不同应激因素对鸡产蛋率的影响及对策

蛋用鸡经雏鸡和育成鸡两个阶段的精心培育．一般于131日龄转群上笼并过渡到成鸡饲养阶段。上笼后为了减少饲料应激。可继续喂育成鸡料,经1周后改喂产蛋前期料。要求140日龄时光照这12．5小时,并于141日龄开始每周增加光照30分钟,直至每天光照达16小时。在正常情况下,母鸡于21周龄开始产蛋,产蛋率逐渐增高．当产蛋率达50％时,再改喂产蛋高峰料,于28～29周龄达产蛋高峰。优良品种产蛋高峰产蛋率可达92％～95％．持续5～6周后产蛋率以每周下降1％左右缓慢下降,产蛋白线、非常平缓,这是正常鸡群产蛋的规律。如果违反这个规律,达产蛋高…     

肉鸡不同生长时期光照模式研究

研究探索了优质肉鸡不同生长时期的最佳光照模式,以期优化生殖系统发育及全面提升生产性能。选用0日龄的优质肉鸡S3系母鸡540只,每组180只,分别针对育雏期、育成期和产蛋期设计三种不同类型的光照模式饲养于三间封闭式鸡舍内,试验期66周。结果表明:(1)14周龄时,第Ⅱ组卵巢表面开始密布着小黄卵泡和大白卵泡,至开产周龄时第Ⅱ组较第Ⅰ组和第Ⅲ组明显密集(P0.05),卵泡表面相对更为光滑;23周龄时,第Ⅱ组输卵管长度更长、管壁更厚(P0.05)。(2)整个产蛋期第Ⅱ组的产蛋率、蛋重和日产蛋量显著高于Ⅰ组和Ⅲ组(P0.05),产蛋后期Ⅰ组产蛋率开始显著低于Ⅲ组(P0.05)。整个产蛋期Ⅱ组料蛋比显著低于Ⅰ组和Ⅲ组(P0.05),死淘率高于Ⅰ组(P0.05),低于Ⅲ组(P0.05)。(3)整个产蛋期内,蛋壳强度、蛋黄重表现为Ⅰ和Ⅲ组显著小于Ⅱ组,产蛋后期蛋壳强度表现为Ⅲ组显著高于Ⅰ组(P0.05),蛋黄重表现为Ⅲ组显著低于Ⅰ组(P0.05)。(4)相关性分析表明了输卵管长与输卵管管壁厚度、最大卵泡直径和产蛋率呈极显著正相关(P0.01),与大、小黄卵泡数、蛋重等呈显著正相关(P0.05)。综合比较三组光照模式,第Ⅱ组在生殖系统发育、产蛋性能及蛋品质方面最优。     

蛋鸡产蛋量突然下降原因及对策

蛋鸡一般于17—18周龄上笼,上笼后喂给产蛋前期料,并自20周龄开始,每周增加1小时光照,直到25—27周龄时每天光照14—16小时为止,同时产蛋率达5%时将饲料改成产蛋日粮。当产蛋率达50%时,换产蛋高峰料,25—29周龄达产蛋高峰,产蛋率可达92%—95%,持续5-6周后产蛋率缓慢下降,大约每周下降1%左右,产蛋曲线非常平缓,这是正常鸡群产蛋的规律。如果,产蛋高峰前后,产蛋量突然下降,而且下降幅度很大,回升很困难,这是不正常的,必然给养鸡业带来严重的经济损失。造成产蛋量突然下降有以下几种因素:1 疾病因素鸡群感染某些疾病会使产蛋量突然下降。比如鸡群患产蛋下降综合症,一般在产蛋率达到高峰或尚未达到高峰使产蛋率由90%突然下降到10%—     

不同增钙方式对初产蛋鸡蛋品质的影响

通过研究不同增钙方式对初产蛋鸡蛋壳钙磷含量、蛋壳质量、蛋品质的影响,以确定初产蛋鸡日粮中钙的增加方式和钙的添加量。选取18周龄海兰灰商品蛋鸡480只,随机分为4组,分别在18周龄、产蛋率5%、50%、90%增加饲粮钙含量,增钙方式:Ⅰ组2.0%、2.2%、2.4%、3.75%,Ⅱ组2.0%、2.5%、3.0%、3.75%,Ⅲ组2.0%、3.0%、3.75%、3.75%,Ⅳ组2.0%、3.75%、3.75%、3.75%。结果表明:当产蛋率达50%时,蛋壳钙含量Ⅲ组显著高于Ⅰ组(P0.05),与Ⅱ、Ⅳ组间差异不显著(P0.05);蛋重、蛋壳、蛋黄、蛋白品质各组间差异不显著(P0.05);蛋壳颜色Ⅲ组最均匀。当产蛋率达90%时,蛋壳钙含量Ⅲ组显著高于Ⅰ、Ⅱ组(P0.05),但与Ⅳ组间差异不显著(P0.05);蛋壳重、蛋壳强度、蛋壳厚度Ⅲ组值最高,显著高于Ⅰ组(P0.05),与Ⅱ、Ⅳ组差异不显著(P0.05);蛋重、蛋黄颜色、蛋白高度各组间差异不显著(P0.05);蛋壳亮度Ⅲ组显著高于Ⅰ、Ⅱ、Ⅳ组(P0.05),且均匀。当蛋鸡5%、50%、90%产蛋率日粮钙水平分别为3.0%、3.75%和3.75%时,可提高蛋品质和蛋壳质量,减少鸡蛋的破损。     

大豆脂肪磷脂粉在产蛋鹌鹑日粮中的应用

选择450只132日龄的健康产蛋鹌鹑随机分为3组,每组6个重复,每重复25只鹌鹑进行了为期30d的饲养对比试验.对照组、试验Ⅰ、Ⅱ组3种日粮分别按照0%、1.5%、3.0%水平以大豆脂肪磷脂粉替代日粮中的玉米,其他日粮组成均相同.以每重复为单位分别测定各组的产蛋数、总蛋重、平均蛋重、产蛋率、平均日采食量、料蛋比、蛋黄颜色、蛋壳厚度和经济效益指标,经单因素方差分析结果表明:总蛋重、平均蛋重、料蛋比和蛋黄颜色组间差异显著(P<0.05),试验Ⅰ、Ⅱ组与对照组间差异显著(P<0.05),两处理间差异不显著(P>0.05),其中,试验Ⅰ、Ⅱ组分别较对照组改善了2.5%、4.6%(总蛋重),7.5%、5.2%(平均蛋重),5.2%、6.3%(料蛋比),35.7%、35.7%(蛋黄颜色);产蛋数、产蛋率、平均日采食量、蛋壳厚度和总经济效益组间差异不显著(P>0.05),平均产蛋率和经济效益有提高趋势,平均日采食量和蛋壳厚度有降低趋势,总经济效益试验Ⅰ、Ⅱ组分别较对照组提高了11.1%、16.3%.结论:在产蛋期鹌鹑日粮中添加1.5%～3%的大豆脂肪磷脂粉不仅可显著改善产蛋鹌鹑的产蛋性能,还能直接提高经济效益和提高蛋产品的商品性能,值得在生产中推广应用。     

产蛋鸭疑似产蛋下降综合征的诊断和综合防治

蛋鸭群发病初期症状不期显，采食和外观无异常；后期表现精神沉郁，采食量明显下降，部分蛋鸭羽毛松乱，下痢，脱肛，少数病鸭时有强直性痉挛症状，死亡率不高。特征性的主要表现为：蛋鸭开产日龄推迟，155日龄才见蛋，产蛋上升缓慢，180日龄产蛋率达45％，220日龄时产蛋率升到70％，高峰产蛋率仅为75％，已达产蛋高峰的则迅速下降到70％左右；产畸形蛋、薄壳蛋等，蛋壳表面粗糙，外面布满石灰状物。发病后期蛋小，蛋变轻；蛋壳色泽变淡，变薄、变软；蛋白、蛋黄色泽正常。常规抗菌素和抗病毒性药物治疗效果不明显。做好蛋鸭、种鸭群的产蛋下降综合征的免疫接种、强化饲养管理、加强生物安全措施和搞好环境控制，可以避免蛋鸭、种鸭群发生产蛋下降综合征，确保鸭业生产稳定和经济效益的稳定。     

蛋鸡开产前后适宜钙水平的研究

选育发育正常的１３ 周龄罗曼商品蛋鸡６００ 只， 随机分为３ 组， 每组２００ 只， 每组４ 个重复。７ 天预试期，其间调整各组鸡使组间体重差异不显著；正式期９８ 天。３ 组鸡日粮组成及营养水平和饲养条件相同，干粉料每天饲喂两次，自由采食及饮水。各组日粮钙水平随产蛋率的增加而增加。试Ⅰ组１４ ～１８ 周龄为２ ．０ ％ ，１８ 周龄～５ ％ 产蛋率为２ ．０ ％ ，５ ％ ～５０ ％ 产蛋率为３ ．４ ％ ，＞ ５０ ％ 产蛋率为３ ．４ ％ ； 试Ⅱ组四个阶段日粮钙水平分别为：０ ．９ ％ 、２ ．０ ％ 、３ ．４ ％ 及３ ．４ ％ ；对照组分别为０ ．９ ％ 、２ ．０ ％ 、２ ．０ ％ 及３ ．４ ％ 。试验期间每日观察鸡的精神状态、采食及粪便情况；每日按组别测定采食量、产蛋率等；每７ 天测一次蛋壳厚度及蛋重。结果表明：①试验期间两试验组鸡健康状况良好，对照组有２ 只鸡瘫痪。②产蛋率达５ ％ 的日龄三组间接近； 达５０ ％ 产蛋率的日龄对照组稍迟于两试验组； 达９０ ％ 产蛋率的日龄试Ⅰ组早于试Ⅱ组２ 天，早于对照组４ 天。③试验期间三组平均产蛋率分别为： ５２ ．４ ％ 、５６ ．３ ％ 及５４ ．７ ％ 、试Ⅰ组与试Ⅱ组差异显著，与对照组差异极显著，试Ⅱ组与对照组差异显著     

粪肠球菌对产蛋后期蛋鸡生产性能、蛋品质及肠道组织形态的影响

试验旨在研究添加不同剂量的粪肠球菌对产蛋后期蛋鸡生产性能、蛋品质及肠道形态结构的影响。选取70周龄产蛋率相近的海兰褐蛋鸡270只,随机分为3个处理,每个处理6个重复,每个重复15只鸡。试验设对照组(饲喂基础日粮)、试验Ⅰ组(基础日粮+3.75 mg/kg粪肠球菌)和试验Ⅱ组(基础日粮+7.5 mg/kg粪肠球菌),预试期7 d,正试期50 d。结果表明,与对照组相比,试验Ⅰ、Ⅱ组产蛋后期蛋鸡产蛋率、产蛋量极显著提高(P0.01),料蛋比极显著降低(P0.01);与对照组相比,试验Ⅰ、Ⅱ组蛋鸡的蛋壳厚度、蛋壳强度、蛋形指数、蛋白高度、哈夫单位、蛋黄相对重、蛋壳相对重均无显著变化(P0.05);与对照组相比,试验Ⅰ、Ⅱ组产蛋后期蛋鸡十二指肠、回肠的黏膜厚度极显著增加(P0.01),回肠绒毛高度显著提高(P0.05)。综上所述,在产蛋后期蛋鸡日粮中添加适宜剂量的粪肠球菌可提高蛋鸡生产性能,改善肠道形态结构。     

北京油鸡不同产蛋期鸡蛋品质分析及变化规律研究

选用北京油鸡为试验材料,在相同的饲养条件下进行饲养。分别在产蛋前期(50%产蛋率)、产蛋中期(43周龄)和产蛋后期(63周龄)进行蛋品质测定。结果表明:蛋壳强度、蛋壳厚度、蛋形指数和蛋壳比率等感官物理指标以及胆固醇等营养化学指标在不同产蛋阶段不存在显著差异,而其余指标存在显著(P0.05)或极显著(P0.01)的差异。蛋品质随着产蛋日龄的增加呈现一定的变化规律。总体而言,北京油鸡鸡蛋大小适中、蛋壳粉色、蛋黄比率高、蛋黄颜色较深,并且在卵磷脂、不饱和脂肪酸、氧化型谷胱甘肽、粗蛋白及粗脂肪等营养化学指标方面具有较高的营养价值。     

产蛋鸡非典型性新城疫并发鸡白痢沙门氏菌病的诊治

1发病情况及流行病学 山东某鸡场蛋鸡4000只于5月龄开始产蛋，7月龄产蛋率达65％，从25周龄开始发病，到32周龄达发病高峰，这期间产蛋率在50％徘徊很久，且软皮蛋和破蛋比例居高不下。     

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 -