Selenium in Pig Nutrition and Reproduction: Boars and Semen Quality—A Review

Selenium plays an important role in boar nutrition via participating in selenoprotein synthesis. It seems likely that selenoproteins are central for antioxidant system regulation in the body. Se-dependent enzyme glutathione peroxidase (GSH-Px) is the most studied selenoprotein in swine production. However, roles of other selenoproteins in boar semen production and maintenance of semen quality also need to be studied. Boar semen is characterised by a high proportion of easily oxidized long chain polyunsaturated fatty acids and requires an effective antioxidant defense. The requirement of swine for selenium varies depending on many environmental and other conditions and, in general, is considered to be 0.15 to 0.30 mg/kg feed. It seems likely that reproducing sows and boars are especially sensitive to Se deficiency, and meeting their requirements is an important challenge for pig nutritionists. In fact, in many countries there are legal limits as to how much Se may be included into the diet and this restricts flexibility in terms of addressing the Se needs of the developing and reproducing swine. The analysis of data of various boar trials with different Se sources indicates that in some cases when background Se levels were low, there were advantages of Se dietary supplementation. It is necessary to take into account that only an optimal Se status of animals is associated with the best antioxidant protection and could have positive effects on boar semen production and its quality. However, in many cases, background Se levels were not determined and therefore, it is difficult to judge if the basic diets were deficient in Se. It can also be suggested that, because of higher efficacy of assimilation from the diet, and possibilities of building Se reserves in the body, organic selenium in the form of selenomethionine (SeMet) provided by a range of products, including Se-Yeast and SeMet preparations is an important source of Se to better meet the needs of modern pig genotypes in commercial conditions of intensive pig production

MIKOTOKSINI I ZDRAVLJE ŽIVOTINJA: OD OKCIDACIJSKOG STRESA DO ISPOLJAVANJA GENA

Mycotoxin contamination of the feed and food is a global problem. There are several unresolved questions in this regard. Firstly, more than 25% of world grain production is contaminated by mycotoxins. In particular, Fusarium mycotoxins (so called field mycotoxins) contaminate up to 100% of the grain. Since these mycotoxins come from the field it is difficult to deal with them and various technological approaches including plant selection for mycotoxin resistance have not produced any significant results. Secondly, in nature there are more than 300 mycotoxins, but analytical techniques for routine mycotoxins analysis have been developed only for about 30 major mycotoxins. Therefore, if there is a conclusion from the analytical lab that “mycotoxins have not been found” this means that 10-30 mycotoxins analyzed were not found. As for others, there is no answer. Thirdly, sampling for mycotoxins analysis is extremely difficult and is an important source of errors. Fourthly, there are no safe levels of mycotoxins, because of synergistic interactions of many mycotoxins: several mycotoxins in low concentrations could cause more problems than a single mycotoxin at a higher dose. Recent results show that in many cases membrane-active properties of various mycotoxins determine their toxicity. Indeed, incorporation of mycotoxins into membrane structures causes various detrimental changes. These changes are associated with alteration of fatty acid composition of the membrane structures and with peroxidation of long chain PUFAs inside membranes. This ultimately damages membrane receptors, causing alterations in second messenger systems; inactivation of a range of membrane-binding enzymes responsible for regulation of important pathways. Finally, this causes alterations in membrane permeability, flexibility and other important characteristics determining membrane function. Detrimental effects of mycotoxins on DNA, RNA and protein synthesis together with pro-apoptotic action further compromise important metabolic pathways. Consequently, changes in physiological functions including growth, development and reproduction occur. Importance of oxidative stress and lipid peroxidation in all these processes is confirmed by protective effects of natural antioxidants against mycotoxin toxicity. However, protective effects of antioxidants including selenium are of limited value and a combination of mycotoxin binders with natural antioxidants could be the next step in preventing damaging effects of mycotoxins in animal and poultry production.Kontaminiranje hrane mikotoksinima je globalni problem. S tim u svezi nekoliko je neriješenih pitanja. Prvo, više od 25% svjetske proizvodnje žitarica kontaminirano je mikotoksinima. Osobito mikotoksini fuzarijuma (tzv.poljski mikotoksini) kontaminiraju do 100% žitarica. Budući da ovi mikotoksini dolaze iz polja teško ih je suzbiti pa i različiti tehnički postupci uključujući i selekciju biljaka na otpornost na mikotoksine nisu dali značajnije rezultate. Drugo, razvijene analize odnose se samo na oko 30 važnijih mikotoksina. Zato ako je i nalaz analitičkog laboratorija da "nisu nađeni mikotoksini" znači da nije nađeno 10-30 analiziranih mikotoksina. Što se tiče ostalih, nema odgovora. Treće, uzorkovanje za analizu mikotoksina vrlo je teško i važan je izvor pogrešaka. Četvrto, nema sigurnih razina mikotoksina zbog sinergetskih interakcija mnogih mikotoksina: nekoliko mikotoksina u malim koncentracijama može prouzročiti više problema nego jedan štetan u većoj količini. Noviji rezultati pokazuju da u mnogo slučajeva svojstva aktivne membrane raznih mikotoksina određuju njihovu toksičnost. Doista, ugrađivanje mikotoksina u strukture membrane uzrokuje razne štetne promjene. Te su promjene povezane s promjenom sastava masnih kiselina strukture membrane i s peroksidacijom drugog lanca PUFA-e u membrani. Ovo konačno oštećuje receptore membrane, prouzročivši promjene drugog niza enzima koji povezuju membranu i odgovorni su za reguliranje važnih puteva. Konačno, to prouzrokuje promjene u propusnosti membrane, fleksibilnosti i drugim važnim značajkama koje određuju funkciju membrane. Štetno djelovanje mikotoksina na DNK, RNA i sintezu bjelančevina zajedno s proapoptotičnim djelovanjem dalje djeluje na važne metaboličke puteve. Konačno dolazi do promjene u fiziološkim funkcijama, uključujući rast, razvoj i reprodukciju. Važnost oksidacijskog stresa i peroksidacije lipida u svim tim procesima potvrđuje zaštitno djelovanje prirodnih antioksidanata protiv toksičnosti mikotoksina. Međutim, zaštitno djelovanje antioksidanata, uključujući selen, ograničene je vrijednosti i kombinacija. Vezanje mikotoksina s prirodnim antioksidantima mogao bi biti sljedeći korak u sprječavanju štetnog djelovanja u proizvodnji životinja i peradi

[Modern biotechnology to assess the expression of chicken genes in relation to productivity and disease resistance] Современные биотехнологии для оценки экспрессии генов кур в связи с продуктивностью и устойчивостью к заболеваниям

This article highlights the main results obtained in the course of the research performed in 2017–2019 on the basis of the International Laboratory of Molecular Genetics and Poultry Genomics of the Department of Zoohygiene and Poultry. A.K. Danilova FGBOU VO MGAVMiB – MBA named after K.I. Skryabin, created under the agreement No. 14. W03.3I.0013 dated February 20, 2017 on the allocation of grants from the Government of the Russian Federation for state support of scientific research conducted under the guidance of leading scientists in Russian educational institutions of higher education. The prospects for the development of the scientific direction  Development of modern biotechnologies for the assessment of gene expression in connection with productivity and resistance to diseases in poultry  are outlined. В данной статье отмечены основные результаты, полученные в ходе выполненных исследований в 2017–2019 гг. на базе международной лаборатории молекулярной генетики и геномики птицы кафедры зоогигиены и птицеводства имени А.К. Даниловой ФГБОУ ВО МГАВМиБ – MBA имени К.И. Скрябина, созданной в рамках договора № 14.W03.3I.0013 от 20 февраля 2017 г. о выделении грантов Правительства Российской Федерации для государственной поддержки научных исследований, проводимых под руководством ведущих ученых в российских образовательных организациях высшего образования. Обозначены перспективы развития научного направления «Разработка современных биотехнологий для оценки экспрессии генов в связи с продуктивностью и устойчивостью к заболеваниям в птицеводстве»

Nutritional modulation of the antioxidant capacities in poultry: the case of vitamin E

Commercial poultry production is associated with a range of stresses, including environmental, technological, nutritional, and internal/biological ones, responsible for decreased productive and reproductive performance of poultry. At the molecular level, most of them are associated with oxidative stress and damages to important biological molecules. Poultry feed contains a range of feed-derived and supplemented antioxidants and, among them, vitamin E is considered as the “headquarters” of the antioxidant defense network. It is well-established that dietary supplementation of selenium, vitamin E, and carotenoids can modulate antioxidant defenses in poultry. The aim of the present paper is to present evidence related to modulation of the antioxidant capacities in poultry by vitamin E. Using 3 model systems including poultry breeders/males, semen, and chicken embryo/postnatal chickens, the possibility of modulation of the antioxidant defense mechanisms has been clearly demonstrated. It was shown that increased vitamin E supplementation in the breeder's or cockerel's diet increased their resistance to various stresses, including high polyunsaturated fatty acids (PUFA), mycotoxin, or heat stress. Increased vitamin E supplementation of poultry males was shown to be associated with significant increases in α-tocopherol level in semen associated with an increased resistance to oxidative stress imposed by various external stressors. Similarly, increased vitamin E concentration in the egg yolk due to dietary supplementation was shown to be associated with increased α-tocopherol concentration in the tissues of the developing embryos and newly hatched chicks resulting in increased antioxidant defenses and decreased lipid peroxidation. Furthermore, increased vitamin E transfer from the feed to egg yolk and further to the developing embryo was shown to be associated with upregulation of antioxidant enzymes reflecting antioxidant system regulation and adaptation. The role of vitamin E in cell signaling and gene expression as well as in interaction with microbiota and maintaining gut health in poultry awaits further investigation

Features of fractal conformity and bioconsolidation in the early myogenesis gene expression and their relationship to the genetic diversity of chicken breeds

Simple Summary In the bodies of animals, including birds, gene expression leads to the synthesis of many proteins. To provide optimal cellular and organismal properties and functions, many genes should work in concert, reaching certain balanced relationships (or networks) between them and the intensities of their expression. Here, we studied the expression of several genes responsible for muscle formation and growth in chick embryos of diverse breeds belonging to various utility types. Using two mathematical (fractal) models and the respective indices, we showed that there are specific coordinated patterns of gene expression in the embryonic breast and thigh muscles. These patterns correlated with growth rate of chicks after hatching and depended on a utility type of the breeds studied. Overall, the proposed models contributed to an expanded understanding of the coordinated gene expression in early development and growth, providing additional characteristics of genetic diversity in chickens. Abstract Elements of fractal analysis are widely used in scientific research, including several biological disciplines. In this study, we hypothesized that chicken breed biodiversity manifests not only at the phenotypic level, but also at the genetic-system level in terms of different profiles of fractal conformity and bioconsolidation in the early myogenesis gene expression. To demonstrate this effect, we developed two mathematical models that describe the fractal nature of the expression of seven key genes in the embryonic breast and thigh muscles in eight breeds of meat, dual purpose, egg and game types. In the first model, we produced breed-specific coefficients of gene expression conformity in each muscle type using the slopes of regression dependencies, as well as an integral myogenesis gene expression index (MGEI). Additionally, breed fractal dimensions and integral myogenesis gene expression fractal dimension index (MGEFDI) were determined. The second gene expression model was based on plotting fractal portraits and calculating indices of fractal bioconsolidation. The bioconsolidation index of myogenesis gene expression correlated with the chick growth rate and nitric oxide (NO) oxidation rate. The proposed fractal models were instrumental in interpreting the genetic diversity of chickens at the level of gene expression for early myogenesis, NO metabolism and the postnatal growth of chicks

Modelling effects of phytobiotic administration on coherent responses to Salmonella infection in laying hens

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

[Mathematical assessment of BAC-based interspecies hybridization data in the process of genomic mapping in the white-throated sparrow as an avian behavioral model] Математическая оценка данных межвидовой БАК-гибридизации в процессе геномного картирования у белошейной зонотрихии как модели поведения птиц

The white-throated sparrow (Zonotrichia albicollis) known for its morphological, behavioral and chromosomal polymorphisms represents a quite new model system to study genomic mechanisms underlying variable behavioral repertoire interwoven with population biology, reproduction and adaptation in this species. It was previously shown that these polymorphisms could be due to chromosomal rearrangements (inversions) on sparrow chromosome 2 (ZAL2) that is characterized by a heterogeneity in two distinct morphs, tan (ZAL2/ZAL2) and white (ZAL2/ZAL2m). To construct a comparative genomic map of ZAL2 and other chromosomes, we used a sparrow genomic BAC library, CHORI-264. Following a cross-species overgo hybridization approach, we screened the library and developed a first-generation BAC-based comparative physical map using the chicken and zebra finch reference genomes. The map includes 640 BAC-gene assignments for 77 loci and serves for further refining the genomic regions and identifying candidate genes that are affected by rearrangements and contribute to the observed behavioral polymorphisms. Mathematical assessment of the BAC-based hybridization data was undertaken to show evolutionary relationships of avian genomes. В настоящей работе представлена математическая оценка межвидовой БАК-гибридизации в процессе геномного картирования у белошейной зонотрихии – вида воробьев, рассматриваемого в качестве удобной модели поведения птиц

Examination of the expression of immunity genes and bacterial profiles in the caecum of growing chickens infected with Salmonella Enteritidis and fed a phytobiotic

This 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

Effects of essential oils-based supplement and Salmonella infection on gene expression, blood parameters, cecal microbiome and egg production in laying hens

Simple Summary Salmonellosis is one of the most severe zoonotic diseases transmitted to humans through animal products (especially poultry meat and eggs). Essential oils (EOs)-based feed additives in poultry nutrition are a possible alternative replacement of antimicrobials to fight this infection. In the present study on laying hens, we tested a phytobiotic, Intebio®, and elucidated formation of immune response and changes in cecal microbiocenosis and biochemical/immunological variables in blood caused by Salmonella. Changes in differential gene expression were observed at both one and seven days post-inoculation in the hens’ intestines, revealing similarities with known mammalian/human tissue-specific expression. The results of this study suggest that the challenge of birds with Salmonella had a negative effect, while phytobiotic intake had a positive effect on the status of their gastrointestinal microbiome, their level of metabolism, and their performance. Abstract 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

Silymarin as a Natural Antioxidant: An Overview of the Current Evidence and Perspectives

Silymarin (SM), an extract from the Silybum marianum (milk thistle) plant containing various flavonolignans (with silybin being the major one), has received a tremendous amount of attention over the last decade as a herbal remedy for liver treatment. In many cases, the antioxidant properties of SM are considered to be responsible for its protective actions. Possible antioxidant mechanisms of SM are evaluated in this review. (1) Direct scavenging free radicals and chelating free Fe and Cu are mainly effective in the gut. (2) Preventing free radical formation by inhibiting specific ROS-producing enzymes, or improving an integrity of mitochondria in stress conditions, are of great importance. (3) Maintaining an optimal redox balance in the cell by activating a range of antioxidant enzymes and non-enzymatic antioxidants, mainly via Nrf2 activation is probably the main driving force of antioxidant (AO)  action of SM. (4) Decreasing inflammatory responses by inhibiting NF-κB pathways is an emerging mechanism of SM protective effects in liver toxicity and various liver diseases. (5) Activating vitagenes, responsible for synthesis of protective molecules, including heat shock proteins (HSPs), thioredoxin and sirtuins and providing additional protection in stress conditions deserves more attention. (6) Affecting the microenvironment of the gut, including SM-bacteria interactions, awaits future investigations. (7) In animal nutrition and disease prevention strategy, SM alone, or in combination with other hepatho-active compounds (carnitine, betaine, vitamin B12, etc.), might have similar hepatoprotective effects as described in human nutrition