Simple SummarySalmonellosis is among the most common infectious poultry diseases that also represent a high risk to human health. The pathological process caused by Salmonella enterica serovar Enteritidis (SE) triggers in the caecum the expression of certain genes, e.g., avian β-defensins (gallinacins), cytokines (interleukins), etc. On the other hand, gut microbiota influences the infection potential of pathogens. The present study aimed at revealing the differential expression of genes associated with the immune system and changes in the bacterial communities in the intestine of growing chickens in response to SE infection. We also tested a feed additive, essential oils-based phytobiotic Intebio, as a potential alternative to antibiotics and showed effects of its administration on the caecal microbiome composition and the expression of some genes related to immunity. The phytobiotic showed its efficiency for application in poultry rearing and production.AbstractThis study was performed to investigate the differential expression of eight immunity genes and the bacterial profiles in the caecum of growing chickens challenged with Salmonella enterica serovar Enteritidis (SE) at 1 and 23 days post inoculation (dpi) in response to SE infection at 19 days of age and administration of the phytobiotic Intebio. Following infection, the genes CASP6 and IRF7 were upregulated by greater than twofold. Chicks fed Intebio showed at 1 dpi upregulation of AvBD10, IL6, IL8L2, CASP6 and IRF7. At 23 dpi, expression of AvBD11, IL6, IL8L2, CASP6 and IRF7 lowered in the experiment subgroups as compared with the control. Examination of the caecal contents at 1 dpi demonstrated a significant decrease in the microbial biodiversity in the infected subgroup fed normal diet. Bacterial content of Lactobacillus and Bacillus declined, while that of Enterobacteriaceae rose. In the infected subgroup fed Intebio, a pronounced change in composition of the microflora was not observed. In the early infection stages, the phytobiotic seemed to promote response to infection. Subsequently, an earlier suppression of the inflammatory reaction took place in chickens fed Intebio. Thus, use of Intebio as a drug with phytobiotic activity in chickens, including those infected with Salmonella, proved to be promising.

One of the main roles in poultry resistance to infections caused by Salmonella is attributed to host immunity and intestinal microbiota. We conducted an experiment that involved challenging Lohmann White laying hens with Salmonella Enteritidis (SE), feeding them a diet supplemented with an EOs-based phytobiotic Intebio®. At 1 and 7 days post-inoculation, the expression profiles of eight genes related to immunity, transport of nutrients in the intestine, and metabolism were examined. Cecal microbiome composition and blood biochemical/immunological indices were also explored and egg production traits recorded. As a result, the SE challenge of laying hens and Intebio® administration had either a suppressive or activating effect on the expression level of the studied genes (e.g., IL6 and BPIFB3), the latter echoing mammalian/human tissue-specific expression. There were also effects of the pathogen challenge and phytobiotic intake on the cecal microbiome profiles and blood biochemical/immunological parameters, including those reflecting the activity of the birds’ immune systems (e.g., serum bactericidal activity, β-lysine content, and immunoglobulin levels). Significant differences between control and experimental subgroups in egg performance traits (i.e., egg weight/number/mass) were also found. The phytobiotic administration suggested a positive effect on the welfare and productivity of poultry.

Practice of layer poultry farming and commercial egg production relies on the optimal use and improvement of the welfare and genetically determined functional abilities of laying hens, their efficient intake of feed and its components, adaptation to housing conditions and resistance to infectious diseases including salmonellosis. Previous studies were focussed on relationships of chicken performance and resistance with the expression profiles of individual genes involved in metabolic processes and immune system, or with genetic markers that can be closely associated with these processes in chickens. In this study, mathematical models of coherent changes in laying hens were developed for the expression of eight genes involved in immunity and metabolism, on the one hand, and biochemical and immunological blood parameters, on the other hand, in response to Salmonella infection and administration of a phytobiotic Intebio. The proposed modelling approach can be a further basis for an in-depth research of the relationship between the gene expression, functional state and welfare of poultry, impact of pathogenic microorganisms and use of immunomodulatory drugs. HIGHLIGHTS Improved egg production and resistance rely on hens' potential in gene expression and metabolism. We developed mathematical models for coherent responses of hens' gene expression and blood indices to Salmonella infection and phytobiotic intake. This approach can be used for further studying relationship between gene expression, functional state, impact of pathogens and antimicrobial drugs.

The use of new sources of by-pass protein in the cow diets to optimize milk production and herd reproduction performance indicators in modern economic conditions is relevant. The article presents data on the use of a protein concentrate containing plant and animal components and its effect on the quality of the milk obtained, the state of the rumen bacterial community and reproduction indicators. The use of protein concentrate of both 1.0 kg and 1.5 kg/head/day contributed to improving the quality and increasing the yield of dry matter of cow's milk by 0.17-0.43 %. During the days in milk, with the use of protein concentrate it was observed that increase the content of Selenomonas by 1.7 % and 4.1%, which cleave the urea, indicates a more efficient use of nitrogen in the diet. The inclusion of protein concentrate in the composition of daily diets helps to improve reproduction indicators, reduce the duration of the service period and the number of semen doses spent.

Породы корниш и плимутрок составляют основу современных специализированных мясных кроссов кур. Селекция отцовской линия породы корниш СМ5 нового российского кросса мясных кур Смена 9 ведется в основном по признакам мясной продуктивности, тогда как материнская линия породы плимутрок СМ9 -прежде всего на эффективность репродукции и жизнеспособность при более низкой, чем у линии СМ5, скорости роста живой массы. В настоящем исследовании мы впервые выявили у кур и петухов родительского поголвья линий СМ5 и СМ9 нового кросса Смена 9 различия, связанные с генотипом и полом, в экспрессии некоторых генов иммунитета и генов, связанных с адаптационным потенциалом, а также в составе и прогнозируемом функциональном потенциале микробиома. Целью работы было сравнение уровня экспрессии генов иммунитета и генов, связанных с адаптационным потенциалом, соответственно в тканях бурсы в печени, а также состава и функций микробиома слепых отростков кишечника у кур и петухов линий СМ5 и СМ9. Эксперименты проводили в виварии СГЦ «Загорское ЭПХ» (Московская обл., 2022 год) на родительском поголовье кур и петухов линий СМ5 и СМ9 39-недельного возраста, содержавшихся в идентичных условиях и получавших одинаковый рацион. От каждой линии и пола отбирали образцы тканей у 5 особей с близкой живой массой. Анализ экспрессии генов в образцах тканей проводили с помощью количественной ПЦР с обратной транскрипцией (RT-qPCR). Тотальную РНК выделяли с помощью мини-набора Aurum™ Total RNA («Bio-Rad», США). ПЦРамплификацию проводили с использованием SsoAdvanced™ Universal SYBR® Green Supermix («Bio-Rad», США) и детектирующего амплификатора ДТлайт (НПО «ДНК-Технология», Россия). В тканях печени проводили анализ экспрессии генов, связанных с адаптационным потенциалом: гены CAT1 транспортера катионных аминокислот 1, HSF1 и HSF2 -факторов транскрипции белков теплового шока 1 и 2, SOD -супероксиддисмутазы, Gpx1 -глутатионпероксидазы, HO-1гемоксигеназы-1. В тканях бурсы анализировали экспрессию генов, связанных с иммунитетом: гены IL8 -интерлейкина-8, IRF7 -регуляторного фактора интерферона 7, PTGS2 -простагландин-эндопероксидсинтазы, AvBD1, AvBD2, AvBD9 и AvBD10 -β-дефензины 1, 2, 9 и 10, Casp6каспазы 6. В качестве референсного контроля использовали праймер для гена β-актина (ACTB). Относительный уровень экспрессии оценивали методом 2  ΔΔCT . Тотальную ДНК для анализа состава микробиома выделяли с использованием набора Genomic DNA Purification Kit («Thermo Fisher Scientific, Inc.», США). Бактериальное сообщество слепой кишки оценивали методом NGSсеквенирования на платформе MiSeq («Illumina, Inc.», США) с праймерами для V3-V4 региона гена 16S рРНК. Реконструкцию и прогнозирование функционального содержания метагенома, семейств генов, ферментов осуществляли при помощи программного комплекса PICRUSt2 (v. 2.3.0). Математическую и статистическую обработку результатов осуществляли методом многофакторного дисперсионного анализа (ANOVA) в программах Microsoft Excel XP/2003 и R-Studio (v. 1.1.453). Полученные результаты показали увеличение экспрессии генов HSF1 и HSF...