Uso prodente e ragioanto degli antibiotici negli animali di interesse zootecnico

Viene riportato l'importanza pratica degli antibiotici nella produzione del latte. Tuttavia, le norme e la pressione dell'opinione pubblica stanno determinando la necessit\ue0 di ridurre il loro uso. Divengono quindi necessari nuovi approcci terapeutici e la necessit\ue0 di ridurre il rischio di malattia. La relazione affronta da un punto di vista scientifico e pratico tali argomenti

Improve mastitis detection through better decisions

Despite all efforts to prevent, control and treat mastitis produced over the last 60 years, this disease is still one of the major sources of dairy farms costs worldwide. In addition to the direct and indirect costs, the need to improve the welfare cow and to reduce the use of antibiotics, increase the burden represented by mastitis. Prevention has been always defined as \u201cthe key\u201d to control mastitis and to reduce the consequences of the disease. Therefore, several different approaches have been suggested, some of them were very successful (i.e. pre and post dipping), while others much less. Prevention should be based on identification of risk factors and on the reduction of these risks. However, prevention is also based on monitoring cow (and udder) status and on identifying alterations potentially leading to a disease status. Often, this latter approach is defined as early diagnosis, but is a very reductive way to define this important part of prevention. There are several systems to monitor cow and udder status, some very well-known and simple (i.e. individual SCC, udder hygiene score, teat score), other more sophisticated and based on the availability of new technologies (i.e. conductivity, NAGase, LDH, IR sensors). Regardless of the system used to monitor mastitis, the key issue is to decide when the cow or the udder are moving from a healthy status to a diseased one and, even more important, what to do when this deviation is observed or registered. Making the right decision is crucial for an effective mastitis control and it will be even more important as long as the use of antibiotics will be constrained. Monitor systems are based on one or few marker(s) and the deviation of the marker(s) suggest the presence of a diseases animal. However, the \u201cdeviation\u201d depends on thresholds defined for an ideal situation, not easily reproducible in practice. Moreover, even if dairy herds often appear very similar, there are significant differences among cows\u2019 responses among herds for many different physiological and pathological markers. Finally, dairy farms are also included in different social and economic environments and these imply that the decisions taken after the same "deviation" may be different as social and economic factors are different. Therefore, marker thresholds, benchmarks, and decision tools should consider economic and biological differences in order to identify the proper approach to solve herd or cow specific problems. The real challenge for researcher and practitioners is not the application of the new technologies, but to identify how to fit these old and new approaches and technologies to the specific dairy herd in order to improve cow health and welfare and to increase herd sustainability

Recovery of Staphylococcus aureus from Centrifuged Quarter Milk Samples

The identification of cows that are positive for mastitis caused by Staphylococcus aureus is difficult under field conditions. The frequency of isolation of S. aureus from quarter milk samples was compared with the frequency of recovery of S. aureus from sediment after centrifugation of those same samples. Overall, 776 quarter milk samples from 194 cows were studied. Cultures that were positive for S. aureus were obtained from 82 samples; 153 sediments from quarter milk samples were also positive for S. aureus. The results of this investigation showed that cultures of the sediment of quarter milk samples increased the number of positive outcomes up to 145.5%, depending on the herd. Using a different group of samples, including samples taken 1 to 5 d or 7 to 10 d after calving and samples taken after intramammary therapy, a 94% increase in cultures that were positive for S. aureus after centrifugation was found compared with cultures of the same quarter milk samples that were not centrifuged. Sedimented cultures may be useful in S. aureus control programs that require the segregation, selective treatment, or culling of cows that are positive for S. aureus

How to Improve Surveillance Program for Shiga Toxin-Producing E. coli (STEC): Gap Analysis and Pilot Study

Several pathotypes of enteric E. coli have been identified. The group represented by Shiga toxin-producing E. coli (STEC) is of particular interest. Raw milk and raw milk products are significant sources of STEC infection in humans; therefore, identifying pathogens at the herd level is crucial for public health. Most national surveillance programs focus solely on raw milk and raw milk cheeses that are ready for retail sale, neglecting the possibility of evaluating the source of contamination directly at the beginning of the dairy chain. To assess the viability of the application of new molecular methodologies to STEC identification in raw milk filters and in calf feces, we analyzed 290 samples from 18 different dairy herds, including 88 bulk tank milk (BTM), 104 raw milk filters (RMF), and 98 calf feces samples. In total 3.4% of BTM, 41.4% of RMF, and 73.4% of calves’ feces were positive for stx, supporting our hypothesis that BTM is not a suitable matrix to assess the presence of STEC at herd level, underestimating it. Our conclusion is that the surveillance program needs critical and extensive improvements such as RMF and calves’ feces analysis implementation to be more efficient in detecting and preventing STEC infections. The epidemiology of these infections and the characteristics of the pathogen clearly show how a One Health approach will be pivotal in improving our capabilities to control the spread of these infections

Factors affecting the patterns of total amount and proportions of leukocytes in Bovine milk

Differential leukocyte count (DSCC) in milk is considered important to improve knowledge of udder immune response. The investigations on milk DSCC were limited by the techniques available until recently, when a high-throughput tool to perform DSCC opened the way to explore these factors in rapid and economically sustainable ways. We hypothesized that DSCC alone does not fully describe the pattern of these cells, since the total amount is also influenced by milk yield and SCC. Therefore, this study was designed to describe DSCC and total amount of different leukocytes in milk during the course of lactation in cows differing in parity and in levels of SCC. This study considered 17,939 individual milk tests from 12 dairy herds in Lombardy Region, where DCC testing was applied in the period of February 2018\u2013December 2019 (23 months). The samples were divided into two subsets\u2014\u201chealthy\u201d (HS) with SCC 64200,000 cells/mL and \u201cinflamed\u201d (IS) with SCC >200,000 cells/mL. Cow in HS have a P + LT average between 5.0 7 108 and 3.0 7 109 cells. In IS cows, the values were 1.6 7 1010 and 2.5 7 1010. Therefore, the presence of a well-defined inflammatory process increased the overall amount of polymorphonuclear neutrophils (PMN) and lymphocytes (LYM) of 1 log, from 1 7 109 to 1 7 1010. The assessment of the total amount of PMN and LYM, to our knowledge, have never been reported in scientific literature; the values observed may be proposed as benchmarks for studies on udder immune response. When data were analyzed by days in milk (DIM),they showed that cows in first and second lactation have a significantly lower amount of PMN + LYM, when compared to cows in third and higher lactation. However, these differences are numerically not very large (7%), and suggest that, in healthy animals, the number of immune cells is kept as constant as possible. In IS, the analysis of trends based on DIM showed that both DSCC and P + LT have a significant negative trend. These data suggest that only in this group, the presence of high SCC as lactation proceeds is associated with a progressive increase in the number of macrophages. To the best of our knowledge, this is the first study describing the pattern of DSCC and the total amount of PMN + LYM in relation to parity, days in milk, and SCC, and it may be considered as the first contribution in the investigation on mammary gland immune response by the means of differential cell counts in milk

Pattern characterization of genes involved in non-specific immune response in Staphylococcus aureus isolates from intramammary infections

Staphylococcus aureus isolated from mammary gland are characterized by different genetic patterns. Ninety four isolates from 33 dairy herds were analyzed by the means of amicroarray to investigate S. aureus virulence patterns and the distribution of genes believed to be involved in immune evasion. None of the 94 isolates considered were MRSA. However, 50% of the isolates belonged to complexes related to MRSA and to human diseases, while only about 25% of them can be considered as exclusively of bovine origin. The distribution of clonal complexes and the different gene patterns observed confirmed the presence of an influence of geographical localization. The assessment of the influence of genes related to immune evasion on quarter milk cell count showed as four of them showed to be significantly associated to an increase quarter milk SCC. These genes could be potential target for developing new vaccines against S.aureus

Linear Mixed-Effects Model to Quantify the Association between Somatic Cell Count and Milk Production in Italian Dairy Herds

Milk production loss due to mastitis in dairy herds is economically important. Before estimating the economic impacts of mastitis, it is crucial to quantify the association between mastitis and milk production. The objective of this study was to estimate the association between somatic cell count (SCC, as an indicator of intramammary infection due to mastitis) and milk production for dairy cows in Lombardy, Italy. The test-day (TD) records data of 3816 dairy herds located in three different geographical areas of Lombardy from January 2016 to December 2018 were used. After data editing, the final dataset comprised 10,445,464 TD records from 2970 farms and 826,831 cows. The analysis was carried out by using a mixed-effects model with six fixed effects (geographical Area, Breed, Days in Milk, Parity, Season and Year) and nested random effects for each cow and herd. The results confirmed that the SCC had a negative association with milk production. On average, this study found that any two-fold increase of SCC resulted in a milk production loss of 0.830 (95% CI: −0.832, −0.828) kg/cow/day in the whole of Lombardy. These results can be used for economic calculations on the costs of mastitis

Differential Somatic Cell Count as a Novel Indicator of Milk Quality in Dairy Cows

Recent available instruments allow to record the number of differential somatic cell count (DSCC), representing the combined proportion of polymorphonuclear leukocytes and lymphocytes, on a large number of milk samples. Milk DSCC provides indirect information on the udder health status of dairy cows. However, literature is limited regarding the effect of DSCC on milk composition at the individual cow level, as well as its relation to the somatic cell score (SCS). Hence, the aims of this study were to (i) investigate the effect of different levels of DSCC on milk composition (fat, protein, casein, casein index, and lactose) and (ii) explore the combined effect of DSCC and SCS on these traits. Statistical models included the fixed effects of days in milk, parity, SCS, DSCC and the interaction between SCS × DSCC, and the random effects of herd, animal within parity, and repeated measurements within cow. Results evidenced a decrease of milk fat and an increase in milk fatty acids at increasing DSCC levels, while protein, casein and their proportion showed their lowest values at the highest DSCC. A positive association was found between DSCC and lactose. The interaction between SCS and DSCC was important for lactose and casein index, as they varied differently upon high and low SCS and according to DSCC levels

From “One Health” to “One Communication”: the contribution of communication in Veterinary Medicine to public health

Despite the fact that health communication is a discipline developed only recently, its importance in human medicine is well recognized. However, it is less considered in veterinary medicine, even if it has the potential to improve public health because of the role of veterinary medicine in public health. For this reason, an One Health approach is useful for communication as well. This approach leads to a \u201cOne Communication\u201d concept, which is the result of the synergy in communicative efforts both in human and in veterinary medicine. Our analysis explores the potential of communication in several veterinary fields: institutions, food safety, companion animal and food-producing animal practice, pharmacology and drugs, wildlife fauna and environment. In almost all the areas of veterinary activity communication can contribute to human health. It takes many forms and use several channels, and this variety of communicative opportunities represent a challenge for veterinarians. For this reason, the communication course should be included in the curricula of Veterinary Medicine Schools. As One Health, One Communication is a strategy for expanding collaborations in health communication and it will enhance public health