Udder Quarters Research Articles

Association between automatic milking system parameters and intramammary infections in dairy cows at dry-off

IntroductionThe current global concern over increasing antimicrobial resistance among animal and human pathogens has motivated efforts to reduce antimicrobial drug use in food animals and its impact on antimicrobial resistance. One such strategy is to use selective dry cow therapy (SDCT) in dairy cows, which involves treating only cows with intramammary infection (IMI) at dry-off. However, efficient methods are needed to identify cows with IMI at dry-off to implement SDCT. Automatic Milking Systems (AMS) data may help farmers identify cows with IMI when individual Somatic Cell Count (SCC) is not routinely tested. This study assessed the correlation between cow-level and quarter-level AMS parameters and IMI at dry-off.Methods & ResultsA total of 733 udder quarters (comprising both Primiparous [PRIM] and Multiparous [MULT] cows) were sampled and categorized for IMI based on bacterial growth and SCC. Data were aggregated both daily and into 7-day and 15-day intervals preceding dry-off. The quarter-level prevalence of bacterial growth at dry-off was 24.28% overall. When stratified by parity, logistic regression analysis at 15 days to dry-off revealed that the average difference in mastitis detection index (MDi) in PRIM, MDi, and standard deviation milk flow rate in MULT were associated with increased odds of IMI at dry-off. Similarly, data from 7 days to dry-off revealed that average peak milk flow rate in PRIM, and MDi in MULT were associated with increased odds of IMI at dry-off. However, an increase in average milk yield was associated with decreased odds of IMI.Discussion & ConclusionOur findings underscore the significance of MDi, milk flow rate, peak milk flow rate, and milk yield in predicting IMI at dry-off. Notably, stronger associations were observed with data collected 7 days preceding dry-off. Further research is warranted to refine and validate algorithms amalgamating these variables for precise IMI prediction in cows at dry-off.

Thermographic assessment of mastitis progression in sahiwal cattle: Insights into the patterns in the natural course of infection

Mastitis is a global concern in the dairy sector, demanding innovative solutions for effective management for quality lifetime milk production. In this study, infrared thermography (IRT) as a non-invasive technology was integrated into routine farm activities for continuous health monitoring of animals. For 30 days, we systematically monitored the udder health status in 40 Sahiwal cows (160 quarters), employing IRT along with the California Mastitis Test (CMT). We also assessed somatic cell count (SCC), microbial identification, and milk quality parameters of representative samples. The thermal imaging data was analyzed, considering both backward propagation from the 0th day to the −10th day and forward propagation from the 0th day to the +10th day. Our findings revealed that on the 0th day, the mean temperatures of the udder surface skin temperature (USST) and teat skin surface temperature (TSST) exhibited differences (p < 0.05) between the quarters affected by sub-clinical mastitis (SCM) and clinical mastitis (CM) in comparison to the healthy quarters, with the highest degree of difference observed. The observed temperature differences between CM and SCM quarters compared to healthy ranged from 1.8 to 3.62 °C and 0.98 to 3.23 °C for USST, and from 1.68 to 3.16 °C and 0.56 to 2.32 °C for TSST, respectively. Furthermore, our observations indicated that both udder and teat quarters responded differently to mastitis. A temperature rise of 1.37 °C in SCM quarters and 1.75 °C in CM quarters was observed between the −10th and -8th day relative to day 0, with the increase being more pronounced in the morning hours. Also, a notable temperature surge occurred during the -2nd and -1st days relative to the 0th day. The log10SCC values and milk quality parameters significantly differed (p < 0.05) between mastitis-affected and healthy samples. In addition, Staphylococcus spp. was identified as the predominant mastitis-causing pathogen in the bacteriological identification conducted in this study. Therefore, IRT efficiently assesses the initiation point of udder infection in Sahiwal cows, aiding in effective udder health management.

Intramammary ozone therapy in Candida mastitis

This study investigated the effect of intramammary ozonated distilled water on treatment success rates for mastitis caused by Candida spp., which resulted from intensive antibiotic use. The study material involved 60 Holstein udder quarters infected with Candida spp., which were divided into an ozone treatment group (n=30) and a control group (n=30). To conduct the study, 25 μg/ml of ozonated distilled water was applied intramammary to each udder quarter from which the causative agent had been isolated. Milk samples were collected on days 6 and 18 after application, and microbiological and mycological analyses were performed on them. The analysis results showed no statistically significant difference in recovery rates between days 0-6 after treatment, but a significant difference emerged between days 6-18 (P

Seasonal assessment of mastitis in crossbred goats: A thermographic approach

Sub-clinical mastitis exhibits a higher prevalence in dairy goats than clinical mastitis, necessitating the adoption of non-invasive diagnostic techniques such as infrared thermography (IRT) to detect this economically significant production disease in the dairy sector. Accordingly, this study aims to employ IR imaging of the udder and teat quarters of lactating crossbred goats (Alpine × Beetal and Sanen × Beetal) across various seasons, utilising IRT, to discern cases of sub-clinical (SCM) and clinical mastitis (CM). Over a year, 100–110 lactating crossbred dairy goats underwent consistent IRT screenings, followed by a comprehensive evaluation of udder health status using the California mastitis test and somatic cell count (SCC). The receiver operating characteristic (ROC) analysis was conducted to establish the cut-off values for different thermographic parameters in this study. The results revealed that the SCC increased significantly (p < 0.01) in healthy, SCM, and CM milk samples across the seasons. The analysis of ROC revealed a comparatively higher sensitivity, specificity, and accuracy for udder thermograms during SCM than CM and vice versa for teat thermograms. IRT analysis reflected a difference (p < 0.01) in the udder and teat thermograms among quarters of healthy, SCM, and CM in summer, winter, autumn, and rainy seasons. A significant increase (p < 0.01) in udder thermograms was observed for quarters affected with SCM and CM relative to healthy, with an increase of 1.89 and 2.94 °C in winter, 0.85 and 1.63 °C in summer, 0.73 and 1.41 °C in rainy, and 1.33 and 2.38 °C in autumn, respectively. Similarly, for teat thermograms it was 1.79 and 2.81 °C in winter, 0.76 and 1.41 °C in summer, 0.70 and 1.37 °C in rainy, and 1.09 and 1.93 °C in autumn, respectively. Therefore, regardless of the seasons examined in this study, IRT proves to be an effective and supportive tool for early mastitis detection in lactating crossbred dairy goats.

Association of Dry Period Length with Automatic Milking System, Mastitis, and Reproductive Indicators in Cows.

The objective of this study was to evaluate the association between dry period (DP) length and various indicators of productivity, reproduction, and udder health in cows managed with an automatic milking system. We analyzed records from 3861 cows, categorizing them into three groups based on their DP duration: (1) <40 days, (2) 40-70 days, and (3) DP > 70 days. Cows with a DP of 40-70 days had an average energy-corrected milk production that was 8.2 kg greater than that of cows with a short DP and 5.0 kg greater than that of cows with a long DP (p < 0.001). Milk from the 40-70-day DP group exhibited the highest lactose concentration (4.64 ± 0.01%). Additionally, cows with the longest DP had the smallest proportion of animals with a milk fat-to-protein ratio of 1.2 to 1.4. Cows with a DP of 40-70 days also showed the lowest milk electrical conductivity across all udder quarters, whereas cows with the shortest DP had the highest conductivity. The highest conception rates were observed in the group with the shortest DP. These results suggest that a DP of 40-70 days is optimal for maximizing milk production and improving both udder health and reproductive performance under AMS. Proper management of DP duration can be an effective strategy for sustainable dairy herd management.

The Influence of Milk Leakage, Udder Pressure and Further Risk Factors on the Development of New Intramammary Infections during the Dry Period of Dairy Cows.

Prevention of new intramammary infection (NIMI) during the dry period (DP) is essential to prevent the development of mastitis in dairy cows. To investigate risk factors for NIMI, 212 cows, comprising a total of 848 udder quarters, were examined in this study. Quarter milk samples were taken on the day of drying off and 7 ± 3 days after calving. Cow- and quarter-level associated risk factors were assessed at the beginning of the DP and after calving. In total, 7.1% of the udder quarters developed an NIMI between the samplings. Non-aureus staphylococci (40.4%) and Gram-negative pathogens (22.8%) were most frequently the cause of NIMI. The observed milk leakage prevalence was 16.7%, with a peak 24 h after drying off. Simultaneously, the udder pressure peaked 24 h after drying off. A significant correlation between milk yield on the day before drying off and milk leakage could be proven. Cows with quarters leaking milk produced an average milk yield of 28.32 kg on the day before drying off. Generalised linear mixed models and odds ratios were calculated to determine the significant risk factors for NIMI during the DP and early lactation. Quarters leaking milk had 3.4 higher odds for NIMI between the samplings compared to quarters without milk leakage. Quarters from cows with dirty udders had 3.1 higher odds of developing an NIMI between the samplings compared to quarters from cows with clean udders. The results of this study demonstrate the importance of dry cow management before drying off and during the critical period of active involution of the udder tissue.

81 Effects of udder quarter location on colostrum yield, nutrients, and immunoglobulin G in beef heifers

Abstract We hypothesized that colostrum total nutrients and immunoglobulin G (IgG) would not be affected by side of the udder, but that they would be greater in the rear versus the front half of the udder due to difference in volume of colostrum produced. Complete colostrum yield was collected individually from each quarter pre-suckling [40.5 ± 21.0 min (SD)] from fall-calving crossbred beef heifers (body weight = 472 ± 34 kg; body condition score (= 5.3 ± 0.4) that were either individually-fed 100% (control; n = 12) or 70% (nutrient restricted; n = 12) of NASEM metabolizable energy and metabolizable protein requirements from d 160 of gestation to calving. Analysis of colostrum lactose, protein, triglycerides, and free glucose was performed using colorimetric assays on a UV-visible light microplate reader. Colostrum IgG was analyzed using a commercially available ELISA kit. Quarter yield, nutrient or IgG concentration, and total nutrients or IgG were analyzed using the mixed procedure of SAS with fixed effects of udder location, nutritional plane, and their interaction in the model. Nutritional plane was not part of the current objective, but was included to account for variation in colostrum yield due to nutrient restriction, as we have previously reported. Separate statistical comparisons were made between the front and rear quarters and between the right and left quarters of the udder, with each quarter considered a sampling unit within each experimental unit (half) for both analyses. The interaction of udder location × nutritional plane did not affect (P ≥ 0.11) any variable. Nutrient restriction decreased (P ≤ 0.03) colostrum yield, total lactose, and total free glucose compared with controls. Front quarters produced less volume (P &amp;lt; 0.001; 36.2% of total); total lactose, protein, and free glucose (P ≤ 0.02; 34.3 to 43.3%); and total IgG (P &amp;lt; 0.001; 33.7%) than rear quarters. Front quarters tended to produce less (P = 0.07; 43.3%) total triglycerides than rear quarters. Lactose concentration was 10.5% greater (P = 0.05) in front compared with rear quarters, but other nutrient or IgG concentrations were not affected (P ≥ 0.18). Udder side did not affect total volume (P = 0.78), total nutrients (P ≥ 0.36), or total IgG (P = 0.79). The left side represented 50.7% of the total volume and 50.1 to 53.4% of total nutrients and IgG produced. Concentration of nutrients and IgG also were not affected (P ≥ 0.31) by udder side. In conclusion, colostrum did not differ between udder sides, but, relative to front quarters, rear quarters produced greater nutrient and IgG yield due to greater colostrum volume with minimal differences in nutrient or IgG concentrations.

Milk yield and quality at udder quarter level are influenced by quarter position, pathogen, and somatic cell score

There is a paucity of information about milk composition and quality at the quarter level from complete milking of the udder, mainly because of the difficulties of sampling procedures which imply the adoption of a vacuum system connected to four independent buckets. The objective of this study was to evaluate the effect of quarter position, intramammary infection status, and somatic cells on milk yield and composition at the mammary quarter level of Simmental cows. Milk samples were collected during three consecutive days, after milking individual mammary quarters of 10 lactating cows separately, for a total of 120 quarter milk samples. Samples were analysed for composition, somatic cell count (SCC), differential SCC, and bacterial culture. Somatic cell count was log-transformed to somatic cell score (SCS) to achieve normality of distribution. Sources of variation of milk yield and quality traits were investigated using a linear mixed model which included the fixed effects of quarter position (1 to 4), pathogen presence (positive or negative), and SCS class (low, medium-low, medium-high, and high). The interaction between cow and quarter position was included as random effect. Quarter position significantly affected milk yield, with rear udder quarters yielding more milk compared to their front counterparts, but with negligible effects on milk composition. Classes of SCS influenced milk composition, in a way that quarters with high SCS had lower lactose content and higher differential SCC. This study is a contribution towards the possibility to better understand physiological processes at cow udder quarter level.

Udder thermogram-based deep learning approach for mastitis detection in Murrah buffaloes

Mastitis, a production disease with multiple etiologies, inflicts significant economic losses among dairy farmers around the globe. In this study, an attempt has been made to detect mastitis through a Convolutional Neural Networks (CNN)-based deep learning model using 7615 udder thermograms of 40 Murrah buffaloes. The thermograms were grouped separately as healthy, sub-clinical (SCM), and clinical mastitis (CM) affected udder quarters based on California Mastitis Test (CMT) scores, Somatic Cell Count (SCC) values and thermal image analysis. Results of thermogram analysis revealed a significant increase (p < 0.01) in the mean values of udder skin surface temperature (USST) among SCM and CM-affected quarters compared to healthy quarters to the tune of 1.32 and 2.61 °C, respectively. The USST showed a strong positive correlation with the CMT score (r = 0.87, p < 0.01) and log10SCC value (r = 0.88, p < 0.01). The sequential (Normal vs. Clinical and Normal vs. Sub-clinical) models had training accuracy and validation accuracy of 0.999 and 0.988, 0.991 and 0.978, respectively. The confusion matrix for Normal vs. Clinical and Normal vs. Sub-clinical models reflected a loss of 0.009 and 0.029, precision of 0.947 and 0.980, and recall of 0.996 and 0.904, respectively. Consequently, the sequential (Normal vs. Clinical and Normal vs. Sub-clinical) models achieved a testing accuracy of 0.970 and 0.943, respectively. Thus, the improved deep-learning CNN models efficiently predicted SCM and CM cases in Murrah buffaloes.

Intramammary treatment of clinical mastitis quarters with ceftiofur does not cause anbiotic residues in adjacent untreated quarters.

The study was carried out in dairy cows to elucidate whether treatment of clinical mastitis quarters with Spectramast® LC (ceftiofur hydrochloride, 125 mg, Zoetis) created a reason for discarding milk from adjacent untreated healthy quarters. The antibiotic was infused once daily in the affected mammary quarter for four days. Forty-nine cows were evaluated after diagnosis of clinical mastitis in three or fewer udder quarters. In all cases, quarters that did not receive treatment had milk samples collected one day after the end of treatment. All milk samples from untreated quarters were below the maximum permissible limit for the presence of antibiotic residues after analysis with the BetaStar S Combo test. Pharmacokinetic and pharmacodynamic characteristics may explain this finding. We conclude that it is feasible to use milk from untreated quarters of animals that have been treated with Spectramast® LC. We also reiterate the need to carry out tests with other pharmacological bases, and that the results found in this experiment cannot be extrapolated to other drugs.Dairy cattle have considerable importance in the development of the Brazilian economy, being directly linked to economic and social progress. In the first half of 2020, 12.1 billion liters of milk were produced in Brazil and in 2019, there was a new record of 25.01 billion liters produced (IBGE, 2020). This production comes from a wide variety of production systems, coming from smallholder farmers as well as from large companies that use the latest technologies available on the market. Dairy production is a complex activity. For one to obtain economical success, several aspects must be monitored. Maintaining the health of animals is a top priority, and the literature suggests that various diseases are a common challenge for dairy producers. Mastitis is the main disease that affects dairy cows, responsible for considerable economic loss and significant zootechnical and productive challenges (Ruegg, ). It is considered the second leading cause of cow culling in dairy herds, behind reproductive problems. Mastitis is characterized by infection of the mammary gland and may or may not occur with inflammation, generating changes in the mammary tissue and properties of the milk. It is classifield into clinical or subclinical mastitis, according to presence or absence of clinical signs, and into contagious or environmental based on the causative agent (Correa et al., ).

Novel lncRNA regulatory elements in milk somatic cells of Holstein dairy cows associated with mastitis

Despite regulatory elements such as long non - coding RNAs representing most of the transcriptome, the functional understanding of long non - coding RNAs in relation to major health conditions including bovine mastitis is limited. This study examined the milk somatic cell transcriptome from udder quarters of 6 Holstein dairy cows to identify differentially expressed long non - coding RNAs using RNA - Sequencing. Ninety - four differentially expressed long non - coding RNAs are identified, 5 of which are previously annotated for gene name and length, 11 are annotated for gene name and 78 are novel, having no gene name or length previously annotated. Significant inflammatory response and regulation of immune response pathways (false discovery rate < 0.05) are associated with the differentially expressed long non - coding RNAs. QTL annotation analysis revealed 31 QTL previously annotated in the genomic regions of the 94 differentially expressed long non - coding RNAs, and the majority are associated with milk traits. This research provides a better understanding of long non - coding RNAs regulatory elements in milk somatic cells, which may enhance current breeding strategies for more adaptable or high mastitis resistant cattle.

Efficacy of an internal teat sealant alone or in combination with an intramammary antibiotic during the dry period treatment in dairy cows

In this study, the aim was to determine the effectiveness of internal teat sealant applied at the dry-off in preventing the formation of subclinical mastitis and to investigate whether this product could be a non-antibiotic alternative to total dry cow treatment. A total of 195 quarters from 52 Holstein and Holstein Crossbreed dairy cows, that did not have clinical mammary infection and were expected to calve within 60 days were used in the study. The quarters were divided into 3 treatment groups as follows: Group 1 (ANTB; n = 64): dry period intramammary antibiotic suspension (Ubrostar®); Group 2 (ORB; n = 65), internal teat sealant (Orbeseal®); and Group 3 (ANTB-ORB; n = 66) intramammary antibiotic and teat sealant combination were performed. All of the quarters were checked for subclinical mastitis on the 20th, 40th and 60th days of lactation. The percentage of animals found to be CMT negative on the 20th day of lactation was 80.65% in G1 (ANTB), 83.60% in Group 2 (ORB), and 87.50% in Group 3 (ANTB-ORB), respectively. There was no quarter with CMT +3 score in G1 and G3, but it was determined in one quarter in G2 (ORB). On the 60th day there were no quarters with CMT +2 and +3 scores in both G1 and G2. No statistically significant difference was found between the CMT results of treatment groups on the 20th, 40th and 60th days of lactation (p &gt; 0.05). In conclusion, it was determined that bismuth subnitrate-based teat canal sealer provided good protection against subclinical mastitis rate in drying healthy udder quarters. However, especially in high risk groups it is important to closely monitor udder health with SCC and/or CMT applications before the dry period and to choose the dry period treatment.

Short milking tube thermogram analysis: an indicator of mastitis in Murrah buffaloes.

In the present study, thermal images of the short milking tube of the milking machine representing four udder quarters independently attached to a milking animal, along with pre-milking and post-milking udder and teat thermograms, were taken using a hand-held digital infrared thermal camera (DarviDTL007) during morning milking of lactating Murrah buffaloes (n = 132) to assess the mastitis status. California mastitis test (CMT) and somatic cell count (SCC) of milk samples were carried out to screen the udder quarters as healthy, subclinical (SCM), and clinical mastitis (CM). The thermograms revealed an increase (p < 0.05) of 2.19 and 3.72ºC in the mean values of short milking tube (SMT) surface temperature among SCM and CM quarters compared to healthy quarters, respectively. The mean values of udder skin surface temperature (USST) for pre-milking, milking, and post-milking of SCM and CM compared to healthy quarters showed an increase (p < 0.05) of 2.17, 1.96, and 1.61ºC and 3.11, 2.88, and 2.73ºC, respectively. Similarly, compared to healthy quarters, the mean values of teat skin surface temperature (TSST) for pre-milking and post-milking of SCM and CM showed an increase (p < 0.05) of 2.12 and 1.66ºC and 3.07 and 2.45ºC, respectively. Also, CMT and SCC results showed a strong positive correlation (r = 0.68-0.91, p < 0.01) with all the thermographic parameters. Thus, thermograms of SMT alone can be used as an efficient detection tool in assessing SCM among Murrah buffaloes.

Seasonal assessment of mastitis using thermogram analysis in Sahiwal cows

“India is the world's leading producer of milk” and demands a non-invasive diagnostic tool like infrared thermography (IRT) to identify the costliest production disease, mastitis. It can form the basis of precision dairy farming. Therefore, the present study focuses on thermal imaging of the udder and teat quarters of Sahiwal cows during different seasons to identify subclinical (SCM) and clinical mastitis (CM) cases using the Darvi DTL007 camera. A total of 24–69 lactating Sahiwal cows were screened out using IRT regularly throughout the year. The intramammary infection status was further assessed using the CMT. The receiver operating characteristic analysis was carried out to develop the current study's cut-off for various thermographic parameters. The incidence for SCM and CM ranged from 26.47 to 38.75% and 17.83–22.79%, respectively during different seasons in Sahiwal udder quarters. The thermogram analysis revealed a significant difference (p < 0.01) in the mean values of the udder and teat surface temperature of Sahiwal cows between healthy, SCM, and CM during different seasons. The mean values of udder skin surface temperature (USST) during different seasons ranged between 29.07 and 36.91 °C, 31.51 to 37.88 °C and 32.42 to 38.79 °C among healthy, SCM, and CM-affected quarters, and correspondingly, the mean values of teat skin surface temperature (TSST) were 28.28 to 36.77 °C, 30.68 to 37.88 °C and 31.70 to 38.73 °C, respectively. Further results revealed an increase (p < 0.01) in the mean values of USST during winter, summer, rainy, and autumn as 2.44, 3.35; 0.97, 1.88; 1.06, 1.83; 1.29, 2.39 °C and TSST as 2.4, 3.42; 1.11, 1.96; 1.21, 2.19, 1.3, 2.4 °C of SCM, CM-affected quarters to healthy quarters, respectively, in Sahiwal cows. Thermograms showed a strong positive correlation with the CMT scores of SCM, CM cases, and healthy samples. Henceforth, irrespective of the seasons studied in the present work, IRT is an efficient, supportive tool for the early identification of subclinical mastitis.

Incomplete milking before drying off does not impair the udder health of cows infected with minor pathogens.

When implementing the transition from regular milk production to the dry period, drying off is mostly conducted simply by abrupt cessation of milking. Efforts to reduce milk synthesis before cessation of milking aim to reduce stress in cows as well as to lower the risk of mastitis. A previous study demonstrated that incomplete milking during the last ten days of lactation gradually reduced the milk yield of healthy, high-yielding cows. However, a reduction period of ten days might be too long for cows with lower yields. Therefore, a follow-up study was conducted on an organic dairy research farm with a lower average milk yield. We investigated whether automated incomplete milking can reduce milk synthesis within one week without impairing the health status of udder quarters infected with minor pathogens. Before drying off, 15 German-Holstein cows with 58 lactating quarters, 21 of which were infected with minor pathogens (coagulase-negative Staphylococci (CNS) and Corynebacterium bovis), were milked twice daily using the software module AutoDry (GEA Farm Technologies) with the 5%-step-down-per-day-program. The level of udder emptying was gradually reduced over 8-10 milkings beginning at a mean milk yield of 17.2 ± 4.4 kg d-1. During the last three milkings before drying off, milking clusters were automatically removed when a milk flow rate of 0.3 kg min-1 was reached. Quarter fore-milk samples were collected at two time points (14 d before and at the date of the last milking, ie drying off) and were analysed for mastitis pathogens and somatic cell count. The gradual reduced emptying of the udder induced a clear decline in milk yield by 0.8 ± 0.3 kg d-1. Within the reduction period, the somatic cell count of quarter foremilk did not change regardless of the infection status. Furthermore, no cow suffered from clinical mastitis. Thus, a reduction in milk synthesis could be achieved within less than one week before drying off without any impairment in udder health of cows, even when infected with minor mastitis pathogens.

Residue Concentrations of Cloxacillin in Milk after Intramammary Dry Cow Treatment Considering Dry Period Length.

Dry cow treatment with an intramammary antibiotic is recommended to reduce the risk of mastitis at the beginning of the next lactation. The dry period may be shortened unintentionally, affecting antibiotic residue depletion and the time when residues reach concentrations below the maximum residue limit (MRL). The objective of this study was to evaluate residue depletion in milk after dry cow treatment with cloxacillin, considering dry periods of 14 (G14d), 21 (G21d), and 28 d (G28d). Overall, fifteen cows with 60 udder quarters were included in the study. For each cow, three of the udder quarters were treated with 1000 mg cloxacillin benzathine (2:1) on d 252, d 259, and d 266 of gestation; one quarter was left untreated. Milk samples were drawn until 20 DIM and milk composition, somatic cell count and cloxacillin residues were analyzed. The HPLC-MS/MS revealed different excretion kinetics for the compounds cloxacillin and cloxacillin benzathine (1:1). All cows showed a cloxacillin and cloxacillin benzathine (1:1) concentration below the MRL of 30 µg/kg after 5 d. In the udder quarters of G21d and G28d, the cloxacillin concentration was already below the MRL at first milking after calving. The cloxacillin benzathine (1:1) concentration in the milk of G28d, G21d, and G14d fell below 30 µg/kg on the 5th, 3rd, and 5th DIM, respectively. Shortening the dry period affects residue depletion after dry cow treatment with cloxacillin. The risk of exceeding the MRL, however, seems low, even with dry periods shorter than 14 d.

Bovine mastitis: Prevalence, causes and associated risk factors in Silte Zone, Ethiopia

Mastitis is an important disease of dairy cows, and it causes huge economic losses to dairy farm owners due to a decrease in milk production, and reduction in milk quality, and an increase in the cost of cow treatment. A crosssectional study was conducted in Southern Ethiopia’s Silte zone from October 2020 to June 2021 aimed to estimate mastitis prevalence, assess related risk factors, and identify prevalent bacterial causes. Three hundred eighty-four lactating cows were examined for abnormalities in udder quarters and teats. Milk samples were tested for subclinical mastitis via the California mastitis test (CMT) and cultured for causative agents from clinical mastitic and CMT-positive cows. The overall prevalence of mastitis was 54.9% (95% CI=49.9-59.9), of which 52.1% (95% CI=47.1-57.1) was subclinical and 2.9% (95% CI=1.6 -5.1) clinical mastitis. From a total of 1536 quarters examined 41 (2.7%) quarters were found blind and 427 (27.7%) quarters were affected by mastitis. Overall, more hind quarters, 236 (55.5%) were affected than the front quarters, 189 (44.5%) of udder. The prevalence of mastitis was significantly higher during early lactation, ≤4 months (p&lt; 0.05); and it was increased with increasing parity (p&lt; 0.05) and age (p&lt; 0.05). Cows with no bedding were more affected than those with bedding (p&lt; 0.05). Multivariable logistic regression showed that cows with round and flat teat ends were 2.84 and 11.85 times more likely to contract mastitis. Also, cows with pendulous udder, producing more than 10 liters per day milk and during the early 4 months of lactation were 1.87, 6.81, and 2.14 more likely affected by mastitis than normal udder, producing less than 10 liters of milk per day and lactation after five months, respectively. Milk samples collected from 211 mastitis-positive cows were cultured using standard bacteriological technique, and the isolated bacteria were Staphylococcus aureus (29.5%), Staphylococcus epidermidis (14.2%), Staphylococcus intermedius (11.6%), Staphylococcus hyicus (11.1%), Streptococcus agalactiae (8.9%), Streptococcus disgalactiae (6.3%), E. coli (5.8%), Streptococcus uberis(5.3%), Klebsiella spp. (1.6%) and Enterococcus spp. (1.1%). Owners should givepro per udder care and are advised to apply dry cow therapy. Extension workers should raise awareness.

Randomized noninferiority field trial evaluating a postmilking teat dip for the prevention of naturally occurring intramammary infections

The aim of this study was to perform a positive-controlled field study under natural exposure conditions to test the efficacy of a newly developed chlorine dioxide-based postmilking teat disinfectant (experimental product, EX) for noninferiority compared with an already established chlorine dioxide-based teat disinfectant (positive control product, PC). After blocking by parity, approximately 200 Holstein cows in early to mid-lactation stages from a dairy farm near Padua, Italy, were randomly assigned to one of 2 groups. Over a 13-wk period between September and December 2021, the teats of cows were dipped with the EX or the PC after each milking. Milk samples were collected from individual quarters of enrolled cows for 13 wk to determine infection status. Teat condition was assessed at wk 1, 5, and 9. Mixed logistic regression was used to analyze the effect of treatment on the incidence of new intramammary infections. For the noninferiority analysis, the upper limit of the 95% confidence interval for the difference in new intramammary infection (NIMI) rate between the 2 treatments (EX - PC) had to be to the left of the critical value d (0.035) to conclude that EX was noninferior to PC in terms of the risk of NIMI. The results showed that the incidence of new infections in the quarters treated with EX (3.1%) was not different from that in the udder quarters treated with PC (2.6%). No overall difference was found between the treatments in terms of teat condition. As the upper limit of the 95% confidence interval of the NIMI rate difference was smaller than the predefined noninferiority limit, we concluded that the EX was noninferior compared with the PC.

Influence of circadian rhythm, breed, stage of lactation, milk yield and parity on body and udder skin surface temperature of lactating cows monitored by infrared thermography

ABSTRACT The objective of the study was to establish baseline thermographic information on body and udder skin surface temperature (USST) of lactating cows in different stages of lactation, milk yield, parity, breed and season. Holstein Friesian crossbred (n = 19 cows) and Deoni lactating cows (n = 14 cows) were monitored for body (i.e. eye) and USST prior to milking using a forward looking infra-red (FLIR) camera. It was observed that the mean body and USST of both crossbred and Deoni cows did not differ significantly. The body and USST of both the breeds were significantly higher by 0.9–1.0°C during evening than morning milking. There was no difference in body and USST between days and between udder quarters. Similarly, stage of lactation, milk yield and parity did not show any influence over body and USST. The body and USST were higher in summer (1.1°C) than in spring and winter seasons. Deoni cows had 1.0°C lesser body and USST than crossbred cows. It is concluded that baseline thermographic information on body and USST would be useful in developing breed-specific thermographic signature for individual animal.

PREVALENCE, ANTIMICROBIAL RESISTANCE PROFILES OF CLINICAL AND SUBCLINICAL MASTITIS IN LACTATING COW WITH ASSESSMENT OF TREATMENT TRIAL

This work investigated the prevalence of bovine mastitis in a dairy farm, Ismalia governrate, Egypt with phynotypic and genotypic clarification of the causative bacteria and their antimicrobial susceptibility. Also a treatment trial with a combination of Cafalexin, Kanamycin was evaluated. The total prevalence of mastitis was 31.82% (119/374) at cow level and 17.01% (247/1452) at quarter level. 261 isolates were detected. (74.33%) belong to staphylococcus spp and (25.67%) to streptococcus spp. as major microorganisms (CNS (42.53%) s.aurus (31.80%) s. uberis (12.26%), s. agalactia (8.81%) and s. dysagalactia(4.59%). The isolates were tested against 15 antimicrobial agents and the highest percentage of resistant bacteria was for AMC, P, C and E. while the lowest rate was for CN, CIP, CL and K. Molecular Characterization of isolated pathogens and antimicrobial resistance genes was performed by PCR on 15 isolates. blaTEM-1 Was the most frequently detected gen followed by aadA1, dfrA1, cmlA, sul1, and tetA. 110 infected udder quarters were enrolled for 21 days to evaluate the treatment with Terrexine LC intramammary suspension 10g on six occasions at 12 h intervals and gentamycin intramuscular injection (1cm/20kg Bw for 3-5 days in cows with systemic reaction. A high significant reduction was recorded for the log10 SSC, log10 TBC and the level of LDH in milk after treatment compared their level before treatment (P-value &lt;0.0001***). The milk season for cows, degree of mastitis or type of microorganism isolated before treatment have no effect on the recovery rate P-value ˃0.05. In conclusion, the emergence of multidrug-resistant strains is greatly increased so antibiotic usage must be Restricted. PCR can help in the rapid detection of the resistant strains. Treatment of mastitis with combination of antimicrobial may reduce drug resistance. Bovine mastitis still needs updated knowledge on the causative microbes and their antibiotic resistance patterns for optimal control and treatment.