中草药饲料添加剂—蛋壳素对蛋鸡产蛋性能及蛋壳质量的影响

试验选用正在产蛋的800只罗曼鸡群，分组饲喂中草药饲料添加剂-蛋壳素，对生产性能进行测定。试验结果表明，在罗曼产蛋粮中添加0.02%的蛋壳素与对照组（不添加蛋壳素组）比较：（1）产蛋量提高6.41%-6.5%;(2)平均蛋重每枚增加0.55-1.1g。（3）破蛋率降低2.5%;(4)饲料转化率提高6.9%-7.28%。另外，蛋壳表面光滑，鲜艳，无沙皮蛋。     

低聚木糖对产蛋后期蛋鸡生产性能及蛋壳品质的影响

为研究在产蛋后期蛋鸡日粮中添加0.025%低聚木糖对蛋鸡生产性能及蛋品质的影响,试验选择427日龄(61周龄)健康罗曼粉商品蛋鸡420只,随机分成2个处理,每个处理7个重复,分别饲喂基础日粮和添加0.025%低聚木糖的试验日粮。试验持续16周(63~78周龄)。结果:低聚木糖组产蛋率比对照组平均提高2.12%(P0.05),料蛋比比对照组平均下降3.74%(P0.01),采食量、产蛋量及蛋重无显著差异。试验组蛋壳强度、蛋白高度和哈夫单位均显著高于对照组(P0.01),分别比对照组提高6.05%、12.43%和9.66%。试验表明:产蛋后期蛋鸡日粮中添加0.025%低聚木糖可显著提高蛋鸡产蛋率和产蛋量,降低料蛋比,提高饲料利用率,还可改善产蛋后期的鸡蛋品质。     

氨基葡萄糖对开产蛋鸡生产性能、蛋品质和蛋壳质量的影响

试验旨在探讨氨基葡萄糖(GlcN)对开产蛋鸡生产性能、蛋品质及蛋壳质量的影响。挑选120日龄、产蛋率为50%的开产罗曼蛋鸡600只,随机分为4个处理组,每处理10个重复,每重复15只鸡。各组试鸡分别采食添加0%、0.2%、0.4%、0.6%GlcN日粮。预试期7 d,正试期30 d。结果表明:与对照组相比,日粮中添加0.4%和0.6%GlcN促进蛋鸡采食(P<0.05),0.6%GlcN组可提高蛋鸡产蛋率、增加蛋重(P<0.05);日粮中添加0.2%和0.6%GlcN可改善蛋鸡饲料转化效率(P<0.05);0.4%和0.6%GlcN组可增加鸡蛋蛋白高度(P<0.01),提高哈氏单位(P<0.05);0.6%GlcN组增加了蛋壳钙含量(P<0.01);0.6%GlcN组提高了蛋壳磷含量(P<0.01),但0.2%GlcN和0.6%GlcN组蛋壳比例降低(P<0.01),而GlcN对蛋壳强度、蛋壳重和蛋壳厚度无显著性影响。综上所述,在蛋鸡开产阶段添加适量GlcN能提高开产蛋鸡生产性能和蛋品质,增加蛋壳钙、磷含量,且0.6%GlcN为适宜添加量。     

提高蛋壳强度的途径

增强蛋壳的质地,减少鸡蛋的破损,和增加产蛋一样,具有重要的经济意义。现介绍几种提高蛋壳强度的方法,供参考。饲料中添加锰。美国研究人员证明在鸡的饲料中添加锰(硫酸锰),就能使母鸡下坚壳蛋。每千克饲料加1.8克锰,就可使蛋壳的强度大为提高。饮水中添加乳酸钙。西德研究人员研究出预防母鸡下畸形蛋、软壳蛋的方法。他们     

用小苏打提高蛋鸡产量和蛋壳硬度

英国皇家化学工业研究人员新近试验研究证实,蛋鸡日粮中添加小苏打有以下三个作用:1、增加蛋壳硬度,减少次品蛋;2、提高产蛋量;3.提高日粮蛋白质的利用率。试验中每吨蛋鸡饲料中添加1～5千克的小苏打可使次品蛋减少1～2％。钾离子、钠离子和氯离子之间的平衡在决定蛋鸡生产性能方面具有重要作用。钠离子和氯离子的平衡只能通过使用含钠的非氯化物如小苏打(碳酸氢钠)来实现。钠离子对维持产蛋也是必不可少的。饲料中添加小苏打可保证血液中钠离子的浓度至足够的水平有利于蛋壳的形成。磷的含量对蛋壳质量也有一定的作用,日粮中添加高质量的小苏     

提高蛋壳质量的综合技术措施

随着集约化、规模化养鸡的迅猛发展,因蛋壳质量不佳而造成的经济损失显得尤为突出,蛋壳质量已成为生产中迫切需要解决的问题,并越来越多地受到养鸡业的重视。一完善饲料营养1日粮中保持适当的钙含量产蛋鸡需要大量的钙来形成蛋壳,当日粮中缺钙就会产薄壳蛋或软壳蛋。一只鸡每天采食50～75克饲料,鸡对饲料中钙的利用率仅为60%。所以,日粮中钙含量应该为3.3%～4%,鸡饲料中添加粉碎粒径为8～12目的海产粗贝壳粉或优质石灰石碎粒,效果很好。2保持饲料适当的钙磷比例钙是构成蛋壳的重要营养成分,钙决定蛋壳的脆性,磷决定蛋壳的韧性和弹性。试验证…     

关于蛋壳质量问题的新认识

蛋壳破损给产蛋业造成巨大经济损失。据美国加州大学的调查，从养禽产蛋到消费者手中，禽蛋的破损率为６％～８％，有时可超过１０％。美国产蛋业每年破损蛋的损失达２．４７～４．７８亿美元。调查表明，破损蛋７５％污染有沙门氏菌，而未破的被污染不足４％。研究者认为，蛋壳易破可能不是由于饲料中微量元素短缺，而是它们的生物效价过低。大多数营养学家相信，有机形式的微量元素如各种螯合物，比无机矿物质的硫酸盐，更易被吸收。可克服商品蛋鸡的蛋壳易破问题。试验证明，添加生物螯合物矿物剂与不添加的对照组相比，蛋壳易破组的蛋壳…     

鲎素抗菌肽对蛋鸡产蛋后期蛋品质及蛋壳超微结构的影响

旨在探索鲎素抗菌肽对海兰褐蛋鸡产蛋后期蛋品质及子宫CaBP-D28k mRNA表达量的影响及其机理探讨。随机选取600只385日龄海兰褐蛋鸡,分为对照组、试验组,每组各3个重复,每个重复100只鸡。对照组饲喂基础日粮,试验组在基础日粮中添加鲎素抗菌肽,鲎素抗菌肽发酵液最适添加剂量为0.01 L/kg,按饲料所需量配比添加,预饲期7 d,试验期35 d。结果显示,与对照组相比,试验组产蛋率提高8.86%(P0.05),料蛋比、破蛋率分别降低2.68%和12.76%(P0.05);试验组蛋壳强度比对照组提高了18.97%(P0.05),哈氏单位、蛋壳相对质量和蛋壳厚度均有上升的趋势;试验组蛋壳表面皴裂纹数较少,裂隙变小,纵切面结构中垂直晶体层完整,栅栏层结构整齐,上下层面平滑,栅栏层气孔数量少,乳头层乳头数目少且宽;试验组蛋鸡子宫内CaBP-D28k mRNA表达水平显著提升(P0.01)。可见,鲎素抗菌肽可提高CaBP-D28k参与产蛋过程中钙的代谢过程,调控蛋鸡体内钙代谢发挥功能作用。     

博落回散对蛋鸡产蛋后期生产性能的影响

本试验旨在研究蛋鸡产蛋后期使用博落回散对其生产性能的影响。试验采用单因子随机分组设计,选取8 000只60周龄的产蛋后期罗曼粉壳蛋鸡,随机分为2个组,每组4个重复,每个重复1 000只,正试期12周。本试验采用玉米-豆粕型粉状日粮,试验组在对照组日粮基础上添加300 mg/kg博落回散（有效成分含量0.375%）。结果表明：蛋鸡产蛋后期日粮中添加300 mg/kg博落回散,产蛋率显著提高3.99%(P<0.05),料蛋比、破蛋率及死亡率分别显著下降3.50%、22.74%和32.10%(P<0.05);在蛋壳质量等级方面,一级和二级蛋壳鸡蛋分别显著提高30.34%、24.60%(P<0.05),三级蛋壳鸡蛋极显著降低37.03%(P<0.01)。由此可见,在产蛋后期日粮中添加300 mg/kg的博落回散能有效改善蛋鸡生产性能,提升蛋壳质量。     

微量元素对蛋壳品质的影响

在工厂化生产条件下,增强蛋壳强度是十分重要的问题。饲养制度、日粮组成以及一些其他因素均会影响蛋壳强度。在研究中曾多次发现,日粮中按每公斤饲料添加60～100毫克锰对产蛋母鸡的产蛋力、蛋的孵化品质以及蛋壳强度均有良好影响。锰和其他微量元素,如锌、铜、氟、钛等对蛋壳基质的形成或蛋壳矿物部分均有影响。作者研究了微量元素(锰、锌、钴、碘)在不同     

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