The swine industry represents a significant contributor to the global meat supply but also exerts considerable pressure on natural resources through feed production, greenhouse gas (GHG) emissions, and nutrient losses. The integration of food industry by-products into pig diets offers a promising pathway to mitigate these environmental impacts while maintaining productivity and animal welfare. Such by-products can serve as nutritionally valuable feed ingredients, reducing waste streams and supporting the principles of a circular economy. This review synthesizes current knowledge on the nutritional properties, environmental implications, and economic advantages of incorporating food industry by-products into pig feeding systems. It further outlines the challenges related to feed safety, variability in composition, and regulatory aspects. Overall, the sustainable valorization of food processing residues as animal feed represents a challenge option to reduce the environmental footprint of pig production without compromising growth performance or health outcomes.

This study investigated the effects of dietary supplementation with pomegranate peel and onion leaf extracts, administered either as an aqueous solution or in cyclodextrin-encapsulated form, on broiler chickens. Day-old ROSS 308 broiler chicks were allocated to non-supplemented (CONTROL), supplemented with aqueous (AQPOMON) and cyclodextrin (CDPOMON) extracts (0.1% /kg DM). Intestinal morphometry was assessed by measuring crypt depth (CD), villus length (VL), and VL:CD ratio in the mid-duodenum, mid-jejunum, and mid-ileum. Tight junction (TJ) protein expression in the mid-duodenum, mid-ileum and mid-jejunum, especially claudin-3, was assessed through immunohistochemistry (IHC), and gene expression of TJ proteins (Zonula occludens 1 (TJP1), claudin-1 (CLDN1), claudin-3 (CLDN3) , and occludin ( OCLDN ) via qPCR in the ileum and cecum. Additionally, 16S rRNA gene sequencing was used to study bacterial diversity in the ileum and cecum. Results showed that VL and CD were variably affected by extract supplementation resulting in decreased VL:CD in all intestinal segments. by the aqueous extract (p<0.05). The AQPOMON diet increased TJ protein gene expression and enhanced the intestinal barrier. Firmicutes, Proteobacteria, and Bacteroidota were the dominant phyla across all groups, with differentially abundant taxa like Campylobacteria (ileum) and Clostridia (cecum) in AQPOMON, and Lactobacillaceae (ileum) and Methanobacteriaceae (cecum) in CDPOMON. The AQPOMON diet proved more effective, than the CDPOMON in improving aspects of broiler intestinal health.

In the present study, we investigated the presence of single nucleotide polymorphisms at the Fibroblast Growth Factor 2 (FGF2) and Signal Transducer and Activator of Transcription 5A (STAT5A) genes loci in the Greek Red Cow breed, using RFLP-PCR analyzes. One hundred seventy-four Greek red cows were used for this study. PCR-RFLP analysis revealed that for FGF2, the frequencies of the genotypes were 0.25, 0.55 and 0.20 for the GG, GA and AA genotypes respectively and the alleles G and A sequences were 0.52 and 0.48, respectively. Genotyping of the GG, GC and CC genotypes of the STAT5A genes revealed that these frequencies were 0.22, 0.48 and CC in the investigated population, while the G and C allelic frequencies was 0.46 and 0.54, respectively. These genotyping analyses presented in this study revealed the presence of all three genotypes for the STAT5A and FGF2 genes loci, indicating that the investigated single nucleotide polymorphisms can be used in the future, in genetic selection improvements schemes, in order to improve the reproductive performance of the Greek Red Cow breed.

In this study, the effects of isoquinoline alkaloids (IQs) on various parameters of rainbow trout (Oncorhynchus mykiss) were investigated. Three different treatments were administered to 300 sub-adult trouts, with four replicates each. The Control group received a basal diet, while the other two groups were fed diets supplemented with an IQs preparation (Sangrovit® Feed Aqua) at 500 and 1000 g/t of feed, respectively. The results demonstrated that the Sang1000 group exhibited significantly higher body weight (BW) and specific growth rate (SGR), but lower feed conversion rate (FCR) and mortality compared to the other groups (P < 0.001). Furthermore, the oxidative status assessment revealed that IQs positively influenced the oxidative status of the fillet but did not impact the oxidative profile of the blood serum. Additionally, the histomorphometry analysis of the intestine and skin indicated that the Sang1000 group had the highest number of goblet cells per villi in the anterior intestine, along with the largest mucoid cell size. Also, gene expression analysis indicated that IQs positively supported growth in trouts. To summarize, the supplementation of fish diets with IQs resulted in improved growth performance, reduced oxidative stress in fillet, and enhanced intestinal histomorphometry in rainbow trouts.

The present study examined the effects of dietary supplementation with extracts of pomegranate (Punica granatum) and onion (Allium cepa), either encapsulated in cyclodextrin (POMALCD group) or in an aqueous (POMALAQ group) form, on breast meat, thigh meat, and liver composition, oxidative stability, cellular signaling pathways, and the gene expression of certain hepatic genes. The results showed that breast and thigh meat contained significantly (p < 0.05) higher moisture content in the group with the aqueous extract, compared to the control and POMALCD groups. Moreover, the protein content was significantly (p < 0.05) higher in the thigh and liver samples of the treated groups in comparison to the control. The iron-induced challenge deteriorated (p < 0.001) the lipid and protein oxidative status of the control group, whereas both supplemented groups showed considerable tolerance in all tissues. The supplementation of pomegranate and onion extracts mitigated or maintained heat shock protein (HSP) levels and elevated (p < 0.05) the Bcl-2/Bad ratio in thigh and breast meat, whereas mitogen-activated protein kinase (MAPK) activation was modulated at a lower rate. After normalization to β-actin expression, quantitative real-time PCR analysis revealed a significant (p < 0.05) induction in the expression of MTR and MSRB1 genes in the liver of the supplemented groups. No differences were observed for the TAT, SMS, and BHMT genes. In conclusion, dietary mixtures of herbal extracts with pomegranate and onion improved protein and lipid oxidative stability in meat, enhanced the hepatic energy status, and exerted ameliorative effects on stress-related proteins. The encapsulated extract of pomegranate and onion, using cyclodextrin as a carrier, appeared to reduce lipid oxidation to a greater extent than the aqueous extract. In contrast, the aqueous extract exhibited higher total antioxidant capacity (TAC) values and provided better protection against protein carbonyl formation.

Abstract The present study was conducted to investigate the effects of a microencapsulated oregano feed additive containing oregano essential oil named “VISNAT 1” on growth performance, intestinal and skin histomorphometry, serum biochemical parameters, fillet oxidative status and fatty acids (FA) profile of rainbow trout (Oncorhynchus mykiss) under conventional farming conditions. Also, changes in the expression levels of both insulin-like growth factor-1 (IGF-1) and growth hormone 1 (GH-1) genes were assessed. A total of 200 sub-adult trouts (52 g±3.2) were randomly allocated into two different treatments with four replicates each. The control group was fed a basal diet, while oregano group was fed diet supplemented with oregano essential oil at the level of 1.0 kg/t of feed. The results indicate that the phytobiotic product beneficially altered feed, fillet and serum oxidative status and improved performance of trouts. Also, oregano essential oil beneficially affected the histopathology and histomorphometry of intestine and skin. Moreover, oregano oil addition in the rainbow trout diet can initiate mitogenic and anti-apoptotic responses in the liver, which is one of the main actions of IGF-1 receptor promoting body growth and health. As a result, oregano essential oil can be used as a supplement on trouts diet but further investigation upon its action should take place.

Abstract In the present study, an herbal feed additive was tested for partial-to-complete replacement of synthetic methionine in poultry diets, along with its effects on performance, breast and thigh meat chemical composition, oxidative stability during refrigerated storage and the expression of five target genes in liver. In a 35 days trial, 600 one-day-old male chicks were randomly allocated to 4 groups with 10 replicates. Birds in the control group were fed a regular maize–soybean-based diet that covered DL-methionine needs while the second group (Meth40) was similar to control but contained only DL – Methionine at 40% of control diet. Diet in third group contained DLMethionine at 40% of control and the herbal feed additive Methiorep TMMeth40+Mrep) with extracts of Boerhavia diffusa, Azadirachta indica, Vigna mungo and Trigonella foenum-graecum. Diet of fourth group was formulated to totally replace DL Methionine by Methiorep TM (Mrep). Body weight gain and feed consumption were weekly recorded. At the end of the trial, all birds were slaughtered and 2 chickens per pen were selected for meat and liver sampling. The liver was tested for the expression of five target genes, namely Methionine synthase (MTR), Tyrosine aminotransferase (TAT), Spermidine synthase (SMS), Methionine sulfoxide reductase (MSRB1) and Betaine homocysteine S-methyltransferase (BHMT). The results showed that the Meth40 group had reduced body weight compared to the Meth40+Mrep group while the Control and Mrep groups had comparable weights. Feed intake and feed conversion ratio did not differ among the experimental groups. Carcass, breast and thigh meat yield were higher in the Mrep and the Control compared to Meth40 and Meth40+Mrep groups. Also, meat oxidation was significantly lower in herbal groups compared to the control group. After normalization to β-actin expression, quantitative real-time PCR analysis revealed an induction in the expression of MTR and SMS genes in the liver of both herbal treated groups. No changes were observed for the TAT, MSRB1and BHMT genes in the herbal treated groups compared to the control or the Meth40 group. In conclusion, herbal feed additives with specific plant extracts may be able to improve both growth performance and antioxidant activity of broiler chickens, phenolic content; yet, they may also support in amino acid efficient use of broiler.

Mycotoxins are secondary metabolites produced mainly by fungi that contaminate animal feed and basic food products throughout the world. Currently, more than 500 mycotoxins are reported and one of the most important concern to public health and agriculture is Fumonisin B1 (FB1). FB1, a mycotoxin produced by Fusarium moniliforme, is a contaminant of animal feed with various and complex cellular effects. Although FB1 has been associated with various diseases in animals, to date few studies have been performed to evaluate the endocrine disrupting effects of FB1 and more particularly the effects in the innate immune mechanisms of farm animals and more specifically in poultry species. As the family of Toll-like receptors (TLRs) is one of the key molecules of the innate immune system, the aim of the present study was to evaluate the transcriptional changes of TLRs in the chicken ovary in vivo, in chicks fed with FB1 and in response to Salmonella Enteritidis (SE) infection. RNA was extracted from the ovaries of sexually mature and aged birds, treated with FB1 and SE. Quantitative real-time PCR analysis revealed that FB1 and SE infection resulted in a significant down regulation of 5 TLR genes in the ovary of sexual mature and aged birds. These findings suggest that the mycotoxin FB1 suppresses the innate immune system of the chicken reproductive organs, through alteration in the expression of certain TLR genes.

Propolis ethanolic extracts, with or without glycerol, were added into pasteurized, non-fat chocolate milk, which was artificially contaminated with Listeria monocytogenes. The addition of propolis ethanolic extracts dissolved into glycerol led to a definite anti-listerial effect in milk stored at 4 ℃, with both propolis concentrations tested (2 or 4 mg of dry propolis ethanolic extract per milliliter of chocolate milk) leading to inhibition of L. monocytogenes growth throughout 20 days of storage. The combined addition of propolis ethanolic extracts with glycerol was also effective in significantly reducing the rate of growth of L. monocytogenes in chocolate milk stored under improper (10 ℃) refrigeration storage conditions (more than five-fold increase in the generation time of L. monocytogenes compared to control trials). Finally, the combined addition of a deodorized propolis ethanolic extract with glycerol resulted in a significant anti-listerial effect upon storage of contaminated milk at 4 ℃ (more than three-fold increase in the generation time of L. monocytogenes compared to controls) and in a smaller anti-listerial effect upon milk storage at 10 ℃ (two-fold increase in the generation time of the pathogen compared to controls). Of note, chocolate milk containing deodorized propolis ethanolic extract and glycerol received a positive consumer acceptability score on the nine-point hedonic scale (median acceptability score of "7"). Hence, propolis may possess a promising role as a natural anti-listerial preservative in dairy drinks.

Propolis is a natural bee-product with documented antimicrobial properties in vitro. The objective of this study was to develop a protocol for adding propolis into milk and to determine whether the addition of propolis can confer anti-listerial activity during the storage of milk under optimal or improper refrigeration conditions. Upon dissolving propolis ethanolic extract (PEE) into glycerol, the PEE-glycerol mixture contained no visible insoluble particles and could be dispersed evenly into milk, without leaving any insoluble material. PEE, with or without glycerol, was added into extended shelf-life milk, artificially contaminated with Listeria monocytogenes. The addition of PEE dissolved into glycerol resulted in a pronounced and dose-dependent anti-listerial effect in milk stored at 4 °C, with the higher concentration tested (4 mg of dry PEE per mL of milk) resulting in complete inhibition of L. monocytogenes growth throughout 30 days of storage. The combination of PEE with glycerol was also effective in significantly reducing the growth rate of the pathogen in milk stored under improper refrigeration (10 °C). Based on a patented PEE-deodorization protocol, the addition of deodorized PEE into milk resulted in a product with average consumer acceptability. However, the PEE deodorization process resulted in reduction or even complete removal of propolis constituents with known antibacterial activity, with a concomitant significant reduction in its anti-listerial effect. Nonetheless, the data presented in this manuscript highlight the strong anti-listerial potential of propolis in milk and suggest that, upon further research on its deodorization and standardization, there may be room for the application of propolis as a natural preservative in dairy beverages.

Recent studies have reported that gene polymorphisms in melanocortin 4 receptor (MC4R) and glutathione peroxidase 5 (GPX5) genes are associated with litter size in pig and can be used as genetic markers in gene assisted selection programs for the improvement of reproductive performance. The objective of this study was to investigate the existence of these polymorphisms in pigs raised in Greece. One hundred pigs raised in Greece were included in the study. DNA was extracted and genotyping was performed using RFLPPCR. For MC4R, genotype GG had a frequency of 0.25, GA 0.55 and AA 0.20, while the frequency of allele G was 0.52 and of A 0.48. For GPX5, genotype AA had a frequency of 0.22, AB 0.48 and BB 0.30, with frequencies of alleles A and B being 0.46 and 0.54, respectively. The molecular results indicated that all genotypes of the two genes were present in the investigated population.

Infection of rooster testis and epididymis by pathogens can lead to impaired fertility, resulting in economic losses in the poultry industry. Antimicrobial protection of rooster reproductive organs is, therefore, an important aspect of reproductive physiology. Salmonellosis is one of the most important zoonotic diseases, caused by Salmonella bacteria including Salmonella Enteritidis (SE) and is usually the result of infection of the reproductive organs. Thus, knowledge of the endogenous innate immune mechanisms of the rooster testis and epididymis is an emerging aspect of reproductive physiology. Cytokines are key factors for stimulating the immune response and inflammation in chickens to Salmonella infection. In the present study the expression profile of 11 pro-inflammatory cytokine genes in the rooster testis and epididymis in vivo and transcriptional changes in these organs during sexual maturation and SE infection were investigated. Gene expression analysis data revealed that in both testis and epididymis nine cytokines namely the IL-1β, IL-6, IL-8, IL-10, IL-12, IL-15, IL-16, IL-17 and IL-18 genes were expressed, while no mRNA transcripts were detected in both organs for IL-2 and IL-4. Furthermore, the expression of various cytokine genes during sexual maturation appeared to be developmentally regulated, while SE infection resulted in a significant up-regulation of IL-1β, −6, −12 and −18 genes in the testis and an increase in the mRNA relative abundance of IL-1β, −6, −12, −16 and −18 in the epididymis of SE-infected sexually mature 28-week-old roosters. These results suggest a cytokine-mediated immune response mechanism against Salmonella infection in the rooster reproductive tract.

The emerging immune system is vulnerable to insult not only during fetal life, but also through colostrum transfer of maternal factors with immunomodulatory functions. The aim of the present study was to examine the effects of maternal undernutrition during late gestation and/or lactation on colostrum and milk synthesis, as well as on immunological parameters in offspring. Pregnant ewes were fed to 100% of nutrient requirements throughout pregnancy and lactation (Control) or to 50% during lactation (R1) or during the last 20 days of pregnancy and lactation (R2). Colostrum samples were collected 3 and 18h after parturition and thymus glands were obtained from 5-month-old offspring. Lamb birthweight did not differ between groups, whereas growth rate was significantly lower in males in the R1 group and in females in both undernourished groups. There was a significant reduction in lactose percentage in the 18-h colostrum of the R2 group. The IgG concentration, as a percentage of protein, was significantly increased in 3-h colostrum samples of the R2 group. Quantitative polymerase chain reaction analysis revealed a significant increase in the expression of Toll-like receptor (TLR) 2, TLR4 and TLR9 in the thymus gland of female lambs in both undernourished groups. In conclusion, early life nutritional imbalances may impact on immune system function in later life due to programming effects.

Salmonellosis is one of the most important zoonotic diseases and is usually associated with consumption of Salmonella Enteritidis (SE) contaminated poultry meat or eggs. Contamination with SE is usually the result of infection of the digestive tract, or reproductive organs, especially the ovary and vagina. Thus, knowledge of endogenous innate immune mechanisms operating in the ovary and vagina of hen is an emerging aspect of reproductive physiology. Cytokines are key factors for triggering the immune response and inflammation in chicken to Salmonella infection. The aim of this study was to investigate the expression profile of 11 proinflammatory cytokines in the chicken embryos during embryonic development, as well as in the hen ovary and vagina in vivo, to investigate whether sexual maturation affects their ovarian and vaginal mRNA abundance and to determine whether cytokine expression was constitutive or induced in the ovary and vagina as a response to SE infection. RT-PCR analysis revealed that several cytokines were expressed in the chicken embryos, and in the ovary and vagina of healthy birds. Expression of various cytokines during sexual maturation appeared to be developmentally regulated. In addition, a significant up-regulation of several cytokines in the ovary and vagina of sexually mature SE infected birds compared to healthy birds of the same age was observed. These results suggest a cytokine-mediated immune response mechanism against Salmonella infection in the hen reproductive organs.

Toll-like receptors (TLRs) and b-defensins (BD) molecules are group of molecules that recognize various microbial components and play a crucial role in the activation of the innate immune system in vertebrate species. Although TLRs gene expression has been studied in various pig tissues, little is known about their expression in porcine reproductive tract. Concerning b-defensins genes, only BD1, 2 and 3 counterparts have been well studied in pigs' reproductive organs. The aim of this study was to investigate the expression pattern of both gene families in pigs' male and female reproductive organs, and embryos, as potential tool for further association studies in respect to immunity and disease resistance. RT-PCR analysis revealed that all of the examined TLR genes were expressed in the reproductive organs of male and female pigs, with TLR3 and TLR5 showing the higher levels and TLR9 the lowest, in all analyzed tissues. BD genes showed a different expression pattern in respect to the examined tissue. In embryos, TLR1 revealed high expression levels, while only BD3, BD108, and BD123 were found to be expressed.

Local breeds are important for the maintenance of genetic diversity and future food security. Nowadays, the worldwide distribution of pigs is dominated by a few breeds, tending towards a severe loss of pig biodiversity. Thus, it is critical to maintain distinct populations of pig breeds. The Greek black pig, a breed raised locally and known for the high quality of its meat for cured products, is the only traditional indigenous pig breed reared in Greece. We investigated the genetic diversity, based on microsatellite analysis, of the Greek black pig and evaluated its genetic uniqueness. One hundred and three pigs from 12 Greek farms were analyzed using 11 microsatellites. The total number of alleles amounted to 135, with a mean number of alleles per locus of 12.27, ranging between 10 and 16 alleles. The observed heterozygosity ranged from 0.363 to 0.825 per locus. The expected heterozygosity ranged from 0.471 to 0.707. The inbreeding coefficient ranged from -0.329 to 0.229. We conclude that the Greek black pig, despite its low population size, has a high degree of genetic variability, which will be useful for breeding programs aimed at maintaining long-term survival of this ancient breed.

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.