Silver and Copper Nanoparticles as the New Biocidal Agents Used in Pre- and Post-Milking Disinfectants with the Addition of Cosmetic Substrates in Dairy Cows.

Mastitis is one of the most common issues for milk producers around the world. Antibiotic therapy is often ineffective, and therefore, scientists must find a new solution. The aim of this paper is to estimate the influence of common and well-known cosmetic substrates and mixtures of nanoparticles (NPs) and cosmetic substrates on the viability of frequently occurring mastitis pathogens, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The obtained results suggest that only collagen + elastin and glycerine influenced and increased bacteria viability. In case of the rest of the cosmetic substrates, the viability of E. coli and S. aureus was decreased, and the results were statistically significant (p ≤ 0.01). Prepared pre-dipping and dipping mixtures decrease (p ≤ 0.01) the viability of the mentioned pathogens. The obtained results of the in vitro analysis are very promising. In the next step, prepared mixtures should be tested in different herd conditions if they can be used in mastitis prevention or decrease the number of subclinical mastitis cases. Furthermore, these mixtures could become an interesting alternative for organic milk production where conventional preparations and antibiotics are forbidden. However, further analysis, especially on the influence of prepared mixtures on other bacteria species and, algae, fungi, are necessary.

In Vitro Evaluation of the Antimicrobial Properties of Nanoparticles as New Agents Used in Teat Sealants for Mastitis Prevention in Dry Cows.

Mastitis prevention and treatment in dry cows are complex issues with limited solutions. The most common is intramammary antibiotic treatment. However, the effectiveness of this treatment varies among countries and even within herds in the same region. Therefore, it is necessary to develop new strategies for dry cow therapy. Metal nanoparticles (NPs), which have strong biocidal properties for treating diseases caused by bacteria, fungi, and algae, are increasingly used to reduce antibiotic use. In this study, AuNPs, CuNPs, AgNPs, PtNPs, NP-FeCs, and their triple complexes were used at different concentrations to evaluate their practical use in treating cows during their dry period. The nanoparticles were in hydrocolloid form and were added separately to form a mixture with beeswax, a mixture with oil, or a mixture based on vegetable glycerin and propylene glycol. The NPs' concentrations were 0.5, 1, 2, and 5 ppm. Gram-positive and Gram-negative bacteria, and fungi isolated from cows diagnosed with mastitis were used to determine pathogen viability. The results indicated that AuNPs, CuNPs, AgNPs, and their complexes show biocidal properties against mastitis pathogens. AgNPs at 5 ppm had the strongest biocidal properties and reduced Streptococcus agalactiae's survival rate by 50%; however, the nanoparticle complexes showed poor synergism. The strongest biocidal properties of NPs in wax and in glycerin mixed with glycol were shown against Escherichia coli. Additionally, low nanoparticle concentrations showed no cytotoxicity for BME-UV1 bovine cells, suggesting that these mixtures might be used for further in vivo testing.

Effect of Feed Additives Supplementation on the Growth Performance, Gastrointestinal Tract Characteristics, and Carcass Composition in Turkey Hens.

In order to increase growth performance and carcass composition, including meat quality, as demanded by modern customers, alternative feed additives are sought after as a result of the withdrawal of antibiotics employed as growth promoters in poultry feeding. Therefore, we conducted a study to see how effective three feed additives added to the diets and water of turkey hens were. The experiment consisted of 200 Big 6 turkey hens divided into two equinumerous groups (C and E), with five subgroups in each. The 14-week-long growth performance study comprised five feeding periods. Both groups of birds were fed complete feed rations with mineral and vitamin supplements. The factor differentiating the groups were effective microorganisms and Humokarbowit added to the birds' diets and garlic extract added to the drinking water in the experimental group (E) only. It was demonstrated that the included feed additives in the diets and water of turkey hens significantly increased (by 10%) the FBW and decreased (by 14%) the FCR throughout the rearing period. Birds from the E group scored significantly higher (by 3.6%) on the dressing percentage, and their muscularity and fattening grade were improved. Turkey fed rations containing the evaluated feed additives had a smaller share of the gastrointestinal tract in the body weight and a shorter duodenum and caecum (p ≤ 0.05). The muscles of turkey hens from group E featured a lower pH24 and were of lighter colour (p ≤ 0.05). To sum up, the use of effective microorganisms and Humokarbowit in the diets and garlic extract in the drinking water of turkey hens should be recommended in view of improved growth performance and carcass composition.

Silver and Copper Nanoparticles Inhibit Biofilm Formation by Mastitis Pathogens.

Bovine mastitis is a common bovine disease, frequently affecting whole herds of cattle. It is often caused by resistant microbes that can create a biofilm structure. The rapidly developing scientific discipline known as nanobiotechnology may help treat this illness, thanks to the extraordinary properties of nanoparticles. The aim of the study was to investigate the inhibition of biofilms created by mastitis pathogens after treatment with silver and copper nanoparticles, both individually and in combination. We defined the physicochemical properties and minimal inhibitory concentration of the nanoparticles and observed their interaction with the cell membrane, as well as the extent of biofilm reduction. The results show that the silver-copper complex was the most active of all nanomaterials tested (biofilm was reduced by nearly 100% at a concentration of 200 ppm for each microorganism species tested). However, silver nanoparticles were also effective individually (biofilm was also reduced by nearly 100% at a concentration of 200 ppm, but at concentrations of 50 and 100 ppm, the extent of reduction was lower than for the complex). Nanoparticles can be used in new alternative therapies to treat bovine mastitis.