Prevalence, Risk Factors, and Relationship between Reproductive Performance and the Presence of Antibodies against Coxiellosis in Dairy Farm Milk Tanks in the Northwest of Spain.

Q fever is a zoonotic disease that has been associated with reproductive problems in animals. As there is little epidemiological data regarding the distribution and risk factors of this disorder in cattle, the objective of this study was to evaluate the prevalence of Coxiella burnetii among dairy herds in the northwest of Spain, and to determine the on-farm risk factors associated with the disease and its effects on reproductive performance. Bulk tank milk (BTM) samples were collected from 262 commercial dairy herds from A Coruña, Lugo, and Pontevedra provinces. Data about location, mean age, and herd management features were obtained. A commercial indirect ELISA kit was used to determine the presence of antibodies against C. burnetii in BTM samples. The relationship between seropositivity to C. burnetii and the risk factors was checked using a Pearson's χ2 test and a classification tree analysis. In addition, a one-way ANOVA test and the Mann-Whitney U test were used to check the impact of seropositivity to C. burnetii on reproductive performance. A total of 60.1% of the farms tested positive for coxiellosis, the herd size, the external purchase of livestock, and the geographical area were identified as the main risk factors. Conception rate and first-service conception rate were significantly lower (p < 0.05) in positive farms (37.1 and 32.9%) compared to negative farms (39.8 and 36.1%). Similarly, positive farms had significant higher incidence of endometritis (13.7% vs. 11.2%, p < 0.05). Consequently, a high seropositivity and slightly negative effects of coxiellosis on reproductive performance were observed, which intensifies the need for further research, including the identification an active infection in positive herds and the characterization of the genotype.

Assessment of Luteal Function Using Rectal Palpation, B-Mode Ultrasonography, and Progesterone Determination to Improve Recipient Selection in Embryo Transfer Programs.

Proper selection of recipients determines the success of embryo transfer (ET) programs. Therefore, the objectives of this study were to assess the accuracy of rectal palpation (RP) in selecting recipients according to the size and firmness of their corpus luteum (CL) compared to ultrasonography (US) and progesterone determination (P4); to check if US or P4 provide additional information to RP with regard to selecting animals with higher odds of maintaining the pregnancy; and to verify the reliability of the presence of a cavity and the volume of the CL within the ovary (%CLOV) as predictors of the ET outcome. In Experiment 1, measurements for the largest and minor diameter (LADCL and MIDCL), CL area, and P4 at ET day were collected, as well as the RP score, in 94 heifers. In Experiment 2, measurements for the LADCL, MIDCL, CL volume, %CLOV, and presence of a cavity were collected, as well as data about the procedure and metabolic markers, in 108 heifers. No differences were found in Experiment 1, whereas in Experiment 2, just a tendency was observed for the variable of veterinarian. Consequently, these results suggest that RP and US are useful methods to select recipients with, that US and P4 do not offer additional data to use to select animals with higher odds of maintaining pregnancy, and that neither %CLOV nor cavitary CL were good indicators for pregnancy rates.

Comparison between transrectal palpation, B-mode and Doppler ultrasonography to assess luteal function in Holstein cattle.

Introduction: Over the years, the most common methods for monitoring reproductive health in cattle have varied from transrectal palpation to B-mode ultrasonography. Nowadays, some portable ultrasound equipment includes the Doppler mode. Therefore, the aim of this study was to compare the accuracy of the different methods to assess corpus luteum (CL) functionality. Methods: In Experiment 1, 53 Holstein lactating cows undergoing a synchronization protocol were examined via transrectal palpation and B-mode scanning. Measurements for the largest diameter (LAD) and subjective size of CL (SCLS) were collected. Data were analyzed using correlation analysis and ROC Curves. In Experiment 2, 30 Holstein non-lactating cows with a CL were administered PGF2α and examined several times after injection, first in B-mode and then with Power Doppler. Measurements for LAD, CL area (CLA) and subjective and objective CL blood flow were collected. Blood samples were taken in both experiments to determine P4 concentration. Data were analyzed using correlation analysis and the GLM repeated measures test. Results: Results for Experiment 1 showed that LAD was more accurate than SCLS. In Experiment 2, CLA was the best measurement to assess CL function, although both subjective and objective CL blood flow offer accurate information 24 h after PGF2α administration. Discussion: Consequently, ultrasonography provides more accurate information about CL function than transrectal palpation. Although CLA seems to be an earlier indicator of luteal function than blood flow, 24 h after the onset of luteolysis, both parameters are valid.

Housing assessment in farms in the Northwest of Spain: main facility weaknesses and strengths.

The aim of this research communication was to examine and report the current situation of dairy farms in the province of Lugo (Galicia, Spain) regarding facility problems. We assessed the facilities of 168 free-stall dairy farms, housing in total 9228 Holstein cows in milk. Housing factors related to the resting area, circulation area, feeding area, ventilation area and milking area, as well as animal-handling features, were evaluated. Distance measurements were performed using a laser metre or a roll metric tape. A survey was conducted to gather information about cleaning and preventive protocols. Our results showed that most farms do not comply with the objective for cubicle measurements, width of the crossovers, type of flooring and presence of a quarantine pen, which may have a negative impact on the health and productivity of the animals. Therefore, to maximise the profits of the farm, the recommendations given in this study may be useful as a guide when building a new farm or remodelling the existing ones.

Relationship between Postpartum Metabolic Status and Subclinical Endometritis in Dairy Cattle.

The aim of this study was to verify the importance of postpartum serum levels of certain metabolic markers as risk factors for subclinical endometritis (SE). Ninety-four Holstein cows were included in the study, and examinations were carried out between 30-45 days postpartum. Rectal palpation, vaginoscopy, transrectal ultrasound, endometrial cytology, and blood sample collections were performed. The percentage of polymorphonuclear neutrophils (%PMN) on the endometrium was evaluated, as well as serum levels of glucose, cholesterol, triglyceride, albumin, hepatic enzymes, urea, non-esterified fatty acids (NEFA), and ß-hydroxybutyrate acid (BHBA). Samples with ≥8% PMN were classified as positive to subclinical endometritis. According to the serum levels of BHBA, cows were classified as clinical ketosis (>2.6 mmol/L), subclinical ketosis (1.2-2.6 mmol/L), and healthy (<1.2 mmol/L). Additionally, body condition score, parity, date of last labor, peripartum issues, insemination date, date of pregnancy diagnosis and milk production information were collected. Data were analyzed using a multiple regression analysis. The results showed that as serum levels of BHBA rose, also did the %PMN, so that up to 60% of cows with clinical ketosis suffered from SE. On the other hand, the %PMN fell as serum levels of urea and albumin increased. Consequently, good postpartum management practices and early detection of metabolic alterations are necessary measures to control predisposing factors and reduce the incidence of SE.

Relationship between motile sperm subpopulations identified in frozen-thawed dog semen samples and their ability to bind to the zona pellucida of canine oocytes.

Studies performed on ejaculates from several species have identified discrete subpopulations of motile sperm. In dogs, motile sperm subpopulations have also been described in fresh and frozen-thawed semen. The subpopulation of the most rapid and progressively motile sperm has been suggested to be the most likely source of fertilizing spermatozoa. However, the significance of subpopulation differences among dogs and ejaculates relative to fertility is not known. The aim of this study was to investigate the relationship between the relative proportion of motile sperm subpopulations in frozen-thawed dog semen samples and their ability to bind to the zona pellucida of canine oocytes. Multiple linear regression analysis indicated that the subpopulation of the most rapid and progressively motile sperm was significantly and positively correlated with zona pellucida-binding assays (ZBA) outcomes: each 10% increase in this subpopulation was associated with an increase of 1.5 sperm bound per oocyte. Subpopulations of hyperactivated-like or locally motile sperm were negatively correlated with the ZBA results. It was concluded that subpopulation differences among frozen-thawed dog semen samples determined differences in the number of sperm bound to the ZP of canine oocytes.

Ovulation induction in rabbit does submitted to artificial insemination by adding buserelin to the seminal dose.

This study was aimed at determining if a GnRH analogue, buserelin, could be used for ovulation induction in rabbit does submitted to artificial insemination (AI) by intravaginal administration, by adding the hormone to the seminal dose. In a first experiment, 39 secondiparous experimental does (Hyplus strain PS19, Grimaud Frères, France, of about 30 weeks of age) were divided into 3 groups of 13 does each, which at the moment of AI received the following treatments, respectively: (1) control: an intramuscular injection of buserelin (0.8 microg/doe), (2) 8 microg/doe of buserelin added to the insemination dose, and (3) 16 microg/doe of buserelin added to the insemination dose. The experiment was done using 3 consecutive cycles at 42 day-intervals (n = 39). Four does from each of the 3 groups had blood taken at the fourth cycle for LH determination at 0, 60, 90, 120 and 150 min relative to AI. Kindling rates were 82% (28/34), 56% (29/36) and 85% (33/39), respectively for treatments 1, 2 and 3. In the does of groups 2 and 3, LH peaks were detected 60 min after AI, whereas in the does from group 1, the LH peak was detected 90 min after AI. Prolificacy was not different for the 3 treatments (average litter sizes ranged from 10.4 to 10.8). In a second experiment, 3 buserelin concentrations (8, 12 and 16 microg/doe) were used intravaginally and compared with the control treatment (0.8 microg/doe, via intramuscular). This experiment was done using 100 nulliparous rabbit does (Hyplus strain PS19, Grimaud Frères, France, of about 19 weeks of age) (4 groups of 25 does each) located on a commercial farm, to test if the previous results would be confirmed under field conditions. Kindling rates were no different (P < 0.05) for the 4 treatment groups [91.7% (22/24), 79.2% (19/24), 87.0% (20/23) and 87.5% (21/24) respectively for the control, 8, 12 and 16 microg of intravaginal buserelin], however, prolificacy was higher when using the maximal dose of intravaginal buserelin (11.7 vs. 9.4 for the control group). It was concluded that buserelin can be used for ovulation induction in rabbit does when included in the seminal dose, with similar AI results as those obtained when the hormone is administered intramuscularly.