杂种肉羊生长期蛋白质需要量及其代谢规律研究

选用 2 4只 4月龄杜泊羊与小尾寒羊杂交一代 ,采用饲养试验和消化试验 ,研究生长杂种肉羊的蛋白需要量及其代谢规律。试验分高、中、低三个蛋白水平。结果表明 :试羊对日粮蛋白质的消化率和代谢率分别为 6 6 .96 %和 34.96 %。生长肉羊代谢粪氮 (MFN)和内源尿氮 (EUN)的排出量分别为 0 .16 4 0g/kgW0 .75·d和 0 .0 997g/kgW0 .75·d。生长肉羊维持可消化粗蛋白质需要量为 2 .5 9g/kgW0 .75·d ,每增重 1kg需可消化粗蛋白 374 .98g。生长肉羊的可消化粗蛋白总需要量 (RDCP ,RCP ,g/d)可按下式计算 :　　RDCP =2 .5 9W0 .75+374 .98△W　　RCP =3.88W0 .75+5 6 0△W　　式中 :W0 .75,代谢体重 (kg) ;△W ,日增重 (kg)     

小尾寒羊泌乳期蛋白质需要量及其代谢规律的研究

选用6只小尾寒羊泌乳母羊，通过饲养试验、消化代谢试验、比较屠宰试验等手段，研究其蛋白质需要量。结果表明，小尾寒羊泌乳母羊代谢粪氮（MFN）和内源尿氮（EUN）的排出量分别为0．1312和0．13459／kg·W0.75·d。小尾寒羊泌乳期维持可消化粗蛋白需要量为1．51W0.75g／d，每产1kg奶需可消化粗蛋白829。小尾寒羊泌乳母羊的可消化粗蛋色总需要量（RDCP，g／d），可按下式求得：RDCP＝1．51W0.75＋82MP式中：W0.75——代谢体重，kg；MP——为产奶量，kg。     

7～10月龄杂交肉牛蛋白质需要量及其代谢规律的研究

选择18头健康、体重(183.58±7.89)kg的6月龄利木赞×鲁西黄牛杂交生长牛,采用饲养试验、消化代谢试验和尼龙袋试验,研究了7~10月龄生长牛的蛋白质需要量及其代谢规律。试验结果表明,本试验日粮的粗蛋白质对7~10月龄生长牛的消化率、沉积率和瘤胃降解率分别为75.93%、35.28%和56.28%。生长牛在7~10月龄时的维持粗蛋白质需要量为6.46 g/kgW0.75.d,增重的粗蛋白质需要量为463.42 g/kg。生长牛在7~10月龄时期,其粗蛋白质需要量(RCP,g/d)、可消化粗蛋白质需要量(RDCP,g/d)和瘤胃降解蛋白质需要量(RDP,g/d)可按下式计算:RCP=6.46W0.75+463.42△W;RDCP=4.91W0.75+351.87△W;RDP=2.76W0.75+198.04△W。     

育成期崂山奶山羊蛋白质需要量研究

为了研究育成期崂山奶山羊蛋白质需要量,试验采用饲养试验、消化代谢试验研究育成期崂山奶山羊蛋白质需要量及氮代谢规律,选用144日龄、体重相近[(14.57±0.32)kg]的崂山奶山羊断奶母羊30只,采用单因素设计,随机分成3个处理,每个处理10个重复,每个重复1只羊,分别饲喂能量、纤维、钙及磷水平基本一致,粗蛋白质(CP)水平分别为10.5%、13.2%和15.8%的3种饲粮。结果表明:15.8%组试验羊具有最高日增重120.86 g/d,极显著高于10.5%组(105.49 g/d),试验羊每增重1 g需要粗蛋白质0.36 g/d。育成期崂山奶山羊蛋白质需要量析因公式分别为RCP=3.27 W0.75+0.38△W、RDCP=2.43 W0.75+0.27△W,沉积蛋白=1.24W0.75+0.12△W[RCP为粗蛋白质需要量(g/d),RDCP为可消化粗蛋白质需要量(g/d),W0.75为代谢体重(kg),△W为平均日增重(g/d)]。     

贵州香猪内源氮与内源氨基酸代谢规律研究

选择3.5～4.0月龄、遗传来源相似、体重(12±2) kg的贵州从江香猪、剑白香猪去势公猪各6头,采用无氮饲粮(NFD)法和NFD+5%酶解酪蛋白(EHC)法进行代谢试验,测定贵州香猪内源氮与内源氨基酸的代谢规律,探索贵州香猪的维持蛋白质和氨基酸需要量.研究显示,贵州香猪内源氮排泄量为0.212 g/d W0.75,内源氨基酸排泄量为1.463 g/d W0.75.结果表明,贵州香猪可消化粗蛋白质维持需要量(DCPm)为1.91 g/d W0.75,可消化氨基酸维持需要量为2.10 g/d W0.75,以Lys为100建立贵州香猪维持需要可消化氨基酸模型为:Lys 100、Thr 54、Val 188、Met 40、Ile 79、Leu 126、Phe 101、His 25、Arg 58、Trp 17.     

青山羊泌乳期母羊的能量需要量研究

选用24只青山羊泌乳母羊,用饲养试验、消化代谢试验、比较屠宰试验及气体能量代谢试验等手段,研究其能量需要量。结果表明,在本试验条件下,试羊的能量表观消化率和代谢率分别为70.4％和85.0％,甲烷能占总能进食量(GEI)的9.20％。维持代谢能需要为502W~(0.75)KJ/天,每产一千克标准乳(FCM)需5060KJ泌乳代谢能。泌乳母羊的维持效率(K_m)为0.845,泌乳效率(K_1)为0.635,热增耗占GEI的14.34％。青山羊泌乳期母羊的代谢能总需要量(MERKJ/天)可按下式求得MER=502W~(0.75)+5060·FCM或:MER=502W~(0.75)+1.578NEL(式中:W~(0.75):kg;FCM:kg/天;NEL:kJ/天)。     

妊娠青山羊蛋白质需要的研究

用前列腺素处理28只5.5月龄的青山羊母羊,使之同期发情,自然交配后分为自由和限制采食两组,进行饲养试验、屠宰试验、内源氮测定试验、消化代谢试验,以研究妊娠青山羊的蛋白质需要。试验结果表明,青山羊妊娠期前三个月,内源性尿氮(Endogenous urine nitrogen,EUN)为0.105 gN/kgW~(0.75)/d,代谢性粪氮(Metabolic fecal nitrogen,MFN)为0.159 gN/kgW~(0.75)/d;妊娠期最后两个月,EUN 为0.460 gN/kgW~(0.75)/d,MFN 为0.055 gN/kgW~(0.75)/d。胚胎、胎盘和胎水中蛋白质沉积量及沉积速度和胚胎、妊娠物增重及增重速度均符合指数曲线。妊娠青山羊的蛋白质需要 Y=0.63W~(0.75)+0.58X_1+0.72X_2,其中:Y—妊娠青山羊粗蛋白每日需要量(g):W~(0.75)—代谢体重(kg);X_1—母体本身增重(g);X_2—妊娠物增重(g)。     

小尾寒羊泌乳期母羊能量需要量及代谢规律研究

选择有代表性的小尾寒羊泌乳母羊6只，分成哺育单羔和双羔两组，每组3只，分泌乳前期（1～30天），泌乳中期（31～60天）和泌乳后期（61～90天）3个阶段进行饲养试验、消化代谢试验、呼吸测热试验及屠宰试验等研究。两组试羊均按NRC（1978）推荐的绵羊泌乳期哺育双羔母羊能量需要量供给代谢能和其它养分。结果表明，在本研究条件下，小尾寒羊泌乳母羊（包括哺育单、双羔者）在整个泌乳期内的平均日干物质（DM）、有机物质（OM）、代谢能（ME）和泌乳量分别为1689g，1571g，19．893MJ和653g。DM、OM和总能（GE）表观消化率分别为70.71％，72．58％和70．34％，代谢率（MEI／DEI）为84．89％。甲烷能占GEI的9．18％。每日畜体产热量（HP）为625．5KJ／kgW0.75。研究还表明：小尾寒羊泌乳母羊的每日维持代谢能和净能需要量分别为582．6和460KJ／kgW0.75，每户1kg原乳需要10802KJ的代谢能。维持效率为0．790泌乳效率为0．479，HI占GEI的18．10％。分析结果证明，试羊的泌乳量、采食量、畜体产热量和能量转化效率在单、双羔之间均无显著差异（P＞0．05）。小尾寒羊泌乳母羊的代谢能总需要量（MER）可用下式估计：羊羔：MER＝576．9W0.75＋10810M；双羔：MER＝588．2W0.75＋10794M；平均：MER＝582．6W0.75＋1     

泌乳期崂山奶山羊适宜蛋白质需要量研究

为了明确泌乳期崂山奶山羊适宜蛋白质需要量,试验选择泌乳中期崂山奶山羊2胎母羊30只,采用单因素随机分组设计分成3组,饲喂蛋白质水平分别为11.06%、13.79%、16.56%的3种TMR日粮,定期测定体重、采食量、产奶量及乳成分。结果表明:16.56%组崂山奶山羊平均产奶量最高,13.79%组羊乳中乳蛋白量、乳脂率均高于11.06%组和16.56%组;泌乳期崂山奶山羊粗蛋白质维持需要量(RCPm)为3.37 g/(kg W0.75·d),转化为可消化粗蛋白质维持需要量(RDCPm)为2.24 g/(kg W0.75·d);泌乳期崂山奶山羊每产1 kg奶需要粗蛋白质129.70 g,可消化粗蛋白质86.42 g。     

杜泊羊生长期能量的代谢规律和需要量

本试验旨在研究杜泊羊生长期能量的代谢规律和需要量。试验采用2×3的析因试验设计,即2种性别(公羊和母羊)、3种能量水平(低、中、高)。饲养试验选取断奶后15 d杜泊羊54只,公母各占1/2,公母各分为3个处理,每个处理3个重复,每个重复3只羊;试验羊自由采食,预试期7 d,正试期60 d。消化代谢试验选取断奶后15 d杜泊羊18只,公母各占1/2,每个处理3只;预试期7 d,正试期7 d。结果表明:杜泊羊公羊的总能消化率(DE/GE)与总能代谢率(ME/GE)分别为63.07%和51.80%,母羊分别为61.59%和50.76%。代谢能需要量公式如下,公羊,ME=31.338ADG+424.728W0.75,母羊,ME=40.649ADG+406.122W0.75,杜泊羊,ME=37.201ADG+399.671W0.75[式中:ME为代谢能(kJ/d),W0.75为代谢体重(kg),ADG为平均日增重(g)]。综合得出,生长期杜泊羊公羊和母羊维持代谢能分别为424.73和406.12 kJ/kg W0.75,每克日增重代谢能需要量分别为31.34和40.65 kJ;增重需要公羊低于母羊,维持需要公羊略高于母羊。生长期杜泊羊饲粮适宜消化能水平为10.66 MJ/kg(风干基础)。     

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.     

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     

Evaluation of the Microbiological Status of Milk and Various Structures in Mammary Glands from Naturally Infected Dairy Cows

A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.     

Development and survival of free-living stages of gastrointestinal nematodes of sheep and goats on pasture in the Nigerian derived savanna

Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L₃) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L₃ developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone.