The Distribution of Boars Spermatozoa in Morphometrically Distinct Subpopulations after In Vitro Exposure to Radiofrequency Electromagnetic Radiation at 2500 MHz and Their Motility.

Anthropogenic radiofrequency electromagnetic radiation (RF-EMR) from wireless technologies has increased dramatically. The boar semen used for artificial insemination is essential in sustaining the pig industry, and additionally it is also exposed to the effects of the RF-EMR of wireless technologies. Furthermore, there are no data on the effects of RF-EMR on semen quality, and this is the first analysis of sperm's morphometric parameters for assessing the effect of RF-EMR on the spermatozoa subpopulations of boars. This study investigated the effect of RF-EMR on in vitro exposed breeding boar semen spermatozoa motility and the proportions of spermatozoa subpopulations according to their morphometric head and tail parameters. The semen samples of 12 boars were divided into control and experimental groups. The samples in the experimental group were exposed in a gigahertz transverse electromagnetic chamber at a frequency of 2500 MHz (the frequency band used in 5G technology) and an electric field strength of 10 Vm-1 for two hours. After exposure, the spermatozoa motility was evaluated for both groups. A morphometric analysis of the semen smears was performed using SFORM software (Version 1.0; VAMS, Zagreb, Croatia). The progressive spermatozoa motility was significantly reduced in the experimental group (74.7% vs. 85.7%). PC analysis and cluster analysis revealed two spermatozoa subpopulations: S1, spermatozoa with a more regular head shape and a smaller midpiece outline, and S2, spermatozoa with a more elongated head shape and a larger midpiece outline. The experimental semen samples had a greater proportion of the S1 spermatozoa subpopulation (68.2% vs. 64.4%). The effect of RF-EMR at 2500 MHz on the in vitro exposed boar semen resulted in decreased progressive spermatozoa motility and a lower proportion of the spermatozoa subpopulation with a higher fertilizing potential.

A Survey Study of Veterinary Student Opinions and Knowledge about Pet Reptiles and Their Welfare.

Exotic pet medicine is rapidly evolving, with reptiles becoming increasingly popular pet animals. Yet, there are only a few literature reports on veterinary perception of reptiles kept as pets. The aim of the study was to assess opinions and knowledge of the Croatian veterinarians-to-be about pet reptiles and their welfare. The questionnaire survey was conducted in the academic year 2019-2020 and included students of all six years of the integrated undergraduate and graduate study at the Faculty of Veterinary Medicine, University of Zagreb. First-year students were surveyed twice, before and after having attended the compulsory course on animal welfare. Questionnaire statements were 5-point Likert scale questions, requiring the students to express their opinions about turtles, lizards and snakes as pets, issues related to their welfare, risks they pose to the health and safety of humans, other animals and the environment, and their self-reported knowledge about pet reptiles. Although expressing higher opinions after having attended the course on animal welfare, first-year student responses remained neutral to most of the statements. Such a trend continued until the end of the study. Student responses revealed that they were uncertain about their knowledge of reptiles as pets, considering different educational areas observed. Study results emphasised the need of alterations in veterinary curriculum and additional student education in reptile medicine. The results obtained have broad implications involving not only the welfare of pet reptiles in clinical practice and elsewhere but also the health and safety of humans and other animals, as well as environmental protection.

Differences in fungal contamination of broiler litter between summer and winter fattening periods.

This study aimed to compare fungal contamination of poultry litter between warm and cold seasons. It was carried out in commercial production conditions over two five-week fattening periods: one in the summer (July-August) and one in the winter (December-January). Broilers were reared on a litter composed of chopped straw and sawdust. Litter fungal concentration and composition were investigated weekly, along with litter temperature, moisture, and pH. Litter concentration of total fungi increased over both fattening periods, with no differences in median concentrations between them. Season also had no effect on yeast, Aspergillus section Nigri, and Cladosporium, Fusarium, and Rhizopus spp. concentrations, while the Aspergillus section Flavi and Aspergillus spp. combined showed higher concentrations in the summer, and Mucor and Penicillium spp. in the winter. Total fungal concentration highly correlated with litter temperature, moisture, and pH, regardless of the season. Our findings can be useful in the assessment and control of potential harmful effect of fungi on the health of poultry and poultry farm workers.

Effect of RNF4-SacII gene polymorphism on reproductive traits of Landrace × Large White crossbred sows.

The aim of the present study was to investigate whether and to what extent the RNF4-SacII gene polymorphism influences reproduction performances in hyperprolific sow lines. The study involved 101 Landrace x Large White crossbred sows, with 461 records collected on the following reproductive traits: Total Number of piglets Born per litter (TNB), Number of piglets Born Alive per litter (NBA), Number of StillBorn piglets per litter (NSB), piglet Pre-Weaning Mortality (PWM) and Number of piglets at Weaning per litter (NW). The least square method with the GLM procedure in SAS with eight effects was used to pursue the data analysis. Study results revealed that TT homozygotes and TC heterozygotes had a significantly higher (p < .05) NW than CC homozygotes for the life-span performance in all parities and first parity analysed. In the fourth parity analysed, TNB and NBA in TC genotype were significantly higher (p < .05) as compared with TT genotype. Based on the life-span performance, significant effect (p < .05) was recorded for order of parity on TNB, NBA and NW, for farrowing season on TNB and NSB, and for lactation length on PWM. In the second parity, significant effect (p < .05) was recorded for sire of boar on NSB and for gestation length on TNB. Only in the fourth parity, significant effect (p < .05) of RNF4 gene was observed on NBA. There was significant additive effect (p < .05) of the RNF4 gene polymorphism identified on NW in all parities analysed, and significant additive and dominance effects (p < .05) on NSB in the third parity analysed. In conclusion, additional research on related production pig genotypes is necessary to elucidate the effect of RNF4 gene mutation on reproductive traits.

Opinions towards Companion Animals and Their Welfare: A Survey of Croatian Veterinary Students.

This survey was the first one investigating opinions of veterinary students in Croatia towards companion animals and their welfare, with special reference to dogs and cats as the most popular companion animals in the European Union. The study included students of all six years of the integrated undergraduate and graduate veterinary medicine study programme in Croatia. First-year students were surveyed twice, before and after having attended the course on animal welfare. Student opinions were assessed on the basis of their mean responses to five-point Likert scale questions and frequency of responses to Yes/No/I do not know questions and ratio scale questions. Study results revealed students to have strongly positive opinions towards companion animals and their welfare. The majority of student statements did not differ significantly between the first and sixth study years or before and after having attended the animal welfare course in the first study year, mostly yielding a straight, non-fluctuating line. Students were not sure whether welfare of companion dogs and cats was compromised. Study results pointed to reliable and reasonable opinions of veterinary medicine students in Croatia towards companion animals and their welfare, as well as to the welfare issues these species may be facing nowadays.

Antioxidant protection and lipid peroxidation in testes and different parts of epididymis in boars.

The antioxidative ability of testes and epididymis to protect spermatozoa from detrimental effects of oxidation processes induced by excessive generation of reactive oxygen species has not been previously studied in detail in boar reproductive tissues. The aim of this study was to investigate differences in level of antioxidative protection, intensity of lipid peroxidation, and values of biochemical parameters in testes and different parts of epididymis in sexually mature boars. The study was performed on five Swedish landrace boars from the same litter aged 10 months kept under same ambient conditions. After slaughtering performed at the end of November; tissue samples of testes and the head, body and tail of epididymis were taken. The activity of glutathione peroxidase, glutathione reductase, superoxide dismutase, γ-glutamyltransferase, acid phosphatase, and lactate dehydrogenase, and concentrations of triacylglycerol, phospholipids, cholesterol, free fatty acids were determined in obtained supernatants from homogenized tissues spectrophotometrically; the concentration of malondialdehyde was determined by high-performance liquid chromatography. Significantly higher activities of glutathione peroxidase and glutathione reductase (P < 0.05) were found in testes compared with epididymis. In testes, a significantly higher activity of superoxide dismutase was found than in the head and tail of epididymis (P < 0.05). Malondialdehyde concentration in head of epididymis was significantly higher than in testes, or the body and tail of epididymis (P < 0.05). Simultaneously, malondialdehyde concentration in testes was significantly higher than in body and tail of epididymis (P < 0.05). In tail of epididymis, significantly higher activities of γ-glutamyltransferase, acid phosphatase, and lactate dehydrogenase were recorded than in testes. Significantly lower concentrations of triacylglycerol and free fatty acids were recorded in epididymis tail in comparison to epididymis head (P < 0.05). It could be concluded that high activities of antioxidative enzymes in testes of boars are essential for the appropriate protection of spermatozoa and cells of testes tissue against oxidative damages. The tissues of testes and epididymis head in boars were more susceptible to lipid peroxidation. Results of the present study indicated physiological importance of antioxidative enzymes in reproductive system in boars, and thus may serve for better understanding the mechanisms of male infertility.

Prevalence of Thermotolerant Campylobacter spp. in Chicken Meat in Croatia and Multilocus Sequence Typing of a Small Subset of Campylobacter jejuni and Campylobacter coli Isolates.

In order to detect thermotolerant Campylobacter spp., 241 samples of fresh chicken meat, at retail in Croatia, were analysed according to a standard method, followed by biochemical test and molecular polymerase chain reaction/restriction enzyme analysis for exact species determination. Campylobacter spp. prevalence was 73.86%. Campylobacter jejuni and Campylobacter coli were isolated from 53.53 and 15.35% of the samples, respectively. In 4.98% of isolates thermotolerant Campylobacter spp. were not determined. The multilocus sequence typing method was used to evaluate genetic diversity of eight Campylobacter jejuni and four Campylobacter coli isolates. To our knowledge, these results of genotyping provided the first data on the presence of sequence types (STs) and clonal complexes (CCs) of Campylobacter jejuni and C. coli isolates in Croatia. By applying the multilocus sequence typing, a new allele of tkt gene locus was discovered and marked tkt508. The C. jejuni ST 6182 and C. coli ST 6183 genotypes were described for the first time, and all other identified genotypes were clustered in the previously described sequence types and clonal complexes. These findings provide useful information on the prevalence and epidemiology of Campylobacter jejuni and C. coli in Croatia.

The effect of rubber flooring on displaying stereotypies in gilts.

The aim of the study was to assess the effect of rubber mats in service unit on displaying stereotypies in gilts. Four 28-day production cycles in all seasons were observed. Each cycle included 28 gilts housed in gestation stalls with slatted concrete floor, which was covered with adjusted mats for 14 gilts (experimental group), while the remaining 14 gilts served as controls. Display of stereotypies and other behaviours observed, mat manipulation and postural behaviours were estimated by direct 1-hour observation of gilts at 2-minute intervals after morning feed supply on days 1, 8, 15 and 28 of each cycle. During the study period, displaying stereotypies was significantly less frequent (P < 0.05) in experimental group as compared with control group. The rate of particular forms of stereotypies, i.e. vacuum chewing, bar biting and teeth grinding, was also significantly lower (P < 0.05 all) in experimental group throughout the study period. A significant negative correlation (P <.05) was found between the service unit air temperature and frequency of displaying stereotypies in control group, which could be attributed to the significantly more common standing posture (P < 0.05) in control gilts in the conditions of lower air temperature. During the cold period, experimental gilts took a lying position significantly more frequently (P < 0.05). In the experimental group of gilts there was no significant correlation (P > 0.05 all) between the frequency of displaying stereotypies and the frequency of lying and other postures observed, as well as between the stereotypy display and the air temperature. There was no significant correlation (P > 0.05 all) between the frequency of mat manipulation and displaying stereotypies in total or its particular forms, suggesting that the less pronounced stereotypy display in experimental gilts may have been influenced by factors other than those observed in the present study.