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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, Aspergillussection Nigri, and Cladosporium, Fusarium, and Rhizopusspp. concentrations, while the Aspergillussection Flaviand Aspergillusspp. combined showed higher concentrations in the summer, and Mucorand Penicilliumspp. 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.

Good air quality in poultry houses is crucial for animal health and productivity. In these houses, air is generally contaminated with noxious gases and microorganisms, the concentrations of which depend on numerous factors including microclimate. In this case study, the relation between microclimate and air concentrations of noxious gases and microorganisms was investigated in extensively reared turkey house. The study was carried out at a family household in Dalmatia hinterland, Croatia, with 50.3±3.1 turkeys kept in the house during the study period. Air temperature, relative humidity, airflow rate, concentrations of ammonia, carbon dioxide, bacteria and fungi in indoor air were measured three times per month from September to December, in the morning, prior to releasing turkeys out for grazing. Air temperature ranged from 9.73 to 26.98 °C, relative humidity from 63.29% to 75.08%, and airflow rate from 0.11 to 0.17 m/s. Lowest ammonia and carbon dioxide concentrations were measured in September (2.17 ppm and 550 ppm, respectively) and highest in December (4.50 ppm and 900 ppm, respectively). Bacterial and fungal counts were lowest in December (2.51×105CFU/m3and 3.27×103CFU/m3air, respectively) and highest in September (6.85×105CFU/m3and 1.06x105CFU/m3air, respectively). Air temperature and relative humidity showed negative correlation with concentrations of noxious gases and positive correlation with air microorganisms (P<0.05 all).

The objective of the present study was to identify the Prolactin Receptor (PRLR) gene polymorphism related to litter size traits. The study included 101 Topigs 20 line of sows with 426 litters. The traits studied were: Total Number of Born (TNB), Number of Born Alive (NBA), Number of Still Born (NSB), and Number of MUMmified (NMUM) piglets. Polymorphism was identified with the polymerase chain reaction-restriction fragment length polymorphism method. Allelic and genotype frequencies and deviation from Hardy-Weinberg equilibrium were verified with the chi-square test. Analysis of litter size traits was performed using the General Linear Model, which included the potential environmental effects. Additive and dominant allele variances were observed by the regression procedure. In the studied population of sows, the frequency of heterozygotes (0.5149) for PRLR gene exceeded the total number of AA (0.0198) and BB (0.4653) homozygotes, which resulted in a high proportion of B allele (0.7228). The results for PRLR showed statistically significant (P<0.05) differences in first parity sows between BB and AB genotypes for TNB and NBA. Significant differences (P<0.05) were recorded in third parity sows between BB and AB genotypes for NBA, and in AA genotype versusAB and BB genotypes for NMUM. The fourth and subsequent parity sows of AA genotype had a significantly higher (P<0.05) rate of NBA as compared with those of AB and BB genotypes. In all parities analysed, the difference between the BB and AB genotypes for NBA was statistically significant (P<0.05). Interpretation of the results at the levels of phenotypes and either additive or dominant variance was quite difficult due to the small number of AA homozygous sows. The calculation model yielded a significant effect (P<0.05) as well as tendency (P<0.1) for the mentioned effects except for age at first farrowing.

AbstractThe study was carried out in a farrowing pen during 6 production cycles of 24 days in the spring-summer period. The effect of season and other microclimate parameters on airborne dust concentration was investigated. Study results showed a decrease in airborne dust concentration in summer period that yielded negative correlation with air temperature (P<0.05). Relative humidity was expected to decrease due to higher ventilation rates, however, a significant increase was recorded in summer (P<0.05) because of higher evaporation caused by floor wash. The decrease in airborne dust concentration was ascribed to temperature elevation due to intensified ventilation rate and relative humidity resulting in higher rate of dust settling.