Dairy management practices associated with incidence rate of clinical mastitis in low somatic cell score herds in France.

An epidemiological prospective study was carried out in French dairy herds with Holstein, Montbéliarde, or Normande cows and with low herd somatic cell scores. The objective was to identify dairy management practices associated with herd incidence rate of clinical mastitis. The studied herds were selected on a national basis, clinical cases were recorded through a standardized system, and a stable dairy management system existed. In the surveyed herds, mean milk yield was 7420 kg/cow per yr and mean milk somatic cell score was 2.04 (132,000 cells/mL). Overdispersion Poisson models were performed to investigate risk factors for mastitis incidence rate. From the final model, the herds with the following characteristics had lower incidence rates of clinical mastitis: 1) culling of cows with more than 3 cases of clinical mastitis within a lactation; 2) more than 2 person-years assigned to dairy herd management; 3) balanced concentrate in the cow basal diet. Moreover, herds with the following characteristics had higher incidence rates of clinical mastitis: 1) milking cows loose-housed in a straw yard; 2) no mastitis therapy performed when a single clot was observed in the milk; 3) clusters rinsed using water or soapy water after milking a cow with high somatic cell count; 4) 305-d milk yield >7435 kg; 5) herd located in the South region; 6) herd located in the North region; 7) cows with at least 1 nonfunctional quarter; and 8) premilking holding area with a slippery surface. The underlying mechanisms of some highlighted risk factors, such as milk production level and dietary management practices, should be investigated more thoroughly through international collaboration.

Expert assessment study of milking and hygiene practices characterizing very low somatic cell score herds in France.

French dairy herds were selected on a national basis through the "Zero Mastitis Objective" Program (ZMP) to display hygiene and milking practices characterizing very low somatic cell score (SCS) herds. The herds selected were stratified in 2 groups. The first group (LOW) included 187 herds within the first 5 percentiles of herds regarding mean SCS for the 36 mo preceding ZMP (36-mo SCS). The second group (MED) included 117 herds within the 50 to 55th percentile of herds regarding 36-mo SCS. Mean milk SCS was 3.09 in the MED herds vs. 1.99 in the LOW herds, which corresponded to 265,000 and 135,000 cells/mL respectively. Moreover, LOW and MED herds did not change from one SCS category to another during ZMP. Potentially explanatory variables, collected by formally trained dairy management experts through observations from attendance at milking and farm visits, were analyzed using multistep logistic regression models. According to final model and expert observations, the probability for a herd to belong to the LOW group was maximized when: 1) winter cleanliness of dry cow shed was good; 2) use of teat spraying was carried out; and 3) California Mastitis Tests were performed at milking. Moreover, the herd probability of belonging to the MED group was maximized when: 1) air admission at teat cup attachment was observed during milking; 2) winter cleanliness of dry cow shed was poor; and 3) the milker spent time during milking to feed calves. Finally, the study highlighted milking and hygiene variables and attitudes appearing as key practices to control herd SCS through precise and safe milking and more attention paid to individual animals and cleanliness of dry cow shed.

Management practices from questionnaire surveys in herds with very low somatic cell score through a national mastitis program in France.

French dairy herds (n = 534) were enrolled in the National 'Zero Mastitis Objective' Program to highlight management practices characterizing very low somatic cell score (SCS) herds. The herds studied were stratified into 2 groups. The first group (LOW) included herds within the first 5 percentiles and the second group (MED) herds within the 50 to 55 percentiles of herds on the basis of mean SCS for the 36 mo preceding the program. Potential explanatory variables, collected through questionnaire surveys, were analyzed using multistep logistic regression models. Twenty-six variables were significant factors in the final models, in which 18 were considered as primary factors for very low SCS. The probability for a herd belonging to the LOW group was associated with: (1) regular use of teat spraying; (2) herdsman precise in his techniques; (3) less than 1 person-year used at activities other than dairy herd; (4) teat dipping after mammary infusion at dry off; (5) heifers kept in a calving pen around parturition; (6) cows locked in feed-line lockups after milking; (7) dry cows with prepartum Ca restriction; (8) heifers on a nondamp pasture; (9) cows culled when at least one damaged teat; (10) heifers at pasture not drinking water from a river; and (11) disinfecting teat ends with alcohol before intramammary infusion at dry off. The probability for a herd belonging to the MED group was associated with: (1) milking cows housed in a straw yard; (2) checking heifers for mastitis only beginning at 2-wk prepartum; (3) no mastitis treatment when at least one clot was observed in milk at successive milkings; (4) distance of herdsman's house to cowshed >300 m; (5) only dirty teats washed before milking; (6) free access of cows from pasture to cowshed during bad weather; and (7) more than 18% of spring calvings. The variables associated with very low SCS should be applied as part of a thorough mastitis-control program adapted to each herd.

Nutritional and food protection against epidemic emerging neuropathy. Epidemiological findings in the unique disease-free urban area of Cuba.

A survey was conducted through the SECUBA (SEguridad alimentaria en CUba y Buena Alimentación) research program in Cuban healthy smokers living in Guantánamo and in Havana. The aim of the survey was to investigate biological and nutritional factors connected with the occurrence of zero epidemic neuropathy (EN) observed in Guantánamo urban area since the disease emerged in Cuba. Blood riboflavin status and carotenoid and selenium concentrations were higher in Guantánamo than in Havana smokers. Food dietary quantities of plantain banana, pepper (Capsicum spp.), bovine meat and milk products were higher in Guantánamo. Inversely, foods rich in cholesterol, especially eggs, were more consumed in Havana. Through riboflavin, carotenoid and selenium contents and specific antioxidants substances (indoleamines, capsaicin), the foods more consumed in Guantánamo could be considered as EN protective factors. Disease protective effects could be exerted via enhancement of defence mechanisms against free radical damage and related mechanisms focused on redox recycling of glutathione and local protection from carotenoids. Finally, the results of the present study should help Cuba, through a better EN control, to improve long-term food safety and define healthier dietary habits.

Relation between serum lipoperoxide concentrations and iron or copper status over one year in Cuban adult men.

The aims of this study were to determine the relations between iron and copper status and lipid peroxidation at different periods over one year in low-income and low-energy intake healthy subjects. The study was conducted in 199 middle-aged healthy Cuban men from March 1995 to February 1996. Iron status was assessed by the determination of serum ferritin, transferrin saturation, whole blood hemoglobin and iron intakes. Copper status was evaluated by the determination of serum copper and copper intakes. Serum thiobarbituric acid substances (TBARS) determination was used as an index of lipid peroxidation. Rank correlations were observed between serum TBARS concentrations and iron or copper status indices at different periods. In period 3 (end of the rainy season), serum TBARS and ferritin concentrations were maximum whereas blood hemoglobin levels and iron intake were minimum. Serum TBARS concentrations were significantly higher than the reference values of the laboratory whereas, iron and copper status were within the reference ranges. These results suggested that iron and copper status may be associated with lipid peroxidation in subjects without metal overloads and that variations over the year needed to be taken in account.

Vitamin B intake and status in healthy Havanan men, 2 years after the Cuban neuropathy epidemic.

A prospective epidemiological study was carried out over 1 year to evaluate vitamin B complex dietary intake and status in Cuba, 2 years after the Cuban neuropathy epidemic of 1993. Of the 199 healthy middle-aged men selected, 141 completed the study. Volunteers were followed up every 3 months for 1 year. Dietary intake and status of thiamin, riboflavin, vitamin B6, folate and vitamin B12 were assessed each time. The dietary intake of vitamin B complex was low, particularly in June and July (folate), and October (thiamin). A deficient status was observed for vitamin B complex, except for vitamin B6. Vitamin B complex intake and status varied over the year. However, dietary intake and status were poorly related. The results prove that healthy Cuban men represent a vulnerable population in terms of vitamin B complex status and stress the necessity to both promote preventive multivitamin supplementation and produce local food rich in vitamin B complex.

Seasonal variations of antioxidant imbalance in Cuban healthy men.

OBJECTIVE: To determine the antioxidant imbalance in healthy Cuban men 2y after the end of the epidemic neuropathy (50 862 cases from 1991 to 1993) and to evaluate its change over 1 y. DESIGN: Prospective study. SETTING: La Lisa health centres (Havana, Cuba). SUBJECTS: One-hundred and ninety-nine healthy middle-aged men were selected and 106 completed the study. Subjects were studied at 3 month intervals over 1 year. INTERVENTIONS: No invervention. MAIN OUTCOME MEASURES: An assessment of dietary intake and the determination of blood lipid peroxides (TBARS), glutathione, diglutathione, glutathione peroxidase, superoxide dismutase, vitamin E, carotenoids, copper, zinc and selenium were performed at each period. RESULTS: While dietary zinc, vitamins C and E, carotenoids and fat dietary intakes and blood concentrations were low for adult men compared to international reference ranges, serum TBARS concentrations were high at every period. Some significant seasonal variations were observed. The lowest carotenoids (P < 0.002) and vitamin C(P = 0.0001) intakes, serum beta-carotene (P = 0.0001) and lutein/zeaxanthin (P < 0.05) concentrations, and the highest blood TBARS (P = 0.0001) and diglutathione (P < 0.001) concentrations were observed at the end of the rainy season (October). This period seemed to pose the greatest risk of antioxidant imbalance. CONCLUSIONS: Cuban men still represent a vulnerable population in terms of antioxidant imbalance. A national program of vegetable growing and increase in fruit and vegetable consumption is now evaluated in Cuba.

Predictive variables for the occurrence of early clinical mastitis in primiparous Holstein cows under field conditions in France.

Holstein heifers from 47 dairy herds in France were enrolled in a field study to determine predictors for clinical mastitis within the first month of lactation. Precalving and calving variables (biochemical, hematological, hygienic, and disease indicators) were collected. Early clinical mastitis (ECM) predictive variables were analyzed by using a multiple logistic regression model (99 cows with ECM vs. 571 without clinical mastitis throughout the first lactation). Two variables were associated with a higher risk of ECM: a) difficult calving and b) medium and high white blood cell (WBC) counts in late gestation. Two prepartum indicators were associated with a lower ECM risk: a) medium and high serum concentrations of immunoglobulin G1 (IgG1) and b) high percentage of eosinophils among white blood cells. Calving difficulty and certain biological blood parameters (IgG1, eosinophils) could represent predictors that would merit further experimental studies, with the aim of designing programs for reducing the risk of clinical mastitis in the first lactation.

Vitamin and nutritional status in Cuban smokers and nonsmokers in the context of an emerging epidemic neuropathy.

A prospective survey was conducted in a random sample of smokers (SMO) and non-smokers (NON) men living in Havana. The aim of the survey was to investigate metabolic and dietary parameters discriminating between SMO and NON volunteers, which could explain underlying mechanisms to the higher risk of Epidemic Neuropathy (51,000 reported cases in Cuba from late 1991) previously demonstrated in the Cuban smoker. Forty three blood markers were determined and dietary intakes evaluated during 4 seasonal periods. alpha-carotene, beta-carotene, beta-cryptoxanthin, total carotenoids and riboflavin blood concentrations were lower in SMO vs. NON subjects. Activities of glutathione reductase and butryrylcholinesterase were lower in the SMO group, as did total protein levels. Copper and thiocyanates were higher in SMO subjects. Most of the dietary parameters did not differ between the two groups of volunteers. Low biologically available quantities of carotenoids and riboflavin from low dietary intakes and depletion through smoking would be the main precipitating factors of Epidemic Neuropathy. Protein depletion and copper delivery via tobacco smoke, sunlight exposure, level of physical activity and high consumption of cigarettes, in a context of low dietary supplies concerning especially B vitamins, were probably aggravating factors through oxidative stress and impairment of cyanide detoxification.

Risk factors for stillbirth in Holstein heifers under field conditions in France: a prospective survey.

Risk factors for stillbirth, defined as birth of a dead calf or a calf dead within 24 h after parturition, were studied in Holstein heifers. Data came from an overall 4-yr prospective survey conducted in French dairy herds. Only heifers that delivered a single calf were included in the study. The stillbirth incidence was 6.9%. The predictive indicators of stillbirth risk were: gestation length, prepartum body condition and dirtiness scores, biochemical and hematological blood parameters measured during the last 2 mo of gestation, and calving conditions. Multiple logistic regressions were run using herd, calving year, calving season, blood sampling-to-parturition interval, and body scoring-to-parturition interval as the fixed effects. The results, expressed as the ratio of the odds of disease occurrence in the exposed and non-exposed subgroups (OR), indicated that dystocia and a body condition score (BCS) higher than 4 before calving were significant risk factors for stillbirth (OR=14.6, P<0.0001 and OR=2.98, P<0.05, respectively). Prepartum circulating neutrophil counts higher than 1950/mm3 (OR=0.50, P<0.05) were associated with a lower risk of stillbirth. A higher occurrence of placental retention, lower fertility and a lower 305-d milk yield were significant consequences of stillbirth.

Biological predictors for early clinical mastitis occurrence in Holstein cows under field conditions in France.

Individual risk factors for clinical mastitis within the first month of lactation (early clinical mastitis, ECM) were analyzed in 695 Holstein multiparous cows (561 ECM- and 134 ECM+) which were clinical mastitis-free during the previous lactation. They belonged to 44 herds from the French Brittany region and were surveyed for 4 years. Individual biological parameter levels during the last 2 months of gestation, production of the preceding lactation and calving conditions and health were the available explanatory variables. The construction and explanation model used multiple logistic regression run with herd as a fixed effect. High precalving plasma ceruloplasmin oxidase (p < 0.01) and low glutamate dehydrogenase (p < 0.05) activities, high 305-day previous-lactation milk yield (p < 0.001) and milk protein content at the last milk-test day before drying-off (p < 0.01) were the significant risk factors for ECM occurrence. Intensive production and unsatisfactory dietary conditions (energy and antioxidants) would increase ECM risk in the dairy cow. Further studies should be conducted to determine if metabolic and/or genetic factors could explain the relationship between ceruloplasmin and subsequent ECM occurrence.

Factors associated with clinical mastitis incidence in French dairy herds during late gestation and early lactation.

A prospective epidemiological survey was conducted in dairy herds in Brittany (France), concerning 139 herd-years. The data were divided into ten 14 herd-year groups (deciles) and three of these were compared using discrimination by barycentric analysis to study herd late gestation and early lactation variables associated with the annual incidence of herd clinical mastitis in the first 60 days of gestation (CMAI). The first decile included herd-years with low CMAI (o to 4.6%), the second decile, herd-years with medium CMAI (11.6 to 14.3%) and the last decile, herd-years with high CMAI (26.3 to 45.5%). Herd data included diet components, milk yield and reproduction parameters, clinical diseases, body condition score, body dirtiness score and circulating biochemical and hematological markers. The high CMAI group had the following characteristics: 1) lower percentages of dried cows supplemented with vitamins 'ADE'; 2) higher levels of plasma ceruloplasmin and higher gamma glutamyl transferase activities (GGT) in the late gestation period; 3) higher percentages of winter calvings (December, January, February). Clinical mastitis risk could be controlled by supplementations with vitamins A, D and E in the late gestation period, because of the potential relationship between oxidative stress and mastitis. Higher GGT activities would be associated with Fasciolasis via common climatic risk factors (rainfall, humidity) for both mastitis and liver flukes. Winter calving and clinical mastitis would be associated with unfavourable hygiene conditions and stress at calving related to high animal density and bad weather conditions. Ceruloplasmin could be a specific predictor for mastitis risk through nutritional, immune and genetic interrelated factors.

Predictive markers in the late gestation period for retained placenta in black-pied dairy cows under field conditions in France.

A prospective ecopathogical survey was conducted in French commercial dairy herds located in Brittany. Previous production and reproduction data and blood parameters were used to identify predictive indicators of risk for retained placenta (RP) in Black-Pied cows. All the cows had delivered a single calf after a dry period of at least 30 d and had produced milk for at least 30 d. The cows with and without retained placenta were allocated to groups according to herd and interval between antepartum blood sampling and calving. Two groups of cows with (RP-positive group, n = 45) and without (RP-negative group, n = 184) retained placenta were compared. Univariate analysis indicated lower plasma glucose concentration, lower monocyte count and higher red blood cell count in the RP-positive group. A multiple logistic regression was run, with herd and blood sampling to calving interval as the fixed effects. It showed that a high red cell count and a low monocyte count were predictive indicators for retained placenta risk, which was found to be lower at third calving. Relationships of circulating indicators with placental retention etiology are discussed in terms of polyunsaturated fatty acid imbalance, its consequences on monocyte and erythrocyte functions, uterine motility and circulatory disturbances.

[Descriptive epidemiology of placental retention in intensive dairy herds in Brittany]. / Epidémiologie descriptive de la rétention placentaire en système intensif laitier en Bretagne.

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.

[Markers of nutritional risk for placental retention: use of blood analysis at the end of gestation]. / Marqueurs du risque nutritionnel de la rétention placentaire: utilité des analyses sanguines en fin de gestation.

A sample of 1,225 calvings was used to detect predictors for retained placenta before parturition: 300 with retention, 925 without. Biochemical analyses showed an increased energy mobilization, hypocalcemia, and lower levels of circulating amino acids and monocytes within the last 2 weeks of gestation in cows with a retained placenta. The results agree with the reported smaller quantity of concentrates supplied to these cows before parturition. More cows with retained placenta were fed cereals but received less phosphorus with the mineral supplementation.

[The ecopathologic approach to the study of the relationship between nutrition and health in the dairy cow]. / Contribution de l'approche écopathologique à l'étude des relations nutrition--santé chez la vache laitière.

An ecopathological approach for examining nutrition-induced health disorders in dairy herds in France is described. Bovine dairy herds were surveyed for 4 yr to detect nutritional risk factors that discriminated between high and low disease incidence rates for retained placenta, milk fever, calf perimortality, metritis, liver disorders and infertility. In the cow, preventive feeding helps avoid nitrogen overnutrition, and reduces the requirements of Ca in the late gestation period, gives a satisfactory balance in polyunsaturated fatty acids before calving. The absence of feedstuffs including toxic components and a feeding system with few feedstuffs and few diet changes are also beneficial factors.

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.

[Nutritional factors and mammary inflammatory infection in the dairy cow. Ecopathological approach during the peripartum period]. / Facteurs nutritionnels et inflammation-infection mammaire chez la vache laitière. Approche écopathologique dans la période du peripartum.

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.