶胶的研究

用Andersen-6级采样器、虎红氯霉素琼脂(RBC)在养殖环境采样,培养后分级计数,按形态学鉴定,并进行空气动力学分析。结果共捕获活性真菌粒子7．77×103CFU。鸡、猪、兔、牛舍气溶胶真菌浓度分别为2．39×103CFU/m3、2．51×103CFU/m3、1．76×103CFU/m3和 1．66×103CFU/m3;平均CMD值分别为3．02 μm、3．52 μm、3．29 μm和3．39 μm;GSD分别为2．03、1．71、1．70和1．69。养殖环境中每分钟可沉积到支气管、直接侵入肺泡和极细粒子的活性真菌量分别是居室的3．4倍、1．4倍和1．9倍;鉴定出21个属,各采样点优势菌群主要有曲霉属、青霉属、链格孢属、枝孢霉属、镰刀菌属等。表明所测养殖环境活性真菌粒子浓度高于原野或居室环境,且其浓度可以通过采用开放式或半开放式结构、合理降低饲养密度及调整舍内温湿度等人为措施来控制;真菌粒子比细菌更易进入呼吸道深部;养殖环境优势真菌属与真菌感染及毒素中毒密切相关。     

冬季大棚养鸭模式中微生物气溶胶对肉鸭应激和生产性能的影响

本研究通过评估不同饲养卫生清洁状况下微生物气溶胶的浓度对肉鸭生产性能的影响,为建立家禽养殖环境微生物气溶胶标准提供参考。选用600只1日龄的樱桃谷肉鸭,随机平均分配到1个对照组(A组)和4个清洁卫生条件逐步变差的试验组(B、C、D、E组),每组3个重复,每个重复40只。使用国际标准的Andersen-6级和AGI-30空气微生物采集器收集各组空气样品,检测微生物气溶胶浓度。检测鸭血清促肾上腺皮质激素(ACTH)浓度变化,评估其应激强度。与此相应地对肉鸭生长性能、屠宰指标等进行检测与评定,分析微生物气溶胶对肉鸭机体的影响。结果显示:当肉鸭舍的微生物气溶胶浓度升高至气载需氧菌为2.96×105CFU/m3、气载真菌为2.63×104CFU/m3、气载革兰氏阴性菌为3.09×104CFU/m3、气载内毒素为41.78×103EU/m3时(D组),该组肉鸭的血清ACTH浓度、料重比、死淘率显著或极显著高于对照组(P0.05或P0.01),该组肉鸭的平均日增重、胸肌率、胸肌重、屠宰率、屠体重显著或极显著低于对照组(P0.05或P0.01)。由此可见,微生物气溶胶可显著降低肉鸭的生产性能,气载需氧菌2.96×105CFU/m3、气载真菌2.63×104CFU/m3、气载革兰氏阴性菌3.09×104CFU/m3、气载内毒素41.78×103EU/m3可初步作为肉鸭养殖环境中的微生物气溶胶上限标准。     

兔舍环境空气微生物气溶胶的检测

采用国际标准ANDERSEN6级微生物空气样品收集器,选用血葡萄糖琼脂培养基,分别对两个不同种兔舍环境空气微生物进行监测。其舍内需氧菌含量分别为4.19×103～5.55×104CFU/m3、6.35×103CFU/m3空气,需氧革兰氏阴性细菌含量分别为3.04×102～3.27×103CFU/m3、4.68×102CFU/m3空气。根据微生物气溶胶颗粒在ANDERSEN-收集器不同层级上的分布情况得知,约有50%的需氧细菌气溶胶颗粒和革兰氏阴性细菌气溶胶颗粒分布在3、4层上,空气动力学直径(Dae50)在2～6μm之间,它们能进入人、畜的气管、支气管,甚至细支气管,对饲养员和动物的呼吸道构成严重威胁。     

鼠李糖乳杆菌对四种霉菌生长的抑制作用

为了探索鼠李糖乳杆菌对黄曲霉、黑曲霉、串珠镰刀菌和禾谷镰刀菌的抑制效果,试验将鼠李糖乳杆菌与黄曲霉、黑曲霉、串珠镰刀菌和禾谷镰刀菌共同培养,测定其抑菌面积、菌丝生长和孢子萌发率。结果表明:鼠李糖乳杆菌在48~72 h对4种霉菌的抑制面积逐渐下降;上清液组黄曲霉、黑曲霉和禾谷镰刀菌的孢子萌发率与对照组相比分别减少了41.70%、26.79%和30.68%(P0.01),全菌液组黄曲霉、黑曲霉、串珠镰刀菌和禾谷镰刀菌的孢子萌发率与对照组相比分别减少了93.48%、17.30%、29.01%和17.54%(P0.01),全菌液组黄曲霉和串珠镰刀菌的孢子萌发率与上清组相比分别减少了51.78%和29.54%(P0.01),上清液组黑曲霉和禾谷镰刀菌的孢子萌发率与全菌液组相比分别减少了9.49%和13.14%(P0.01或P0.05);48小时时上清液对黑曲霉和串珠镰刀菌菌丝生长的抑制效果优于黄曲霉和禾谷镰刀菌,全菌液对4种霉菌菌丝生长均有明显的抑制作用。说明鼠李糖乳杆菌对霉菌生长具有较好的抑制作用,对黄曲霉和串珠镰刀菌的抑制效果较好,全菌液的抑菌效果优于上清液或沉淀。     

霉菌毒素对生猪生产的影响及防治

真菌在自然界中广泛存在,且种类繁多。导致动物中毒的常见霉菌毒素有：曲霉菌属的黄曲霉、烟曲霉等;镰刀菌属的禾谷镰刀菌、三线镰刀菌、雪腐镰刀菌等;青霉菌属的黄绿青霉、桔青霉等。霉菌的适宜生长温度为20～30℃。在80%～90%的湿度环境下，     

培养法和染色法对养殖环境中微生物气溶胶浓度的检测

比较不同检测方法对微生物气溶胶检验效果的影响。采用国际标准的AGI-30空气采样器,收集空气样品,分别用培养计数法和DAPI(4,6-联脒-2-苯基吲哚)染色计数法来比较不同养殖环境中微生物气溶胶的浓度。培养计数法测得鸡舍、猪舍和牛舍环境中微生物气溶胶的浓度分别为5.73×105～6.72×106cfu/m3空气,9.5×105～4.01×106cfu/m3空气,5.4×104～8.33×105cfu/m3空气,而DAPI染色计数的浓度分别为8.0×106～3.25×108cell/m3空气,1.5×107～2.28×108cell/m3空气,9.0×105～5.93×107cell/m3空气。培养计数法所得浓度仅为DAPI染色计数法的0.04%～10.4%。染色计数法可能会更加客观的反映环境中微生物气溶胶的浓度。     

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.     

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.     

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.     

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.     

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.     

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.