Studies on the dilution of turkey semen.

1. A series of experiments were conducted to determine the effect of diluent, holding temperature and dilution rate on the viability of turkey semen. 2. No significant difference was observed in the fertility of the undiluted controls and semen diluted with Lake's solution to a final rate of 1:4 and maintained at 25 degrees C or 5 degrees C for 30 min. Under these conditions as few as 25 million sperm per weekly insemination were needed for optimum fertility. 3. Turkey semen exhibited the typical "dilution effect", increased respiration with a corresponding decline in fertilising capacity, when diluted at rates of 1 : 8 and 1 : 12.     

Antigenicity of two turkey astrovirus isolates

Astroviruses are positive-sense single-stranded RNA viruses. These viruses cause gastroenteritis in humans and in a variety of animal species, including turkey poults. Only human astroviruses are well characterized antigenically. In the current study, two turkey astrovirus isolates, TAstV1987 and TAstV2001, were antigenically compared using cross-neutralization tests in turkey embryos, as well as cross-reactivity of the two isolates by an enzyme-linked immunosorbent assay (ELISA). The antigenic relatedness values (R) were calculated using the Archetti and Horsfall formula. The R value based on the cross-neutralization tests was 0.56%, which indicates that TAstV1987 and TAstV2001 belong to different serotypes; the R value of the two viruses based on ELISA was 70.7%, which suggests these two viruses share common antigen(s).     

全球鸭和火鸡生产现状

近年来各种禽肉产量均有不同程度的增加，其中鸭肉的增加量最大，1993—2002年间鸭肉的产量增加了近90％(从171万t增加到321万t)(表1)。同期禽肉的产量增加了53％(从4140万t增加到6340万t)。而火鸡肉产量的增加较慢，仅有27％(从408万t增加到517万t)(表2)。这期间，禽肉中鸭肉产量与火鸡肉产量之间的差异进一步缩小(从237万t减少到196万t)。     

Environment-genetic influences on immunocompetence

The immunological responses of an animal are changing continually in response to perceived environmental changes. This is because the genetic background, the lifelong environment of animals and their interaction greatly influence immunological responsiveness. An animal's genetic background influences all factors related to immunocompetence. Among these are age of onset of immunocompetence, responsiveness to specific antigens, antibody titers, type of antibody and immune response, as well as the persistence of the responses. Defense by immunity must require considerable resources, because chickens with a high antibody response are smaller and have poorer feed efficiencies than those chickens whose antibody response is lower. An increase in the effectiveness of one defensive factor may result in reduced effectiveness of another factor. For example, chickens selected for a high antibody titer response to antigen have reduced effectiveness of macrophages. Environmental stresses influence the immune response. Stress at the time of the animal's contact with antigen results in a reduced antibody response. After the antibody response begins, stress has little effect. Stress promotes the sensitization of cell-mediated immunity but inhibits its effectiveness. A short-term stressor such as weaning is followed, in about 24 h, by a short period of reduced immunocompetence, even though lymphoid mass may be reduced. Reduced immunocompetence during stressful periods can be reduced by employing adrenal blocking chemicals, or by socializing animals to their handlers.     

Clinical outbreak of Bordetella avium infection in two turkey breeder flocks

An acute upper respiratory disease was observed in two broad-breasted white (BBW) turkey primary breeder flocks. Associated clinical signs included sneezing, depression, and a deep dry cough originating from large conducting airways. Morbidity reached approximately 15-20% of the hens in an affected house. None of the turkeys died, and total feed consumption was not affected. A minimal effect upon egg production was noticed. Sera from an acutely affected flock exhibited a marked rise in titer to Bordetella avium compared with preinfection sera samples. In Case 1, B. avium was isolated in pure culture from affected birds. In Case 2, B. avium was diagnosed by serological results and clinical signs; bacteriological examination was not attempted. The findings presented here are consistent with an acute clinical outbreak of B. avium-induced turkey rhinotracheitis (turkey coryza) in BBW turkey breeder hens.     

Review on small ruminant conservation status and prospects in India

Tropical Animal Health and Production - Small ruminants always play a major role in the agricultural economy of India. They provide livelihoods to numerous small and marginal farmers. The diversity...     

植物激素对2个紫花苜蓿品种再生体系的影响

采用MS为基本培养基,附加不同浓度的2,4-D、KT和NAA,对"盛世"和"甘农4号"2个紫花苜蓿品种进行了组织培养再生体系的研究。结果表明:下胚轴是愈伤组织诱导的最佳外植体材料;2,4-D浓度增加对"甘农4号"紫花苜蓿出愈率影响不明显,但"盛世"紫花苜蓿的出愈率随着2,4-D浓度的增加呈显著升高趋势;2个品种的最佳愈伤组织诱导培养基为MS+2 mg/L 2,4-D+0.3 mg/L KT+30g/L蔗糖+7.5 g/L琼脂;最适分化培养基为MS+KT0.5 mg/L+NAA0.1 mg/L+蔗糖20 g/L;最佳诱导生根的培养基为1/2 MS+NAA0.5 mg/L。     

青贮玉米新品种的特性与推广

1 青贮玉米的优点 青贮玉米是将带棒的青绿秸秆直接制作成青贮饲料,节省了掰棒、脱粒等生产环节,跳过了粮食收购商和饲料加工厂这两大流通环节,从而节约了生产成本.此外,青贮玉米一般在玉米乳熟末期到腊熟期收获,这时玉米灌浆已经完成,籽粒的营养价值和在黄熟后收获没有显著差异,但整株的粗蛋白质、粗脂肪、可溶性碳水化合物及消化率都明显高于收获籽实后的青玉米秸秆.     

空间搭载对2个紫花苜蓿品种过氧化物酶同功酶的影响

经神州3号飞船搭载的2个紫花苜蓿品种阿尔冈金和三得利种子,种植后出现矮化植株,阿尔冈金和三得利分别选取9株和8株,利用聚丙烯酰胺凝胶垂直板电泳技术对这些单株及其对照进行过氧化物酶同工酶分析,结果表明:阿尔冈金和三得利的酶谱带数为5～7条,在相对迁移率(Rf)17.93％处,所选单株都有谱带出现,此带为2个品种的公共带;...     

遮阴对两个绿豆品种光合作用和生长发育的影响

为了确定绿豆(Phaseolus aureus)作为套种作物的适宜性,以小槐花园叶绿豆和大花叶子绿豆两个品种为试验材料,通过田间试验和盆栽试验对其耐阴能力及其机理进行了研究。测定不同遮阴处理(全光照、遮光率30%和72%)下,绿豆在初花期的叶片光合参数、叶绿素含量和光合酶(Ru BPCase)活性,研究绿豆生长发育和营养品质对弱光的响应。结果表明,在遮光30%时,大花叶子绿豆的净光合速率(P_n)、气孔导度(G_s)、蒸腾速率(T_r)、水分利用效率(WUE)和Ru BPCase活性较全光照显著下降了24%、18%、12%、13%和21%(P0.05),而小槐花园叶绿豆无显著变化(P0.05)。在遮光72%时,两种绿豆的P_n、G_s、T_r和WUE等光合参数均显著下降了约11%。在遮光30%时,大花叶子绿豆的营养生长受到显著影响而小槐花园叶绿豆无显著变化;但在遮光72%时,两种绿豆的营养生长均受到显著抑制,干物质产量比全光照降低了约34%。两种遮阴处理与全光照相比,种子产量显著降低了约37%。综上可知,小槐花园叶绿豆具有一定的耐阴能力,能耐30%的遮光,适宜作为林果行间的套种作物。     

Comparative gait analysis of two strains of turkey, Meleagris gallopavo

1. Economic requirements have encouraged farmers to select broad-breasted strains of turkeys (Meleagris gallopavo). These birds are very heavy (more than 30 kg), have pectoral hypertrophy and are frequently lame. Traditional turkeys, closer to wild birds, weigh 9 kg on average. 2. Gaits, which are motor pattern expressions, seem to be linked to species morphology. However, no significant differences are evident between the gaits of traditional and broad-breasted strains. 3. Yet, posterior views of the walk of both strains show lateral oscillations, which are very slight in the traditional one but very marked in the broad-breasted one. 4. In the latter, modification of the centre of gravity path may increase the energetic cost of walking and be associated with problems of lameness. 5. Therefore, if the genetic pool permits an increase in weight of broad-breasted turkeys, then extrinsic factors, such as gravity constraints, may limit this evolution.     

Studies on the energy and protein values of soya bean meal and two varieties of field beans using colostomised laying hens

Classical metabolisable energy values (at 90 per cent dry matter) for soya bean meal, Minor's tick bean meal and Throws MS bean meal determined in balance experiments using colostomised laying hens were 2.57, 2.47 and 2.39 kcal/g respectively. True digestibility coefficients for the crude protein of the beans were 90, 84 and 81 per cent respectively; the amino acid digestibility coefficients were generally close to those for crude protein.     

坪用草地早熟禾28个品种扩展性的比较研究

在室内盆栽和田间穴播条件下对引自欧、美等国的28个坪用草地早熟禾品种的扩展性进行了比较研究，扩展性的评价参数采用最大扩展距离（MED），实际覆盖面积（ACA），潜在覆盖面积（PCA）和分薛能力（TC），结果表明：供试品种的扩展性存在极显著差异（P＜0．01），盆栽3月龄的分薛率和分薛数品种间的变化分别为19．1％－83．5％和1．1－2．9蘖／株，田间播种当年生长季末品种间测定参数的变化值MED为27．3－63．5cm/株，ACA为240．4－930．2cm^2／株，PCA为306．6－1670．2cm^2/株，TC为245．5－567．8蘖／株，依据上述4个参数进行平均数加权聚类分析表明，供试品种的扩展性可分为最大，中等和最小3个级别，扩展性最大的品种为Baronie,Fylking,Geronimo,Julia,Mardona,Monoply等6个，中等的品种18个，如Barlin,Baron,Merit,Ram 1和Sydsport等；最小的包括Andante,Compact,Conni和Elysee4 个品种。     

赣北茶区茶树害虫种类研究(Ⅱ)

2 8　粉虱科　Ａｌｅｙｒｏｄｉｄａｅ2 8 1　黑刺粉虱　ＡｌｅｕｒｏｃａｎｔｈｕｓｓｐｉｎｉｆｅｒｕｓＱｕａｉｎｔａｎｃｅ　全区普遍 ,危害茶树叶。2 8 2　珊瑚粉虱　Ａｌｅｕｒｏｃａｎｔｈｕｓａｕｃｕｂａｅｋｕｗａｎａ　修水 ,危害茶树叶。2 9　蜡蚧科　Ｃｏｃｃｉｄａｅ2 9 1　红腊蚧　ＣｅｒｏｐｌａｓｔｅｓｃｅｎｔｒｏｒｏｓｅｕｓＣｈｅｎ　全区普遍 ,危害茶树枝、叶、果。2 9 2　日本腊蚧　ＣｅｒｏｐｌａｓｔｅｓｊａｐａｎｉｃｕｓＧｒｅｅｎ　修水 ,危害茶树枝。2 9 3　褐软蚧　Ｃｏｃｃｕｓｈｅｓｐｅｒｉｄｕ…     

Molecular characterization of the capsid gene of two serotypes of turkey astroviruses

Astrovirus infections mainly cause acute gastroenteritis in children and young animals. Human astroviruses are well characterized antigenically and genetically. However, information on turkey astroviruses is limited. We isolated two astroviruses (TAstV1987 and TAstV2001) from turkeys and classified them as two different serotypes using a virus neutralization test. To elucidate the differences between these two isolates at the molecular level, further genetic characterization and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis were carried out. The sequences of the complete capsid protein gene of these two isolates were obtained by cloning and sequencing. The percentage nucleotide and predicted amino acid identities for these two sequences along with those of 16 other capsid protein gene sequences from human and animal astroviruses retrieved from GenBank were calculated using MegAlign. The results showed that TAstV1987 and TAstV2001 had 73.3% nucleotide and 82.8% amino acid identities, respectively. An unrooted Neighbor-joining phylogenetic tree of these sequences was generated using MEGA 3 software with 1000 bootstrap replicates. The results of evolutionary analysis showed that TAstV1987 was closely related genetically to another virus, designated TAstV-2, whereas TAstV2001 was not as close to TAstV-2 as TAstV1987. The analysis of the capsid proteins of the two viruses by SDS-PAGE revealed that they had different band patterns, indicating that their capsid proteins consisted of different viral proteins. The findings in this study revealed the molecular differences in the capsid protein gene of TAstV1987 and TAstV2001, which may provide the molecular basis of the antigenic differences between these two serotypes of turkey astroviruses.     

Serological investigations on reticuloendotheliosis in turkey flocks

Four meat turkey and one turkey breeding flocks were surveyed for antibodies against reticuloendotheliosis virus (REV) at different intervals using commercial enzyme-linked immunosorbent assays. In addition, serum samples collected from 18 flocks at different ages were also tested for antibodies against REV. No antibodies were detected in any of the four meat turkey flocks that were surveyed. In the breeder flock, 20%) of tested samples from 1-day-old poults were positive. Between the fourth and 12th weeks all samples that were tested yielded negative results. At 16 weeks of age 15% of samples yielded a positive reaction, but antibodies could not be detected 4 weeks later. Examination of serum samples from 18 different flocks at various ages revealed that antibodies could be detected in five flocks. The percentage of positive sera per flock ranged between 10 and 40%.