Practice relevant rapid tests for milk progesterone in cattle compared with a laboratory-connected routine method

Four commercially available semiquantitative milk progesterone tests (Ovucheck-Praxistest: Cambridge Veterinary Science/Smith Kline), Progestassay-Milchprogesteron (Pitman-Moore/Janssen), Reprostrip-Progesteron-Schnelltest (Noctech/Albrecht), Enzygnost-Milchprogesteron (IQ, 'Bio' UK/Hoechst Veterin?r) were examined for their accuracy by using them for the determination of progesterone levels of 64 milk samples, i.e. 1556 single assays. Several test series were performed, using codified samples and changing sequences. Three or four test persons respectively, performed the tests independently and classified the samples semiquantitatively. These test results were then compared to the results acquired by measuring the progesterone levels of the same samples by means of an approved quantitative, labor-bound progesterone test (Hormonost: Biolab). These control tests were performed at a specialized routine labor, by different personnel and at a different location. Lastly, in 48 out of the 64 sampled animals the reproductive status could be evaluated clinically and was taken into account as well. Samples yielding high progesterone levels, i.e. greater than or equal to 9 ng/ml were classified correctly in 84.4 to 96.5% of the cases, whereas samples with low levels (less than or equal to 2.5 ng/ml) were classified correctly in 68.8 to 90.0% of the cases only. Samples ranging between this spectrum (greater than 2.5 less than 9 ng/ml) were classified correctly only in 42.1 to 52.6% of the cases. However, this range appears to be of the most interest for the veterinary practitioner since cows in proestrus or early interestrus tend to have mild progesterone levels within these values. On the other hand, clinical findings are often insufficient for a proper diagnosis just in these animals.(ABSTRACT TRUNCATED AT 250 WORDS)     

Recent advances in filtered-air positive-pressure (FAPP) housing for the production of disease-free chickens

Design and performance information on a filtered-air positive-pressure (FAPP) housing system for disease-free poultry flocks is presented. The system includes many special features that result in excellent biological security, easy cleanup and maintenance, efficient control of environment, and a centralized alarm in the event of problems. The system has now housed eight flocks without any major problems. Based on its performance thus far, it should be useful as a reliable housing system for disease-free poultry.     

A new virus disease of watercress in England1

In 1983 plants showing symptoms typical of watercress chlorotic leafspot agent (WCLSA) were found in Kent (GB). Later, plants showing similar symptoms were found in Dorset (1986) and Hampshire (1987), the main watercress-producing regions of England. These plants, unlike those infected with WCLSA, contained virus particles which were isometric with diameters of 37-38 nm. An antiserum to the virus was produced, with a titre in immunodiffusion tests of 1/128 and this gave good results in immunosorbent electron microscopy (ISEM) and ELISA tests on crude plant sap. Purified preparations of the virus reacted positively in ISEM and immunodiffusion tests with an antiserum to watercress yellow spot virus, a partially described virus occurring in France. Tests suggest that the crook root fungus Spongospora subterranea f.sp. nasturtii is probably the vector of this virus but other means of transmission cannot be excluded. Virus incidence within watercress beds varied, with little or no infection in the water inlet region of the bed where there are also low levels of crook root infection, higher levels in the central region and highest levels at the outlet region where crook root infection is also highest.     

Construction and Development of the Dagangshan Forest Ecosystem Research Station

Established by the former Ministry of Forestry in 1986, Dagangshan Forest Ecosystem Research Station is one of the 14 national key sites in the field of ecosystem research. In this paper, the basic situation of Dagangshan Forest Ecosystem Station is described, including geographic location, natural conditions, biological resources, research conditions, instruments, achievement, prospects etc.     

The effects of bovine growth hormone and thyroxine on growth rate and carcass measurements in lambs

The effects of bovine growth hormone (GH) and thyroxine (T4) on growth and carcass characteristics were assessed in Dorset ram lambs. Lambs in four groups (n = 10/group) were treated for 30 d as follows: controls, 3.33 mg (6 IU) GH/d (s.c.); 5-mg T4 implant (s.c.) on d 1 and a 10-mg T4 implant 21 d later; GH + T4. Blood samples were collected at 3-d intervals for analysis of GH, T4, triiodothyronine, somatomedin-C and testosterone concentrations. Six lambs/group were slaughtered for carcass measurements and composition. Daily GH injections increased (P less than .005) baseline plasma GH levels 10-fold, whereas plasma T4 concentrations were increased 10% (P less than .10) by the implants. Somatomedin-C increased with time in all groups, but the increments from d 0 to d 30 were higher (P less than .05) with GH treatment. Average daily gain (mean = 352 g/d), feed consumption and feed to gain ratio were not affected (P greater than .1) by GH or T4 treatment in ram lambs. Hot carcass weight and dressing percentage were increased (P less than .05) by T4. Growth hormone increased carcass protein content (P less than .005) and muscle weights while reducing carcass fat (P less than .05). Carcass composition was not altered by T4 alone, and the T4 x GH interaction was not significant; however, the combination of T4 and GH resulted in greater muscle and protein weight than did either hormone alone or no hormone administration. There were no differences in bone length or in the metacarpal growth plate width among groups. The beneficial effects of GH on carcass composition were not further enhanced by administration of thyroxine.