Prevalence, risk factors, and effects on fertility of cytological endometritis at the time of insemination in Norwegian Red cows

Exploring uses for an algorithmically generated Animal Welfare Indicator for welfare assessment of dairy herds

On-farm welfare assessment is time-consuming and costly. Assessing welfare using routinely collected herd data has been proposed as a more economical alternative. The online Animal Welfare Indicator (AWI), developed by a Norwegian dairy cooperative, applies an algorithm to routinely collected health, production, and management data to "indicate" aspects of animal welfare at herd level. The overall AWI score is based on 10 AWI subindicator scores, representative of elements of animal welfare such as claw health, udder health, and mortality. Our cross-sectional study explored 2 ways in which the AWI may enable more efficient welfare assessment of Norwegian dairy herds. First, we investigated using the AWI to reduce the duration of on-farm assessments by replacing on-farm measures. Second, we examined reducing the number of on-farm welfare assessments by using the AWI to predict which herds have poorer welfare with respect to specific on-farm measures. Using Spearman rank analyses, we investigated if the AWI scores for 157 herds were associated with 24 on-farm welfare variables measured contemporaneously by Welfare Quality assessment. The mortality AWI subindicator score and the percentage mortality in the previous 12 mo were moderately correlated, as were the udder health AWI subindicator score and the percentage high somatic cell count (SCC) in the previous 3 recordings. Only negligible or weak correlations were found between the other AWI scores and the on-farm assessment variables. We built Generalized Linear Models using AWI scores as independent variables to predict herds with poorer welfare. Herds were classified as having poorer welfare based on their results in specific on-farm welfare measures. We evaluated the models' predictive ability and accuracy. Moderately accurate models were built for predicting poorer herds with respect to high SCC, mortality, and moderate or severe lameness. The other models were less accurate. The AWI scores were generally unsuitable as replacements of on-farm welfare measures. The AWI subindicators for udder health and mortality could replace the on-farm welfare measures related to those 2 topics, but there was some overlap in the data used to calculate them. Despite a lack of independence, the use of those 2 AWI subindicators may marginally reduce the duration of on-farm assessments. A prediction model based on AWI scores showed potential for identifying herds with poorer welfare in terms of moderate or severe lameness, facilitating more efficient use of resources for on-farm lameness assessment. As a consequence of the data used in the AWI, it was only reflective of health-related welfare outcomes.

Salvia miltiorrhiza ameliorates endometritis in dairy cows by relieving inflammation, energy deficiency and blood stasis

Introduction: According to traditional Chinese veterinary medicine, endometritis is caused by a combination of Qi deficiency, blood stasis, and external evil invasion. Salvia miltiorrhiza is a traditional Chinese medicine that counteracts blood stasis and has additional demonstrated effects in boosting energy and restraining inflammation. Salvia miltiorrhiza has been employed in many traditional Chinese prescriptions that have proven effective in healing clinical dairy cow endometritis. Methods: the in vivo effect of Salvia miltiorrhiza in treating endometritis was evaluated in dairy cows. In addition, bovine endometrial epithelium cell inflammation and rat blood stasis models were employed to demonstrate the crosstalk between energy, blood circulation and inflammation. Network analysis, western blotting, qRT-PCR and ELISA were performed to investigate the molecular mechanism of Salvia miltiorrhiza in endometritis treatment. Results: The results demonstrate that treatment with Salvia miltiorrhiza relieves uterine inflammation, increases blood ATP concentrations, and prolongs blood clotting times. Four of the six Salvia miltiorrhiza main components (SMMCs) (tanshinone IIA, cryptotanshinone, salvianolic acid A and salvianolic acid B) were effective in reversing decreased ATP and increased IL-1β, IL-6, and IL-8 levels in an in vitro endometritis model, indicating their abilities to ameliorate the negative energy balance and external evil invasion effects of endometritis. Furthermore, in a blood stasis rat model, inflammatory responses were induced in the absence of external infection; and all six SMMCs inhibited thrombin-induced platelet aggregation. Network analysis of SMMC targets predicted that Salvia miltiorrhiza may mediate anti-inflammation via the Toll-like receptor signaling pathway; anti-aggregation via the Platelet activation pathway; and energy balance via the Thermogenesis and AMPK signaling pathways. Multiple molecular targets within these pathways were verified to be inhibited by SMMCs, including P38/ERK-AP1, a key molecular signal that may mediate the crosstalk between inflammation, energy deficiency and blood stasis. Conclusion: These results provide mechanistic understanding of the therapeutic effect of Salvia miltiorrhiza for endometritis achieved through Qi deficiency, blood stasis, and external evil invasion.

The microbiota of uterine biopsies, cytobrush and vaginal swabs at artificial insemination in Norwegian red cows

The individual resistance or tolerance against uterine disease in dairy cattle might be related to variations in the uterine tract microbiota. The uterine tract microbiota in dairy cattle is a field of increasing interest. However, its specific taxonomy and functional aspects is under-explored, and information about the microbiota in the endometrium at artificial insemination (AI) is still missing. Although uterine bacteria are likely to be introduced via the vaginal route, it has also been suggested that pathogens can be transferred to the uterus via a hematogenous route. Thus, the microbiota in different layers of the uterine wall may differ. Norwegian Red (NR) is a high fertility breed that also has a high prevalence of subclinical endometritis (SCE), an inflammation of the uterus that has a negative effect on dairy cattle fertility. However, in this breed the negative effect is only moderate, raising the question of whether this may be due to a favorable microbiota. In the present study we investigated the endometrial microbiota in NR at AI by biopsy and cytobrush samples, and comparing this to the vaginal microflora. The second objective was to describe potential differences at both distinct depths of the endometrium, in healthy vs SCE positive NR cows. We sampled 24 lactating and clinically healthy Norwegian red cows in their second heat or more after calving, presented for first AI. First, we obtained a vaginal swab and a cytobrush sample, in addition to a cytotape to investigate the animal's uterine health status with respect to SCE. Secondly, we acquired a biopsy sample from the uterine endometrium. Bacterial DNA from the 16S rRNA gene was extracted and sequenced with Illumina sequencing of the V3-V4 region. Alpha and beta diversity and taxonomic composition was investigated. Our results showed that the microbiota of endometrial biopsies was qualitatively different and more even than that of cytobrush and vaginal swab samples. The cytobrush samples and the vaginal swabs shared a similar taxonomic composition, suggesting that vaginal swabs may suffice to sample the surface-layer uterine microbiota at estrus. The current study gave a description of the microbiota in the healthy and SCE positive NR cows at AI. Our results are valuable as we continue to explore the mechanisms for high fertility in NR, and possible further improvements.

Comparative evaluation of two commercial pregnancy-associated glycoproteins tests for early detection of pregnancy in dairy cattle

The aim of this study was to determine and compare the diagnostic accuracy of two pregnancy-associated glycoproteins tests (IDEXX on-farm pregnancy test [OFPT] and IDEXX rapid visual pregnancy test [RVPT]) for early pregnancy diagnosis in dairy cattle. Blood samples were collected from Holstein cows (n = 317) by coccygeal venipuncture 28-31 days after artificial insemination (AI). The OFPT and RVPT were performed on the farm within 2 h after blood collection using whole blood or blood serum. Transrectal ultrasonography (USG) was performed for pregnancy diagnosis on day 32 post-AI as a gold standard. One-hundred fourteen cows were diagnosed as pregnant and 203 were determined to be nonpregnant. Furthermore, embryonic mortality was detected in four of the nonpregnant animals, based on fragmented/dispersed embryonic membranes and the absence of heartbeat. Sixteen and 14 false positive results (13 jointly for both tests) were obtained for the RVPT and OFPT, respectively. Three false negative results were obtained for the RVPT. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for the OFPT were 100%, 93.1%, 89.1%, 100% and 95.6%, and for RVPT were 97.4%, 92.1%, 87.4%, 98.4% and 94.0%, respectively. The ability of both tests to distinguish between pregnant and open cows was very good (AUC of both tests above 0.9). The OFPT and RVPT almost perfectly agreed with each other. According to McNemar's analysis, false positive results have been caused difference between the two pregnancy tests and USG. In conclusion, both the RVPT and OFPT proved to be reliable and practical methods for pregnancy diagnosis 28-31 days after AI in dairy cows. However, the results of both pregnancy tests were affected by the occurrence of embryonic mortality around the time of their employment.

Obtaining an animal welfare status in Norwegian dairy herds-A mountain to climb

Introduction

Knowing the national status of animal welfare, one can identify welfare problems and set a benchmark against which improvements can be compared. Such a status is potentially invaluable for tangible, sustained animal welfare improvement. The objective of this cross-sectional study was to report the status of animal welfare in Norwegian loose-housed dairy herds as assessed using the Welfare Quality^® Assessment Protocol. Additionally, we investigated if the welfare status varied on a regional basis.

Methods

In total, 155 herds in eight of Norway's eleven counties were assessed by six trained Welfare Quality^® assessors. This article presents the herd prevalences of common welfare issues in dairy production in Norway, as well as integrated welfare scores. To determine whether welfare status varied regionally in Norway, generalized linear modeling was used to estimate the mean welfare score for five regions in the four Welfare Quality^® principles: A. Good feeding, B. Good housing, C. Good health, and D. Appropriate behavior. These estimated mean welfare scores and their 95% confidence intervals were subsequently assessed for significant variation.

Results

Encouraging findings included the low mean herd prevalence of 'very lean' cows (3.0%) and the high proportion of cows (59.8%) which could be touched during avoidance distance testing, indicating a positive relationship between stockpeople and their cattle. Challenges affecting the welfare of Norwegian dairy cows were also identified. Of particular concern were issues related to the cows' environment such as prolonged times needed to complete lying down movements and integument alterations. No herd was completely free of changes to the integument and, on average, 77.9% of each herd were affected either mildly or severely. Animal welfare did not appear to vary much between the five regions assessed. Our investigation revealed significant regional variation between two regions (Trøndelag and Vestlandet North) in only the Welfare Quality^® principle Good housing (p < 0.01).

Discussion

The almost complete absence of regional variation demonstrates that animal welfare status generally varies most at herd level. In conclusion, both welfare challenges and encouraging findings were identified in loose-housed Norwegian dairy herds. To improve animal welfare, herd-specific interventions are most likely to be effective in these herds.

Individual and Combined Effects of Diseases and Cytological Endometritis on Reproductive Performance and Culling of Dairy Cows: Preliminary Results

The objective of this study was to evaluate the effect of calving-related disorders/clinical diseases (DIS) and cytological endometritis (CYTO) on the reproductive performance and culling of dairy cows. In a total of 119 multiparous Holstein cows, DIS were recorded and CYTO was diagnosed at 40 ± 2 d in milk. Onset of luteal activity was defined as the first postpartum measurement of milk progesterone >5 ng/mL. A dummy variable containing all four possible permutations between DIS and CYTO statuses was created. The pregnancy rates after first artificial insemination were 57.7, 42.9, 23.0 and 15.8% for the DIS−/CYTO−, DIS+/CYTO−, DIS−/CYTO+ and DIS+/CYTO+ groups, respectively. The hazard of pregnancy was affected by DIS−/CYTO+ and DIS+/CYTO+ health statuses (hazard ratio (HR) = 0.43 and 0.29, respectively), whereas DIS+/CYTO− and DIS−/CYTO− cows had a similar hazard to pregnancy. The hazard of onset of luteal activity was affected by DIS+/CYTO+ health status (HR = 0.45), but not by DIS+/CYTO− and DIS−/CYTO+ health statuses. Compared with DIS−/CYTO− cows, DIS−/CYTO+ and DIS+/CYTO+ cows had 4.24 and 5.57 times the odds of being culled, respectively. Culling was not affected by DIS+/CYTO− health status. In conclusion, CYTO+ status, irrespective of DIS status, decreased the pregnancy rate. When DIS+ and CYTO+ were combined, they had an additive negative effect. Our preliminary findings suggest that the far-reaching consequences of clinical diseases on fertility and culling can be mediated through the development of CYTO. Further investigations including a larger number of cows are required to confirm these results.

Heritability of subclinical endometritis in Norwegian Red cows

Subclinical endometritis (SCE) is highly prevalent in dairy cows, causing negative effects on reproductive outcomes and the producer economy. Genetic selection for animals with better resilience against uterine disease should be prioritized due to both sustainability and animal welfare. Therefore, the aim of the present study was to estimate the heritability of SCE in the Norwegian Red (NR) population. Moreover, future perspectives of the condition as a fertility phenotype for breeding are discussed. A total of 1,642 NR cows were sampled for SCE at the time of artificial insemination, using cytotape. The percentage of polymorphonuclear cells (PMN) in each sample was established by cytology, through the counting of 300 PMN and epithelial cells. The mean percentage of PMN was 5%. Different trait definitions were examined, and SCE was defined as binary traits, based on the following cut-off levels of PMN: Cyto0 = PMN >0, Cyto3 = PMN >3%, Cyto5 = PMN >5%, Cyto10 = PMN >10%, and Cyto20 = PMN >20%. The mean ranged from 0.07 (Cyto20) to 0.59 (Cyto0). We also analyzed PMN as a continuous variable using percent PMN. Information on the animals and herds was obtained from the Norwegian Dairy Herd Recording System. The pedigree of cows with data included a total of 24,066 animals. A linear animal model was used to estimate the heritability. The only trait definition that had an estimated genetic variance larger than the standard error was Cyto5, with an estimated heritability of 0.04. For all other definitions, the genetic variance was not significantly different from zero. A cut-off level of 5% PMN has been established as a general threshold for the definition of SCE in earlier literature. The standard errors of the estimated variance components were relatively large, and results should be interpreted with caution. However, the current study indicates that SCE is heritable at a similar level to that of clinical endometritis and metritis, and has potential as a future fertility phenotype to be used for breeding purposes. A more feasible method to diagnose SCE is needed to establish larger data sets.

Assessment of different diagnostic methods for the identification of subclinical endometritis in dairy cows with pathological puerperium and their reliability to conceive

The aim of study was to evaluate different methods for subclinical endometritis (SCE) diagnoses and their accuracy to predict pregnancy. The study was performed on 51 postpartum cross breed dairy cows with pathological puerperium. Artificial insemination (AI) was done in spontaneous estrus. Endometrium samples were taken by cytotape (CT), cervical mucus (CM) samples by Metricheck and smears for crystallization degree were obtained at AI day. Blood serum samples for progesterone (P4) concentration determination were taken at AI day and 17 days later. Cows were examined by ultrasound 35 days after AI to confirm pregnancy. Percent (%) of polymorphnuclear leukocytes (PMNs) taken by CT were expressed by ROC curve (with cut-off point set at 1%). Out of the total of 51 cows involved in the study, 13.73% true positive and 41.17% true negative cows were found (54.90%). The content of CM sampled with Metricheck was altered in 11 cows (21.57%), and one of them was pregnant (1.96%). An average macroscopic CM value for pregnant cows was 0.06±0.24 vs. 0.39±0.79 for non-pregnant (p<0.05). An average value of CM crystallization in pregnant cows was 2.50±1.04 vs. 1.85±1.15 in non-pregnant (p<0.05). P4 concentration was not statistically different at AI day, but was statistically significantly higher 17 days later in pregnant cows (p = 0.002). CT alterations may be a reliable diagnostic tool for SCE diagnosis, while macroscopic CM alterations may be used for CE detection. P4 determination is beneficial in pregnancy diagnosis while CM crystallization degree is helpful in determination of best time for AI.