Development of new nanomaterials that inhibit or kill bacteria is an important and timely research topic. For example, financial losses due to infectious diseases, such as diarrhea, are a major concern in livestock productions around the world. Antimicrobial nanoparticles (NPs) represent a promising alternative to antibiotics and may lower antibiotic use and consequently spread of antibiotic resistance traits among bacteria, including pathogens. Four formulations of zinc nanoparticles (ZnA, ZnB, ZnC, and ZnD) based on phosphates with spherical (ZnA, ZnB) or irregular (ZnC, ZnD) morphology were prepared. The highest in vitro inhibitory effect of our NPs was observed against Staphylococcus aureus (inhibitory concentration values, IC50, ranged from 0.5 to 1.6 mmol/L), followed by Escherichia coli (IC50 0.8–1.5 mmol/L). In contrast, methicillin resistant S. aureus (IC50 1.2–4.7 mmol/L) was least affected and this was similar to inhibitory patterns of commercial ZnO-based NPs and ZnO. After the successful in vitro testing, the in vivo study with rats based on dietary supplementation with zinc NPs was conducted. Four groups of rats were treated by 2,000 mg Zn/kg diet of ZnA, ZnB, ZnC, and ZnD, for comparison two groups were supplemented by 2,000 mg Zn/kg diet of ZnO-N and ZnO, and one group (control) was fed only by basal diet. The significantly higher (P < 0.05) Zn level in liver and kidney of all treated groups was found, nevertheless Zn NPs did not greatly influence antioxidant status of rats. However, the total aerobic and coliform bacterial population in rat feces significantly decreased (P < 0.05) in all zinc groups after 30 d of the treatment. Furthermore, when compared to the ZnO group, ZnA and ZnC nanoparticles reduced coliforms significantly more (P < 0.05). Our results demonstrate that phosphate-based zinc nanoparticles have the potential to act as antibiotic agents.

The study was designed for the comparison of barrows and gilts of two contrasting genotypes in terms of growth ability, carcass value and meat quality. A total of 76 pigs (from 7 ± 1 kg to 95 ± 6 kg) of the indigenous breed Prestice Black-Pied (PB) and the commercial hybrid of Large White × Landrace × Large White_sireline (CH) were included in this study. The groups were balanced regarding genotype and sex. Live weight at the age of 79 days (p < 0.001), live weight at slaughter (p < 0.01), average daily gain (p < 0.001), weight of carcass and left carcass side (p < 0.05) and ham proportion (p < 0.001) were higher in the CH group. The values of the given parameters were higher in barrows than in gilts. The effect of genotype and sex interaction was observed in lean meat content (p < 0.05) and backfat thickness (p < 0.01). The CH gilts showed the highest lean meat content and the lowest backfat thickness compared to the lowest values in the PB barrows. The value of pH₄₅ (p < 0.01) and intramuscular fat content were higher in the PB group. The lightness (p < 0.001), yellowness (p < 0.01), drip loss (p < 0.05) and protein content were lower in the PB group. Higher values of lightness (p < 0.05), yellowness (p < 0.05) and cholesterol content (p < 0.05) were observed in the boars. Oxidative stability of the meat (malondialdehyde content) was more favorable in the PB pigs. The effect of genotype and sex interaction was confirmed for the pH₂₄ value (the highest value was found in the PB barrows and the lowest in the CH barrows, p < 0.001) and for the dry matter content (lowest in the PB gilts and highest in the CH barrows, p < 0.05). Overall, the PB pigs were characterized by inferior growth and carcass parameters, however, with more favorable parameters for meat quality.

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, the scientific journal of the Mendel University in Brno, Czech Republic

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, the scientific journal of the Mendel University in Brno, Czech Republic

Knotweeds (Reynoutria spp.) are plants producing useful secondary metabolites, including stilbenes (resveratrol and piceid have been studied more thoroughly) and emodin. Many studies have shown the positive effects of resveratrol on the health status of humans and animals. Resveratrol has been added into pigs’ diet as a pure extract, but it has never been supplemented into the fodder with knotweed biomass which contains other secondary metabolites, thus we would expect it would provide a more complex effect. The study objective is to discover whether the 2 weight percent addition of knotweed into pigs’ diet will have positive effects on their health. We compared two groups of Prestice Black-Pied pigs, the experimental group was fed by fodder with the knotweed rhizomes additive, the control group without knotweed additive. Investigated parameters were feed consumption, the composition of excrements, weight increment, muscle-to-fat ratio, fatty acid composition and blood haematology and biochemistry. The addition of knotweed stimulated a whole range of physiological changes. It positively stimulated weight growth and increased the back fat and proportion of muscle, but statistically significant only in gilts. On the other hand, the changes in fatty acid composition seemed to be unsatisfactory. It is the first study of the effects of knotweed on pigs’ development, and more detailed research is desirable.

The aim of the experiment was to analyze the reproductive performance of sows and the losses and growth of piglets in three different systems of farrowing houses. A total of 120 sows of the Prestice Black-Pied breed were included in the study with 40 litters evaluated in each of the systems. The housing systems compared were conventional farrowing cages, pens with temporary fixation, and free farrowing pens. The housing system significantly affected the length of pregnancy (p < 0.05). Its effect was 0.35 days shorter in the sows in the free-farrowing system than in the cage technology and 0.6 days shorter than in the temporary fixation. Housing also influenced the onset of post-weaning oestrus (p < 0.01), which occurred 0.31 days earlier in the sows in a free-farrowing system and in those in pens with temporary fixation. A significant effect of housing on the overall losses of piglets (p < 0.05) was also found. The crushing of piglets by sows was also significantly affected by the housing system (p < 0.05), with the highest incidence found in the free-farrowing system. The effect of the housing system on the individual weaning weight of piglets was also found to be significant (p < 0.001). The piglets of the sows in the free housing system showed higher growth intensity when compared to piglets in the other housing systems. In conclusion, it can be stated that the lowest losses caused by the crushing of piglets were found in the cage systems. However, the combined system seems to be very perspective in terms of losses of piglets. The free-farrowing system has positive effects on the growth of piglets.