Meng Zeng

The Leizhou goat is a vital indigenous breed, yet its disease resilience can complicate early health monitoring. The white blood cell (WBC) count is a key indicator of immune status, but its relationship with the gut microbiota remains uncharacterized in this breed. This study aimed to characterize the fecal microbiota of Hainan black goats stratified based on their WBC counts. The goats were stratified into Lower, Middle, and High WBC groups based on peripheral WBC counts to compare their fecal microbiota and identify potential associations with systemic immunity. Significant differences in microbial alpha- and be-ta-diversity were observed among the groups, with the High WBC group showing the greatest richness. The microbiota was dominated by Bacillota and Bacteroidota at the phylum level. Linear discriminant analysis Effect Size (LEfSe) identified specific taxa en-riched in each group, such as Ruminococcusin the High WBC group. Critically, Spearman correlation analysis demonstrated significant positive correlations between WBC counts and the relative abundance of genera like unclassified_f_Oscillospiraceae and unclassi-fied_c_Clostridia. These findings demonstrate that WBC counts are significantly associated with distinct shifts in the gut microbial community structure of Hainan black goats. The identified WBC-associated microbial biomarkers suggest a link between the gut microbi-ome and host immune regulation, providing a foundation for future research on microbi-ota-mediated health assessment in goats.

In intensive breeding systems, goats reared for meat production are often housed in group pens at high stocking densities. This study aimed to investigate the correlation between expressed behaviours and stocking density, and to compare the time budget of these confined goats with that of pasture-based goats. A detailed ethogram of 19 mutually exclusive behavioural activities was developed. Behavioural observations were conducted continuously over 72 h on group pens selected for their variation in stocking density and homogeneity in breed, age, body condition and acclimation period since arrival. Using the scan-sampling method (96 scans per goat daily), data were collected from 42 goats. The time budget, expressed as the mean frequency (%) ± standard deviation for each behavioural activity, was calculated. The associations between time budget and stocking density were assessed via bivariate analysis, with the strength and direction of relationships quantified using Pearson’s correlation coefficient (r). Results indicated that self-grooming and Bipedal stance/Climbing were positively correlated with increased space allowance (i.e., lower stocking density), suggesting their potential utility as positive welfare indicators for housed fattening goats in group pens. Furthermore, the time budget differed notably from pasture-based patterns, primarily characterized by resting (53.09% ± 2.72%), eating (16.05% ± 2.88%), and moving (2.30% ± 0.75%).

This study investigated the effects of Bacillus subtilis (B. subtilis) supplementation on microbiota and metabolites in the feces of Leizhou goats. Eight Leizhou goats were used in a replicated 4 × 4 Latin square design according to their gender (nanny goats and billy goats) with a 4 × 2 factorial arrangement of treatments that included four B. subtilis additive doses (control [0 g/d; NC, BC], low [2.5 g/d, NL, BL], medium [5 g/d, NM, BM], and high [7.5 g/d, NH, BH]) and 28 d periods (n = 4 per group), each consisting of 27 d adaption and 1 d sample collection. After collecting 32 fecal samples, 16S rRNA gene sequencing and LC-MS were performed to analyze microbial composition and metabolites, respectively. At the genus level, the relative abundance of Rikenellaceae_RC9_gut_group was significantly higher (p < 0.05) in the NM group than in the NC group. The relative abundance of Treponema sp. was significantly lower (p < 0.05) in the NM group than in the NC group. In billy goats, the relative abundances of UCG-005 and Rikenellaceae_RC9_gut_group were significantly higher (p < 0.05) in the BH group than in the BC group. The relative abundance of Treponema sp. was significantly lower (p < 0.05) in the BL, BM, and BH groups than in the BC group. Furthermore, metabolomic analysis revealed that B. subtilis significantly altered the concentrations of glucose metabolism modulators (1-deoxynojirimycin, 1-DNJ) and certain bioactive peptides. Many amino acid metabolic pathways were also enriched. Correlation analysis demonstrated close connections between differential metabolites and the top 10 bacterial genera in fecal samples. These results provide new insights into the impact of B. subtilis on the microbial community and metabolic profile of the feces of Leizhou goats. In this experiment, the appropriate doses of B. subtilis for nanny goats and billy goats were 5 g/d and 7.5 g/d, respectively, but the optimal doses still need to be verified based on performance-based feeding tests in the next study.

This study investigates the effects of rumen-protected methionine and lysine (RPML) on the fecal microbiota of Leizhou goats, focusing on growth performance and fecal microbial community composition. A total of 10 three-month female Leizhou goats (9.90 ± 0.08 kg) were randomly assigned to one of two dietary treatments: a CON group fed a basal diet and an RPML group receiving the basal diet supplemented with 1.5 g/d/head of rumen-protected methionine and 4.5 g/d/head of rumen-protected lysine. Results indicated that RPML significantly enhanced average daily gain (ADG) and final body weight (FBW), as well as significantly decreased the ratio of dry matter intake (DMI) to ADG (p < 0.001). Fecal microbiota composition showed a decrease in abundance of UCG-005, Phascolarctobacterium, and norank_f__Bacteroidales_RF16_group and an increase in others like Christensenellaceae R-7 and unclassified_c__Clostridia (p < 0.05). Moreover, the correlations between the abundance of certain bacterial genera and the concentrations of short-chain fatty acids (SCFAs) suggest that the modulation of the gut microbiota is associated with improved growth performance and feed efficiency in Leizhou goats, indicating that RPML supplementation can modulate the gut microbiota to improve growth performance and feed efficiency in Leizhou goats.

The objective of this study was to evaluate the effect of fecal bacterial community and metabolomics in goats when consuming a lower-protein diet with different energy levels. Eight healthy Leizhou goats, with 11 ± 0.78 kg of body weight, were selected and housed individually in cages. The animals were randomly allocated to a lower-protein diet that varied with four metabolites energy levels (7.01, 8.33, 9.66, and 10.98 MJ/kg DM) in a replicated 4 × 4 Latin square design. Notably, energy-dependent microbial restructuring was observed at both phylum and genus levels. At the phylum level, the relative abundances of Firmicutes and Spirochaetote increased linearly, whereas the Bacteroidota and Patescibacteria decreased linearly with increasing dietary energy levels (p < 0.05). The relative abundances of Verrucomicrobiota increased quadratically, whereas others decreased quadratically with increasing dietary energy levels (p < 0.05). At the genus level, a total of 316 bacteria were identified in the 32 fecal samples. The relative abundances of Christensenellaceae_R-7_group, unclassified_f__Lachnospiraceae, Ruminococcus, norank_o__Clostridia_UCG-014, Treponema, [Eubacterium]_siraeum_group, and [Eubacterium]_ruminantium_group increased linearly, whereas the Oscillospiraceae_UCG-005, norank_f__[Eubacterium]_coprostanoligenes_group, Prevotellaceae_UCG-004, unclassified_c__Clostridia, norank_f__Ruminococcaceae, unclassified_f__ Oscillospiraceae, and others decreased linearly with an increasing dietary energy levels (p < 0.05). In addition, the metabolomic analysis of feces showed that there are many differential metabolites in goats when consuming a lower-protein diet with different energy levels; for example, lipid metabolism and amino acid metabolic pathways were increased in MLE, MHE, and HE groups compared to the LE group. In conclusion, this study provides further information regarding the effects on fecal bacterial community composition and metabolites in goats when consuming a lower-protein diet with different energy levels.

Leizhou goats are famous for their delicious meat but have inferior growth performance. There is little information on rumen-protected fat (RPF) from the Leizhou goat. Hence, we observed the effects of RPF on growth, fecal short-chain fatty acids, and bacteria community with respect to Leizhou goats. Twelve goats (13.34 ± 0.024 kg) were selected and assigned randomly to one of two treatments: (1) a control diet (CON) and (2) 2.4% RPF with a control diet (RPF). The final body weight and average daily gain (ADG) were greater (p < 0.05), and the dry matter intake (DMI): ADG was lower (p < 0.05) in the RPF group than in the CON group. There were no differences in DMI between the CON and RPF groups. The concentrations of total short-chain fatty acids, acetate, propionate, and butyrate were lower (p < 0.05) in the RPF group than in the CON group. The relative abundances of Ruminococcus, Rikenellaceae_RC9_gut_group, Treponema, norank_f__norank_o__RF39, Eubacterium_siraeum_group, and Ruminococcus_torques_group were lower (p < 0.05) in the RPF group than in the CON group. The relative abundances of Bacteroides, norank_f__norank_o__Clostridia_UCG-014, norank_f__Eubacterium_coprostanoligenes_group, Eubacterium_ruminantium_group, norank_f__Oscillospirale-UCG-010, Oscillospiraceae_UCG-002, and Family_XIII_AD3011_group were greater (p < 0.05) in the RPF group than in the CON group. It was concluded that RPF could improve the goats’ growth performance by regulating their fecal bacteria communities.

Mixed ensiling of Stylosanthes guianensis and Pennisetum sinese is an alternative method to improve the nutrient composition of feeds for healthy and green ruminant production in the tropics. This study examined the fermentation quality, nutritional composition, and microbial population in silage to select the most suitable ratio of mixed silage containing different proportions of S. guianensis and P. sinese. It was completely randomized and consisted of four treatments with five replications based on fresh weight as follows: S0, 100% P. sinese; S15, 85% P. sinese + 15% S. guianensis; S30, 70% P. sinese + 30% S. guianensis; and S45, 55% P. sinese + 45% S. guianensis. The silage samples were opened and detected after ensiling for 30 days. The results showed that the content of dry matter and crude protein in mixed silage increased with the increase in S. guianensis, while the content of acid detergent fiber decreased significantly, and the maximum or minimum value appeared in the S45 group. As the proportion of S. guianensis increased, the pH, ammonia nitrogen, and acetic acid in mixed silage gradually increased, but the lactic acid content decreased. In addition, the content of lactic acid bacteria and yeast showed a significant downward trend. Further study showed that there was a complex correlation between nutrient compositions, fermentation characteristics, and microbial numbers in mixed silage, especially dry matter, crude protein, and lactic acid bacteria. From the sensory evaluation of silage, S30 was excellent and exhibited an aromatic smell, a hazel color, and the loosest texture. However, from the results of the proportion of organic acids in mixed silage fermentation and further principal component analysis, the highest comprehensive score was in the S15 group. Considering the nutritional compositions and fermentation quality, the optimum ratio of mixed fermentation between S. guianensis and P. sinese in this experiment was 30:70.

Recently, a report in Viruses has highlighted the problem of porcine circovirus-like (PCL) virus