Alexandros Theodoridis

Transcriptional profiling of Toll-like receptors in chicken embryos and in the ovary during sexual maturation and in response to Salmonella enteritidis infection

One of the key members of the innate immune system in many vertebrate species is the family of Toll-like receptors (TLRs). These molecules, which initiate the innate immune response and mount an anti-microbial response in both vertebrates and invertebrates, have recently been identified in the chicken genome. The recent findings of chicken TLRs (cTLRs) expression in ovarian follicles during follicular growth and in response to lipopolysaccharide (LPS) infection are very important for reproductive physiology due to the transovarian transmission of Salmonella enteritidis (SE) in laying hens. The aim of this study was to investigate the expression of the ten cTLRs identified to date, in the chicken ovary in vivo and embryos during early embryonic development, to investigate whether sexual maturation affects their ovarian mRNA abundance and to investigate the transcriptional changes of TLRs in the chicken ovary in response to SE infection. RNA was extracted from embryos from day 3 to day 10 of embryonic development as well as from the ovaries of healthy prepubertal, sexually mature and aged birds, and from sexually mature and aged SE infected birds. RT-PCR analysis revealed that all TLRs apart from TLRs 1-1 and 2-2 were expressed in the ovary of sexually mature chickens, while all TLRs apart from TLR1-1 were expressed in the chicken embryos during embryonic development. Quantitative real-time PCR analysis revealed that the ovarian mRNA abundance of TLRs differ with respect to sexual maturation. SE infection resulted in a significant induction of TLR4, and 15 in the ovary of sexual mature birds, and in a significant induction of TLR15 in the ovary of aged birds, while a significant down-regulation was observed for TLR3 in the ovary of aged birds. These findings suggest that a TLR-mediated immune response mechanism exists in the chicken ovary.

Effects of sexual maturation and Salmonella infection on the expression of Toll-like receptors in the chicken vagina.

Toll-like receptors (TLRs) are a critical component of the innate immune response in many vertebrates, including avian species. The recent findings of chicken TLRs (cTLRs) expression in ovarian follicles and in the chicken ovary in vivo, as well as the changes in their expression in response to lipopolysaccharide or Salmonella enteritidis (SE) infection, have broad implications for reproductive physiology and for the prevention of transmission of zoonotic diseases to humans through the consumption of contaminated poultry eggs. Because the main route of egg contamination is from infection of the oviduct and mainly from the vagina, the aim of this study was to investigate the expression of the ten cTLRs identified to date in the chicken oviduct in vivo, to determine whether sexual maturation affects their mRNA abundance and to investigate whether SE infection alters the expression of TLRs in the chicken vagina. RNA was extracted from the vagina of healthy prepubertal, sexually mature and aged birds, and from sexually mature and aged SE infected birds. RT-PCR analysis revealed that all types of cTLRs apart from TLR1-1 were expressed in the vagina of sexually mature birds. Quantitative real-time PCR analysis revealed that the mRNA abundance of TLR2-1, 2-2 and 4 differ with respect to sexual maturation in the chicken vagina. SE infection resulted in a significant induction of TLR5 and 15 in the vagina of sexually mature birds, and in a significant induction of TLR2-1, 4 and 15 in the vagina of aged birds, while a significant down-regulation was observed for TLR7 in the vagina of sexually mature birds. These findings suggest that a TLR mediated immune response mechanism exists in the chicken vagina, playing a crucial role in preventing microbial pathogens from being incorporated into newly forming eggs.

Changes in the expression of Toll-like receptors in the chicken testis during sexual maturation and Salmonella infection

Rooster infertility is a major concern in the poultry industry and chicken male reproductive organs are the infectious tissues of various pathogenic microorganisms. Protection of the chicken male reproductive organs from pathogens is therefore an essential aspect of reproductive physiology. Recently Toll-like receptors (TLRs) have been identified as one of the key components of innate immunity in vertebrate species and have been reported to be expressed in the reproductive organs in various female species, including the chicken. However, mechanisms of antimicrobial protection of male reproductive organs mediated by TLRs are poorly understood. The objectives of this study were to determine the expression profile of the entire family of the ten chicken TLR genes in the chicken testis, to investigate whether sexual maturation affects their testicular mRNA abundance and to determine the changes in their expression levels in response to Salmonella enteritidis (SE) infection. RNA was extracted from the testis of healthy pre-pubertal, sexually mature and aged birds, and from sexually mature SE infected birds. RT-PCR analysis revealed that all TLRs, apart from TLR1-1 (TLR6), were expressed in the chicken testis. Quantitative real-time PCR analysis revealed that the testicular mRNA abundance of certain TLRs was developmentally regulated with respect to sexual maturation, while SE infection resulted in a significant induction of TLR2-1, 4, 5, 15 and 21 in the testis of sexually mature birds compared, to healthy birds of the same age. These findings provide strong evidence to suggest a key role of TLRs in the innate immune responses of chicken testis against Salmonella colonization.

Reproductive performance of sows was improved by administration of a sporing bacillary probiotic (Bacillus subtilis C-3102).

This field study assessed the efficacy of a probiotic based on viable spores of Bacillus subtilis C-3102 (Calsporin; Calpis Co. Ltd., Japan) on the health status and productivity of sows and their litters through 2 full, sequential reproductive cycles from service of the first cycle to weaning of the second cycle. Fifty-six sows were allocated to 2 experimental groups, an untreated control (T1) group and a probiotic-treated (T2) group that received the same basal feed as the T1 group plus the probiotic at an approximate allowance of 30 g/t of feed (3 × 10(5) cfu/g). The offspring of T1 and T2 sows were offered basal and T2 creep feed (3 × 10(5) cfu/g), respectively. Health and zootechnical parameters of sows and piglets were recorded. Feeding the probiotic to sows and piglets resulted in significant benefits, observed in both cycles: 1) improved sow body condition during pregnancy (P < 0.05), 2) increased sow feed consumption, 3) reduced sow weight loss during lactation (P < 0.05), 4) reduced sow weaning-estrus interval (P < 0.05), and 5) higher BW of piglets at weaning (P < 0.05). Additionally, a significant (P < 0.05) improvement in piglet birth weight and in the number of piglets weaned was observed in the second cycle of T2 sows, while a significant improvement of mean daily gain of piglets from birth to weaning was observed in the first cycle of T2 sows. Microbiological examination of fecal samples showed that probiotic treatment significantly reduced both Escherichia coli and Clostridium spp. in piglet feces, particularly during the second cycle. The data suggested that continuous feed supplementation with the probiotic is beneficial for both sows and piglets, since zootechnical benefits were observed in both cycles.

Temporal changes in the expression of avian β-defensins in the chicken vagina during sexual maturation and Salmonella infection

Avian β-defensins (AvβDs) constitute a family of antimicrobial peptides that are critical to innate immunity in chickens, providing protection against microbial pathogens including Salmonella Enteritidis (SE). As apart from the digestive tract another main route of SE colonization in birds is via infection of the oviduct and specifically of the vagina, the aim of this study was to investigate the expression of the complete family of AvβDs, in the chicken vagina in vivo, to determine whether sexual maturation affects their mRNA abundance and to investigate whether SE infection alters the vaginal AvβDs expression. Expression analysis revealed that 11 members of the AvβD family were expressed in the chicken vagina. Quantitative real-time PCR analysis revealed that the mRNA abundance of five AvβDs was up regulated and of one AvβD was down regulated with respect to sexual maturation. In addition SE infection resulted in a significant induction of AvβD5, 7, 10, 11, 12 and 14 in the vagina of sexually mature birds, and in a significant induction of AvβD5 and 11 in the vagina of aged birds. These findings provide strong evidence to suggest that an AvβD-mediated immune response mechanism exists in the chicken vagina providing protection against bacterial pathogens including Salmonella species.

Technical indicators of economic performance in dairy sheep farming

In this study, the level of technical efficiency of 58 sheep farms rearing the Chios breed in Greece was measured through the application of the stochastic frontier analysis method. A Translog stochastic frontier production function was estimated using farm accounting data of Chios sheep farms and the impact of various socio-demographic and biophysical factors on the estimated efficiency of the farms was evaluated. The farms were classified into efficiency groups on the basis of the estimated level of efficiency and a technical and economic descriptive analysis was applied in order to illustrate an indicative picture of their structure and productivity. The results of the stochastic frontier model indicate that there are substantial production inefficiencies among the Chios sheep farms and that these farms could increase their production through the improvement of technical efficiency, whereas the results of the inefficiency effects model reveal that the farm-specific explanatory factors can partly explain the observed efficiency differentials. The measurement of technical inefficiency and the detection of its determinants can be used to form the basis of policy recommendations that could contribute to the development of the sector.

Effects of sexual maturation and Salmonella infection on the expression of avian β-defensin genes in the chicken testis

Rooster infertility is a major concern in the poultry industry and protection of the male reproductive organs from pathogens is an essential aspect of reproductive physiology. During the last years, research on antimicrobial protection has elucidated the critical role of the antimicrobial peptides avian β-defensins (AvBDs) in the innate immunity in chickens. AvBDs have been reported to be expressed in the hen reproductive organs, providing protection against microbial pathogens including Salmonella Enteritidis (SE). However, mechanisms of antimicrobial protection of rooster reproductive organs and especially the testis, mediated by AvBDs are poorly understood. The aim of this study was to investigate the expression of the complete family of the 14 AvBD genes, in the rooster testis in vivo, to determine whether sexual maturation affects their testicular mRNA abundance and to investigate whether SE infection alters their expression. Expression analysis revealed that 9 members of the AvBD family, namely AvBD1, 2, 4, 5, 6, 9, 10, 12 and 14 were expressed in the testis. Quantitative real-time PCR analysis revealed that the mRNA abundance of three AvBDs was up regulated and of three AvBDs was down regulated with respect to sexual maturation. In addition, SE infection resulted in a significant induction of AvBD4, 10, 12 and 14 in the testis of sexually mature roosters. These findings provide strong evidence to suggest that an AvBD-mediated immune response mechanism exists in the rooster testis providing protection against bacterial pathogens including Salmonella species.

Consulting for Sustainable Development, Information Technologies Adoption, Marketing and Entrepreneurship Issues in Livestock Farms☆

Consulting agricultural services constitute a major key for implementing successfully sustainable development EU goals in rural areas. Today, in the context of the Rural Development Programme 2007-2013, there are initiatives for funding crop and livestock farms and entrepreneurship. Presently, there are bureaus offering consulting services and reliable information to t he Greek farmers regarding Information Technologies adoption and innovative e-tools, marketing and processing of agricultural products, certificated agro-products (ISO), modernization of agricultural holdings, etc. Farmers have the opportunity to participate in EU funded measures that support the development of new activities, such as innovative actions, marketing services, new information technologies software and web tools and promote production innovations through specific investments. This paper aims to study and evaluate the adoption of consulting from livestock farms and discuss future opportunities. The study is based on primary data collected from the prefecture of Rodopi, in Thrace/Northeastern Greece, through a farm management survey which was carried out during September and December 2011. A sample of 120 livestock farmers between the ages of 20 and 70 was surveyed for the empirical application of this study using a well-structured questionnaire. The survey took place in private consulting bureaus and locally at farms. The collected data were coded and statistically analyzed using SPSS. Data was classified with cluster analysis in order to identify and describe groups with common attitudes among farmers. Findings show that 54% of the farmers in the sample are interested in consulting and adopt information technology solutions, marketing and entrepreneurship issues, aiming to sustainability in the context of EU goals. The results also indicate that 63% of the farme rs have already participated in a program, while 37% have participated in the schemes promoting the establishment of young farmers. Moreover, 55% of them would prefer to be consulted by private consulting bureaus rather than government consulting divisions. Private consulting bureaus satisfy farmers who consider them as a significant support in their attempt to achieve the contemporary EU goals for sustainable development through the adoption of information technologies tools and innovative trade and marketing techniques. Farmers can be further classified in two groups that share similar either innovative or traditional aspects about Greek agriculture trends, in relation to their social characteristics.

Protective effect of crocetin on bovine spermatozoa against oxidative stress during in vitro fertilization.

Oxidative stress is one of the major factors that contribute to poor semen quality and low rates of in vitro fertilization. Crocetin, a main constituent of saffron (Crocus sativus L.) possesses potent antioxidant activity, by scavenging reactive oxygen species (ROS) and/or enhancing the activity of intracellular antioxidant enzymes. The aim of this study was to investigate, for the first time, the effect of crocetin on the quality characteristics of bull spermatozoa and fertilization rate. For this reason, frozen/thawed bovine spermatozoa were incubated with crocetin (1, 2.5, and 5 μm), for 120 or 240 min, in the presence of a negative control, and evaluated in terms of motility, viability, acrosomal status, DNA fragmentation index, intracellular ROS, and lipid peroxidation. In order to evaluate the impact of crocetin on cleavage and blastocyst rate, the compound was added in the IVF medium at the previously identified optimal concentration (2.5 μm). The results indicate that incubation of spermatozoa with 2.5 μm of crocetin resulted in a statistically significant lower production of superoxide anion and hydrogen peroxide, lower lipid peroxidation, and in better maintenance of motility parameters, viability, and acrosomal integrity, with a very small number of cells with DNA fragmentation, compared to the other groups (p < 0.05). The presence of crocetin (2.5 μm) in the fertilization medium also resulted in a significant increase in acrosome‐reacted spermatozoa and blastocyst production, compared to the control group (p < 0.01). These data indicate that crocetin (2.5 μm) positively affects bovine sperm quality characteristics during a 240‐min incubation and improves its fertilizing ability, directly and/or indirectly, by regulating ROS concentration and lipid peroxidation.

Dairy Farmers’ Strategies against the Crisis and the Economic Performance of Farms☆

Abstract Dairy farming in Greece constitutes a particular case of livestock farming, because of its highly entrepreneurial nature. The modern Greek dairy cattle farming is predominantly based in Northern Greece, where more than 80% of Greek cow milk is produced. Since the 2000s the dairy cattle sector is characterized by a rapid increase in the mean size of farms, which permits them to undertake investments in machinery and buildings and to have access to improved genetic material for the achievement of higher productivity. Nevertheless, this development renders dairy farms vulnerable to volatile economic conditions, as they are heavily dependent on capital endowments. The main purpose of this study is to examine the consequences of the economic crisis on the dairy cattle sector and the strategies undertaken by farmers to cope with it. The analysis is based on data from a questionnaire survey of farmers in Northern Greece. Strategies undertaken by dairy farmers in order to face the crisis and to ensure the survival of their businesses are recorded through a set of Likert-scale questions. Technical and economic data are also analyzed in order to examine the economic performance of farms, revealing that the sampled dairy farms are viable, with satisfactory economic results, with capital returns of 6.2% annually. Based on the Likert-scale data, dairy farmers adopt active strategies to face the crisis, by undertaking investments and augmenting their farm sizes, while they deem that the crisis does not have catastrophic results on the profitability of their farms. On the other hand, strategies which entail less expenses and/or diminished productivity are unpopular among dairy farmers. Finally, the vast majority of respondents claim to have seen negative consequences on their farms from the recent measures concerning the prolongation of the duration of fresh milk in retail markets: lower quality, increased vulnerability to international competition, shrinking dairy sector.