Martina Lichovníková

Comparison of Microbiomes between Red Poultry Mite Populations (Dermanyssus gallinae): Predominance of Bartonella-like Bacteria

Blood feeding red poultry mites (RPM) serve as vectors of pathogenic bacteria and viruses among vertebrate hosts including wild birds, poultry hens, mammals, and humans. The microbiome of RPM has not yet been studied by high-throughput sequencing. RPM eggs, larvae, and engorged adult/nymph samples obtained in four poultry houses in Czechia were used for microbiome analyses by Illumina amplicon sequencing of the 16S ribosomal RNA (rRNA) gene V4 region. A laboratory RPM population was used as positive control for transcriptome analysis by pyrosequencing with identification of sequences originating from bacteria. The samples of engorged adult/nymph stages had 100-fold more copies of 16S rRNA gene copies than the samples of eggs and larvae. The microbiome composition showed differences among the four poultry houses and among observed developmental stadia. In the adults’ microbiome 10 OTUs comprised 90 to 99% of all sequences. Bartonella-like bacteria covered between 30 and 70% of sequences in RPM microbiome and 25% bacterial sequences in transcriptome. The phylogenetic analyses of 16S rRNA gene sequences revealed two distinct groups of Bartonella-like bacteria forming sister groups: (i) symbionts of ants; (ii) Bartonella genus. Cardinium, Wolbachia, and Rickettsiella sp. were found in the microbiomes of all tested stadia, while Spiroplasma eriocheiris and Wolbachia were identified in the laboratory RPM transcriptome. The microbiomes from eggs, larvae, and engorged adults/nymphs differed. Bartonella-like symbionts were found in all stadia and sampling sites. Bartonella-like bacteria was the most diversified group within the RPM microbiome. The presence of identified putative pathogenic bacteria is relevant with respect to human and animal health issues while the identification of symbiontic bacteria can lead to new control methods targeting them to destabilize the arthropod host.

Pre-caecal Digestible Phosphorus in Maize and Wheat for Broiler Chickens

ABSTRACT 1. The objective of this study was to determine the coefficient of pre-caecal digestion of P in maize (3.9 g/kg of total P, 0.83 g/kg of phytate P, 138 FTU [phytase units]/kg) and wheat (3.17 g/kg of total P, 1.94 g/kg of phytate P, 666 FTU/kg) in broilers according to the WPSA protocol. 2. For the diets, monosodium phosphate was used as an additional P supplement. Two sets of diets containing 200, 460 and 740 g/kg of wheat or 200, 500 and 740 g/kg of maize were formulated. A total of 288 21-d-old male broilers (Ross 308) were assigned to 24 cages (8 birds per cage) and the 6 test diets were assigned to cages. The coefficient of pre-caecal digestion of P was determined by the indicator method and linear regression. 3. In both ingredients, pre-caecal digestible P increased linearly with increasing inclusion levels of maize or wheat (P < 0.05). The coefficients of digestion of pre-caecal P were estimated to be 0.18 for wheat and 0.33 for maize.

The effect of genotype on the behaviour of free range chickens

The purpose of this experiment was to investigate the behaviour of fast- and slow growing chickens, when the birds had access to the outdoors. Fifty of both 1-day-old male chicks of a laying hybrid ISA BROWN (IB) and broilers ROSS 308 (RS) were kept in two pens in the same building. In each group ten birds were marked with a colored spray. From three weeks of age the birds had access to the outdoors. From the age of one to seven weeks old, one day a week the marked birds were observed from 8:00 to 18:00 every ten minutes and the activity was noted. At 49 and 90 days old twenty birds were slaughtered and the strength of bones was measured. The behaviour was expressed as percentage of the time spent in activity. The average time that the birds spent eating during the 7 week period was almost the same in IB and RS. On average, IB birds spent significantly higher (P<0.05) an amount of time moving around, but until the fifth week of age there was no significant difference between these genotypes. In IB, movement was the more frequent activity. The resting sitting down was the most frequent activity in RS and since three weeks of age they spent significantly more (P<0.05) time with this activity than IB. On average, the IB birds spent significantly more (P<0.05) time scratching than did the RS. No aggression or pecking was observed in the IB males during the whole test period. The strength of the femur was significantly higher in RS in comparison with IB in both ages (49d - P<0.001, 90d - P<0.05). Although the rules for organic farming dictate that the chickens have to have enough outdoor area to move around in, the fast growing broilers do not use it.

The effect of soybean meal replacement with raw full-fat soybean in diets for broiler chickens

ABSTRACT The aim of this study was to examine the effects of soybean meal replacement by multiple levels of raw full-fat soybean (REFS) in broiler diets on the growth performance, apparent ileal amino acids digestibility (AIAAD), intestinal histometric characteristic, pancreas weight and trypsin activity in digesta. In the experiment, in total 208 × ROSS 308 male chickens were used to examine the effect of RFFS on growth performance, AIAAD, intestinal morphology and trypsin activity in the intestinal content. Four dietary treatments were used: control group (without RFFS) and groups containing 4%, 8% and 12% of RFFS. The experiment lasted from 10th to 38th day of age. The presence of RFFS in broiler diets markedly decreased body weight and feed conversion ratio merely in group fed by 12% of RFFS in its diet. The AIAAD was lower when diets contained RFFS in all observed amino acids expect methionine. Higher AIAAD was obtained in RFFS12 in comparison with RFFS8 and RFFS4 due to a higher weight of pancreas and higher trypsin activity. Pancreas weight and trypsin activity increased with increasing RFFS in the diets. The morphology parameters villus height and crypt depth were negatively affected by the presence of RFFS.