利用牛小肠液冻干粉法研究不同加工处理玉米瘤胃非降解残渣中干物质和淀粉的小肠消化率

牛小肠液冻干粉(BIF)法是一种常用的体外法,该法利用小肠中的各种酶研究营养物质的小肠消化情况,具有较好的稳定性和可重复性。本试验进行了BIF的制备、酶活性的检测及底物用量与培养时间的优化筛选,利用BIF研究不同加工处理(膨化、制粒、压扁、烘炒)玉米在泌乳奶牛瘤胃非降解残渣中干物质(DM)和淀粉的小肠消化率。结果表明,BIF的用量为0.5g/0.5g饲料,最佳培养时间为8h。膨化玉米组的DM和淀粉的小肠消化率显著高于颗粒玉米、烘炒玉米、压扁玉米及对照玉米组(P<0.05),其他组之间差异均不显著(P>0.05),这与瘤胃中的降解情况不同,可能与玉米的不同加工处理有关;各组DM和淀粉的小肠消化率之间比较,差异均不显著(P>0.05)。从BIF培养的结果来看,小肠消化率低于文献报道的小肠淀粉消化率,可能是BIF培养的底物为瘤胃未降解的残渣,与直接通过十二指肠灌注淀粉的组成有很大的差异。     

不同处理方法对双低菜籽饼蛋白质瘤胃降解率及小肠消化率的影响

试验采用甲醛和醋酸两种方法处理双低菜籽饼,试验用瘤胃液来自成年杂交牛,体外试验测定这两种不同处理方法对双低菜籽饼蛋白质瘤胃降解率及小肠消化率的影响。结果表明,甲醛处理可显著降低双低菜籽饼蛋白质瘤胃降解率,提高UDP消化率和小肠表观真蛋白(P <0 . 0 1) ,而醋酸处理对双低菜籽饼蛋白质瘤胃降解率、UDP消化率影响不大(P >0 .0 5 ) ,但可显著提高小肠表观真蛋白(P <0. 0 5 )。     

玉米的加工处理对瘤胃液pH的影响

目前,提高淀粉消化率的研究主要是从加工处理方法对其影响的角度考虑。对玉米进行加工处理,改善淀粉在瘤胃和小肠中的降解和消化特性,从而达到优化瘤胃发酵、改善营养物质利用率、提高反刍动物生产性能,减少环境污染的目的。瘤胃内pH值是反映瘤胃内部的环境状况及饲料在瘤胃内的发酵程度和模式的主要内环境指标,本试验主要研究含不同加工处理玉米的日粮对瘤胃pH值的影响,以探讨不同玉米加工处理方法的可行性。     

不同食品加工副产品的瘤胃降解特性与小肠消化率的测定

本试验旨在测定胡麻饼(FM)、DDGS、麦麸皮(WB)、白酒糟(DG)、干啤酒糟(DBG)、苹果渣(AP)的瘤胃降解规律以及小肠消化率。试验选用3头体重为650 kg左右、安装有永久性瘤胃瘘管的荷斯坦奶牛,采用尼龙袋法测定其有机物(OM)、粗蛋白(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的瘤胃降解率以及粗蛋白(CP)和氨基酸(AA)的小肠消化率。结果表明:不同食品加工副产品常规营养成分存在差异;不同食品加工副产品的瘤胃有效降解率之间差异显著(P0.05),高低顺序为OM:WBDDGSDBGAPFMDG,CP:WBDBGFMAPDDGSDG,NDF:WBFMDDGSDBGAPDG,ADF:DBGAPFMDDGSWBDG;测定样品的CP和各种AA成分小肠消化率差异显著(P0.05),其中CP和TAA高低顺序为CP:FMDDGSWBDBGDGAP,TAA:FMDDGSDGWBDBDAP。由此可见,不同食品加工副产品的营养成分含量、瘤胃降解特性不同,为小肠提供可消化粗蛋白潜力也不同。     

移动尼龙袋法测定蛋白质饲料过瘤胃氨基酸的小肠消化率

试验测定了不同蛋白质饲料氨基酸的瘤胃降解率和瘤胃非降解残渣氨基酸的小肠消化率,旨在为建立饲料氨基酸小肠消化率数据库提供参考依据,以期指导日粮的配制。试验选用3头装有瘤胃瘘管和十二指肠瘘管的荷斯坦奶牛作为试验动物,采用瘤胃尼龙袋法和小肠尼龙袋法分别测定豆粕、葵花粕、芝麻粕、菜籽粕和棉粕的氨基酸含量、氨基酸的瘤胃降解率和小肠消化率。结果表明,不同的饲料过瘤胃氨基酸小肠消化率是不同的。同种饲料不同过瘤胃氨基酸的小肠消化率也不同。     

移动尼龙袋法测定能量饲料过瘤胃氨基酸的小肠消化率

试验测定了不同能量饲料过瘤胃氨基酸小肠消化率,旨在为建立饲料氨基酸小肠消化率数据库提供参考依据,以期指导日粮的配制。试验选用3头装有瘤胃瘘管和十二指肠瘘管的荷斯坦奶牛作为试验动物,采用移动尼龙袋法分别测定米糠饼、米糠粕、大麦、麦麸和玉米麸质饲料过瘤胃氨基酸的小肠消化率。结果表明不同能量饲料过瘤胃氨基酸小肠消化率是不同的。同种能量饲料不同过瘤胃氨基酸的小肠消化率也不同。     

不同加工工艺小麦对肉牛养分消化率、小肠消化酶活性及血清代谢产物含量的影响

本试验旨在研究不同加工工艺小麦对肉牛养分消化率、小肠消化酶活性及血清代谢产物含量的影响。试验采用4×4拉丁方设计,选取4头30月龄平均体重为(400±10)kg的利鲁杂交(利木赞牛×鲁西黄牛)阉牛,安装永久性瘤胃、十二指肠近端和回肠末端瘘管。4种饲粮分别为:粉碎小麦饲粮、破碎小麦饲粮、压片小麦饲粮和膨化小麦饲粮。共进行4期试验,每期预试期13 d,正试期3 d。结果表明:1)膨化小麦饲粮干物质、有机物、粗蛋白质、中性洗涤纤维和酸性洗涤纤维的消化率均显著高于其他处理小麦饲粮(P<0.05);小麦破碎处理和粉碎处理干物质和有机物的消化率均显著高于压片处理(P<0.05);而小麦粉碎处理中性洗涤纤维和酸性洗涤纤维的消化率则显著低于其他各处理(P<0.05)。2)小麦破碎处理显著提高了十二指肠和回肠食糜中脂肪酶和胰蛋白酶活性(P<0.05),压片处理次之;压片处理显著提高了回肠食糜淀粉酶活性(P<0.05),粉碎和破碎次之。3)不同加工工艺小麦对血清代谢产物及全血指标没有显著影响(P>0.05)。综合以上结果,对小麦进行不同加工处理,能影响肉牛养分利用率和小肠中消化酶的活性,但没有影响肉牛血清代谢产物及全血指标。     

用绵羊小肠液冻干粉测定饲料过瘤胃淀粉小肠消化率方法的研究

本试验旨在以玉米为样本筛选用绵羊小肠液冻干粉测定精饲料瘤胃非降解残渣淀粉小肠消化率的最佳培养条件。分别研究了小肠液冻干粉用量(0.2、0.3、0.4、0.5和0.6g)对16h玉米瘤胃非降解残渣干物质和淀粉小肠消化率的影响;离体培养时间(4、8、12、16、20和24h)对16h玉米瘤胃非降解残渣干物质和淀粉小肠消化率的影响。结果表明,在本试验条件下,绵羊小肠液冻干粉测定玉米瘤胃非降解残渣淀粉小肠消化率的最佳用量为0.45g小肠液冻干粉/0.56g玉米瘤胃非降解残渣,最佳培养时间为12h。利用绵羊小肠液冻干粉测定常用饲料过瘤胃残渣淀粉小肠消化率的方法是可行的。     

蛋白质补充料来源对肉牛日粮淀粉瘤胃发酵和小肠消化的影响

为了研究日粮蛋白质补充料来源对肉牛日粮淀粉瘤胃发酵和小肠消化的影响,选择体重600kg左右的荷斯坦(Holstein)公牛3头,安装瘤胃、真胃瘘管,按3×3拉丁方实验设计分别饲喂以豆粕、全脂大豆、过瘤胃蛋白质料为蛋白质补充料来源的3种不同日粮,以三氧化二铬(Cr2O3)作真胃食糜标记物,全收粪法收集粪样,测定真胃食糜和粪中的淀粉流量及在瘤胃内、真胃后段消化道(简称肠道)的表观消化率。结果表明:日粮蛋白质补充料来源对瘤胃及全消化道的淀粉表观消化率没有显著影响(P>0.05),瘤胃和全消化道淀粉的表观消化率分别为78.65%和97.19%。     

不同加工处理的玉米干物质和淀粉在绵羊瘤胃内降解规律的研究

以4头装有永久性瘤胃瘘管的内蒙古半细毛羯羊为试验动物,采用4×4拉丁方试验设计,在1.3M饲养水平上利用尼龙袋法测定了不同加工处理(制粒、烘烤、蒸汽处理)的玉米在绵羊瘤胃中干物质和淀粉的降解率。结果表明:制粒处理能明显提高干物质和淀粉在瘤胃中的降解率(P<0.01),烘烤处理能明显降低干物质和淀粉在瘤胃中的降解率(P<0.05),蒸汽处理对干物质在瘤胃中降解率无明显影响(P>0.05),但能够显著提高淀粉在瘤胃中的降解率(P<0.05)。     

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