Dairy-heifer management in the Netherlands.

The objective of this study was to describe the Dutch rearing performance of dairy heifers by the evaluation of performance indices at weaning, breeding and calving. The second objective was to determine the extent to which dairy farmers use pre-set rearing targets and data monitoring for the evaluation of their rearing results. A questionnaire was sent to 3000 randomly chosen dairy cattle farmers to survey their heifer-rearing practices. Almost a third of the farmers (n=959) completed and returned the questionnaire. Of the farms responding, 29% realised an age at first calving of < or =24 months, 51% from 25 to 27 months, and 20% of > or =27 months. The farmers indicated that the average body weight after calving was within the range 525-550 kg. Average wither height class was 141-145 cm. Most farmers estimated the body-condition score of their heifers at calving to be 3-3.5. In 29% of the cases, weaning occurred at an age of < or =8 weeks, 35% at 9-10 weeks of age and 36% at > or =11 weeks of age. Most farmers (81%) commenced breeding at an age of > or =15 months. Intermediate evaluation of the rearing policy by means of performance goals and measurements was limited, and many of the reported performance indices on age and body weight were outside the range of the recommended target values. These results indicated that the common Dutch heifer-rearing management system could be improved considerably.

Cross-sectional serological survey on gastrointestinal and lung nematode infections in first and second-year replacement stock in the netherlands: relation with management practices and use of anthelmintics.

A cross-sectional survey was carried out on 86 farms randomly distributed in The Netherlands. After housing following the first and the second grazing season (FGS and SGS) serum samples were collected to determine IgG levels against Cooperia oncophora and Dictyocaulus viviparus, and the pepsinogen content. A questionnaire was used to inquire on grazing management practices and the use of anthelmintic drugs. On 80.7 and 60.2% of the farms FGS and SGS animals, respectively, were treated at least once with an anthelmintic drug. The percentage for the SGS animals indicates that the use of anthelmintic drugs in those animals has increased enormously over the last 10-15 years. Generally, parasitic nematode control in the FGS is good on most farms, but it can be characterised as being overprotective. There is a tendency that if anthelmintic drugs are used in the FGS they also are used more often in the SGS. On 12 farms (14%), no anthelmintic drugs were given in the FGS and the SGS. These farms did not differ from the others with respect to management practices in any obvious way. The serological results were in general very low, indicating low levels of exposure to gastrointestinal nematode infection in both FGS and SGS animals. This was not surprising in view of the good to high level of nematode control practices reported by the farmers. Although not statistically significant, a consistent result was that serological results for the SGS animals were more often positive or on average higher on those farms where FGS parasite control tended to be excessive. For D. viviparus, a prevalence rate of 41% positive farms was found. Following comparison with previous data, it is speculated that lungworm (sero-)prevalence in replacement stock may be declining as a result of continuing high levels of parasite control in replacement stock. It is concluded that the results confirm previous surveys, lending support to the conclusion that parasitic nematode control on Dutch dairy farms, certainly in FGS calves, is good but tends to be overprotective.

Subgrouping of bovine respiratory syncytial virus strains detected in lung tissue.

Bovine respiratory syncytial virus is an important respiratory pathogen in cattle. Recently, subgroups of BRSV have been identified, based on antigenic differences. However, little is known about subgroups of BRSV that circulate in the cattle population. Therefore, we determined the reactivity of monoclonal antibodies (mAbs), directed against the G, F, or P protein of BRSV, with lung tissue from 47 calves, that suffered from severe respiratory disease. Fourteen animals (30%) proved to be infected with BRSV, because they all reacted with mAbs against the P or F protein, as detected by fluorescent antibody tests. Monoclonal antibodies against the G protein were able to discriminate between the BRSV-positive specimens: 7 strains were identified as subgroup A strains, and 5 strains as subgroup AB, which is introduced as BRSV subgroup in this paper. Two strains could not be identified unambiguously. It is concluded that BRSV subgroup A and AB were associated with severe respiratory disease, and that strains belonging to either subgroup circulated concurrently in the cattle population in the Netherlands.

[Homeopathy and isopathy, science or faith?]. / Homeopathie en isopathie, wetenschap of geloof?

The present paper is the result of a study of the literature investigating the effectiveness of potentiated agents. The object is to supply an answer to the question of the extent to which homeopathy and isopathy have a scientific basis. The most universally accepted requirements which scientific research has to comply with having been enumerated and explained, a number of experimental studies in the fields of homeopathy and isopathy are put to the test of these requirements. An important consideration is the extent to which a scientific approach to these methods of treatment is possible. In addition, the question is asked what can be the background of the increasing popularity of this method of treatment. The conclusion emerges that the literature available does not make it possible to pass a verdict on the question whether homeopathy and isopathy are scientifically justified or not. With the possible exception of one experiment, none of the studies are up to the standards set in every respect.