Management of calves in commercial dairy farms in Mecklenburg-Western Pomerania, Germany and its impact on calf mortality and prevalence of rotavirus and Cryptosporidium parvum infections in pre-weaned calves.

In a cross-sectional study, impact of management in dairy farms on calf mortality rates and prevalence of rotavirus and Cryptosporidium parvum in feces of calves was investigated. Sixty-two commercial dairy herds in Mecklenburg-Western Pomerania, Germany, were stratified selected in 2019. We performed in-person interviews and fecal specimens in samples of all-female calves of age 7 up to 21 days. Management data were documented on farm level. A Multiscreen Ag-ELISA was performed to determine rotavirus and Cryptosporidium parvum. Associations between two calf mortality rates, detection of C. parvum and rotavirus, and predictors were examined with GLM models. In farms with routine vaccination against respiratory diseases, 31-days mortality rate was 4.2% +/-1.26 compared to 7.6% +/-0.97 (p = 0.040) on non-vaccinating farms. Six-months mortality was lower in farms that continued feeding milk to calves during periods of diarrhea compared to farms that did not (6.9% +/-0.8 vs. 12.4% +/-2.3). In case of a routine shifting of calves from the calving box into calf boxes less C. parvum was detected compared to an individual moving of calves (33.3% +/-2.6 vs. 19.6% +/-5.3; p = 0.024). Our model confirms a positive association between occurrence of aqueous feces and frequency of detection of C. parvum (45.4% +/-23.6 vs. 21.4% +/-18.7; p < 0.001). Frequency of detection of rotavirus was lower in farms that reported a defined amount of applicated colostrum per calf than in farms that presented a range of colostrum instead of a defined amount. This study indicates the potential for mitigation of risk factors for mortality in calves.

Evaluation of an electronic cowside test to detect subclinical ketosis in dairy cows.

The objective of this study was to determine the diagnostic performance of an electronic beta-hydroxybutyrate (BHBA) hand-held meter (Precision Xtra) for use in dairy cattle. Specific objectives were to compare the electronic BHBA meter with serum BHBA concentrations determined photometrically and 2 commonly used chemical cowside tests (Ketostix, Ketolac) and to evaluate accuracy in a field study employing 35 investigators. Of the 196 blood samples collected in experiment 1, 17 (8.7%) contained > or =1,200 micromol of BHBA/L of blood and 10 (5.1%) contained > or =1,400 micromol of BHBA/L of blood. Pearson correlation coefficients were highly significant for all tests. The highest correlation coefficient (0.95) was found between measurements of whole blood BHBA determined with the Precision Xtra test and the serum BHBA concentrations determined photometrically. Correlation coefficients between serum BHBA and BHBA in urine using Precision Xtra and Ketostix, and milk using Ketolac were lower. The Precision Xtra test was both 100% sensitive and specific at > or =1,400 micromol of BHBA/L of whole blood. Using milk and urine, positive and negative predictive values were considerably lower for both chemical tests as well as for the electronic meter. In the second study undertaken with 35 bovine veterinary practices, 926 blood samples were collected. In this study, the Precision Xtra test had sensitivities of 88 and 96% at 1,200 and 1,400 micromol of BHBA/L of whole blood, respectively. Specificities were 96 and 97%, respectively. Level of agreement was lower in the second study employing multiple investigators. Considerable differences in variance occurred among investigators. We conclude that the electronic hand-held BHBA measuring system using whole blood is a useful and practical tool to diagnose subclinical ketosis. Sensitivity and specificity are excellent for a cowside test and higher than 2 commonly used chemical dipsticks (Ketostix and Ketolac).

Relationships between the concentration of insulin-like growth factor-1 in serum in dairy cows in early lactation and reproductive performance and milk yield.

The objective of this study was to evaluate the relationships of different insulin-like growth factor-1 (IGF1) measures [5 distinct IGF1 concentrations on particular days, area under the curve (AUC), and linear regression coefficient] in the postpartum period in lactating dairy cows and reproductive performance. A total of 417 healthy multiparous Holstein-Friesian cows were enrolled in the study. Serum samples for the determination of the concentration of IGF1 were collected on d 0, 4, 10, 20, and 40 postpartum (pp). The concentration of total IGF1 in serum was determined by immunometric chemiluminescence immunoassay. All cows were examined for vaginal discharge as a sign of clinical endometritis at 20 d pp by external inspection and rectal palpation. The mean concentration of IGF1 ranged from 57 +/- 18.9 ng/mL within the first 12 h pp to 74 +/- 19.9 ng/mL at 40 d pp. On d 10 pp, first and all artificial insemination conception rates were greater in cows with IGF1 concentrations above the median compared with cows with IGF1 concentrations below the median. Cows with greater AUC (second to fourth quartile) conceived earlier (11.4, 16.0, and 18.8 d) than cows in the first IGF1 quartile (117.0 +/- 43.6). Proportion of cows pregnant within 200 d pp increased significantly from the first to the third IGF1 quartile of AUC (58.7, 66.7, and 74.0%). The proportion of cows culled decreased from the first to the fourth IGF1 quartile. Correlations between IGF1 measures and days to pregnancy were significant (except for the linear regression coefficients) but low (R(2) = 0.0009 to 0.025). Differences between single or composite measurements of IGF1 were not significant. We could also demonstrate a statistically significant correlation between the concentration of IGF1 in serum and the average 10-d milk production (31.6 to 44.0 kg). In conclusion, our study indicates that single or multiple measurements of IGF1 concentration in the postpartum period have very limited value to predict individual fertility in dairy cows.

[Seasonal influence on the microbiological colonization on surfaces of milk liners and flushing adapters in a newly installed milking parlor]. / Jahreszeitliche Einflüsse auf die mikrobielle Besiedlung milchbenetzter Oberflächen in einer neu installierten Melkanlage.

A field trial was conducted to evaluate long term and seasonal effects on the development of mictobiological colonization in a newly installed milking parlor. The milking equipment was a 2 x 34 side-by-side milking parlor in a commercial dairy herd in Germany. The 1st batch of samples was taken before beginning of milking and in weekly intervals for a period of two months in winter 2002. The 2nd batch of samples was collected in summer 2003. After sampling the diagnostic material was kept in Amies medium at 4 degrees C until analysis. Samples were analyzed from the mouthpiece, the shank of the liner and the flushing adapter. The samples were collected immediately after disinfection of the milking equipment. They were analyzed qualitatively and quantitatively according to the official German guidelines (Amtliche Sammlung von Untersuchungsverfahren, paragraph 35, LMBG). Mesophil aerobe total plate count, S. aureus, E. coli, Coliforms, Streptococci, Yeast and Lactobacilli were considered. Results indicate a relationship of microbiological colonization of the surface of the milking technique with season and location of sampling. The microbiological colonization was higher in summer than in winter. There were more mesophil aerobe pathogens on the flushing adapters than on mouthpiece and shank of the liner.

[Influence of time of initiation of a prostaglandin F2alpha protocol in dairy cows with puerperal endometritis]. / Untersuchungen zum Zeitpunkt der Prostaglandin F2alpha-Applikation bei der Behandlung der chronischen Endometritis des Rindes.

A field trial was conducted to elucidate the effect of the time of initiation of a repeated PGF2alpha-application in a 14 day interval for treatment of endometritis in dairy cows. On a commercial dairy farm in Brandenburg, Germany, a total of 494 dairy cows were examined by rectal palpation and adspection for signs of endometritis (vaginal discharge, enlarged uterus) between day 20 to 26 post partum (dpp). We performed two further examinations by rectal palpation and external adspection to monitor the puerperal phase (34.-40. dpp, 55.-61. dpp). All cows with symptoms of an endometritis were treated with PGF2alpha (0.15 mg R-Cloprostenol, Preloban, Intervet Deutschland GmbH Unterschleissheim) twice in a 14-day interval. In the group "Early" (n = 146) the first injection of Cloprostenol was administered at time of the 1st examination. In the group "Late" (n = 129) an identical treatment was administered in cows with endometritis, however it was started 14 days later (34.-40. dpp). The incidence of endometritis was 57.7% in the group "Early" and 53.5% in the group "Late" at the first time of examination. The 1st service conception rates for treated cows were 34% in the group "Early" vs. 37% in the group "Late". In the group "Early" differences were found in days open between treated cows with endometritis and untreated controls without symptoms of endometritis (99.1 d vs. 110.8 d, p > 0.05). In the group "Late", days open for treated (106.8 d) and untreated cows (108.0 d) were similar. The severity of endometritis influenced the percentage of cows pregnant at 200 dpp. Regarding cows with a severe endometritis (E2 and E3) the percentage of pregnant cows 200 dpp was higher in the group treated early (E2: 78.4%; E3: 80.0%) than in the group with the late initiation of the treatment (E2: 68.6%; E3: 54.5%, p < 0.05). Cows with a moderate endometritis (E1) had a similar percentage of pregnant cows (200 dpp) as the untreated cows without endometritis. It is concluded that application of PGF2alpha in the 4th and 6th week post partum in a 14 day interval in cases of severe endometritis is more effective than the application of the same treatment two weeks later.

[Relationship between morphological characteristics of the teat duct and prevalence of intramammary infections with Streptococcus agalactiae in dairy cows]. / Beziehungen zwischen morphologischen Eigenschaften des Strichkanales und der Prävalenz intramammärer Infektionen durch Sc. agalactiae bei Milchkühen.

The objective of the study was to determine the relationship between morphological findings of the surface of teat duct particularly the level of ceratosis and the prevalence of intramammary infections (IMI). The study was conducted on a commercial dairy herd housing about 3000 lactating dairy cows. We examined 891 quarters in the middle of lactation. Duplicate samples of quarter foremilk were collected monthly. The bacteriological status of quarters was determined according to the recommendations of IDF. At the same time teats were evaluated by clinical examinations. The appearance of teat skin lesions and the status of the teat duct especially the existence of hyperceratosis (HC) was documented. Four classes of teat duct hyperceratosis were defined: without, slight, medium and severe HC. The rate of IMI in different classes of hyperceratosis of teat duct was compared by Chi-square analysis. Prevalences of intramammary infections were determined three times (P1, P2 and P3) during the study period. Prevalence of infection was high for S. aureus (P1: 5.6% vs. P2: 4.5% vs. P3: 4.3%), Sc. agalactiae (P1: 2.7% vs. P2: 2.6% vs. P3: 2.8%) and CNS (P1: 10.7% vs. P2: 8.8% vs. P3: 9.6%). Furthermore we detected IMI caused by other streptococci, yeast, E. coli and mixed infections. A positive correlation between status of HC and prevalence of IMI for Sc. agalactiae was found. At the second and third sampling time the rate of intramammary infection with Sc. agalactiae in quarters with medium HC (P2: 9.21% and P3: 13.73%) differed significantly (p < 0.05) compared to groups without (P2: 1.56% and P3: 1.91%) and slight hyperceratosis (P2: 2.33% and P3: 2.56%). The results of our study indicate a correlation between morphology of teat duct surface, especially regarding to Sc. agalactiae. On one hand HC can cause high intramammary infection rate with Sc. agalactiae. On the other hand it is possible that HC is the consequence of a quarter infection with Sc. agalactiae. Further research is required.

[Effects of the intensity of a post partum examination on the fertility performance of high yielding dairy cows]. / Einfluss der Intensität der Puerperalkontrolle auf die Fruchtbarkeitsleistung von Hochleistungskühen.

Two methods for a scheduled post partum examination were compared on a commercial dairy farm. In Group 1, all cows (n = 601) were examined by rectal palpation between day 20 and 26 post partum for signs of endometritis (vaginal discharge, enlarged uterus). In Group 2, all cows (n = 652) were examined by external inspection for vaginal discharge as a sign for endometritis. In both groups all cows with endometritis were treated twice with prostaglandin F2 alpha (25 mg of dinoprost) in a 14-day interval. The proportion of cows with signs of endometritis was 33.3% and 17.2% in Group 1 and Group 2, respectively (p < 0.05). In Group 1, the conception rate (39.0% vs 49.3%) and the proportion of cows pregnant (60.5% vs 72.6%) were lower for cows with endometritis than for cows without endometritis. In Group 2, no significant differences were found in reproductive performance for cows with and without signs of endometritis. No significant differences in reproductive performance were found for cows with endometritis between the two groups. Also, for cows without endometritis no significant differences in reproductive performance were found between the groups. It is concluded that the post partum examination by rectal palpation was more sensitive in finding cows with endometritis. However, with regard to the reproductive performance the more sensitive method was not more effective than the method based on systematic external inspection.

[Prevention of intramammary infections in dairy cows by the use of a premilking teat dip method with a foaming iodophor dip agent]. / Prophylaxe von Infektionen der Milchdrüse beim Milchrind durch die Anwendung eines Zitzendippverfahrens vor dem Melken mit einem schaumbildenden, jodophoren Dippmittel.

In this study we investigated the efficacy of premilking teat dipping with a foaming iodophor teat dip in a negative controlled field study. Incidence of new intramammary infections (IMI), incidence of clinical mastitis, influence on somatic cell count (SCC) and the characteristics of udder tissue and teats were used as parameters to evaluate clinical efficacy. Predipping was compared with a negative control using a split-udder experimental design. Right teats were predipped with a foaming disinfectant containing 0.27% iodine while left teats served as controls. The latter were conventionally cleaned with damp cloth towels and dried manually with disposable paper towels ("best cleaning practice"). All teats were dipped after milking with the same dip. There were no differences between treated and control quarters with respect to incidence of new IMI during the study period (treated quarters: 6.6% vs. untreated: 6.95%), incidence of clinical mastitis (30 cases in the treatment group vs. 39 cases in the control group) and geometric mean of SCC of quarter milk samples. Spectrum of detected pathogens was also comparable. Condition of udder tissue and teat ducts did not differ between treated and control quarters.

[The clinical effectiveness of a post milking teat disinfection method with a foaming iodophor teat dip]. / Untersuchungen zur klinischen Wirksamkeit eines Zitzendesinfektionsverfahrens nach dem Melken mit einem schaumbildenden jodophoren Dippmittel.

The effect of postmilking teat dipping with a foaming iodophor agent on incidence of intramammary infections (IMI), incidence of clinical mastitis, somatic cell count and the characteristics of udder tissue and teat was investigated in a positively controlled field study. Two groups of animals were compared. Teats were dipped with a foaming iodophor in the treatment group (TG, 122 animals) while teats in the control group (CG, 121 animals) were dipped with a conventional iodophor teat dip with the same iodine content. A bacteriological examination of quarter milk samples divided the study period in two parts. The incidence of new IMI did not differ between the groups (1st part of trial: TG vs. CG: 6.84% vs. 9.16%, 2nd part of trial: 7.78% vs. 7.82%). There were no differences between the treatment groups regarding incidence of clinical mastitis. We detected 0.64 clinical cases per 100 days in the treatment group vs. 0.50 in the control group. The development of SCC was comparable in both groups. Teat skin and teat duct conditions showed variation during the study period. Clinical efficacy of postmilking teat disinfection with a foaming iodophor was comparable to the treatment with a conventional iodophor product.

Characterization of mouse macrophage differentiation antigens by monoclonal antibodies.

Monoclonal rat antibodies to mouse macrophage antigens were prepared. For immunization phagocytic cells in the spleens of mice recovering from sublethal irradiation were used. Specificities of the monoclonal antibodies obtained were determined on cells of normal mouse cell populations as well as on cells of a panel of mouse cell lines. In an attempt to monitor expression of differentiation-related antigens two models of in vitro-induced macrophage differentiation were used: differentiation of cells of the myeloblast line Ml; CSF-1-induced differentiation of bone marrow cells. The results obtained clearly show that during maturation from undifferentiated to highly differentiated cells of the macrophage lineage expression of antigens recognized by the MIV 38, MIV 55, MV 87, and MV 114 monoclonal antibodies is enhanced. At the same time, expression of antigens recognized by the MIV 52, MIV 113, and MIV 116 monoclonal antibodies diminishes at a similar rate. The suitability of these monoclonal antibodies for the characterization of differentiation states of mouse macrophages is discussed.

Phenotypic characterization of three long-term-cultured murine resident macrophage lines.

The antigenic phenotypes of three long-term cultured murine resident macrophage lines selected in vitro from cell suspensions of different tissues--namely MAY 1 (from the peritoneal cavity), MASP (from the spleen) and MALU (from lung tissue)--were determined using a panel of monoclonal antibodies. The results indicate that all three cell lines belong to the mononuclear phagocyte system and express characteristics indicating a rather high differentiation state. However, there was a significant difference in antigen expression between the two macrophage lines obtained from solid tissues (MASP from spleen and MALU from lung), which were very similar in their antigenic pattern, and the MAY 1 line obtained from the peritoneal cavity, which seemed to be less well differentiated. The antigenic profile of the "mesothelial" cell population associated with the MASP line indicates that this cell population is difficult to characterize and to include in a particular lineage.