The aim of this study was to compare the diversity and composition of fecal bacteria in goats and cows offered the same diet and to evaluate the influence of animal species on the gut microbiome. A total of 17 female goats (Blond Adamellan) and 16 female cows (Brown Swiss) kept on an organic farm were fed pasture and hay. Bacterial structure in feces was examined by high-throughput sequencing using the V4–V5 region of the 16S rRNA gene. The Alpha diversity measurements of the bacterial community showed no statistical differences in species richness and diversity between the two groups of ruminants. However, the Pielou evenness index revealed a significant difference and showed higher species evenness in cows compared to goats. Beta diversity measurements showed statistical dissimilarities and significant clustering of bacterial composition between goats and cows. Firmicutes were the dominant phylum in both goats and cows, followed by Bacteroidetes, Proteobacteria, and Spirochaetes. Linear discriminant analysis with effect size (LEfSe) showed a total of 36 significantly different taxa between goats and cows. Notably, the relative abundance of Ruminococcaceae UCG-005, Christensenellaceae R-7 group, Ruminococcaceae UCG-010, Ruminococcaceae UCG-009, Ruminococcaceae UCG-013, Ruminococcaceae UCG-014, Ruminococcus 1, Ruminococcaceae UCG-002, Lachnospiraceae NK4A136 group, Treponema 2, Lachnospiraceae AC2044 group, and Bacillus was higher in goats compared to cows. In contrast, the relative abundance of Turicibacter, Solibacillus, Alloprevotella, Prevotellaceae UCG-001, Negativibacillus, Lachnospiraceae UCG-006, and Eubacterium hallii group was higher in cows compared with goats. Our results suggest that diet shapes the bacterial community in feces, but the host species has a significant impact on community structure, as reflected primarily in the relative abundance of certain taxa.

Infrared thermography (IRT) has been recently applied to measure lacrimal caruncle temperature non-invasively since this region is related to the sympathetic response, and it seems a promising technique that is able to infer negative emotions in sheep (e.g., fear). However, the scientific literature so far is limited in understanding whether a caruncle’s temperature changes also in response to positive emotional states in sheep. Through classical conditioning, we aimed to assess how a positive or a negative event affects the physiological (lacrimal caruncle temperature measured with IRT and cortisol levels) and behavioral responses of sheep (ear position). Fourteen ewes from the same flock were randomly assigned to two treatment groups: positive (n = 7) and negative (n = 7). Each group was then trained through classical conditioning to associate a neutral auditory (ring bell) stimulus to an oncoming event: for the positive group, the presence of a food reward (maize grains), while for the negative one, the opening of an umbrella. After three weeks of training, before (at rest) and after (post-treatment), lacrimal caruncle temperature was non-invasively measured via IRT, and saliva samples were gently collected to measure cortisol levels. During treatment, sheep behavior was videorecorded and then analyzed using a focal animal sampling technique. At rest, the eye’s lacrimal caruncle temperature was similar in both groups, while post-treatment, a significant increase was shown only in the negative group (t-test; p = 0.017). In the anticipation phase, sheep in the positive group kept their ears forward longer compared to those in the negative one (Mann–Whitney; p < 0.014), 8.3 ± 2.1 s and 5.2 ± 4.2 s, respectively. The behavioral response observed reflects a learnt association between a neutral stimulus and events with different emotional valence. Cortisol concentration slightly increased in both groups post-treatment. Our results confirm that IRT is a non-invasive technique that can be useful when applied to assess how positive and negative events may affect the physiological response in sheep.

In this study, we investigated the effect of the dietary inclusion of Hermetia illucens larvae oil on the diversity and structure of the bacterial community of the caecal content of Japanese quails (Coturnix japonica). A total of 40 quails, equally selected for slaughter from 100 animals which were divided evenly into four treatment groups including control group (C) with a diet containing corn oil and 3 experimental groups with partial (25%, 50%) or total (100%) substitution of corn oil by H. illucens larvae oil, here referred to as Black soldier fly larvae oil (BSFO): BSFO 25, BSFO 50 and BSFO 100, respectively. After slaughtering (42 days of age), the microbiota of caecal samples was examined by high-throughput sequencing using the V4-V5 region of the 16S rRNA gene. In all the studied groups the dominant phylum was Firmicutes with prevailing families of Ruminococcaceae and Lachnospiraceae. Caecal microbiota was meaningly influenced on genus level. The linear discriminant analysis effect size (LefSe) analysis for the differential taxa abundance showed that Lactobacillus was significantly increased in BSFO 25 group, Fusicatenibacter was significantly enriched in all the experimental groups fed larvae oil (BSFO 25, 50 and 100) and Subdoligranulum was highly elevated in BSFO 100 group. The analysis revealed statistical dissimilarities between the control group (C) and the groups with 50% and 100% oil replacement (BSFO 50 and 100). The bacterial diversity was significantly suppressed in the samples of quails fed the diet with a total inclusion of H. illucens oil (BSFO 100). The results showed the considerable effect of Black soldier fly larvae oil on the caecal microbiota of Japanese quails.

Background: The poultry industry is increasingly looking for sustainable feed ingredients which support animal productivity. Insects, such as the larvae of Hermetia illucens , represent a promising alternative protein source that has a positive effect on gut health. Aim: The aim of this study is to evaluate the effects of a partial replacement of soybean meal with H. illucens larvae meal on the caecal microbiota of laying hens. Methodology: A total of 162 hens were divided equally into three treatment groups: a control group (C) with a diet containing corn–soybean meal and two treatment groups (HI25, HI50) in which 25% and 50% of the soybean meal protein was replaced by H. illucens larvae meal protein. At 40 weeks of age, 30 animals (10 per group) were slaughtered and the bacterial community of the caecal content was analysed by high‐throughput sequencing using the V4–V5 region of the 16S rRNA gene. The DNA was extracted using the PowerSoil DNA Kit, the library preparation was performed using the NEBNext Fast DNA Library Prep Set kit and sequencing was performed using the Ion Torrent PGM. The bacterial diversity was assessed by alpha and beta diversity indices, and the differential abundance of taxa was determined using LEfSe analysis. Results: Firmicutes and Bacteroidetes were the dominant phylum in all groups. Alpha diversity indices showed no significant differences between diets, however, beta diversity measures showed statistical dissimilarities between the three studied groups. Several beneficial genera, including Alistipes , Christensenellaceae R‐7 group, Parabacteroides , Butyricimonas and Parasutterella , were enriched in the HI50 group, while Lactobacillus , Bifidobacterium , Blautia and the opportunistic pathogen Enterococcus were reduced. Conclusion: The consumption of H. illucens larvae meal showed beneficial effect on the microbiota of the caecum of laying hens, with 50% replacement showing the strongest positive effects, suggesting that this is the most effective amount under the given conditions. Further research should explore microbial functions and long‐term impacts, and validate the optimal levels of insect meal inclusion.