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Biomedical subjects

F J Grommers

Publications and source records attributed to F J Grommers.

At least 19 recordsLinked to original sources
PubMed1997

The effect of discontinuation of postmilking teat disinfection in low somatic cell count herds. I. Incidence of clinical mastitis.

Results are described of a split-udder trial on the effect of discontinuation of postmilking teat disinfection on the incidence of clinical mastitis in seven dairy herds with a low bulk milk somatic cell count and a high incidence of clinical mastitis. Overall incidence of clinical mastitis was non-significantly lower (18%), whereas the incidence of the most prevalent pathogen associated with clinical mastitis, Escherichia coli, was significantly lower in quarters for which postmilking teat disinfection was discontinued. We concluded that discontinuation of postmilking teat disinfection may decrease the incidence of clinical Escherichia coli mastitis in herds for which standard mastitis prevention measures are executed adequately, bulk milk somatic cell count is low, and incidence of clinical mastitis is high. However, because an increase in intramammary infections with contagious pathogens may occur, care is recommended when advising discontinuation of postmilking teat disinfection.

Animals↗
PubMed1997

The effect of discontinuation of postmilking teat disinfection in low somatic cell count herds. II. Dynamics of intramammary infections.

Results of a 20 month split-udder trial on the effect of discontinuation of postmilking teat disinfection on intramammary infections (IMI) with major and minor pathogens in seven dairy herds with a low somatic cell count are described. The incidence of Escherichia coli IMI was found to be significantly lower, whereas the incidence of IMI with Staphylococcus aureus and minor pathogens was significantly higher in quarters for which postmilking teat disinfection was discontinued than in disinfected quarters. It was concluded that discontinuation of postmilking teat disinfection decreased the incidence of E. coli IMI, accompanied by a, from a practical point of view, acceptable rise in somatic cell count. However, the possible increase in the incidence of S. aureus IMI calls for careful monitoring of the dynamics of IMI with contagious pathogens, when postmilking teat disinfection is discontinued in an attempt to reduce E. coli mastitis.

Animals↗
PubMed1997

Effect of natural infection with minor pathogens on susceptibility to natural infection with major pathogens in the bovine mammary gland.

OBJECTIVE: To evaluate the effect of natural udder infection with minor pathogens on subsequent natural infection with major pathogens. SAMPLE POPULATION: 7 dairy herds with low bulk milk somatic cell count. PROCEDURE: During a 20-month prospective study, milk samples were collected from diary cows at regular intervals and from quarters with clinical signs of mastitis. Incidence of intramammary infection was calculated in uninfected quarters and in quarters infected with minor pathogens. A within-cow, matched case-control analysis was used to evaluate the effect of minor pathogens on subsequent infection with major pathogens. RESULTS: Quarters infected with minor pathogens had higher somatic cell count than did uninfected quarters. In quarters infected with Corynebacterium bovis, the rate of infection with major pathogens was lower, whereas in quarters infected with coagulase-negative Micrococcaceae, the rate of infection with major pathogens was higher than that in uninfected quarters. From the within-cow comparison, it appeared that, in quarters infected with minor pathogens, infection with major pathogens was significantly lower than that in comparable control quarters not infected with minor pathogens. CONCLUSIONS: Minor pathogens have a protective effect against infection with major pathogens. The protective effect of C bovis against subsequent infection with major pathogens appears to be greater than the effect of coagulase-negative Micrococcaceae.

Animals↗
PubMed1996

[Growth promotors in animal husbandry: between fancy and fact].

The use of growth promotors, such as steroid hormones, beta-agonists and somatotropins, may result in animal health and welfare risks and raise ethical questions. From this point of view some fundamental statements are discussed. Growth promotors do not contribute to an efficient production of essential nutritional needs for man. There is a need for a consistent policy aiming at sustainable agriculture and world food supply. Animal husbandry cannot be regarded as a simple technical-economical enterprise because of the intrinsic biological values involved. If growth promotors are almost exclusively judged on safety criteria than questions of principle are avoided. The choice to use growth promotors cannot be left to self-regulation based on self-interest and/or be made subject to international trade agreements governed by economic considerations only. In the production of food the price for the protection of the environment and the animals ought to be paid. It is time to make future oriented choices.

Animal Husbandry↗
PubMed1995

[Well-being--intrinsic value--integrity. Developments in the reevaluation of the domesticated animal].

Owing to selective breeding and conditioning to husbandry methods, domestication has resulted in modification of the anatomy, physiology, and behaviour of animals. Nevertheless, domestic animals cannot be regarded and treated as artificial products. Public interest and concern about the welfare of domestic animals has led to the recognition of the intrinsic value of animals and, in extension of this, to the ethical principle of respect for the integrity of animals. The sensibility and acceptance of these principles by those involved in ethical decision-making depends on their fundamental views about humans and the living world. In order to make judgements about the use of, and interference with, animals, it is desirable to clarify these personal views. The principle of respect for the integrity of animals leads to considerations and arguments beyond animal health and welfare. This is shown by three examples: declawing of cats, caesarean section in cattle, and laying hens in battery cages.

Animal Welfare↗
PubMed1995

[Subclinical and clinical mastitis on dairy farms in The Netherlands: epidemiological developments].

In this review a number of the main epidemiological developments in the field of udder health in the Netherlands are summarized. The changes considering the bulk milk somatic cell count are described, as are the population dynamics of subclinical mastitis. Additionally, clinical mastitis caused by Escherichia coli and Staphylococcus aureus and their risk factors are reviewed. Finally, some future developments and the possible applications of these developments are discussed.

Animals↗
PubMed1995

[Veterinary medicine and organic animal husbandry. II. Organic animal husbandry: a challenge for veterinary medicine].

Biological agriculture serves as an example on an endeavour to achieve durability. Government policies offer possibilities for the further development of biological animal husbandry. Biological veterinary practice places emphasis on the promotion of animal health, rather than on the treatment of disease. Because the aim is to reduce medication, this goal is consistent with the approach of biological animal husbandry. These new developments are of interest to veterinary practitioners and require professional knowledge to be adapted to the biological way of thinking.

Animal Husbandry↗
PubMed1993

[Embryo research: ethics of technology and technique of ethics].

A short survey is given of the aims and methods used in embryo research. Ethical aspects of research and possible applications lead to the conclusion that questions are raised that concern society as a whole. In the last decade the awareness in this respect has increased. Methodology of broad ethical judgement and decision making however is still in a stage of development. It is suggested to strive for: 1) clarification of fundamental views on values in (human) life, 2) answering the question: who decides about what, and 3) determination of decision making procedures.

Animal Husbandry↗
PubMed1993

[Overcharging: keeping both feet on the ground and going a step forward].

The intrinsic value of animals and their place in human society influence veterinary practice. The role-responsibility of the veterinarian is under pressure of practical circumstances, client requests and constraints of breeding and management systems. A reflection on human needs as related to the intrinsic value and welfare of animals, is required inside and outside the profession. It is in the interest of life to think and act out of total ecological concepts. In order to be better prepared to deal with ethical problems in practice, students should receive adequate training. The assumed value-free research and the need for outside financial support are a hindrance for research projects that aim at sustainability of human and animal life. It is concluded that the profession needs a philosophy about her objectives.

Animal Welfare↗
PubMed1993

Within-herd and between-herd variation in diagnosis of clinical mastitis in cattle.

In a set of data on farmer-observed clinical mastitis in cattle, all milk samples were scored with regard to milk color and milk texture (presence of flakes and viscosity). During a 1-year period, 1,106 milk samples were collected from 125 farms with a bulk milk somatic cell count < 150,000 cells/ml. The overall variation, the between-herd variation, and the within-herd variation of the scores were evaluated and compared with each other. Differences between farmers were found for the scores on the visual characteristics per sample. However, these differences were not related to the reported number of cases of clinical mastitis per year. It was concluded that the diagnostic capability of farmers whose herds had low somatic cell counts did not have a negative influence on the validity of farmer-observed clinical mastitis incidence. However, care should be taken in herds with a low frequency of cases.

Analysis of Variance↗
PubMed1993

Preinfection chemotactic response of blood polymorphonuclear leukocytes to predict severity of Escherichia coli mastitis.

Experimental mastitis was induced by inoculating rear right quarters of 10 healthy cows with 10(3) cfu of Escherichia coli. The chemotactic responses of peripheral blood polymorphonuclear leukocytes at d-6, -5, -2, -1, and immediately prior to inoculation were measured. Chemiluminescence of polymorphonuclear leukocytes was measured immediately prior to inoculation. Severity of the experimental mastitis was assessed by bacterial growth in the inoculated quarters. Results of this study indicated that severity of the experimental mastitis may be predicted by the chemotactic response in vitro of polymorphonuclear leukocytes isolated from the peripheral blood at d 2, d 1, and immediately prior to inoculation. The number of circulating polymorphonuclear leukocytes immediately prior to inoculation also showed a negative relationship with the severity of mastitis. No relationship existed between preinfection chemiluminescence of polymorphonuclear leukocytes and the severity of the experimental mastitis.

Animals↗
PubMed1993

Blood polymorphonuclear leukocyte chemotaxis during experimental Escherichia coli bovine mastitis.

The relationship between the severity of experimental Escherichia coli mastitis and the chemotactic response of blood polymorphonuclear leukocytes was investigated before and during mastitis. Experimental E. coli mastitis was induced in 10 healthy cows by inoculation of the rear right quarters with 10(3) cfu of E. coli. Cows were classified into two groups based on the severity of the mastitis. Bacterial growth in the inoculated quarter was used as parameter that indicated severity. Before and during experimental mastitis, the chemotactic response and the number of circulating polymorphonuclear leukocytes were greater for the moderately diseased cows than for the severely diseased cows. During the first 24 h of the experimental mastitis, the chemotactic response of polymorphonuclear leukocytes decreased in both groups. Recovery of the chemotactic response of white blood cells was more rapid in moderately diseased cows than in severely diseased cows. Possibly, the larger proportion of band neutrophils (the less chemotactically active band neutrophils) partially accounts for the lower chemotactic response of the circulating polymorphonuclear leukocytes during experimental mastitis in the severely diseased cows.

Animals↗
PubMed1993

A randomized blind trial on dry cow antibiotic infusion in a low somatic cell count herd.

The objective of the study was to evaluate the effect of administration of antibiotics to cows at dry-off in a low SCC herd. Cows were infused at dry-off with an intramammary antibiotic on the left or the right side of the udder. Selection of the infused quarters was random, and all people evaluating the occurrence of mastitis were unaware of which half of the udder was infused. The quarters that were infused with an antibiotic showed a significantly lower incidence of clinical mastitis in the dry period. Quarters that were uninfused had 10 cases of clinical mastitis versus 1 case in quarters that were infused with antibiotics. The quarters that were infused showed a reduction of minor pathogens at calving. The uninfused quarters showed little evidence of spontaneous cure during the dry period. Milk leaking was frequent during the drying off period. Milk leaking was also associated with the occurrence of clinical mastitis later in the dry period. Cows that leaked milk had a four times greater risk of clinical mastitis in the dry period.

Animals↗
PubMed1993

Severity of experimental Escherichia coli mastitis in ketonemic and nonketonemic dairy cows.

The severity of experimental Escherichia coli mastitis in relation to in vitro chemotaxis of polymorphonuclear leukocytes was investigated in cows during negative energy balance. The negative energy balance was induced by feed restriction. Cows were classified into two groups, ketonemic and nonketonemic, based on the beta-hydroxybutyrate concentration in the peripheral blood at the moment of inoculation. Bacterial growth in the inoculated quarter was used as a parameter to indicate the severity of experimental mastitis. In the nonketonemic cows, experimental mastitis ranged from moderate to severe. Severity of experimental mastitis was negatively related to preinfection chemotactic response of polymorphonuclear leukocytes. In contrast, the course of experimental mastitis in the ketonemic group was relatively severe in all cows, regardless of preinfection chemotactic response.

3-Hydroxybutyric Acid↗
PubMed1991

Risk factors for clinical mastitis in herds with a low bulk milk somatic cell count. 2. Risk factors for Escherichia coli and Staphylococcus aureus.

The incidence rate of clinical mastitis due to Escherichia coli and Staphylococcus aureus was studied in 125 herds with a low annual bulk milk somatic cell count (less than 150,000 cells/ml). Risk factors that were offered to a multivariate Poisson regression model included general management, housing, cleaning procedures, cow and cubicle cleanliness, feeds and feeding, dry cow management, milking procedures, machine milking, disease prevention, and milk production. Some differences in epidemiology between E. coli and S. aureus were observed. In the S. aureus model, more milking procedure and milking machine variables were present. The milk production, drinking water source, amount of bedding, and ventilation were other important factors in the S. aureus model. Teat disinfection was an important risk factor in the E. coli model but was much less important in the S. aureus model. Cleaning procedures were more important in the E. coli model. The main breed on the farm and percentage of cows leaking milk were other important factors in the E. coli model.

Animal Husbandry↗