日粮蛋白质水平对梅花鹿营养物质消化代谢的影响

试验选择4头三锯梅花鹿 ,按4×4拉丁方设计 ,进行了氮平衡试验。研究了日粮蛋白质水平对氮消化与沉积规律及血液某些相关指标的影响。结果表明 ,随着日粮蛋白质水平的提高 ,氮的进食量显著增加 ;氮的表观消化率、氮沉积量也显著增加。随着食入氮量的提高 ,血清尿素氮浓度直线上升。     

不同日粮采食水平对青年母水牛尿中嘌呤衍生物排出规律的影响研究

为了探讨青年母水牛尿中嘌呤衍生物排出量的变化规律,试验选取3头24月龄左右、体重相近的青年瘘管母水牛,采用随机区组试验设计.分别饲喂3种不同采食水平的试验日粮.结果表明:随着采食水平的降低,营养物质的表观消化率呈递增趋势(P<0.05);粪氮(P<0.01)、尿氮(P<0.05)呈递减趋势;尿中嘌呤衍生物的排出量显著降低(P<0.05),且与微生物氮估测值之间有显著的回归关系:Y=3.542 7X-25.285 0(R2=0.990 7;n=3),Y=6.209 3X+7.567 9(R2=0.990 7;n=3;P<0.05),与可消化有机物干物质采食量之间也有存在显著的线性相关:Y=6.209 3X+7.567 9(R2=0.996 1;n=3;P<0.05);肌酸酐的排出量稳定在40 mmol/d左右,各处理间无显著差异(P>0.05).     

日粮蛋白质进食量对杂交育成母牛氮代谢的影响

为研究西杂育成母牛(西门塔尔牛(♂)×中国黄牛(♀))不同蛋白质进食量的氮代谢情况,选取16头体重在350 kg左右的育成母牛随机分为4组,蛋白质进食量分别为干物质1.4、2.3、3.3、4.2 kg/d,粗饲料限制自由采食,进行消化代谢试验。结果表明:随日粮蛋白质进食量的升高可消化氮量、氮沉积量明显增加,并使尿中氮排泄量显著增加(P<0.05);育成母牛氮沉积(Y)和日粮粗蛋白进食量(X)存在显著的相关关系:Y(g/(kgW0.75.d))=49.8X(g/d)-248.8(n=16,r=0.84,P<0.05)。     

应用纤维素酶评定秸秆饲料的消化率及其影响因素的研究

应用纤维素酶+胃蛋白酶法评定了6种秸秆饲料在绵羊体内的消化率。试验结果表明:酶解的消化率(X)与体内干物质消化率(DMD),有机物消化率(OMD),和能量消化率(ED)之间有显著的相关性,求出估测方程为: 体内:DMD(％)=6.95+0.75X r=0.89(P<0.01),RSD=1.81 OMD(％)=9.39+0.80X r=0.76(P<0.05),RSD=3.25 ED(％)=0.92X-1.75 r=0.78(P<0.05).RSD=3.54 酶解法具有良好的重演性和稳定性(变异系数平均4.66％)。     

日粮不同蛋白质水平对肥育宁乡猪养分消化率和氮能代谢的影响

为了探讨日粮蛋白质水平对肥育宁乡猪营养物质消化率和氮能代谢的影响,选用平均体重为(65.0±2.5)kg的去势宁乡公猪9头,随机分为3组,每组3个重复,每个重复1头猪,饲喂蛋白质水平分别为10.41%、12.91%和15.43%的日粮,试验期为8 d,采用全收粪法.结果表明,日粮干物质和能量的表观消化率以12.91%蛋白质日粮组最高,粗蛋白质消化率随日粮蛋白质水平升高而降低(P<0.05);氮摄入量、粪氮、尿氮和总氮排出量、氮表观可消化量和氮沉积量及粪能和尿能排出量均随日粮蛋白质水平升高而升高(P<0.01),而氮的总利用率、表观消化率、代谢能及代谢能/总能随日粮蛋白质水平升高而降低(P<0.05).上述结果提示,日粮蛋白质水平影响能量和粗蛋白质的消化率、氮的沉积和排泄,宁乡猪日粮适宜蛋白质水平为12.91%.     

饲粮添加包被蛋氨酸和包被叶酸对杜寒杂交二代公羔生长性能、养分消化代谢和瘤胃微生物蛋白质合成的影响

本试验旨在研究饲粮添加包被蛋氨酸(coated methionine,CM)和包被叶酸(coated folic acid,CFA)对杜寒杂交二代公羔生长性能、养分消化代谢及瘤胃微生物蛋白质合成的影响。采用2×2完全随机试验设计,试验因素为按照试验动物体重添加CFA(0 mg,CFA-或4 mg·(kg·d)~(-1),CFA+)和CM(0 g,CM-或0.1 g·(kg·d)~(-1),CM+)。将40只体重相近((30.08±1.34) kg)的4月龄杜寒杂交二代公羔随机分为4组,分别饲喂基础日粮(CM-CFA-)、基础日粮+CFA 4 mg·(kg·d)~(-1)(CM-CFA+)、基础日粮+CM 0.1 g·(kg·d)~(-1)(CM+CFA-)、基础日粮+CFA 4 mg·(kg·d)~(-1)+CM 0.1 g·(kg·d)~(-1)(CM+CFA+)。试验期85 d,其中预试期15 d,正试期70 d,在试验期结束前10 d开展消化代谢试验。试验结果表明:1)饲粮添加CFA显著提高了1～30 d平均日增重和饲料转化率(P0.05),而添加CM仅显著提高了1～30 d饲料转化率(P=0.036),对1～30 d平均日增重无显著影响(P0.05);饲粮中添加CFA、CM显著提高了杜寒杂交二代公羔31～60 d和1～60 d平均日增重及相应阶段饲料转化率(P0.05),二者对1～60 d饲料转化率具有显著互作效应(P=0.007);2)饲粮添加CFA显著提高了干物质、有机物、中性洗涤纤维和酸性洗涤纤维的表观消化率(P0.05),饲粮添加CM有提高有机物表观消化率的趋势(P=0.066)及增加干物质消化率的趋势(P=0.095),二者对养分消化率无显著互作效应(P0.05);3)饲粮添加CFA、CM显著降低了尿能排出量,显著提高了能量消化率和代谢率(P0.05);通过显著降低粪氮、尿氮及总排泄氮(P0.05),从而显著提高了氮的表观消化率和沉积氮水平(P0.05),且二者同时添加对减少氮排泄、提高氮消化率有显著互作效应(P0.05);4)饲粮添加CM、CFA显著提高嘌呤衍生物的尿排泄量,提高瘤胃微生物蛋白质合成量(P0.05)。饲粮添加CM、CFA提高干物质和有机物表观消化率,改善总能消化率和代谢率,增加氮表观消化率和氮沉积量,促进杜寒杂交二代公羔的生长。     

不同精粗比例TMR日粮对中产奶牛氮代谢的影响

应用随机分组试验设计,将40头荷斯坦奶牛随机分为4组.Ⅰ组为对照组,Ⅱ、Ⅲ和Ⅳ组为试验组,TMR日粮精粗比例依次为50%:50%,40%:60%,35%:65%,30%:70%.研究不同精粗比例对奶牛蛋白质消化代谢的影响.结果表明:随日粮粗饲料比例增加,各组总氮采食量、粪氮、尿氮均差异不显著(P>0.05);试验Ⅱ组奶氮显著高于试验Ⅲ组和Ⅳ组(P<0.05);氮表观消化率总体呈增加趋势,其中试验Ⅱ组显著高于Ⅰ组(P<0.05);试验Ⅱ组氮表现代谢率最高,相关分析得出:氮表现代谢率(y,%)与血清尿素氮(x,mmol/L)呈极显著负相关(P<0.01):y=-5.28x+66.55,r2=0.65;氮转化率呈增加趋势,分析得出粗饲料采食量(x,kg/d)与氮转化效率(y,%)呈显著二次曲线相关(P<0.05):y=-0.063x2+1.76x+2.42,r2=0.62;氮沉积量呈增加趋势,其中试验Ⅱ组最高,当计入再循环尿素氮后,氮沉积量(y,kg/d)与氮采食量(x,kg/d)之间存在显著的线性相关(P<0.05):y=0.4x-0.06,r2=0.41.因此通过对比分析可知,TMR日粮精粗比例为40%:60%(试验Ⅱ组)最有利于蛋白质的消化代谢和利用.     

豆秸加工方式和用量对辽宁绒山羊日粮营养物质消化代谢的影响

试验选用24只2.5岁,体况良好,体重相近(36.02±1.62)kg的辽宁绒山羊公羊,采用2×3因子设计,研究了豆秸加工方式(揉搓5~7 cm,揉搓1~3 cm)和添加量(豆秸占粗饲料比例为30%、50%、70%)对辽宁绒山羊日粮营养物质消化和氮代谢的影响。结果表明:随着豆秸添加量的增加,粗饲料干物质采食量(P<0.05),NDF摄入量显著降低(P<0.01),NDF消化率(P<0.01),食入氮(P<0.01),可消化氮(P<0.01)和沉积氮显著降低(P<0.01);揉碎豆秸组氮表观消化率、氮的总利用率显著高于揉切豆秸组(P<0.05),不同加工方式的可消化氮、氮沉积和NDF消化率均无显著差异(P>0.05)。加工方式和豆秸添加量对食入氮、可消化氮的互作效应显著(P<0.01),表现为30%揉碎豆秸组的食入氮和可消化氮低于50%揉碎豆秸组。豆秸添加量的增加,降低了粗饲料干物质采食量、纤维消化率、氮沉积;揉搓粒度1~3 cm提高了氮表观消化率和氮的总利用率,但倾向于降低食入氮,对可消化氮、沉积氮和纤维物质消化率无显著影响。     

饲粮铜源及水平对育成期雄性水貂生长性能、营养物质表观消化率及氮、铜代谢的影响

本试验旨在研究饲粮铜源及水平对育成期雄性水貂生长性能、营养物质表观消化率及氮、铜代谢的影响。采用3×3+1双因素试验设计,设3种铜源(硫酸铜、碱式氯化铜、蛋氨酸铜)和3个铜添加水平(10、25、40 mg/kg),1个对照组。选择60日龄健康、体重接近的美国短毛黑雄性水貂120只,随机分成10组,每组12个重复,每个重复1只貂。预试期7 d,正试期45 d。结果表明:1)水貂的平均日采食量随饲粮铜添加水平的增加呈极显著线性增加(P0.01),并且平均日增重随饲粮铜添加水平的增加也呈线性增加(P=0.053)。2)水貂的粗脂肪表观消化率随饲粮铜添加水平的增加呈极显著线性增加(P0.01),并且粗蛋白质表观消化率随饲粮铜添加水平的增加也呈显著线性增加(P0.05)。3)水貂铜摄入量、粪铜排泄量、尿铜排泄量以及铜沉积量均随饲粮铜添加水平的增加呈极显著线性增加(P0.01),然而铜的表观吸收率却随饲粮铜添加水平的增加呈极显著线性降低(P0.01)。水貂对碱式氯化铜和蛋氨酸铜的表观吸收率极显著高于对硫酸铜的表观吸收率(P0.01)。水貂氮沉积量随饲粮铜添加水平的增加而呈显著线性增加(P0.05)。由此可见,基础饲粮中铜含量为8.05 mg/kg时,饲粮添加40 mg/kg的铜能改善育成期雄性水貂生长性能,提高水貂粗脂肪表观消化率;育成期雄性水貂对碱式氯化铜和蛋氨酸铜的表观吸收率高于对硫酸铜的表观吸收率。     

限饲对东北梅花鹿消化代谢及尿嘌呤衍生物排出量的影响

试验选取4只体况相近的3岁东北梅花鹿公鹿,采用4×4拉丁方设计,饲喂同一种日粮,分4个不同限饲水平A(2.5kg/d)、B(2.0kg/d)、C(1.5kg/d)、D(1.0kg/d),利用尿嘌呤衍生物法并结合消化代谢试验,测定限制饲喂条件下东北梅花鹿尿嘌呤衍生物组成及排出量,可消化干物质和可消化有机物进食量与尿嘌呤衍生物排出量(PD)的关系及各种营养物质消化率。试验结果表明:东北梅花鹿尿中嘌呤衍生物包括49%～56%尿囊素、35%～38%尿酸、6%～15%黄嘌呤和次黄嘌呤;限饲条件下,东北梅花鹿尿中嘌呤衍生物、肌酐酸排出量无显著性差异(P>0.05);可消化干物质DDM(Ir=0.8592,n=16,P<0.001)和可消化有机物DOMI(r=0.8605,n=16,P<0.001)与尿中嘌呤衍生物排出量(PD)均存在显著的线性正相关;限饲使可消化干物质、可消化有机物质进食量和粗蛋白消化率显著降低(P<0.05),使干物质、有机物质、中性洗涤纤维、酸性洗涤纤维及钙、磷表观消化率均显著降低(P<0.05);限饲对尿氮和粪氮排出量无显著性影响(P>0.05),而显著影响氮沉积量(P<0.05),且随饲喂量降低,氮沉积逐渐减少,当饲喂量降到D水平时,出现了氮的负平衡,表明氮的摄入量已不能满足梅花鹿维持需要,需要动用内源氮来满足自身维持需要。     

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.     

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.     

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.     

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 -