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B Faye

Publications and source records attributed to B Faye.

At least 19 recordsLinked to original sources
PubMed1998

Qualitative interaction between the observer and the observed in veterinary epidemiology.

The phenomenon of qualitative interaction between the research activity and the studied object exists in veterinary epidemiology, as in all observation-based disciplines. Observational studies carried out under farm conditions strongly involve the farmers and the farm's usual advisors in the data collection. This leads to various biological and sociological interactions between the observer and the observed that can modify the results of the study. Some methodological considerations are proposed in order to consider such qualitative interaction, from the designing of the study through to the interpretation of the results. Examples are presented to illustrate these ideas.

Animal Diseases↗
PubMed1997

Interrelationships between herd management practices and udder health status using canonical correspondence analysis.

The relationships between the herd-level distribution of udder health measures (traumatic, physical, functional and congestive udder disorders, clinical mastitis and somatic cell counts (SCC) greater than 400 x 10(3) ml-1) and farm (general hygiene, milking practices and housing system) and aggregated individual characteristics were studied by canonical correspondence analysis (CCA). This is a correspondence-analysis technique in which the axes representing disease patterns are expressed as linear combinations of potentially explanatory variables. These main axes can be drawn so that the distribution of diseases for combinations of the main-explanatory managerial variables can be visualized. The type of quarantine for newcomers, type of animal housing, presence of shelter at pasture, use of udder towel before milking, milk production and loss of body condition after calving, were strongly correlated with udder health status. Mastitis and physical udder disorders were associated with the combination of no introduction of replacement heifers and low loss of body condition after calving. Congestive disorders were more common on farms when no quarantine for newcomers was combined with high loss of body condition after calving. Higher clinical and subclinical mastitis incidence risks were associated with the combination of no udder towel, loose housing with high animal density and high milk production. In most cases, clinical mastitis and high SCC were explained by the same covariates but with contrasting levels of those covariates.

Animal Husbandry↗
PubMed1997

Factors affecting the distribution of clinical mastitis among udder quarters in French dairy cows.

Factors related to the distribution of clinical bovine mastitis between rear and front quarters were studied using data from a 4 year survey of commercial dairy herds in western France. The study involved 844 mastitis cases affecting 597 lactations of 500 French Friesian cows from 44 herds. Risk factor hypotheses were related to certain aspects of lactation, udder conformation and management practices. Distribution was modelled using a hierarchical logistic regression. Rear quarters were affected in 61.9% of cases. The only significant risk factor was the cow's parity; rear quarter clinical mastitis was more frequent in primiparous than in multiparous cows. In this retrospective study, udder conformation did not seem to play a significant role in mastitis distribution. No overdispersion parameter was observed, indicating that each mastitis case could be considered as an independent event.

Animals↗
PubMed1996

[Informal care of malaria: determinants of demand and supply inventory. A study conducted in Touba City (Senegal)].

In Senegal, identifying the determining factors of the informal health care demand for malaria on the one hand and the supply's inventory in that condition on the other hand, are prerequisites to the definition of any realistic pharmaceutical policy. Wanted to make these parameters available in the city of Touba which shows religious and administrative particularities as compared to the rest of Senegal, by conducting a study on malaria morbidity and by submitting to people and informal health care providers two different questionnaires. Besides a malaria morbidity rate of 7.4%, the resort to informal health care was linked to economic reasons for 64% of householders resorting to this type of health care. Sociocultural determining factors were also identified. Among health care providers whom community's request is important, we observed the relevance of the malaria regular diagnosis as compared to established references. However we did not observed it as far as treatment and chemoprophylaxis are concerned. The supply is done along underground lines. The training of these informal health care providers and their integration in the general health care system should be considered.

Adolescent↗
PubMed1996

A method for describing disease patterns during the life span of dairy cows.

This study presents some guidelines for describing the health status of dairy cows over their entire life span. It aims to define some types of health-paths (trajectories) described in terms of disease patterns (at the lactation level) and related to cow characteristics (breed, production potential) and farms. The data were collected over a 20-year period on three experimental farms. Eight diseases were analysed: clinical mastitis, lameness, placental retention, foot rot, digestive disorders, milk fever, metritis, and arthritis. The statistical procedures used were correspondence analysis of time-indexed tables and hierarchical ascending clustering. A total of 28 health-paths were identified and 16 of these (the most common) are described in detail. At the lactation level, eight disease patterns were defined: high incidence of disease other than mastitis (1), predominantly mastitis plus milk fever (2), predominantly foot rot (3), very low incidence of disease (4), mastitis plus digestive disorders (5), very high mastitis incidence (6), low incidence of disease (7), foot rot plus digestive disorders (8). Disease patterns 3 and 6 were more common in shorter life spans (< or = 4 lactations). Conversely, health profiles 2 and 4 were generally related to the longest life spans. These results will be included in a future model of the life span of dairy cows which will also take into account other performance parameters such as milk production and reproduction.

Aging↗
PubMed1996

[Descriptive epidemiology of placental retention in intensive dairy herds in Brittany].

The influences of several risk factors (temporal, mechanical, zootechnical and nutritional) on the incidence of placental retention (PR) were tested. The study was conducted in Brittany on 5,240 calvings of Black-Pied females belonging to 47 herds surveyed over a period of four consecutive years. For twin births, the PR-incidence levels were only decreased in the case of calves born alive. Single calvings were associated with PR after more than three artificial inseminations, or when stillbirths, dystocia or shortened gestational periods were observed, but the frequency varied in relation to calving rank. Increased total amounts of concentrate and cake supplied at the end of the gestational period decreased the incidence of PR in heifers. Shorter dry periods and high levels of milk production increased the risk of PR in multiparous cows. The frequency at which PR was observed in both cows and heifers was lower in autumn. Milk production and fertility were decreased in animals having experienced PR. In addition, they were subject to more uterine disorders than other cows during the subsequent lactation, whatever number of calves had been carried. Milk fever in the third lactation and metabolic diseases in the fourth were more frequently observed following PR.

Animal Husbandry↗
PubMed1995

Metabolic profiles and risks of diseases in camels in temperature conditions.

A survey of 65 female camels has been conducted over a 1-year period in France to determine their metabolic profiles and to study the correlations between this profile and the feeding and health status in temperate conditions. The following parameters were measured: protein (albumin, globulin, total protein), urea, glucose, free fatty acid, liver enzymes (GLDH, GGT, GOT), minerals (Ca, Mg, Cu, Zn) and ceruloplasmin. The values obtained were similar to those reported in desert areas throughout the world, but the standard deviation was generally higher. This important variation might be due to the large variability of feeding conditions: albumin (36.4 +/- 4.7 g/l), total globulin (32.7 +/- 5.1 g/l), total protein (69.2 +/- 6.1 g/l), urea (30.0 +/- 14.8 mg/100 ml), glucose (111.0 +/- 12.2 mg/100 ml), FFA (0.15 +/- 0.15 mmol/l), GLDH (5.8 +/- 10.8 IU/l), GGT (10.1 +/- 5.8 IU/l), GOT (48.1 +/- 14.3 IU/l), calcium (10.2 +/- 6.5 mg/100 ml), magnesium (2.6 +/- 0.3 mg/100 ml), copper (65.4 +/- 20.2 micrograms/100 ml), zinc (34.6 +/- 7.8 micrograms/100 ml), ceruplasmin (41.4 +/- 2.6 UO). The season, the mineral supplementation and the health status had a significant effect on the metabolic profile of the she-camels.

Animal Diseases↗
PubMed1995

Predictive model of mastitis occurrence in the dairy cow.

Mastitis occurrence within a lactation and times of mastitis onset were studied for about 1000 cows. The number of mastitis cases within a lactation was modeled through overdispersed Poisson regression with individual and herd covariants. The results emphasized the role of the herd variable. Increased production potential increased the number of cases per lactation at a rate of 1.4/10 kg. Calving month also played an important role. The incidence of mastitis was greater when calving took place in early autumn or winter, which led to an expanded housing period. The interval from calving to the first case of mastitis and the intervals between successive cases were modeled for cases occurring during lactation through random selections from fitted gamma distributions, these distributions being truncated to consider the lactation length. The results of both steps can be used to simulate mastitis occurrence in different conditions.

Animals↗
PubMed1995

[Mortality of dairy cows in an ecopathologic survey in Brittany].

Although rare, natural death in dairy cows represents a serious economical loss. In a sample of intensive dairy farms, the mean yearly mortality rate was estimated to be 0.96%. There were various causes known (metabolic, accidental, calving-related, respiratory) and unknown (1/3 of the cases). No significant annual or seasonal variation was observed, although the beginning of the grazing period seemed to be associated with a higher mortality rate. The cows with a parity of 7 or more had a higher probability of dying (mortality rate: 3.5%). The post-partum period was also associated with a higher number of deaths. The inter-herd variability was significant, with mortality rates running between 0 and 4.24%. Nutritional diseases, digestive disorders and trauma were predisposing factors of natural death.

Animal Husbandry↗
PubMed1994

A highly sensitive assay of melatonin at the femotogram level in human plasma by gas chromatography/negative ion chemical ionization mass spectrometry.

A highly sensitive and specific assay was developed for routine analysis of melatonin at the femotogram level in human plasma. Melatonin and the deuterated internal standard [(2H4)melatonin] were measured by gas chromatography/negative ion chemical ionization mass spectrometry with methane as the reagent gas. A simple liquid-liquid extraction procedure was used to isolate the two compounds of interest from the complex biological matrix. Melatonin was converted to the fluorinated derivative with pentafluoropropionic anhydride. The mass spectrometer was tuned to monitor the very intense and stable ions at m/z 320 and 323 which were generated into the ion source by a dissociative capture process. This assay was conducted with 1 ml of plasma and the quantification limit of the method was statistically calculated as 0.5 pg ml-1. The very low relative standard deviations and mean percentages of error calculated during the within-day or between-day repeatability assays have clearly demonstrated the ruggedness of the technique for the routine quantitative measurement of melatonin in plasma. Some results on the melatonin circadian rhythm are presented to illustrate the applicability of this powerful gas chromatographic/mass spectrometric method.

Circadian Rhythm↗
PubMed1994

[Toxicity of cholestatic bile acids on intrahepatic biliary cells of the rat].

The aim of this study is: 1. to isolate intrahepatic biliary epithelial cells and, 2. to study the toxicity of cholestatic biliary acids on these cells. Cells were isolated from rats with proliferated bile duct-cells, that were induced by a 21 days bile duct ligation. They were characterized by glutamyltranspeptidase and cytokeratins 7 and 19 using histochemical or immuno cytochemical methods. Isolated cells were incubated with different concentrations (250, 500, 1000 and 2000 microM) of cholestatic biliary acids, lithocholate sulfate (LCS) and taurolithocholate sulfate (TLCS. Cells viability is estimated by three methods: Trypan blue, LDH release and MTT test. We obtained purified fractions of non parenchymal liver cells enriched in biliary epithelial cells (> 95%). On these cells, we showed toxicity of LCS and TLCS and determined CI 10 and CI 50 of these acids which were respectively 800 microM and 2 mM for LCS; 1.4 and 2 mM for TLCS. These results indicate that cholestatic biliary acids (LCS and TLCS) are toxic for biliary cells. This cytotoxicity can be probably a possible mechanism of cholestasis.

Animals↗
PubMed1994

[The reliability of data in ecopathologic investigations].

The reliability of information gathered during ecopathological investigations is a constant concern, requiring a rigorous strategy to limit risks of error. These risks are all the more important when there are human shortcomings (farmer or investigator) as opposed to technical shortcomings (results of laboratory tests). A dual strategy can be implemented to guarantee reliability: ensuring reliable collection of data by attention to the human element (selection of farmers, training of investigators, organisation of professional partners), and ensuring the collection of reliable data by attention to facts (quality of the questionnaire, harmonization of procedures, objective interpretation of qualitative findings, quality of data-processing support, timing of data collection, verification procedures). The argument is supported by numerous examples provided by teams of ecopathologists.

Animals↗
PubMed1994

[Data exploration using post-factorial analysis: use of structured data interrogation software].

The language for interrogating data (LID) allows the graphical and numerical exploration of a cloud of points resulting from a factorial analysis. The interest of a post-factorial analysis in epidemiology is shown in the present paper: a measure of the department effect; a measure of year effect; an assessment of the adjustment on one factor in the framework of a survey on the risk factors of milk quality.

Animals↗
PubMed1994

Farming practices associated with the 'udder infection' complex.

A total of 4,129 dairy cows from 47 dairy farms were submitted each year after calving to a milk sampling for bacteriological examination. Six criteria defined the udder infection complex: frequency of minor, major and rare pathogens; rate of clinical and subclinical mastitis; and index of gravity of mastitis. Forty-seven variables described practices and their associations with the type of farms (defined by the above 6 criteria) were studied. The associated variables were dipping practices, covering of the milking parlour, disinfection practices, housing cleanliness and milk production.

Animal Husbandry↗
PubMed1994

[Nutritional factors and mammary inflammatory infection in the dairy cow. Ecopathological approach during the peripartum period].

The relationships between nutrition and udder inflammation/infection were studied in the dairy cow using an ecopathological approach. The study ('enquête écopathologique Bretagne') was performed over 4 yr in French herds with high-lactating cows. A long distribution time of Italian ryegrass silage and a low quantity of dietary cereal-based concentrates in the first 2 months of lactation was linked with low milk leukocyte counts, probably due to a high dietary energetic level or to a polyunsaturated fatty acid imbalance and a subsequent decrease in the synthesis of leukotriene LTB4. In the late gestation period, a long distribution time of fresh English rye-grass, which induced high uraemia and a larger distribution of vitamins A, D and E, was related to lower frequencies of major pathogens in the milk.

Animal Feed↗
PubMed1994

Impact of udder disorders on culling of dairy cows.

Data from a prospective longitudinal study carried out from 1986 to 1990 in 47 commercial Holstein dairy herds from western France were used to quantify the effects of udder health disorders on the risk of culling. Logistic regression was used to assess the relationship between 4 udder health disorders and early and late culling. Teat injuries were associated with an increased risk of early culling in the current and following lactations. Mastitis and high milk cell count were associated with an increased risk of late culling in the current and following lactations, respectively.

Abortion, Veterinary↗
PubMed1994

[Trajectory types of health status during the life of the dairy cow].

This paper presents a first approach of the health over the whole life-cycle of dairy cows, a scale which is intended to define a trajectory. Trajectories are defined as the chain of health profiles on the lactation scale, which are characterized by major disorders: foul of the foot; lameness; arthritis; calving disorders; mastitis; digestive and metabolic disorders; and no disorders. A few examples of trajectories are discussed for life-cycles lasting 4 lactations.

Animals↗