Staphylococcus aureus adlb gene is associated with high prevalence of intramammary infection in dairy herds of northern Italy: A cross-sectional study

Staphylococcus aureus is a major mastitis pathogen in dairy cattle worldwide, responsible for substantial economic losses. Environmental factors, milking routine, and good maintenance of milking equipment have been described as important factors to prevent intramammary infections (IMI). Staphylococcus aureus IMI can be widespread within the farm or the infection can be limited to few animals. Several studies have reported that Staph. aureus genotypes differ in their ability to spread within a herd. In particular, Staph. aureus belonging to ribosomal spacer PCR genotype B (GTB)/clonal complex 8 (CC8) is associated with high within-herd prevalence of IMI, whereas other genotypes are generally associated with individual cow disease. The adlb gene seems to be strictly related to Staph. aureus GTB/CC8, and is a potential marker of contagiousness. We investigated Staph. aureus IMI prevalence in 60 herds in northern Italy. In the same farms, we assessed specific indicators linked to milking management (e.g., teat condition score and udder hygiene score) and additional milking risk factors for IMI spread. Ribosomal spacer-PCR and adlb-targeted PCR were performed on 262 Staph. aureus isolates, of which 77 underwent multilocus sequence typing. In most of the herds (90%), a predominant genotype was identified, especially Staph. aureus CC8 (30%). In 19 of 60 herds, the predominant circulating Staph. aureus was adlb-positive and the observed IMI prevalence was relevant. Moreover, the adlb gene was detected only in genotypes of CC8 and CC97. Statistical analysis showed a strong association between the prevalence of Staph. aureus IMI, the specific CCs, and carriage of adlb, with the predominant circulating CC and presence of the gene alone explaining the total variation. Interestingly, the difference in the odds ratio obtained in the models for CC8 and CC97 suggests that it is carriage of the adlb gene, rather than the circulation of these CCs per se, that leads to higher within-herd prevalence of Staph. aureus. In addition, the model showed that environmental and milking management factors had no or minimal effect on Staph. aureus IMI prevalence. In conclusion, the circulation of adlb-positive Staph. aureus strains within a herd has a strong effect on the prevalence of IMI. Thus, adlb can be proposed as a genetic marker of contagiousness for Staph. aureus IMI in cattle. However, further analyses using whole-genome sequencing are required to understand the role of genes other than adlb that may be involved in the mechanisms of contagiousness of Staph. aureus strains associated with high prevalence of IMI.

Promoting Judicious Antimicrobial Use in Beef Production: The Role of Quarantine

Judicious antimicrobial stewardship in livestock industry is needed to reduce the use of antimicrobials (AMU) and the associated risk of antimicrobial resistance. Biosecurity measures are acknowledged for their role against the spread of diseases and the importance in reducing AMU in different species. However, their effectiveness in beef production has been scarcely considered. The aim of this study was to investigate the effect of the quarantine strategy on AMU in beef cattle. A total of 1206 Charolaise animals in five farms were included in the trial. Roughly half of the animals followed the standard procedure of the fattening cycle (no-quarantine; NO-QUA group) and half followed a 30-day period of quarantine (QUA group) since their arrival. Performance and antimicrobial data were recorded and a treatment incidence 100 (TI100it) per animal was calculated. Penicillins was the most used class of antimicrobials. Differences between groups were significant for males only, with NO-QUA group having greater TI100it (3.76 vs. 3.24; p < 0.05) and lower body weight at slaughter (713.4 vs. 723.7 kg; p < 0.05) than QUA group. Results suggest that quarantine strategy can reduce AMU in males without compromising their performance, whereas further investigation is needed for females.

The influence of different production systems on dioxin and PCB levels in chicken eggs from Emilia-Romagna and Lombardy regions (Italy) over 2017-2019 and consequent dietary exposure assessment

Hen eggs from farms with different production systems (organic, free range, barn, and in cage) sited in two regions of Italy (Emilia-Romagna and Lombardy) were collected from 2017 to 2019 to monitor the levels of 17 polychlorinated dibenzo-p-dioxin/dibenzofurans (PCDD/Fs), 12 dioxin-like polychlorinated biphenyls (dl-PCBs) and the 6 non-dioxin-like polychlorinated biphenyl indicators (ndl-PCBs). Average concentrations of PCDD/Fs (0.21 pg WHO₍₂₀₀₅₎-TEQ/g fat), PCDD/Fs + dl-PCBs (0.43 pg WHO₍₂₀₀₅₎-TEQ/g fat) and ndl-PCBs (6.41 ng/g fat) were below the maximum limits established at European level in eggs, but significantly higher amounts of PCDD/Fs and PCDD/Fs + dl-PCBs were found in eggs from free-range housing system compared to barn, cage, and organic ones. The potential dietary intake of the monitored contaminants by Italian population age groups through the consumption of locally produced eggs was also evaluated. Exposure levels to PCDD/Fs plus dl-PCBs were below the tolerable weekly intake (TWI) of 2 pg WHO₍₂₀₀₅₎-TEQ/kg bw/week recently set by the European Food Safety Authority (EFSA). However, the younger population was found to be more vulnerable than other age groups to exposure to these contaminants. Specifically, the preferential consumption of free-range eggs by infants, toddlers, and children contributed more than 30% to the TWI. The results confirm the need to continuously monitor the levels of chemical contaminants in the environment and provide a reminder of the importance of targeted intervention measures aimed to reduce their occurrence in food and feed, firstly by improving the management practices on egg-producing farms.

Best Farming Practices for the Welfare of Dairy Cows, Heifers and Calves

Simple Summary

The evolving change in societal attitudes regarding animal care and use has led to two main streams of thought. On one hand, there is the concept of “animal rights”, emphasizing that animals should have the same rights as humans, and as such should never be used to benefit humans (e.g., for food, clothing, entertainment, education, research, and even pet ownership). Animals should be able to live a life free of human interference and exploitation. On the other hand, many people agree that humans are responsible for animals and for their care; animals can be used to benefit humans if properly cared for, and their needs are met; abuse and neglect are banned. This is the “animal welfare” (AW) point of view, based on humane treatment, ensuring the physical and mental fitness of animals, as required by current EU legislation. Now, the point is that to fulfill the basic requirements of animal welfare animals are ensured a life worth living, especially given that they can feel emotions. In view of ensuring not only compliance with minimum legislative requirements, but also optimal farming conditions (above minimum legislative requirements), growing attention is attributed to best farming practices. In this work, a list of best practices proposed by the Italian National Reference Centre for Animal Welfare (CReNBA) has been collected to ensure a good quality of life for dairy cows, heifers and calves kept in intensive rearing systems.

Abstract

The concept of animal welfare (AW) has many meanings. Traditionally, AW has been considered as freedom from disease and suffering. Nowadays, growing attention goes to the concept of “positive animal welfare” (PAW), which can be interpreted within the concept of quality of life (QoL), thinking about a “balance of positives over negatives” and a “life worth living”. In this vision, where the QoL represents a continuum between positives and negatives, the Italian National Reference Centre for Animal Welfare (CReNBA), within the Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna (IZSLER), has developed a welfare assessment protocol for dairy cows, heifers, and calves in loose housing systems, including both animal-based and non-animal-based indicators, in which not only hazards but also benefits are identified. This protocol is part of an integrated monitoring system called “ClassyFarm”, belonging to the Italian Ministry of Health and developed by IZSLER. The aim of this paper is to extrapolate from the mentioned protocol, a list of 38 best farming practices (on managerial and equipment factors) for ensuring a high level of welfare in dairy cattle. All stakeholders (veterinarians, farmers, competent authorities, consumers, etc.) can benefit of these best practices as a guide or toolbox to ensure a life worth living for these animals.

The Relationship between Animal Welfare and Antimicrobial Use in Italian Dairy Farms

Information regarding the relationship between animal welfare (AW) and antimicrobial use (AMU) in dairy cows is limited. The current study aimed to investigate this relationship on Italian farms and to identify potential targets of AMU reduction. The study was performed at 79 Italian dairy farms housing over 15,000 cows during 2019. AW was scored with an on-farm protocol assessing farm management and staff training, housing systems, and animal-based measures. AMU was estimated using a defined daily dose per kg of animal biomass (DDDAit/biomass) for Italy. The median AW score was 73% (range: 56.6-86.8%). The median AMU was 4.8 DDDAit/biomass (range: 0-11.8). No relationship between the total AMU and AW was found. Management and staff training were positively associated with the use of the European Medicines Agency's category B antimicrobials, which are critical for human medicine, and with intramammary products for dry cow therapy. In those farms, antimicrobial stewardship should aim to reduce the category B antimicrobials and selective dry cow therapy. Our results underline the importance of implementing both an integrated monitoring system (AW, AMU, etc.) and antimicrobial stewardship tailored to the specific needs of each dairy farm.

Welfare Assessment: Correspondence Analysis of Welfare Score and Hematological and Biochemical Profiles of Dairy Cows in Sardinia, Italy

The need for animal welfare definition and assessment is increasing worldwide, and several studies have been conducted to help fill the knowledge gaps regarding the welfare of cattle. However, further studies are needed to provide valid synthetized measures for welfare evaluation. The aim of this study was to assess the welfare status of 16 Sardinian dairy cattle farms, based on the developed Animal Welfare and Biosecurity Evaluation checklist (AWB-EF) and the corresponding hematological, biochemical, and electrophoretic profiles of these animals. Considering the AWB-EF as gold standard, blood samples were collected from 230 Holstein breed dairy cattle, aged between 3 and 8 years, out of the periparturient period, and with no clinical signs of specific pathologies. Principal Component (PC) and correlation analyses were performed to simplify phenomena interpretation and assess positive/negative associations. Four PCs were able to explain 76% of the total variability, and six laboratory parameters were strongly associated with the AWB-EF score (Spearman's correlation coefficient ≥ 0.40, p-Value < 0.05), reflecting the real health status of the animals. Given the complexity of animal welfare as a multidimensional concept and the need to include both animal-based and non-based measures in welfare evaluation, the present work represents a sound basis for future evaluation and veterinary health planning.

Animal welfare and biosecurity assessment: a comparison between Italian and Irish beef cattle rearing systems

Context European beef production is facing fresh challenges on various fronts: increasing public concern on animal welfare; declining EU meat consumption; and, conversely, expected growth in global demand for meat. The Italian National Reference Centre for Animal Welfare (CReNBA) has developed an assessment protocol for collecting information about beef cattle welfare and biosecurity conditions, with the intention of better understanding animal needs and disseminating best practices. Aims The protocol was applied on Italian and Irish farms, and the results were used as a starting point for a specific statistical analysis for comparing animal welfare and biosecurity levels in the two countries. Methods The protocol consists of animal-based measures and non-animal-based measures (management-based and resource-based indicators) and has been designed to determine the major hazards and benefits that can influence cattle health and welfare, including the presence of biosecurity issues. The outcomes of welfare and biosecurity assessments conducted during November 2016–July 2017 of 40 Irish beef herds reared indoors were compared with those of 85 Italian beef units assessed over the same period. Differences obtained within each beef-unit distribution were calculated by the VARNC index (diversity index), and a distance estimate of the beef-unit distribution from a hypothetical ideal condition was calculated by using the distance from ideal (dfi) index. Key results The dfi index revealed that Irish farms were closer to the ideal condition for the measures ‘experience and training of stockpersons’, ‘water provision’, ‘handling facilities’, ‘restraint facilities’, and ‘temperature, humidity and ventilations conditions’. Italian farms were closer to the ideal condition for ‘diet calculation and feed quality’, ‘feeding management’, ‘feeding place dimension’, ‘cleanliness of water points’, ‘cleanliness of floors’, ‘type of floors’, ‘cleanliness of animals’, and ‘integument alterations’. In contrast to the Italian farms, there was particular awareness of the importance of biosecurity on Irish farms. Conclusions The results revealed intrinsic management and housing differences between the two rearing systems, although only few dissimilarities were found in the animal outcomes: in fact, the assessment of the animal-based measures gave very similar results for the two countries, except for ‘cleanliness of the animals’ and ‘integument alterations’. Implications In the face of global challenges affecting the pursuit of farming sustainability, farmers should be encouraged to improve safeguards for animal welfare and reduce the spread of animal diseases. This can be achieved by facilitating knowledge exchange internationally.

Exploring potential risk factors of antimicrobial use in beef cattle

Livestock species are major contributors to the increase of antimicrobial (AM) resistance which is a worldwide concern for both human and animal health. The over-use of AM is widely acknowledged, however, unlike pigs, poultry and dairy cattle, knowledge on potential risk factors affecting AM usage (AMU) in beef industry is limited. Hence, this study aimed to investigate the impact of farm, breed, sex and season of arrival of purchased beef cattle on AMU in Italian beef cattle. Data on 1063 batches were collected from January 2016 to April 2019 from specialised beef fattening farms located in the north of Italy. Information on breed, sex, date of arrival, performance traits and AM agents used on farm was collected, and the treatment incidence 100 (TI100) indexes per batch were calculated using the defined daily dose animal estimated according to Italian summaries of product characteristics. Factors affecting TI100 indexes were investigated using a cross-classified multilevel model. Farms largely differed in terms of AMU. Males had greater AMU than females (P < 0.001), likely due to their higher susceptibility to disease. Statistically significant differences were observed between seasons of arrival with summer and spring having lower TI100 indexes than winter and autumn (P < 0.001). Indeed, winter is commonly linked to an increase in respiratory diseases in beef cattle. Finally, the TI100it indexes tended to be different among breeds with Blonde d'Aquitaine and Limousine having greater AMU compared to the other breeds. Results of this study provided valuable information on potential risk factors of AMU in beef production which may be useful to address its reduction. For instance, the development of tailored management strategies for specific breeds, targeted approaches to improve the health of males as well as greater care towards batches purchased in winter are possible advice to implement on-farm for a more responsible AM stewardship.

Effect of welfare standards and biosecurity practices on antimicrobial use in beef cattle

Antimicrobial use (AMU) in livestock species and the associated antimicrobial resistance are a global concern, thus strategies for their reduction and a more judicious use are needed. Previous research has revealed a link between improved animal welfare, biosecurity and AMU reduction in pig and dairy sectors, however, little is known about the beef sector. This study aimed to investigate the impact of welfare standards and biosecurity on AMU in beef cattle. Data on performance traits and AMU were collected over a 3.5 year time from 27 specialised beef farms and a treatment incidence was calculated using the defined daily dose for animals. An on-farm assessment was carried out by assigning a score from 0 (very poor) to 100% (very good) to 3 sections: welfare, biosecurity and emergency management. The highest average score was obtained for the welfare section (76%) followed by emergency management (39%) and biosecurity (24%). This suggests that major focus on strategies for the implementation of biosecurity measures and emergency management is needed, due to the low scores reported. A statistically significant lower AMU was observed with improved level of welfare. These results may be helpful for farm benchmarking and highlight the importance of improved animal welfare for an efficient antimicrobial stewardship.

Incidence of milk leakage after dry-off in European dairy herds, related risk factors, and its role in new intramammary infections

The incidence of milk leakage (ML) after dry-off (DO) and related risk factors was studied in 1,175 dairy cows from 41 commercial herds in 8 European countries: Belgium, Czech Republic, Denmark, France, Germany, Italy, the Netherlands, and Spain. Milk leakage was assessed twice for 30 s each during 3 visits at 20 to 24 h, 30 to 34 h, and 48 to 52 h after DO. Information related to dry-cow management and udder health was collected at herd and cow level, including individual somatic cell count (ISCC) from test-day controls and occurrence of clinical mastitis cases from DO until 30 d in lactation. Mixed-effect logistic regression analyses were used to identify possible risk factors for ML and to study the association between ML and new intramammary infections. Intramammary infections were defined as clinical mastitis cases during the dry period and in the first 30 d in lactation or a rise in ISCC from before to after the dry period (threshold: 200,000 cells/mL) or both. Milk leakage was observed in 24.5% of the cows between 20 and 52 h after DO, where the herd incidence varied between 0.0 and 77.8%. The reduction in number of milkings in the weeks before DO had statistically significant effect on the ML incidence. When the milking frequency was reduced from 3 times/d to 2 or maintained at twice a day, cows had 11 (95% CI = 3.43-35.46) or 9 (95% CI = 1.85-48.22) times higher odds of leaking milk, respectively, compared with cows where the milking frequency was reduced from twice to once a day. Also, the milk production 24 h before DO was associated with ML incidence. Hence, cows with a milk production between 13 and 21 L or above 21 L had 2.3 (95% CI = 1.48-3.53) and 3.1 (95% CI = 1.79-5.3) times higher odds of leaking milk, respectively, compared with cows with a milk production below 13 L. A higher ML incidence was present in the group of cows with an average ISCC in the last 3 mo before DO ≥200,000 cells/mL (odds ratio = 1.7; 95% CI = 1.13-2.41) compared with cows with an average ISCC <100,000 cells/mL. Quarters with ML tended to have 2.0 times higher odds of developing clinical mastitis compared with quarters not leaking milk. Cows with ML tended to have 1.5 times higher odds of intramammary infections (i.e., an increase of ISCC or clinical mastitis) compared with cows without ML.

Use of antimicrobials in beef cattle: an observational study in the north of Italy

Antimicrobial resistance is a worldwide issue whereby a more prudent use of medications is needed, especially for those antimicrobials (AM) classified as 'highest priority critically important antimicrobials' (HPCIAs) which are likely contributors to the development of resistance. So far, data on antimicrobial use (AMU) in EU are mainly reported at sales level while information on real use, mostly in beef production, is poor. The most reliable indicator to measure AMU is the treatment incidence (TI100) calculated by using the Defined Daily Dose Animal (DDDA) as stated by the European Medicines Agency (EMA). Although Italy ranks second among EU countries with regard to the AM sales in livestock production, data on AMU of the Italian beef production is still lacking, whereby the aim of this study was to provide information on the current scenario of AMU in Italian beef cattle. Data were collected from January 2016 to April 2019 from specialized beef fattening farms located in the north of Italy yielding a final dataset of 1376 batches. Data on performance and AM agents used in the study were collected and TI100 indexes per batch were calculated according to both Italian and EMA's DDDA. A Kruskal-Wallis test was used to check for differences between years and seasons. Results showed a significant variation between years and seasons with a reduction of TI100 based on Italian DDDA as time progressed (P < 0.05). However, about 40% of the total amount of treatments administered were HPCIAs with macrolides accounting for the 27.7% of the total amount. The most common reasons of administration of AM were respiratory diseases (68.9%) and lameness (17.6%). Penicillins was the class of AM used on the highest proportion of batches (84.4%) showing that broad-spectrum AM were widely exploited among herds. In summary, despite a general reduction of AMU in beef cattle over time, a great use of HPCIAs was still observed suggesting that AM stewardship for Italian beef production should pay particular emphasis on the reduction of HPCIAs use. This shows how overall knowledge on where efforts need to be optimized is important to develop targeted strategies for a more responsible AM stewardship. Results of the current study may also contribute to define national and EU benchmark criteria for AMU, as a comparison with studies carried out in other countries or on other food-producing sectors is still challenging to achieve.

PCDD/Fs, DL-PCBs, and NDL-PCBs in Dairy Cows: Carryover in Milk from a Controlled Feeding Study

A feeding study was carried out to investigate the kinetics in cow milk of the 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), the 12 dioxin-like polychlorinated biphenyls (DL-PCBs), and the 6 non-dioxin-like PCBs (NDL-PCBs) regulated by the European (EU) legislation. A fortified ration (ΣPCDD/Fs and DL-PCBs: 24.68 ng TEQ/day/cow; ΣNDL-PCBs: 163.99 μg/day/cow) was given to the animals for 49 days, followed by 42 days on clean feed. EU maximum limit for TEQ_{PCDD/F+DL-PCB} was exceeded in milk after 1 week of exposure, while for ΣNDL-PCBs, after 5 weeks. Milk compliance was restored after 1 week on clean feed, but to return to the basal TEQ_{PCDD/F+DL-PCB} it took 42 days. At the end of the study, ΣNDL-PCBs had not yet reached the basal level. The carryover rate of ΣNDL-PCBs was 25.4%, while the carryover rate of TEQ_{PCDD/F+DL-PCB} was 36.9%. The latter was mainly affected by the 12 congeners contributing most to the toxic equivalent (TEQ) level, explaining the fast overcome of the maximum limit in milk.

Diagnostic value of composite milk sample vs single quarter milk sample for the detection of Staphylococcus aureus intra-mammary infections in cattle

Staphylococcus aureus (S. aureus) is one of the most important causes of mastitis in dairy cattle. Control and eradication programs of S. aureus intra-mammary infections (IMI) are based on different factors included the correct detection and management of the infected cows. The present study aimed at evaluating the efficacy of composite milk samples (CMS) analysis, compared to quarter milk samples (QMS) analysis, for the bacteriological detection of S. aureus intra-mammary infections. During 2016, 661 CMS (hygienically collected) and 2644 QMS (aseptically collected) were obtained from 661 cows in 5 herds. All the samples were submitted to S. aureus bacteriological culture and somatic cell count (SCC) analysis. QMS bacteriological analysis on blood agar plates was able to detect 236 cows excreting S. aureus, while the bacteriological analysis of CMS, using selective agar, identified 229 positive cows. The concordance was 95% with an excellent Cohen's κ (0.89). Relative sensitivity and specificity of CMS vs QMS, considered as the reference test, were 91.5% ± 2.1 and 96.9% ± 1.3 (CI 95%), respectively. In addition, the relative sensitivity of CMS improved as the number of infected quarters per cow and the number of colony forming units (cfu) per sample increased. The predictive value of CMS results was better when paired with SCC data, in particular CMS showed better negative predictive value when SCC was <200,000 cells/mL and better positive predictive value when SCC was>200,000 cells/mL. The probability for a cow to be S. aureus positive was 56.4% in case of SCC > 200,000 cells/mL, while it was 18.6% in case of SCC < 200,000 cells/mL. The average SCC in CMS was significantly higher in positive cows and the value rose as the number of infected quarters per cow increased. Given the intermittent excretion of S. aureus in milk from dairy cows, it could be more advantageous to carry out several serial CMS, rather than few QMS, being CMS an easier to collect and less expensive milk sampling method. Thus, bacteriological examination of CMS, combined with SCC data of the same sample, could be extremely useful for the success of S. aureus IMI control plans, because repeated CMS are easier to be performed and could be more easily proposed to the farmers.

Disease risk assessment by clinical immunology analyses in periparturient dairy cows

A disease prediction system was investigated in a case-control study in the dry period of high-yielding dairy cows. Blood samples of 75 cows from 26 herds were collected before calving between -23 and -33 days (T1) and also between -2 and -6 days (T2) to investigate a panel of clinical immunology and chemistry parameters. Cows with abnormal serum lysozyme and interleukin-6 concentrations showed a greater disease prevalence until the 60th day in milk compared with non-responder cows (P<0.05 and lower at T1). Differences in disease prevalence were observed on the basis of T1 data, and also by combining the results at T1 and T2. The other laboratory parameters under study were not predictive of a disease risk. Results indicate that environmental stressors in the dry period may cause a negative imprinting of the innate immune response, underlying predisposition to later disease occurrence.

Case-study and risk management of dioxins and PCBs bovine milk contaminations in a high industrialized area in Northern Italy

Milk supplied to a dairy plant in Brescia City (Northern Italy) was found to be contaminated by dioxin like PCBs at levels above the European (EU) action limit (2 pg WHO-TEQ/g fat). As a consequence, 14 dairy farms were sampled individually, in order to identify and possibly eliminate the source of contamination. All the farms were located in Brescia or just nearby, an area that is characterized by a strong industrialization. Four out of the 14 farms showed contamination levels above the legal maximum limit set by European Commission at 5.5 pg WHO-TEQ/g fat for the sum of dioxins and DL-PCBs. Concentrations of 8.16, 6.83, 5.71 and 5.65 pg WHO-TEQ/g fat were detected. In the three most polluted farms, cow ration was substituted with feed coming from uncontaminated areas and the time needed to reduce milk pollution was evaluated. In all the three farms, contamination levels dropped below the EU legal limit after only 1 month from the removal of the pollution source. In each sampled farm, DL-PCBs were the major contributors to the total WHO-TEQ level, with percentages up to 87% in the most contaminated one. PCB 126 WHO-TEQ value explained by itself large part of this contamination, and its decrease was fundamental for the reduction of milk contamination levels. This study provides an example of an on-field successful emergency intervention that succeeded in decontamination of dairy cows, allowing a fast restart of their production activity.

Aflatoxin control in maize by Trametes versicolor

Aspergillus flavus is a well-known ubiquitous fungus able to contaminate both in pre- and postharvest period different feed and food commodities. During their growth, these fungi can synthesise aflatoxins, secondary metabolites highly hazardous for animal and human health. The requirement of products with low impact on the environment and on human health, able to control aflatoxin production, has increased. In this work the effect of the basidiomycete Trametes versicolor on the aflatoxin production by A. flavus both in vitro and in maize, was investigated. The goal was to propose an environmental loyal tool for a significant control of aflatoxin production, in order to obtain feedstuffs and feed with a high standard of quality and safety to enhance the wellbeing of dairy cows. The presence of T. versicolor, grown on sugar beet pulp, inhibited the production of aflatoxin B1 in maize by A. flavus. Furthermore, treatment of contaminated maize with culture filtrates of T. versicolor containing ligninolytic enzymes, showed a significant reduction of the content of aflatoxin B1.

Investigation of the origin of prednisolone in cow urine

After a two-year period of the frequent detection of prednisolone-positive bovine urine samples in the Italian region of Lombardy, studies were initiated to investigate the source. Because the majority of positive samples were detected at the slaughterhouse, researchers hypothesised that, together with increased cortisol and cortisone, a small quantity of prednisolone could be produced by the cows in stressful situations. In the present study, three dairy cows underwent intramuscular treatments with tetracosactide hexaacetate, a synthetic analogue of adrenocorticotropic hormone, to simulate stress. The animals were slaughtered at the end of the study. The results indicated that prednisolone could be detected occasionally in the non-stressful state, but was consistently found in the urine of stressed cows (concentrations ranged from 1.01 to 4.08 ng/mL). To confirm the stress condition, urinary cortisol and cortisone were also detected at high concentrations in the urine, typically at concentrations of hundreds of nanograms per millilitre. The results of this preliminary study did not reveal the metabolic pathway responsible for prednisolone but suggested that this corticosteroid could be produced endogenously.

Seasonal pattern of mortality and relationships between mortality and temperature-humidity index in dairy cows

The 2 studies described investigated seasonal variations of mortality and temperature-humidity index (THI)-mortality relationships in dairy cows. Mortality data were extracted from the Italian Bovine Spongiform Encephalopathy databases, which contain records on cows older than 24 mo that died on a farm from all causes (98% of total records), were slaughtered in an emergency state, or were sent for normal slaughter but were sick in the preslaughter inspection (2% of total records). Both studies evaluated mortality data during a 6-yr period (2002 to 2007). The seasonal pattern study was conducted throughout Italy and was based on 320,120 deaths. An association between season and deaths was found for all 6 yr. Summer and spring were the seasons with the highest and lowest frequency of deaths (15,773.3 +/- 2,861 and 11,619.3 +/- 792.3), respectively, and within summer months, the number of deaths in July and August (5,435 +/- 284 and 5,756 +/- 676.2, respectively) was higher than in June (4,839 +/- 344.8). The THI-mortality relationships study was carried out only for deaths (51,240) reported for the Lombardia and Emilia Romagna regions. For this study, the mortality databases were integrated with THI data, which were calculated by using data from 73 weather stations. Each farm where deaths were recorded was assigned the THI values (maximum and minimum) calculated at the closest weather station for each day the events (deaths) were reported. Analysis of data indicated that approximate THI values of 80 and 70 were the maximum and minimum THI, respectively, above which the number of deaths in dairy farms starts to increase. Maximum and minimum THI values of 87 and 77 were the upper critical THI above which the risk of death for dairy cows becomes maximum. This study defined quantitative relationships between mortality risk and THI in dairy cows and may help to provide emergency interventions and mitigation measures, which may ensure survival of dairy cows and reduce replacement costs associated with heat stress-related mortality.

Short communication: isolation of Prototheca species strains from environmental sources in dairy herds

Composite milk samples from 548 cows, and samples from feces, feed, bedding, water, liners (before and after milking), and the postdipping product were aseptically collected from 2 Italian dairy herds from February to November of 2006. Prototheca zopfii was isolated from 11.9% of milk samples, 15% of feces, and 33.3% of bedding samples. No viable cells of P. zopfii were observed in water before washing procedures, whereas 25 to 28.6% of samples from water used for washing both refrigeration tanks and milking equipment were contaminated with this yeast-like microalga. Analogously, the presence of P. zopfii was detected only on swabs collected from the liners after milking. Interestingly, in 1 of the 2 herds, water from the drinking trough was contaminated by viable cells of both P. zopfii and the related environmental species Prototheca stagnora. No viable cells were observed in cow feed. On the basis of the results presented herein, P. zopfii seemed to be widespread throughout the environments of dairy herds where outbreaks of bovine mastitis had occurred.

Definition of a solvent system for spherical crystallization of salbutamol sulfate by quasi-emulsion solvent diffusion (QESD) method

In this paper we describe how the spherical crystallization process by QESD method can be applied to a water-soluble drug, salbutamol sulfate. The type of solvent, antisolvent, and emulsifier and the concentration of emulsifier to be used for the production of spherical particles with a size range 80-500 microm are determined. Furthermore, the solvent/antisolvent ratio and the temperature difference between them (Delta T) are studied. It was observed that, in the case of salbutamol sulfate, the Delta T value has no influence on the formation of spherical particles. A very large metastable zone of salbutamol sulfate in water could explain this phenomenon. Finally, the influence of emulsifier concentration and of maturation time on the size of spherical particles is studied. The results show that these two parameters must be fixed to control the size of the recovered particles.