The spread of antibiotic resistance genes (ARGs) in the environment exacerbates the contamination of these genes; therefore, the role plants play in the transmission of resistance genes in the food chain requires further research. Giant pandas consume different bamboo parts at different times, which provides the possibility of investigating how a single food source can affect the variation in the spread of ARGs. In this study, metagenomic analysis and the Comprehensive Antibiotic Resistance Database (CARD) database were used to annotate ARGs and the differences in gut microbiota ARGs during the consumption of bamboo shoots, leaves, and culms by captive giant pandas. These ARGs were then compared to investigate the impact of bamboo part consumption on the spread of ARGs. The results showed that the number of ARGs in the gut microbiota of the subjects was highest during the consumption of bamboo leaves, while the variety of ARGs was highest during the consumption of shoots. Escherichia coli, which poses a higher risk of ARG dissemination, was significantly higher in the leaf group, while Klebsiella, Enterobacter, and Raoultella were significantly higher in the shoot group. The ARG risk brought by bamboo shoots and leaves may originate from soil and environmental pollution. It is recommended to handle the feces of giant pandas properly and regularly monitor the antimicrobial and virulence genes in their gut microbiota to mitigate the threat of antibiotic resistance.

There is an urgent need to find a way to improve the genetic diversity of captive South China tiger (SCT, Panthera tigris amoyensis), the most critically endangered taxon of living tigers, facing inbreeding depression. The genomes showed that 13 hybrid SCTs from Meihuashan were divided into two groups; one group included three individuals who had a closer relationship with pureblood SCTs than another group. The three individuals shared more that 40% of their genome with pureblood SCTs and might be potential individuals for genetic rescuing in SCTs. A large-scale genetic survey based on 319 pureblood SCTs showed that the mean microsatellite inbreeding coefficient of pureblood SCTs decreased significantly from 0.1789 to 0.0600 (p = 0.000009) and the ratio of heterozygous loci increased significantly from 38.5% to 43.2% (p = 0.02) after one individual of the Chongqing line joined the Suzhou line and began to breed in the mid-1980s, which is a reason why the current SCTs keep a moderate level of microsatellite heterozygosity and nucleotide diversity. However, it is important to establish a back-up population based on the three individuals through introducing one pureblood SCT into the back-up population every year. The back-up population should be an important reserve in case the pureblood SCTs are in danger in the future.

Understanding how individual personality traits relate to stress and abnormal behaviors is essential for improving animal welfare and management. However, few studies have quantitatively examined these relationships in giant pandas. This study aimed to investigate how personality traits predict stereotypic behavior and physiological stress responses in captive giant pandas under a simulated transport context. Stereotypies are abnormal repetitive behaviors thought to reflect stress coping, and personality is increasingly recognized as a factor shaping animal welfare. We compared non-stereotypic (n = 16) and stereotypic (n = 16) giant pandas using keeper-based ratings, crate-entry training, and urinary cortisol. Intraclass correlation and principal component analyses identified two personality components, activity and timidity. Non-stereotypic pandas were significantly less timid (p = 0.005), whereas activity did not differ (p = 0.355). In crate-entry training, non-stereotypic pandas tended to enter faster (48.5 vs. 139.5 s; p = 0.074), and timidity was strongly correlated with latency (ρ = 0.74, p < 0.01). Censoring-aware analyses treating 300 s as right-censoring further supported this pattern (stratified Cox (Hazard Ratio) HR = 3.09, 95% CI 0.93–10.25; likelihood-ratio p = 0.052; log-normal accelerated failure-time model time ratio = 0.36, p = 0.054). Urinary cortisol showed no between-group difference after adjustment (geometric mean ratio = 0.93, 95% CI 0.57–1.49; p = 0.75), with consistent sensitivity analyses. These findings indicate that stereotypic pandas are more timid, and higher timidity predicts slower adjustment to a stress context, highlighting the value of personality assessment in management to mitigate stereotypies and improve welfare, while inconsistent cortisol results warrant further study.

Neopterin is a well-characterized marker of cell-mediated immunity. Here, we used neopterin as a biomarker to identify the cellular immunity status of breeding giant pandas throughout gestation. Urine samples were collected from captive adult female giant pandas that had entered estrus and were either naturally bred and/or artificially inseminated (AI) during the breeding seasons at the Chengdu Research Base of Giant Panda Breeding. This study was divided into two parts. In the first part, we examined the urinary neopterin and progesterone (Pg) profiles during pregnancy in parturient and nonparturient individuals. From the day of mating to the Pg peak, there was no correlation between neopterin and Pg in both parturient individuals (n = 3) and nonparturient individuals (n = 3). During the period when the Pg dropped from its peak to approximately 100 ng/mg Cr, the changes in neopterin and Pg showed a negative correlation in parturient individuals, while there was no correlation between the changes in neopterin and Pg in nonparturient individuals. Subsequently, urine samples were categorized into four phases based on the reproductive status of giant pandas: (1) Estrus phase (Es); (2) Primary Pg increase phase (S1), during which Pg levels rise from the day of mating to 100 ng/mg Cr; (3) Secondary Pg increase phase (S2), during which Pg levels rise from 100 ng/mg Cr (inclusive) to their peak value; and (4) Post-peak Pg decline phase (S3), during which Pg levels decrease from their peak (inclusive) until they drop to approximately 200 ng/mg Cr. Analysis revealed that differences between parturient and nonparturient females emerged in the S3 phase. Compared to nonparturient individuals, neopterin concentrations showed sustained elevation in parturient pandas during the S3 phase. The second part of the study, building on the findings of the first part, specifically focused on analyzing the urine samples of giant pandas during the S2 and S3 phases. Statistical analysis of an expanded sample of individuals (including those from the first part) revealed a significant difference in the neopterin mean S3/S2 ratio between the parturient group (mean S3/S2 = 1.71 ± 0.12; n = 14) and the nonparturient group (mean S3/S2 = 0.85 ± 0.04; n = 17). Correspondingly, parturient individuals gave birth 5 to 16 days after the end of the S3 phase (this time corresponds to the point when Pg levels decrease to approximately 200 ng/mg Cr). The results revealed the validity and applicability of using the neopterin mean S3/S2 ratio (1.71 ± 0.12) for diagnosing successful pregnancy in mated female giant pandas.