Degree of synchronous feeding behavior of two types of laying hybrid hens in battery cages with a feeder space of 12 cm per hen

There is a considerable lack of scientific evidence on the necessary feeder space with respect to the legal requirement that all hens of one battery cage must be able to feed simultaneously. Moreover it is likely that hens from different lines, differing in weight and width, have different space needs at the feeding trough. In order to ascertain the degree of simultaneous feeding in two types of laying hybrids with different weights, feeding activity was recorded in 29 cages, populated with four hens each with a feeder space of 12 cm per hen. Recordings took place over 6 days at seven feeding times under ad libitum feeding conditions. In all cages, the lighter and apparently slimmer LSL-hens (Lohmann Selected Leghorn, white) were able to feed simultaneously. However, for the somewhat heavier and apparently broader LT-hens (Lohmann Tradition, brown) this could not be observed in two of 16 cages. Nevertheless, was the average proportion of cages higher in LT-hens in which synchronous feeding of all hens could be noted at least once within each 30 minutes observation period. These were 35% of cages (LT) compared to 18% in LSL-hens (p < 0.001). Therefore, not only the physical space needs, but also possible differences in social and feeding behaviour may affect synchrony in different lines. In general, the proportion of observation time with simultaneous feeding was low (3.3% in LT, 1.7% in LSL, n.s.). As there are no comparable figures available for different feeder space allowances from the literature, an assessment of the presented data is not possible. Investigations on the synchrony of feeding behaviour in small groups of laying hens under varying environmental conditions and in different layer lines should be continued.     

Effect of far-infrared radiation on the antioxidant activity of rice hulls

After far-infrared (FIR) radiation onto rice hull, a methanolic extract was prepared for the determination of antioxidant ability. After 30 min of FIR treatment, the radical scavenging activity and total phenol contents of rice hull extracts increased from 47.74 to 79.63% and from 0.12 to 0.19 mM, respectively, compared to control. Inhibition of lipid peroxidation in extracts was also increased from 41.07 to 47.96%. According to the GC-MS analysis, more phenolic compounds (p-coumaric acid, 3-vinyl-1-oxybenzene, p-hydroxybenzaldehyde, vanillin, p-hydroxybenzoic acid, and 4,7-dihydroxyvanillic acid) were detected in FIR-irradiated rice hull extract. These results indicated that FIR radiation onto rice hull could liberate and activate covalently bound phenolic compounds that have antioxidant activities.     

Preliminary evaluation of diagnostic tests using horses experimentally infected with trypanosoma evansi

Seven surra negative horses were intravenously inoculated with 3 x 10(6)Trypanosoma evansi parasites derived from a camel. One horse was maintained as an uninfected negative control. Three antigen and three antibody detection tests were evaluated for diagnosis of infection in horses. The microhaematocrit centrifugation test (MHCT) was the most sensitive, first detecting parasites between one and three days (x 2.4) post infection (p.i.). The antigen (ag)-ELISA detected antigen between three and ten days (x 6.6) p.i. The latex agglutination test (LAT) first gave positive results on day 3 (x 3.0) p.i. Following the treatment of horses with trypanocidal drugs, the MCHT and the mouse inoculation test (MIT) became negative. Antigen levels using LAT declined and reached pre-infection levels in five out of six horses during the period of observation (92-279 days). Antigen levels using the ag-ELISA declined as well but did not reach pre-infection levels in any of the six horses.Three antibody detection techniques, ab-ELISA, card agglutination test (CATT), and immunofluorescent antibody test (IFAT) detected antibodies in the blood of all seven infected horses but not in the uninfected control. However, the ab-ELISA did not discriminate clearly between sera from infected and uninfected horses because unacceptably high ELISA background readings were detected in 15% of the surra negative horses shipped to the UAE from the UK. The ELISA antibody increased above pre-infection levels in the six horses experimentally infected, but not in one horse. In this horse the ELISA antibody level exceeded the cut-off level only after the reoccurrence of the T. evansi infection. The IFAT detected antibodies 15.7 days p.i. in all infected horses.     

Epidemiology of bovine brucellosis in Northern Ireland between 1990 and 2000

Between 1990 and 2000, 317 herds of cattle in Northern Ireland were identified as being seropositive to Brucella abortus, and 68 per cent of them were attributed to transmission from neighbouring herds or to local spread. Of particular significance were three primary outbreaks in 1997, which resulted in significant secondary and tertiary spread. Three spatial clusters were identified, corresponding to two of the primary outbreaks, and the herd density and within-herd spread were highest in the largest cluster. Abortions in an infected herd and the disease-risk status of the disclosure test were positively associated with an increased within-herd prevalence.     

Inhibitory activity of homoisoflavonoids from Caesalpinia sappan against Beauveria bassiana

Four homoisoflavonoids, 4-O-methylsappanol (1), protosappanin A (2), brazilin (3) and caeasalpin J (4), isolated from Caesalpinia sappan, were tested for inhibitory activity against Beauveria bassiana. Compound 1 showed activity against this fungus.     

Field evaluation of a PCR for the diagnosis of chlamydial abortion in sheep

A total of 94 vaginal swab samples and 195 serum samples collected from aborted ewes in 15 flocks were examined by pcr and a complement fixation test, respectively. In addition, 172 samples of stomach contents from fetuses from different flocks submitted for the diagnosis of abortion during the four lambing periods between 2000 and 2004 were tested by pcr. Chlamydial dna was detected in seven vaginal swabs obtained from five of the 15 flocks and in six samples of fetal stomach contents. The results of pcr and flock serology for Chlamydia were positive in five of the 15 flocks and negative in eight.     

子午岭地区植被演替过程中土壤养分及酶活性特征研究

选择植被自然恢复不同年限的阳坡梁坡地作为研究对象,采用时空互代法研究子午岭地区植被恢复过程中土壤养分和酶活性的变化.结果表明,植被恢复140 a内,不同土层土壤有机质含量、全氮含量、蔗糖酶活性、脲酶活性、碱性磷酸酶活性和过氧化氢酶活性增加,且表土层(0～20 cm)土壤养分含量和酶活性高于下层土壤(20～40 cm).以裸露地为对照,土壤0～20 cm土层,有机质含量、全氮含量、蔗糖酶活性、脲酶活性、碱性磷酸酶活性和过氧化氢酶活性分别增加了23.8%～534.9%、9.3%～300.0%、213.6%～521.5%、40.4%～286.5%、22.7%～232.2%和3.2%～22.4%,土壤速效磷含量呈现波动变化, 过氧化氢酶活性变化幅度比其他三种酶低.土壤有机质含量与全氮、速效磷含量密切相关;土壤蔗糖酶与土壤有机质、全氮均为极显著的相关关系(0.930/0.918);土壤脲酶活性与全氮含量相关系数最高(0.804);土壤碱性磷酸酶活性与有机质、全氮含量都呈极显著相关(0.977/0.984);土壤过氧化氢酶活性与全氮含量极显著相关,相关系数达0.996.     

Identification of the surface components of Trypanosoma evansi.

125I-labelling was used to characterise the surface components of five stocks of Trypanosoma evansi. Two components of 67 and 60.5 kD were labelled in two of the stocks, a single 60.5 kD component in two other stocks and no components in the remaining stock. These differences are probably related to the labelling method and biochemical differences between the stocks.     

DNA diagnosis in veterinary medicine: II. Polymerase chain reaction (PCR)

DNA diagnostic has become very important for genetic and infectious diseases. With a new method, called the polymerase chain reaction (PCR), specific pieces of genomes from viruses, bacteria, parasites or even cells can be amplified more than hundred million fold in a very short time period. For the following reasons this opens a new dimension in diagnostics: (1) The technique is so sensitive that a single virus, bacterium, parasite or cell is sufficient to be detected provided part of its nucleic acid sequence is known. (2) The material does neither need to be fresh nor be stored under special conditions since the nucleic acids are much more stable than e.g. enzymes or other proteins. (3) The method is quicker than the usual immunodetection methods. (4) The polymerase chain reaction has been standardized recently so that it can be carried out in diagnostic laboratories. The purpose of this minireview is to give an introduction into the basic technique and to mention possible and already existing applications in veterinary medicine.