Dynamics and Diversity of Microbial Contamination in Poultry Bedding Materials Containing Parts of Medicinal Plants

Abstract

Microorganisms thriving in poultry bedding materials during their exploitation are involved in the development of several diseases and disfunctions of animals. They can also contaminate food products and pose risks to the environment and human health. This study provides an analysis of dynamics and diversity in microbiological contamination observed during the exploitation of poultry bedding materials containing parts of medicinal plants: Satureja hortensis, Origanum vulgare, Melissa officinalis, Salvia officinalis, and Thymus vulgaris, compared with standard types of beddings: straw chaff and straw pellets. The research was carried out in two 42-day experimental cycles involving in total 2400 broiler chickens. Each week, the total count of mesophilic bacteria, fungi and yeasts, the presumptive presence and count of Staphylococcus sp., Escherichia sp., Listeria sp., Salmonella sp., and Candida sp. were determined by culturing on selective media, along with pH and moisture measurements. After 35 days of the experiment, a reduction of the total count of mesophilic bacteria above 1 log compared to the control (11.86 vs. 13.02 log CFU/g) was observed. As the count of yeasts decreased after 21 days, an increase in the total count of bacteria was reported, which indicates a strong competition between microorganisms. The results improve our understanding of the temporal effects of using materials containing parts of medicinal plants on the microbial contamination in poultry litter.

Keywords: Candida; Escherichia; Listeria; Origanum vulgare; Salmonella; Satureja hortensis; Staphylococcus; broiler house; pellets; poultry litter.

Figure 1

Experimental setting—allocation of bedding materials to compartments with animals: (a) 1st experimental cycle; (b) 2nd experimental cycle.

Figure 2

Experimental setting—1st day of bedding materials use by animals: (a) pelletised materials containing parts of medicinal plants; (b) straw chaff (control).

Figure 3

Changes in the moisture content in the tested bedding materials during: (a) 1st experimental cycle; (b) 2nd experimental cycle. All values are means of three independent replicates ± SD, except the last bars for each day, which are the means-of-means. For each day, means with a common lowercase letter are not significantly different by the Tukey test at the 5% level of significance. For different days, means-of-means with a common uppercase letter are not significantly different by the Tukey test at the 5% level of significance. Pairwise comparisons between materials are presented only for observations from the same day. Pairwise comparisons between days are presented only for means-of-means. No pairwise comparisons between cycles are presented.

Figure 4

Changes in the count of microorganisms of Staphylococcus sp. in the tested bedding materials: (a) 1st experimental cycle; (b) 2nd experimental cycle. All values are means of three independent replicates ± SD, except the last bars for each day, which are the means-of-means. For each day, means with a common lowercase letter are not significantly different by the Tukey test at the 5% level of significance. For different days, means-of-means with a common uppercase letter are not significantly different by the Tukey test at the 5% level of significance. Pairwise comparisons between materials are presented only for observations from the same day. Pairwise comparisons between days are presented only for means-of-means. No pairwise comparisons between cycles are presented.

Figure 5

Changes in the count of microorganisms of Escherichia sp. in the tested bedding materials: (a) 1st experimental cycle; (b) 2nd experimental cycle. All values are means of three independent replicates ± SD, except the last bars for each day, which are the means-of-means. For each day, means with a common lowercase letter are not significantly different by the Tukey test at the 5% level of significance. For different days, means-of-means with a common uppercase letter are not significantly different by the Tukey test at the 5% level of significance. Pairwise comparisons between materials are presented only for observations from the same day. Pairwise comparisons between days are presented only for means-of-means. No pairwise comparisons between cycles are presented.

Figure 6

Changes in the count of microorganisms of Listeria sp. in the tested bedding materials: (a) 1st experimental cycle; (b) 2nd experimental cycle. All values are means of three independent replicates ± SD, except the last bars for each day, which are the means-of-means. For each day, means with a common lowercase letter are not significantly different by the Tukey test at the 5% level of significance. For different days, means-of-means with a common uppercase letter are not significantly different by the Tukey test at the 5% level of significance. Pairwise comparisons between materials are presented only for observations from the same day. Pairwise comparisons between days are presented only for means-of-means. No pairwise comparisons between cycles are presented.

Figure 6

Changes in the count of microorganisms of Listeria sp. in the tested bedding materials: (a) 1st experimental cycle; (b) 2nd experimental cycle. All values are means of three independent replicates ± SD, except the last bars for each day, which are the means-of-means. For each day, means with a common lowercase letter are not significantly different by the Tukey test at the 5% level of significance. For different days, means-of-means with a common uppercase letter are not significantly different by the Tukey test at the 5% level of significance. Pairwise comparisons between materials are presented only for observations from the same day. Pairwise comparisons between days are presented only for means-of-means. No pairwise comparisons between cycles are presented.

Figure 7

Changes in the count of microorganisms of Salmonella sp. in the tested bedding materials: (a) 1st experimental cycle; (b) 2nd experimental cycle. All values are means of three independent replicates ± SD, except the last bars for each day, which are the means-of-means. For each day, means with a common lowercase letter are not significantly different by the Tukey test at the 5% level of significance. For different days, means-of-means with a common uppercase letter are not significantly different by the Tukey test at the 5% level of significance. Pairwise comparisons between materials are presented only for observations from the same day. Pairwise comparisons between days are presented only for means-of-means. No pairwise comparisons between cycles are presented.

Figure 8

Changes in the count of microorganisms of Candida sp. in the tested bedding materials: (a) 1st experimental cycle; (b) 2nd experimental cycle. All values are means of three independent replicates ± SD, except the last bars for each day, which are the means-of-means. For each day, means with a common lowercase letter are not significantly different by the Tukey test at the 5% level of significance. For different days, means-of-means with a common uppercase letter are not significantly different by the Tukey test at the 5% level of significance. Pairwise comparisons between materials are presented only for observations from the same day. Pairwise comparisons between days are presented only for means-of-means. No pairwise comparisons between cycles are presented.

Figure 8

Changes in the count of microorganisms of Candida sp. in the tested bedding materials: (a) 1st experimental cycle; (b) 2nd experimental cycle. All values are means of three independent replicates ± SD, except the last bars for each day, which are the means-of-means. For each day, means with a common lowercase letter are not significantly different by the Tukey test at the 5% level of significance. For different days, means-of-means with a common uppercase letter are not significantly different by the Tukey test at the 5% level of significance. Pairwise comparisons between materials are presented only for observations from the same day. Pairwise comparisons between days are presented only for means-of-means. No pairwise comparisons between cycles are presented.