Incidence Of Subclinical Mastitis Research Articles

Incidence of subclinical mastitis in cows of Peri urban areas of Hyderabad

Incidence of subclinical mastitis in cows of Peri urban areas of Hyderabad

Effect of a 60-day organic selenium-supplemented diet on the decrease of somatic cell counts in goat milk.

Selenium is an important element in nutrition, showing great potential in the udder health of dairy goats and in the control of subclinical mastitis. However, there are few studies that evaluated the influence of selenium supplementation on subclinical mastitis in goats. The aim of this study was to evaluate the incidence of subclinical mastitis in dairy goats supplemented with organic selenium (Se yeast) in a semi-arid region. Sixteen Saanen × Toggenburg crossbred lactating goats were allocated randomly into two treatments: with and without addition of organic selenium (Se) to the concentrate. Milk samples were collected every 20days from each udder half to determine the somatic cell count (SSC), chloride content, pH, electrical conductivity, microbiological isolation, composition, and selenium contents. The highest serum selenium concentrations in the blood of these goats occurred at 42days of supplementation (P < 0.001). Goats which received organic selenium supplementation had higher serum selenium concentrations (P < 0.05). The milk composition variables did not differ (P > 0.05) between the tested treatments, teats, and collections. After 60days of supplementation, a difference was observed (P < 0.05) between treatments for SSC, chloride content, and pH. Addition of organic selenium to the diet of dairy goats after 60days of supplementation was promising in reducing the somatic cell count, consequently improving milk quality.

Is AMR in Dairy Products a Threat to Human Health? An Updated Review on the Origin, Prevention, Treatment, and Economic Impacts of Subclinical Mastitis

Bovine mastitis is the most frequent and costly illness impacting dairy herds worldwide. The presence of subclinical mastitis in dairy cows has an impact on the decreased output of milk and milk quality, culling of affected cows, mortality rate, as well as mastitis-related treatment expenses, generating significant financial loss to the dairy industry. The pathogenic bacteria invade through the mammary gland, which then multiply in the milk-producing tissues causing infection, and the presence of pathogenic bacteria in milk is concerning, jeopardizes human health, and also has public health consequences. Intervention to promote herd health is essential to protect public health and the economy. This review attempts to provide an overview of subclinical mastitis, including mastitis in different species, the effect of mastitis on human health and its pathogenic mechanism, the prevalence and incidence of subclinical mastitis, and current preventive, diagnostic, and treatment methods for subclinical mastitis. It also elaborates on the management practices that should be followed by the farms to improve herd immunity and health. This review brings the importance of the threat of antimicrobial resistance organisms to the dairy industry. Furthermore, this review gives a glimpse of the economic consequences faced by the farmers and a futuristic mastitis market analysis in the dairy industry.

88 Association between the incidence of subclinical mastitis and embryonic/fetal loss in dairy cows at high-altitude conditions

Reproduction, Fertility and Development is an international journal publishing original research , review and comment in the fields of reproduction and developmental biology in humans, domestic animals and wildlife

Epidemiological investigation of mastitis in lactating buffalo cows in Nineveh governorate, Iraq

The study's objective was to investigate the incidence and predisposing factors of mastitis in lactating buffalo cows in the Nineveh governorate. A total of 160 recently calved buffalo cows were followed up in a prospective study during the first three months of lactation. Cases of clinical mastitis (CM) were investigated, and milk was sampled to identify the increase in somatic cell count (SCC) as an indicator of subclinical mastitis (SCM). Several epidemiological factors that can predispose to mastitis were also investigated. The incidence of CM was 9.4%, mostly recorded during the first ten days (4 days on average). The average CM duration per case was 35 ± 4.9 days. Different changes and clinical findings were revealed in milk and affected udder. The incidence of SCM (i.e., SCC > 200,000 per mL) was 83.75%, mostly recorded during the first month of lactation. Furthermore, the odds of SCM were high in winter. The study concluded that the incidence of CM in buffalo cows is very low. The chronic form characterizes CM, SCM is more common than CM, and winter is a predisposing factor for the infection. Examination of several control measures of mastitis is important to improve the production and hygiene of buffalo milk in Nineveh governorate.

Risk factors associated with subclinical mastitis and its effect on physico-mineral features of camel milk.

This study was carried out to determine the risk factors implicated in camel subclinical mastitis as well as the physico-mineral features of camel milk, there by examining the effect of this disease on those parameters. Milk samples were obtained from 125 lactating multiparous she-camels (aged 10-12years) during early lactation from December 2020 to April 2021. The samples were screened for the presence of subclinical mastitis using the somatic cell count (SCC) test. In total, 73 (58.4%) samples showed the presence of subclinical mastitis, whereas the remaining 52 (41.6%) samples showed negative results for subclinical mastitis. Standard methods were used to appreciate the pH and mineral composition of the milk samples, such as Ca, Na, Cl, and K contents. In camels, unhygienic udder condition was identified as the major risk factor for the incidence of subclinical mastitis. Calf mortality and increased herd size were associated with a higher prevalence of subclinical mastitis. Tick infestations were also significantly associated with increased disease risk. Use of antisuckling devices, increase in milk yield, and weakness of body condition were identified as main risk factors and were primarily associated with the disease. However, udder lesions and deformities, milking frequency, and owner visits had no significant influence on the occurrence of subclinical mastitis. The overall mean pH value was 6.54 ± 0.01 and the mean values of Ca, Na, Cl, and K contents were 148.24 ± 2.55, 53.83 ± 1.52, 124.99 ± 1.80, and 240.22 ± 3.80mg/100g, respectively. When the level of milk from healthy animals and that from camels with subclinical mastitis (SCC > 2.4 × 105) were compared, it showed that Na and Cl contents were significantly increased (p < 0.05) with the increase in SCC (56.52 vs.50.07 and 128.26 vs.120.40mg/100g, respectively). In contrast, there were no notable changes (p > 0.05) in the Ca, K, and pH values. In conclusion, udder hygiene, calf mortality, herd size, tick infestations, use of antisuckling devices, higher milk yield, and body condition were identified as the major risk factors that predispose the camels to subclinical mastitis. Furthermore, an increase in the Na and Cl levels in camel milk was observed along with udder inflammation. Consequently, the elevated Na and Cl levels in milk can be a sign of subclinical mastitis in camels.

Subclinical Mastitis Detected during the Last Gestation Period Can Increase the Risk of Stillbirth in Dairy Calves.

We hypothesized that subclinical mastitis detected during the last gestation period can increase the risk of stillbirth in dairy calves. The aim was to investigate the relation of subclinical mastitis detected during the last gestation period and its pathogens with the stillbirth of calves. Cows from the 210th day of pregnancy were selected for the study. They were divided into two groups: the first group-subclinical mastitis was confirmed on the farm by the California mastitis test (CMT); the second group of cows-mastitis was not confirmed by the CMT test. Groups of cows were compared according to the results of their calving-the number of stillborn calves. A stillborn calf was defined as a calf that dies at birth or within the first 24 h after calving, following a gestation period of 260 days. Our results suggest that decreasing the incidence of subclinical mastitis during the last gestation period (from the 210th day of pregnancy) can decrease the risk of stillbirth in dairy calves. Further, it is important to identify the pathogen because the highest risk of stillbirth was found in cows with mastitis caused by Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae, pathogenic Staphylococci and other Streptococci. Cows at the first calving had a 1.38-1.65-times higher risk of having stillborn calves than cows of parity ≥ 2. From a practical point, veterinarians and farmers can consider the effect of subclinical mastitis during late gestation on the risk of stillbirth and it could help for strategies of optimizing reproductive performance in dairy cows.

Prevalence of subclinical mastitis among dairy cattle and associated risks factors in China during 2012–2021: A systematic review and meta-analysis

Bovine mastitis, especially subclinical mastitis (SCM), is one of the most prevalent and economically costly diseases in the dairy industry worldwide. Understanding the prevalence and spatial distribution of bovine SCM and its associated risk factors will facilitate the prevention and control of the disease.We reviewed published studies pertaining to epidemiological surveys of SCM among dairy cows during the past decade (2012−2021) in China from inception to March 20, 2020, with PubMed, Clinical Trial, VIP, CNKI and databases being used to identify English and Chinese articles.Therefore, we retrieved 41 studies related to epidemiological surveys of SCM among dairy cows, using our eligibility criteria. We demonstrated that the prevalence of SCM in dairy cows was 37.7% during the selected periods, indicating a slight increase in the incidence of SCM in a comparison between 2012 and 2016 and 2017–2021. The estimated prevalence of SCM was 36.4%–50.2% in the seven regions, which was no statistically significant difference. The highest prevalence of SCM was 72% in Inner Mongolia Autonomous Region, and the lowest prevalence was 19% in Hubei Province.The variation in diagnostic methods was not significant in the studies. Dairy cows' parity was a risk factor associated with the prevalence rate of SCM. Cow's age might affect the prevalence of SCM during the selected periods. This study may facilitate the control with specific strategies to reduce costs and antibiotics overuse, enhance food safety and public health.

Interaction of blood calcium with luteal activity, energy metabolites and somatic cells count in post-partum dairy cows.

The aim of the research was to assess whether there was a link between serum calcium (Ca) after calving and serum progesterone, milk somatic cells count and Ca, and other blood metabolites in Achai and crossbred cows. Based on blood calcium level shortly after calving, thirty cows from both breeds were divided into a moderate group (≤10.0mg/dl of Ca) and a high group (>10.0mg/dl of Ca), with samples collected at 0, 7, 14, 21, 28 and 35days post-partum, respectively. On day 35 of the post-partum, crossbred and Achai cows with high blood Ca recorded significantly (p<.01) higher serum progesterone, glucose, triglyceride and milk Ca compared with moderate blood Ca group; however, serum cholesterol was significantly (p<.01) higher in both breeds under high blood Ca. Incidence of subclinical mastitis was significantly (p<.01) higher in crossbred and Achai cows under high blood Ca. The results showed that blood progesterone (OR=2.095), glucose (OR=1.024), triglyceride (OR=4.571), cholesterol (OR=1.111) and milk Ca (OR=1.141) resulted in a greater concentration in crossbred compared to Achai cows. A significant (p<.01) correlation was found between blood Ca and other blood metabolites (progesterone, glucose, triglyceride and cholesterol) in both breeds. In conclusion, greater serum Ca concentration after calving is associated with greater serum progesterone, glucose, triglyceride and milk Ca in crossbred cows; however, the incidence of subclinical mastitis increased.

The Risk Factor of Subclinical Mastitis Incident in Dairy Cattle in KPSP Ijen Makmur, Banyuwangi

Mastitis is an inflammatory disease in the internal tissue of the mammary gland. Subclinical mastitis does not show any changes in the shape of the mammary gland and to detect it can be examined the number of somatic cells in milk. Subclinical mastitis uses the California Mastitis Test (CMT) method as preliminary research to obtain preliminary data on the incidence of subclinical mastitis in KPSP Ijen Makmur, Licin District, Banyuwangi Regency. This research is descriptive research. The detection for this research was carried out by taking milk samples in cows per purposive and reacted CMT reagents issued circularly for 10-15 seconds. Observation of results is determined based on changes inconsistency with the existence of gel and the results of interview farmers as supporting data. The results showed that the influencing factors incidence of subclinical mastitis in KPSP Ijen Makmur, Licin District, Banyuwangi Regency were milk production, age and amount of lactation. In contrast, the biggest factor for reducing the risk of subclinical mastitis is udder health followed by body conditions measured by Body Condition Score.

Association Between Recycled Manure Solids Bedding and Subclinical Mastitis Incidence: A Canadian Cohort Study.

Recycled manure solids (RMS) are increasingly used as bedding for dairy cows. However, potential impact of RMS bedding on animal health is not well described. The objective of this study was to evaluate subclinical mastitis incidence in cows housed on RMS bedding. Twenty RMS farms and a comparative group of 60 straw-bedded farms were enrolled in a 1-year longitudinal study (2018–2019). Data from 11,031 dairy cows were collected. Variations of individual somatic cell count were evaluated using three different methods. First, we compared the cow's mean lactation linear score between cows housed on the two bedding types. Then, we compared across bedding types the risk for a given cow of having a milk test with a linear score ≥ 4. Finally, we evaluated the dynamics of somatic cell count using pairs of tests within a cow. More specifically, we considered that only pairs of DHI tests where the first test yielded a linear score < 4 were at risk of an incident subclinical mastitis event. Then, we defined a newly acquired subclinical mastitis when the second test was ≥ 4. All models were adjusted for putative confounders. We could not highlight a significant association between bedding type and cow's mean lactational linear score (least square mean of 2.47 in cows from RMS farms vs. 2.37 in straw farms; 95%CI for linear score's difference: −0.20, 0.40). Furthermore, we could not find an association between bedding type and the risk of a high linear score (≥ 4). For the latter, cows housed on RMS had 0.93 times the risk of having a high linear score than straw-bedded cows (%95 CI: 0.68, 1.28). Moreover, cows on recycled manure solids farms had 0.73 time the risk of acquiring subclinical mastitis when compared to straw-bedded farms. Again, this risk was not statistically significant (%95 CI: 0.54, 1.00). In our study, RMS bedding was not associated with subclinical mastitis, as measured by somatic cell count, when compared to cows housed on a more conventional bedding, straw bedding.

Environmental factors affecting milk composition in Holstein cattle breed

The incidence of mastitis in dairy herds is one of the main difficulties faced by dairy farmers, with a negative effect on the productivity of the herd and the welfare of the animals. Somatic cell count in milk is an indicator of udder health and frequency of clinical and subclinical mastitis incidence in dairy herds, and it is also often used to determine quality payments to dairy producers. Milk urea can be an indicator of the nutritional status of the dairy cows. The interpretation of these parameters assists in making important management decisions with regards to the health status and nutrition of dairy cattle. The objective of this study was to identify and evaluate environmental factors (farm, season, parity and stage of lactation) which affect the milk production and composition of Holstein breed, using field data. The presented research included 25,460 individual milk samples which were analysed as part of the Dairy Herd Improvement program, from 11 Holstein dairy farms in the region of Vojvodina, Northern Serbia. Analyses of raw milk samples were carried out on the FOSS instruments - CombiFossTMFT+, a combination instrument consisting of the MilcoScanTMFT+ and the FossomaticTMFC. Statistical data processing was carried out by applying General Linear Model procedure, Statistics 13. Farm, season of milk control, parity and stage of lactation were included in the models as fixed effects. Significant differences in milk urea concentrations and somatic cell count were observed between farms (P&lt;0.01), seasons (P&lt;0.01), parity (P&lt;0.01) and stage of lactation (P&lt;0.01). Results showed that there were a highly significant (P&lt;0.01) positive relationships between milk urea (MU) concentration and milk yield, MU and milk fat content, and between MU and solids non-fat (SNF), also between somatic cell count (SCC) and milk fat content, between SCC and protein content, as well as in between SCC and SNF. Highly significant negative relationships were found between milk urea and protein content and SCC, and between SCC and daily milk yield and lactose content. Proper analyses and interpretation of obtained results of milk samples obtained within the Dairy Herd Improvement program could contribute to better health management on the farms and it could have a positive impact on composition and nutritional value of milk, as well as on milk safety. It would be important to carry out further research in order to facilitate the detection of subclinical mastitis with MU as a potential indicator.

Genetic parameters for milk yield, casein percentage, subclinical mastitis incidence and sexual precocity using Bayesian linear and threshold models

Context The economic efficiency of a dairy system is associated with the animal’s productive and reproductive abilities. Therefore, selection criteria should include milk production and quality traits as well as traits related to health and fertility. Since such phenotypes can present non-normal distributions, the use of threshold models is appropriate to study the genetic variation of such traits. Aim To estimate variance components for dairy production and functional traits in a Brazilian Holstein cattle population using linear and threshold models under a Bayesian approach. Methods Data comprised 64 657 test-day records for milk yield (MY, kg/day), casein percentage (CP, % of milk) and subclinical mastitis incidence (SCM), along with 4460 records for sexual precocity (PREC) from 5439 cows. Both SCM and PREC were defined as binary traits. Genetic analyses were based on linear (for MY and CP) and threshold (for SCM and PREC) models using Bayesian estimation. Non-informative and informative priors were considered for variance components, and these models were compared using the deviance information criterion (DIC) and the absolute difference between DIC (Δ). Key results Posterior means of heritability for MY, CP, SCM and PREC were 0.14, 0.39, 0.13 and 0.38 (based on non-informative priors) and 0.13, 0.27, 0.13 and 0.44 (considering informative priors), respectively. The model based on non-informative priors was better (lower DIC) for CP, whereas for PREC, the best model used informative priors. No differences between priors (Δ &lt; 5) were observed for MY and SCM. Conclusions Threshold models were adequate for the analysis of non-normally distributed traits. The use of informative priors can be beneficial if specification is based on results from similar databases and models. Due to their high genetic variation, CP and PREC can be considered as selection criteria in animal breeding programs. In turn, accurate genetic evaluation for MY and SCM will depend on the pedigree and the information from genetically correlated traits. Implications Our study contributes to the understanding of the variation under important dairy production traits in a tropical Holstein population and provides information on the use of Bayesian threshold models as an appropriate method for the evaluation of non-normally distributed phenotypes.

Correlation between teat length and lactation periods on the level of subclinical mastitis occurrence in Sappy Valley Farm

This study aims to determine the correlation between dairy cattle teat length at several lactation periods and subclinical mastitis profile. This study used 43 dairy cattle at several lactation periods. The lactation periods of the cows studied were lactation periods 1, 2, and 3. Subclinical mastitis testing used IPB-1 Mastitis Test, and teat length was measured using a measuring tape (cm). The data is taken and then analyzed using the average and described. The results showed that the average teat length of 5.11 cm did not experience subclinical mastitis, while the average teat length was 5.48 cm, 6.09 cm, and 7.28 cm, respectively, had subclinical mastitis. The highest incidence of subclinical mastitis is influenced by teat length and lactation period. The length of the teat and the lactation period, the higher the severity of subclinical mastitis. These findings are essential for a practical clinical diagnostic approach in dairy cattle with subclinical mastitis.

Sanitary practices associated with animal welfare in the control of mastitis in the dairy herd

Agricultural practices are a powerful tool with health management contributing to the improved performance of production of animal welfare. The study aimed to verify that farming practices are important tools in the control of bovine mastitis and the degree of knowledge of the producers with respect to the practices. Guided visits were carried out the rural properties, when they were distributed educational materials and tools, made from recyclable material, used in the management of sanitary practices related to animal welfare. To evaluate the physiological profile were collected biological samples such as: blood, feces and milk, and for assessing the sanity and animal welfare were used a questionnaire. Blind 20 cows were selected for a total of 79 rooms of which breast; 36 rooms were negative to the CMT, but 12 were of these were positive to Staphylococcus and microbiology microorganism of higher occurrence. Animal welfare was compromised by the incidence of Subclinical Mastitis, infestation of flies and the absence of prophylactic measures. It is concluded that the use of good agricultural practices is a suitable tool associated with the animal welfare and important in the identification of bovine mastitis, and a lack of information and knowledge regarding best practices, especially in relation to preventive management.

The relationship between subclinical mastitis and reproductive performance of etawa crossbreed (PE) goat in Kokap, Kulonprogo, Yogyakarta

Etawa crossbreed (PE) goat farm has been well developed in Kokap, Kulonprogo, and Yogyakarta. The important aspects that support it are doe’s health and reproductive performance. This study aimed to determine the relationship between subclinical mastitis incidence and reproductive performance of the does. This study used 84 does from four different farms, which tested using California Mastitis Test (CMT) to determine the mastitis status. The reproductive performance data gained through a questionnaire and the relation to the mastitis status was analyzed using Chi-square. The result showed that the prevalence of subclinical mastitis was 16.67 % (14 does). In the non-mastitis does, 75.71% had long calving interval (CI), 88.57% had long days open (DO), 44.29% had Litter size (LS) 1, and 12.86% had service per conception (S/C) more than 2. Meanwhile, in the mastitis group, the does with long CI was 71.43%, long DO was 85.71%, LS 1 was 28.57%, and S/C > 2 was 14.29%. The chi-square analyses showed no relationship between subclinical mastitis cases with long CI (X2=0.22), long DO (X2=0.09), LS 1 (X2=1.19), and high S/C (X2=0.02). It can be concluded that there was no relation of mastitis cases to reproductive performance of PE does in Kokap, Kuloprogo, and Yogyakarta.

Associations of udder biometry with subclinical mastitis in Gir crossbred cows

The investigation was undertaken on 110 Gir crossbred cows of different order of lactation and stage of lactation maintained at Research Cum Development Project on Cattle, MPKV, Rahuri. The overall least squares means of udder length, udder width, udder depth and udder circumference were 65.23 ± 1.45, 63.24 ± 1.45, 19.03 ± 0.51 and 86.49 ± 1.50 cm respectively. The least squares analysis of variance showed significant (P&lt;0.05) effect due to order of lactation on udder length in crossbred cows. Also, order of lactation had significant (P&lt;0.01) effect on udder width and udder circumference. However, stage of lactation exerted non-significant influence on all udder measurement traits. In crossbred cows udder length had positive and significant (P&lt;0.01) correlation with udder width, udder circumference and udder depth. The correlation of udder width with udder circumference and udder depth was positive and highly significant (P&lt;0.01). There was positive and significant (P&lt;0.01) correlation of udder circumference with udder depth. The frequencies of trough, round, goaty and pendulous type udder in crossbred cows were 63.64%, 8.18%, 11.82% and 16.36% respectively. Among 110 cows 48 (43.64%) cows were found positive for subclinical mastitis. The higher occurrence of subclinical mastitis was observed in cows having pendulous udder (66.66%) followed by goaty (53.84 %), round (44.44 %) and trough (35.71 %) shape udder. Maximum number of positive subclinical mastitis cases were found in larger udder length (&gt;75 cm), udder width (&gt;75 cm), udder depth (&gt;25 cm) and udder circumference (&gt;95 cm). Highest occurrence (78.26%) of subclinical mastitis was found in cows of sixth and above lactation. Maximum occurrence of subclinical mastitis was noted in cows which were in late (46.15%) stage of lactation followed by early (40%) and mid (37%) stage of lactation. The traits udder shape, udder length and udder depth had positive and significant association with incidence of subclinical mastitis in crossbred cows.

Management practices related to the incidence of sub clinical mastitis (SCM) in lactating dairy cow in Banyuwangi, Indonesia

Mastitis is one of the overwhelming diseases in the dairy cow industry and it has reduced milk yield, quality and increased cow’s culling rate. This study was carried out to establish the prevalence of subclinical mastitis in the lactating dairy cow in Banyuwangi regency, East Java, Indonesia. Forty-nine milk samples from 13 head dairy cows were tested for subclinical mastitis using the California Mastitis Test (CMT). The descriptive statistics were performed, and the association between the management practice and incidence of subclinical mastitis was also analyzed using GLM. The result shows that subclinical mastitis was associated with milking type, washing before milking, pre-dipping with warm water and post dipping with iodine. Based on this result, we conclude that mastitis in Banyuwangi is relatively high and need more corcern related to management practice to prevent and reduce SCM incident in lactating dairy cow.

Partial budget analysis of culture- and algorithm-guided selective dry cow therapy

The objectives of this study were to (1) use partial budget analysis to estimate the cash impact for herds that switch from blanket dry cow therapy (BDCT) to culture- or algorithm-guided selective dry cow therapy (SDCT) and (2) conduct a sensitivity analysis to investigate effects in situations where SDCT increased clinical and subclinical mastitis risk during the subsequent lactation. A partial budget model was created using Monte Carlo simulation with @Risk software. Expenditures associated with dry-off procedures and health outcomes (clinical and subclinical mastitis) during the first 30 d in milk were used to model herd-level effects, expressed in units of US dollars per cow dry-off. Values for each economic component were derived from findings from a recent multisite clinical trial, peer-reviewed journal articles, USDA databases, and our experiences in facilitating the implementation of SDCT on farms. Fixed values were used for variables expected to have minimal variation within the US dairy herd population (e.g., cost of rapid culture plates) and sampling distributions were used for variables that were hypothesized to vary enough to effect the herd net cash impact of one or more DCT approach(es). For Objective 1, herd-level udder health was assumed to be unaffected by the implementation of SDCT. For culture-guided SDCT, producers could expect to save an average of +$2.14 (-$2.31 to $7.23 for 5th and 95th percentiles) per cow dry-off as compared with BDCT, with 75.5% of iterations being ≥$0.00. For algorithm-guided SDCT, the mean net cash impact was +$7.85 ($3.39-12.90) per cow dry-off, with 100% of iterations being ≥$0.00. The major contributors to variance in cash impact for both SDCT approaches were percent of quarters treated at dry-off and the cost of dry cow antibiotics. For Objective 2, we repeated the partial budget model with the 30-d clinical and subclinical mastitis incidence increasing by 1, 2, and 5% (i.e., risk difference = 0.01, 0.02, and 0.05) in both SDCT groups compared with BDCT. For algorithm-guided SDCT, average net cash impacts were ≥$0.00 per cow dry-off (i.e., cost effective) when mastitis incidence increased slightly. However, as clinical mastitis incidence increased, economic returns for SDCT diminished. These findings indicate that when SDCT is implemented appropriately (i.e., no to little negative effect on health), it might be a cost-effective practice for US herds under a range of economic conditions.

Mastitis Incidence in First-Calf Heifers on the Small Farms of the Republic of Armenia

The article presents the results of scientific research aimed at studying mastitis incidence in first-calf heifers and the affection of udder quarters in the mastitic first-calf heifers on eleven small farms in the Kotayk and Ararat regions of Armenia. According to the results of scientific research, subclinical mastitis incidence in first-calf heifers made 32.3 %, while the number of affected udder quarters was 78 (per 100 animal units). The clinical mastitis was diagnosed in 10.7 % of firstcalf heifers and the number of affected udder quarters was 25. Upon the research results, the experimental farms were provided with practical recommendations on prevention of mastitis in first-calf heifers.