代乳品能量和蛋白质水平对肉犊牛生产性能和瘤胃发酵的影响

本试验旨在筛选夏南牛与德国黄牛杂交肉犊牛适宜能量和蛋白质水平的代乳品。选取夏南牛与德国黄牛杂交新生犊牛40头,按日龄和体重相近的原则随机分为4组,每组10头犊牛,21日龄断母乳并饲喂4种不同能量和蛋白质水平的代乳品,分别为高能量高蛋白质组(HEHP组,消化能16 MJ/kg,粗蛋白质25%)、高能量低蛋白质组(HELP组,消化能16 MJ/kg,粗蛋白质22%)、低能量高蛋白质组(LEHP组,消化能14 MJ/kg,粗蛋白质25%)、低能量低蛋白质组(LELP组,消化能14 MJ/kg,粗蛋白质22%)。90日龄断代乳品,试验结束。结果发现:1)代乳品能量和蛋白质水平对犊牛(21~90日龄)的日增重有显著影响(P0.05),HEHP组(524.12 g)显著高于LELP组(432.48 g)(P0.05);2)代乳品能量和蛋白质水平对体尺的影响主要体现在胸围的发育,77和90日龄LELP组胸围显著小于HEHP组(P0.05);3)各组瘤胃液p H,乙酸、丙酸、丁酸、戊酸含量和乙酸/丙酸未出现显著性差异(P0.05),氨态氮浓度LEHP组显著高于LELP组和HELP组(P0.05),HELP组和LEHP组异丁酸含量显著高于LELP组(P0.05),LELP组异戊酸含量显著小于其他各组(P0.05)。综合得出,高能量水平(消化能16 MJ/kg)代乳品有助于肉用犊牛生长性能发挥和瘤胃发酵,高蛋白质水平(粗蛋白质25%)代乳品能为犊牛提供充足蛋白质供其吸收利用,低能量低蛋白质水平(粗蛋白质22%,消化能14 M J/kg)的代乳品不利于犊牛生长发育。     

日粮粗蛋白质及能量水平对架子牛肥育效果影响的研究

试验采用2～3岁,体重在305～350kg的架子牛,按高蛋白高能量(精料1号)、高蛋白低能量(精料2号)、低蛋白高能量(精料3号)、低蛋白低能量(精料4号)四组日粮进行为期90d的肥育。试验结果表明,当架子牛体重在320～420kg的情况下,高蛋白高能量日粮组日增重明显高于其他三组(P<0.01)。当体重超过420kg以上时,高蛋白高能量组日增重与低蛋白高能量组比较差异显著(P<0.05),与其他两组比较差异极显著(P<0.01)。从经济效益上分析,由高到低,依次为高蛋白高能量、低蛋白高能量、高蛋白低能量、低蛋白低能量。结论:架子牛肥育前期日粮(按风干计)的粗蛋白质水平应达到13.5%～14.0%,消化能在11.60～11.70MJ/kg;肥育后期粗蛋白质水平应达到12%,消化能要在11.80MJ/kg以上。     

不同代乳品及饲喂方式对荷斯坦奶公犊生产犊牛白肉影响的研究

为研究代乳粉(主要含乳类制品)液态饲喂和代乳料(主要含植物类饲料等)干喂对荷斯坦奶公犊生产犊牛白肉的影响,试验选用20头健康无病、体重和出生日期相近的荷斯坦奶公犊,随机分为2组,每组10头,进行了120 d的生长育肥试验。Ⅰ组饲喂市售的代乳粉(粗蛋白质22%,粗脂肪16%);Ⅱ组饲喂配制的代乳料(粗蛋白质22%,消化能16 MJ/kg)。结果表明:①Ⅱ组犊牛0~90 d平均日增重高于Ⅰ组犊牛,91~120 d平均日增重显著低于Ⅰ组犊牛(P< 0.05),但两组犊牛0~120 d平均日增重和试验末重均无显著差异(P> 0.05)。②不同代乳品及饲喂方式对奶公犊营养物质表观消化率均无显著影响(P> 0.05)。③Ⅰ组犊牛的胴体重、屠宰率和眼肌面积均显著高于Ⅱ组犊牛(P< 0.05),分别比Ⅱ组高11.88%、11.04%和8.12%,但两组间的胴体产肉率无显著差异(P> 0.05);两组犊牛背最长肌的pH、剪切力、蒸煮损失和肉色均无显著差异(P> 0.05),但Ⅰ组犊牛的失水率比Ⅱ组犊牛高20.83%(P< 0.01);Ⅰ组犊牛背最长肌中粗脂肪含量极显著高于Ⅱ组犊牛(P< 0.01),但两组犊牛背最长肌中水分、粗蛋白质、粗灰分、钙、磷和铁的含量均无显著差异(P> 0.05)。④Ⅱ组犊牛的饲养成本比Ⅰ组降低45.38%。综上所述,饲喂代乳料的犊牛可获得与饲喂代乳粉犊牛相似的生长性能和肉品质,显著降低饲养成本。     

营养水平对肉犊牛营养物质消化率和血清指标的影响

研究不同能量、蛋白质水平的代乳品对南方地区哺乳期肉用犊牛营养物质消化和血清指标的影响,进而确立代乳品能量和蛋白质参数,为南方地区肉犊牛的饲料配制提供数据支持。采用2×2因子设计,犊牛代乳品的能量水平为16、14 MJ/kg,粗蛋白水平为25%、22%,共计4种。选取新生犊牛40头,21日龄断母乳并根据日龄和体重一致原则分为4个处理组,每组10头犊牛,分别饲喂上述4种代乳品,于77~85日龄进行消化试验并静脉采集血液。结果显示相同能量水平,犊牛对代乳品中粗脂肪和钙的表观消化率随粗蛋白水平的升高而提高(P0.05);较低粗蛋白水平代乳品,随其能量水平的升高,粗蛋白消化率显著提升(P0.05);低能低蛋白组(DE:14 MJ/kg,CP:22%)营养物质消化率略小于其它各组。饲喂低能量水平代乳品时,随其粗蛋白水平的升高,犊牛血清中尿素氮含量显著降低(P0.05);而饲喂高能量水平代乳品时,随其粗蛋白水平的升高,犊牛血清谷草转氨酶含量显著提高(P0.05);代乳品能量和粗蛋白水平对犊牛其它血清指标均无显著影响(P0.05)。高能量水平(DE:16 MJ/kg)有助于犊牛粗蛋白质消化吸收,高蛋白水平(CP:25%)有助于犊牛对粗脂肪和钙的利用,低能低蛋白水平(DE:14 MJ/kg,CP:22%)日粮不利于犊牛营养物质消化吸收。     

饲喂代乳粉对早期断奶犊牦牛生长性能的影响及经济效益分析

为研究饲喂代乳粉对早期断奶犊牦牛生长性能的影响以及产生的经济效益,试验选用30日龄,体重(26±2.6)kg犊牛30头,随机分成3组,每组10头犊牛,每组公母各半,Ⅰ、Ⅱ组分别饲喂高蛋白含量代乳粉、高脂肪代乳粉,对照组按传统方法进行母乳喂养。结果表明:饲喂代乳粉能显著提高早期断奶犊牦牛的体增重和日增重(P0.05);饲喂代乳粉对早期断奶犊牦牛的体高、体斜长和胸围没有显著影响(P0.05);犊牦牛早期断奶能显著提高母牦牛的发情率、受胎率(P0.05),缩短牦牛生产周期,显著提升代乳粉饲喂阶段的经济效益(P0.05)。综合分析,饲喂代乳粉对早期断奶犊牦牛无论在犊牛生产性能方面还是经济效益方面都有显著效果,应在生产中推广应用。     

日粮能量、蛋白水平对辽宁绒山羊精液品质的影响

本试验以辽宁绒山羊种公羊为对象研究了日粮能量、蛋白质水平对种公羊精液品质的影响.采用单因子随机试验设计,将18只成年种公羊按照采精量、产绒量和年龄平均分为3组,每组6只.日粮设两种蛋白质水平(360 g和310 g),能量设两个水平(19 MJ和16 MJ),组合成3种饲粮:高能量高蛋白组(HEHP)、高能量低蛋白组(HELP)和低能量低蛋白组(LELP).3组种公羊分别随机对应3种饲粮.结果表明,日粮蛋白质水平显著影响采精量、密度、有效精子数和冻精产量,日粮能量水平对采精羊百分率有显著影响,日粮能量和蛋白质水平对鲜精活力和冻精活力无显著影响,高能量高蛋白组的精子产量、采精羊百分率、精子活力最高.种公羊配种期日粮能量蛋白质的适宜水平分别为19 MJ和360 g.     

饲喂水牛奶及代乳粉对水牛犊牛营养代谢及生长性能的影响

为了对比水牛奶与代乳粉对水牛生长发育及营养物质代谢的影响,试验选取初生犊牛16头,根据犊牛出生顺序依次分为对照组(8头)和试验组(8头),以克服出生时对各组产生的差异。对照组饲喂水牛奶,试验组饲喂能量水平实测值为20.35 MJ/kg的代乳粉。饲养试验从水牛犊牛7日龄之后计起,持续90 d,饲养试验期间水牛犊牛自由采食精料及饲草。饲养试验结束时,即从水牛犊牛的90日龄起从饲养试验的水牛犊牛中每组选出4头开始为期8天的消化代谢试验,消化代谢的前5天为适应期,后3天为粪尿样采集期。试验结果表明,在试验期间,两组犊牛的平均日增重分别为0.51 kg/d、0.34 kg/d,水牛奶组与代乳粉组间差异极显著(P0.01),水牛奶组的总能和总氮摄入也显著高于代乳粉组(P0.05);水牛奶组和代乳粉组犊牛对饲料能量的利用效率差异均不显著(P0.05);水牛奶组对氮的利用效率高于代乳粉组;水牛奶组的90日龄体重、胸围、腹围、胸宽和胸深显著高于代乳粉组(P0.05)。由此可知,提高饲粮的能量水平有利于水牛犊牛的能量代谢、氮代谢和生长发育。     

断奶至出栏期生长獭兔营养水平的研究

为研究断奶至出栏(5月龄)期间生长獭兔能量、粗蛋白的营养需要量,选择132只35日龄和45日龄断奶獭兔分两次试验,每次设低能量高蛋白(第1组:DE 10.97MJ/kg、CP 18.98%)、高能量高蛋白(第2组:DE11.31MJ/kg、CP 19.36%)、高能量中蛋白(第3组:DE 11.31MJ/kg、CP 17.37%)和低能量中蛋白(第4组:DE 10.72MJ/kg、CP17.40%)4个组.15～17周生长发育和被毛品质测定结果显示:①4种饲粮对断奶至出栏期獭兔的日增重无显著的影响(P＞0.05).饲粮中消化能高低对獭兔采食量有调节作用,高能量高蛋白有利于饲料利用率的提高.②高蛋白饲粮(低能量或高能量)有利于提高优质獭兔皮的比例,高能量中蛋白不利于被毛质量的提高.③断奶到出栏期獭兔饲粮含DE 10.97MJ/kg、CP 18.98%和DE11.31MJ/kg、CP 19.36%有利于獭兔被毛品质的提高.     

后备犊牛提高能量和蛋白质摄入量对乳腺发育的影响

本研究旨在确定在2~14周龄提高后备犊牛日粮能量和蛋白质摄入量是否会影响乳腺的发育。在2周龄时,将荷斯坦后备犊牛随机分为4组,采用2×2析因试验设计,即在阶段1(2~8周龄)设计2个蛋白质和能量摄入水平(中等摄入水平用M表示;高能量和蛋白质摄入水平用H表示),在阶段2(8~14周龄)设计2个蛋白质和能量摄入水平(用L表示低能量和蛋白质摄入水平;用H表示高能量和蛋白质摄入水平)。这样可保证所有4组(ML、MH、HL、HH)犊牛均可保持在平均初始体重接近。在阶段1,M组日粮由标准代乳粉(21.3%粗蛋白质、21.3%粗脂肪)和粗蛋白质水平为16.5%的谷物混合精料组成,代乳粉的摄入量按犊牛体重的1.1%进行饲喂,而谷物混合精料进行限饲,从而使犊牛日增重控制在400g。而L组犊牛在阶段2仅饲喂谷物混合精料。在阶段1,H组日粮由高蛋白质代乳粉(30.3%粗蛋白质,15.9%粗脂肪)和粗蛋白质21.3%的谷物混合精料组成,代乳粉的摄入量按犊牛体重的2%进行饲喂,而谷物混合精料进行自由采食。在阶段2,H组犊牛仅饲喂21.3%的谷物混合精料。在试验中,犊牛通过饲喂代乳粉在7周龄进行陆续断奶,并分别在8周龄(屠宰11头)和14周龄(屠宰41头)进行比较屠宰试验,从乳房的1/2,并根据距离乳头的远近距离,分别在靠近乳头的乳腺近区、中区、远区进行软组织采样,用于软组织容量、蛋白质含量、脂肪含量、DNA含量、RNA含量和外周软组织测定。总的软组织、软组织DNA、软组织RNA以及DNA浓度、RNA浓度在阶段2饲喂H组日粮的犊牛均有所增加。被乳腺上皮占据的软组织不受日粮处理影响,但是在阶段2,用Ki67作为上皮细胞增殖标记,结果表明,与阶段1中H日粮组犊牛相比,在阶段1饲喂M日粮组犊牛上皮细胞增殖较快。日粮不影响软组织中蛋白质的百分含量、RNA/DNA比率。在2~8周龄,提高日粮能量和蛋白质摄入水平则可提高软组织量和乳腺软组织中DNA和RNA的含量,而没有提高软组织中脂肪的沉积量。日粮处理同时也影响了乳腺软组织的发育和软组织下管状上皮细胞增殖。而这些变化对以后泌乳潜力的影响还不清楚。     

犊牛代乳粉对早期断奶犊牛生长发育的影响

选用出生后吃完初乳的荷斯坦母犊24头分为试验组和对照组,对照组饲喂鲜牛奶6kg/d/头,试验组饲喂代乳粉800g/d/头。结果表明:经过60d的饲喂试验,试验组比对照组多增重5.31kg(P<0.01),试验组犊牛日增重比对照组提高了88.5g(P<0.01),试验组犊牛的体高和胸围的增长速度均高于对照组。从经济效益来看,进食代乳粉组犊牛比对照组节省成本263.42元/头(鲜奶价格按2元/kg计算)。     

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.     

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 -