蛋鸡对能量和蛋白质需要与环境温度的数学模型

蛋鸡对日粮食入量、代谢能和蛋白质的需要与环境温度呈负相关。高温时,提高日粮碳水化合物含量作为采食量减少的补充能量,对保持蛋鸡高产能力无益。在25℃以内,蛋白质的需要量随温度的上升而减少,但高蛋白日粮对维持高温下的产蛋量有良好作用。气温在30℃以上,每鸡每日代谢能食入量应在240～260千卡,蛋白质16～18克。在试验温度和生产条件下,蛋鸡对代谢能量(ME)和蛋白质(CP)需要量与环境温度的数学公式分别为:ME(kcal/bird·day)=(177.38-2.42T)W_(kg)+3.65△Wg+2.1E_gCP(g/bird·day)=(0.4829-0.005376T+0.0001265T~2)E_g     

生长鸡在人工气候条件下生长发育特点的研究——Ⅰ.环境温度对生长鸡的能量和蛋白质需要的影响(1)

作者首使用国产SS—400A型人工气候粔对来航鸡中雏的营养需要与环境的关系作了研究。结果,在体重、日粮采食量、能量食入量、蛋白质食入量方面,温度间的差异显著(P<0.05),日粮蛋白水平间的差异不显著(P>0.05)。环境温度在20～25℃之间,提高日粮蛋白水平对增重无作用。30℃时,20％蛋白水平的日粮对增重有良好作用,但不能消除高温的应激影响。因此,可以认为,20℃是蛋用中雏对能量和蛋白质需要增加的环境温度的下限(阈值),25℃为上限。     

不同环境温度下日粮营养因素对蛋鸡生产性能影响的关联度分析

用星杂288蛋鸡研究了不同温度环境下(17.4～33.1℃),不同日粮营养水平对产蛋鸡生产性能的影响,并对试验数据进行了灰色关联度分析。高温显著降低产蛋量、蛋重和蛋壳厚度(P<0.01),显著提高蛋白高度和哈夫单位(P<0.05),但对蛋型指数无影响。关联度分析表明,17.4～25.2℃下影响产蛋量的主要营养因素为蛋白质食入量(CPI)与总磷食入量(TPI);29.3～33.1℃下TPI上升为首位因素,其次为CPI。影响蛋重、蛋型指数、哈夫单位和蛋白高度的主要因素为ME食入量(MEI)、饲料采食量(FI)与钙食入量(CaI);17.4～21.0℃下影响蛋壳厚度的主要因素为FI与CaI;而在25.2℃下则为MEI与FI、CaI;高温下(29.3～33.1C)日粮营养水平对蛋壳厚度无显著影响,高温为其降低的主要因素。     

在热带地区喂饲不同蛋白和能量水平的褐壳蛋用鸡的性能

用900只新母鸡(Warren Studler Sex—Sal Link),在336天产蛋期,上笼饲养,研究三种代谢能水平和每一代谢能水平又有三个蛋白水平的饲养效果(三种能量水平:2400千卡/公斤、2600千卡/公斤、2800千卡/公斤的饲粮,每一代谢能水平又有三个蛋白水平;16％、18％、20％)。饲粮蛋白水平对母鸡饲养日产蛋率、蛋重、哈呋单位,饲料采食量、饲料转化比、每打蛋的饲料成本、热能采食量、蛋的总重和最终体重,没有显著的影响。使用这三种蛋白水平的饲粮,每鸡每天消耗的蛋白量都超过20克,并且蛋白质的消耗量是随着饲粮蛋白水平的增加而显著增加。最高蛋白水平(2800千卡/公斤)组的母鸡,明显地降低了产蛋率和饲料、蛋白采食量。随着饲粮能量水平的提高,每打蛋饲料成本显著增加。中等能量水平(2600千卡/公斤)和最高能量水平(2800千卡/公斤)组的母鸡,它们对热能的采食量和最终体重相似,但与获得最低能量水平(2400千卡/公斤)组的母鸡相比,它们采食的能量和最终体重较高。饲粮能量水平对总蛋重、哈呋单位,每打蛋耗料和母鸡的死亡率,没有显著影响。尽管月平均温度是在26.8℃至35.2℃之间,产蛋率最高的组,年产蛋率可达71％至73％。这样的年产蛋率可以和温暖气候饲养的母鸡的产蛋率相匹敌。蛋重、哈呋单位与温暖地区报导的材料相近。这试验,推荐用16％蛋白和2400千卡/公斤代谢能的饲粮饲养褐壳蛋用鸡。     

岭南黄肉鸡前期日粮适宜蛋白质和能量水平的研究

试验旨在研究岭南黄肉鸡前期 (0～ 4周 )日粮适宜的蛋白质 (CP)和能量水平 (ME)。采用二因子试验 ,设计 4 (CP)× 4 (ME)共 16个处理。每处理三个重复 ,每重复 16只母雏。蛋白质水平分别为 18%、19 5 %、2 1%、2 2 5 % ,代谢能 (ME)水平分别为 11 3、11 9、12 5、13 1MJ/kg。结果表明 ,综合考虑增重和饲料报酬两个指标 ,岭南黄鸡生长前期 (0～ 4周 )日粮适宜的CP和ME水平分别为 2 1 0 %和12 5MJ/kg。     

推算鸡日粮代谢能值(AME)与氮校正代谢能值(MEN)的简易公式和方法

<正> 式中a与b按规定系分别用氧弹式热量计测定每一克风干日粮的含能量与每1克70℃烘干鸡粪尿的含能量,X与Y系在代谢试验中记录每鸡每日风干日粮平均食入量与每鸡每日70℃烘干粪尿平均排出量。AME为1公斤风干日粮中代谢能量(千卡)。     

性别、年龄和饲料对肉用仔鸡皮肤抗张强度的影响

本实验所使用的鸡,原来是在测定能量:蛋白质(E/P)比对鸡肉感官质量的影响的饲养试验所用的肉用仔鸡。用这些鸡的皮肤检查性别、年龄和饲料对肉用仔鸡皮肤抗张强度的可能影响。材料与方法材料来源公鸡从一群420只7日龄白洛克公鸡中随机选取280只,加翅标,分为6组。所用幼雏料的E/P比为120～170千卡/蛋白质(％)。自5周龄至屠宰,分别用含130～180千卡/蛋白质(％)的肥育料饲养。每组35只鸡;只有在饲养试验中用做参照的一组有105只,其饲粮为140千卡/蛋白质(％)。     

能量和蛋白质的含量对肉鸡的影响

把三种饲料(1号饲料含蛋白质25%,代谢能3140千卡/公斤;2号饲料含蛋白质22%,代谢能3360千卡/公斤;3号饲料含蛋白质22%,代谢能3140千卡/公斤)随机分配饲喂204只商品肉用仔鸡以评价其蛋白质和能量的含量对鸡体和胴体重量的影响。鸡只饲喂7周后测定日粮的消化率,并将其屠宰进行胴体测定。三种饲料并不显著地影响采食量、饲料转化率和日增重:采食量(公斤)分别为18.07、17.84、17.97,相应饲料转化率分别为1.96、1.90、2.02。喂1号料的鸡对干物质和蛋白质消化率提高。用1、2、3号     

环境温度对产蛋鸡营养需要的影响

蛋鸡的饲料食入量受季节影响,夏季减少冬季增加。为了使蛋鸡不受饲料食入量变化的影响,保持高的生产力,必须按其饲料食入量校正营养物质饲喂。作者在可控温度室条件下两次试验了环境温度对蛋鸡生产的影响。试验1的室内温度控制在7,10,15,20,25,30,和35℃,蛋鸡按16％和19％的蛋白质水平,2.54和2.99卡/克的可代谢能水平饲喂六周。蛋白质水平对产蛋量和蛋壳厚度无影响。饲料食入量(FI,克/只日)受温度(T℃)的影     

添加抗坏血酸和棕榈油对产蛋鸡生产性能的影响

在奈及利亚的 Zaria 地区的炎热季节,进行了两次试验.在5个月试验期内的最高温度范围,鸡舍内为31～39.15℃,鸡舍外为29.69～37.18℃.两次试验选用72只33周龄的“雪弗579”父母代产蛋鸡,将其逐一称重.随机置入多层鸡笼。每6只鸡设一重复组,任意挑选3个重复组喂给4种处理日粮中的一种日粮.试验Ⅰ:在配制的等氮量(含粗蛋白15.92%)和等能量(2805千卡 ME/kg)的玉米—豆饼粉型的基础日粮中,每千克分别添加0、200、400和600毫克     

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