This study aimed to evaluate the in vitro antimicrobial activities of two types of insect fats extracted from black soldier fly larvae (HI, Hermetia illucens L.) and yellow mealworm larvae (TM, Tenebrio molitor L.) and their effects as dietary replacement of soybean oil (S) on cecal fermentation pattern, and fecal and cecal microbiota in rabbits. A total of 120 weaned rabbits were randomly allotted to three dietary treatments (40 rabbits/group) —a control diet (C diet) containing 1.5% of S and two experimental diets (HI diet (HID) and TM diet (TMD)), where S was totally substituted by HI or TM fats during the whole trial that lasted 41 days. Regarding the in vitro antimicrobial activities, HI and TM fats did not show any effects on Salmonella growth. Yersinia enterocolitica showed significantly lower growth when challenged with HI fats than the controls. The insect fat supplementation in rabbit diets increased the contents of the cecal volatile fatty acids when compared to the control group. A metataxonomic approach was adopted to investigate the shift in the microbial composition as a function of the dietary insect fat supplementation. The microbiota did not show a clear separation as a function of the inclusion, even if a specific microbial signature was observed. Indeed, HI and TM fat supplementation enriched the presence of Akkermansia that was found to be correlated with NH3-N concentration. An increase in Ruminococcus, which can improve the immune response of the host, was also observed. This study confirms the potential of HI and TM fats as antibacterial feed ingredients with a positive influence on the rabbit cecal microbiota, thus supporting the possibility of including HI and TM fats in rabbit diets.

Bianca di Saluzzo (BS) and Bionda Piemontese (BP) are two Italian chicken breeds, mainly reared for meat production, primarily in antibiotic-free farming. However, technical information on their growth pattern is still missing. At hatching, 150 unsexed chicks of each breed were weighed, labeled, and reared in indoor pens up to 8 w of age. At 8 w of age, the chicks were separated by sex and randomly transferred to growing pens with access to an external paddock (15 birds/pen; 4 pens/sex for each breed). The body weight (BW) was recorded biweekly for each bird, from hatching to 32 w of age. In order to identify an improvement strategy, the objectives of our study were to analyze the growth pattern of these birds using the Gompertz mathematical model and compare results with other chicken breeds. Polymorphism of the PAX7 gene was also analyzed to test its association with growth traits. Both BS and BP are close to unselected native breeds and, among the Italian local poultry, they are confirmed to be slow-growing birds with an intermediate size between heavy and light chicken breeds. Regarding the PAX7 gene, two alleles were found, F and G, and showed an association with the actual BW in the BP females from 14 w of age onwards. The G allele always exhibited a more favorable effect than the F allele. In small size poultry population, a delicate balance between preservation of biodiversity and performance improvement should be considered. Consequently, the most proper way could be an approach based on a mating scheme to keep inbreeding under control, increase growth rate, and improve commercial maturity.

Cats are usually spreaders of allergens that are critical for sensitive people; the Siberian cat is a breed supposed to be low level allergenic, according to some breeders’ statements. The sequence of the two genes, namely Ch1 and Ch2, that code for the allergen Fel d 1, the major allergen responsible for outbreaks of allergy symptoms, is not yet known in the Siberian cat, and finding this was the aim of our investigation. Notably, our work is the first survey of the genetic structure of these genes in Siberian cats. The comparison of the sequences of Siberian cats, non-Siberian cats, and sequences present in the National Center for Biotechnology Information database revealed a considerable number of mutations; some of those detected in the Siberian cat, due to their position in exon regions, could affect the Fel d 1 allergenic properties. Therefore, further investigations are recommended to assess if the identified mutations can be responsible for a reduced-allergen synthesis and can be used as markers for selection of low level allergenic cats.

The purpose of this study was to investigate the effects of high levels of Tenebrio molitor dietary inclusion (15%) on molecular mechanisms that influence poultry health in a broiler chicken diet. The global gene expression of four tissues (breast, liver, jejunum, and caecum) was evaluated using the RNA-Seq approach. The analysis of differentially expressed genes suggested that the use of Tenebrio molitor leads to the overexpression of genes related to protein elongation required for tissue growth and development in the gut and liver. It would also appear to contain nutrients that reduce the expression of genes related to the immune system and inflammation of the mucosa. The dietary inclusion of Tenebrio molitor in poultry could also lead to a possible inactivation of the growth factor and a reduction of tissue free-radicals. No genes alterations have been detected in liver RNA expression that would discourage the use of larvae in feeding broilers.

This study investigated the feasibility of using blood feather transcriptomics to detect sex-differences and gene response to physiological changes in chickens. The identification of molecular markers associated with metabolism in poultry typically requires invasive sampling of tissues, such as liver. Feathers represent a promising non-invasive biological source of RNA: the quill pulp of growing feathers contains living cells capable of active transcription. Growing feathers were collected from 150-day-old male and female chickens (Bionda Piemontese, slow-growing breed) raised under a free-range system and fed two finishing diets differing in lipid content: low-lipid (LL, ether extract 3.6%) and high-lipid (HL, ether extract 9.3%). RNA was extracted from quill pulp and subjected to whole RNA-Seq analy-sis. Differential gene expression and functional enrichment analyses were performed us-ing the RaNA-Seq platform. A total of 17,360 transcripts were detected and used for downstream analyses. Across all individuals, three genes associated with ether lipid metabolism (PLA2G10, PLA2G4F, and ENPP6) were consistently upregulated in chickens fed the HL diet. Sex-specific responses were also observed. In roosters, HL feeding significantly affected genes involved in lipid transport and metabolic regulation within the PPAR signaling pathway, including APOA1 and SLC27A4. In contrast, hens showed differential expression primarily in pathways related to apelin signaling, extracellular matrix remodeling, and cardiovascular function rather than classical lipid metabolism pathways. These findings demonstrate differential responses to dietary treatments between males and females and reveal metabolic differences, confirming the need for sex-specific anal-yses in this local breed. In conclusion, feather RNA-Seq successfully captured diet-induced molecular responses and revealed sex-specific metabolic adaptations to dietary lipid levels. This study demon-strates that quill pulp represents a practical and ethically favorable alternative to tradi-tional tissue sampling and may support future nutrigenomic and genetic improvement studies. The findings support the development of non-invasive biomarkers applicable to genetic selection and precision nutrition, ultimately supporting more sustainable poultry production.

In this study, an exploratory transcriptomic investigation was conducted to evaluate the feasibility of using feather transcriptomics to detect sex differences and gene responses to physiological changes in chickens. Feathers represent a promising non-invasive biological source of RNA, as the feather pulp of growing feathers contains living cells capable of active transcription. Growing feathers were collected from 150-day-old male and female chickens (Bionda Piemontese, a slow-growing breed) raised under a free-range system and fed two finisher diets differing in lipid content: low-lipid (LL, ether extract 3.6%) and high-lipid (HL, ether extract 9.3%) diets. RNA was extracted from feather pulp, and 12 pools were subjected to whole RNA-Seq analysis. The study was designed as 2 × 2 factorial experiments investigating the effects of diet and sex on gene expression. A total of 17,360 transcripts were detected and used for downstream analyses. Differential gene expression and functional enrichment analyses were performed. The main effects of diet and sex were estimated with an additive design using the DEseq2 package, while for the sex-specific diet analyses, subgroup comparisons were conducted on the RaNA-Seq platform. The analysis of the main effect of diet reveals that three genes associated with ether lipid metabolism (PLA2G10, PLA2G4F, and ENPP6) were upregulated in chickens fed the HL diet. In roosters, HL feeding significantly altered the expression of APOA1 and SLC27A4, suggesting an effect on lipid transport and metabolic regulation within the PPAR signaling pathway. In contrast, hens showed differential expression primarily in pathways related to apelin signaling, extracellular matrix remodeling, and cardiovascular function, rather than classical lipid metabolism pathways; additionally, gene set enrichment analysis indicated a limited enrichment of linoleic acid metabolism, suggesting secondary involvement of lipid metabolic processes. These findings are consistent with those in the literature reporting sex-related differences between males and females. The results further suggest that transcriptomic responses to dietary lipid supplementation can be investigated through the expression of selected candidate genes in feather pulp. Among the genes identified, PLA2G10, PLA2G4F, ENPP6, APOA1, and SLC27A4 emerged as potential molecular markers associated with dietary treatment, and the importance of sex-dependent transcriptional responses was highlighted. In conclusion, this study demonstrates the potential of feather pulp as a viable source of RNA for transcriptomic analyses in live chickens, providing a minimally invasive alternative to conventional tissue sampling. These preliminary results also support the hypothesis that feathers represent a practical and ethically favorable tissue for future nutrigenomic and genetic improvement studies, ultimately supporting more sustainable poultry production.