Common clinical findings identified in working equids in low- and middle-income countries from 2005 to 2021.

Despite several millions of working equids worldwide, there are few published studies regarding the epidemiology of their health and welfare. Data collected by non-governmental organisations (NGOs) operating in the working equid sphere therefore have important epidemiological value and could be used towards animal health surveillance. The aim of this study was to identify common clinical findings and mortality patterns of working equids in low- and middle-income countries and investigate their epidemiology using data collected from an international NGO. A retrospective analysis was conducted to determine the proportion of clinical findings and mortality risk by equid species, year and region. Negative binomial regression models were generated to investigate differences in mortality risk and proportion of key clinical findings between equid species, hemispheres and calendar month. A total of 4,313,606 presentations were reported from 14 countries between January 2005 and March 2021 (mean 22,121; SD ± 7,858 per month). Wounds and abscesses were the most reported clinical finding for all equid species (mean proportion 35%; SD ±0.19 of all findings). A higher proportion of wounds (mean proportion 41.7%; SD±0.2) was recorded in donkeys than mules or horses (P<0.001). Mules had higher reported mortality risk (1.2%; 95% CI 0.94-1.46%) than horses (0.4%; 95% CI 0.36-0.55%; p<0.001) or donkeys (0.2%; 95% CI 0.14-0.22%). Work-related wounds were the predominant finding in working equids, particularly so in donkeys. Prevention strategies should focus on improvements to work equipment and practices for all equids. Future investigations required include refinement of diagnostic approaches for donkeys and investigation of risk factors to understand the higher mortality in mules. Routine monitoring of clinical findings reported by national or international NGOs could be included in animal health surveillance strategies, although standardisation of data for this purpose is needed so that changes in prevalence following implementation of prevention strategies can be monitored.

Comparing Nutritional Values and Bioactivity of Kefir from Different Types of Animal Milk.

The growing interest in fermented dairy products is due to their health-promoting properties. The use of milk kefir grains as a starter culture made it possible to obtain a product with a better nutritional and biological profile depending on the type of milk. Cow, buffalo, camel, donkey, goat, and sheep milk kefirs were prepared, and the changes in sugar, protein, and phenol content, fatty acid composition, including conjugated linoleic acids (CLAs), as well as antioxidant activity, determined by ABTS and FRAP assays, were evaluated and compared. The protein content of cow, buffalo, donkey, and sheep milk increased after 24 h of fermentation. The fatty acid profile showed a better concentration of saturated and unsaturated lipids in all fermented milks, except buffalo milk. The highest content of beneficial fatty acids, such as oleic, linoleic, and C18:2 conjugated linoleic acid, was found in the cow and sheep samples. All samples showed a better antioxidant capacity, goat milk having the highest value, with no correlation to the total phenolic content, which was highest in the buffalo sample (260.40 ± 5.50 µg GAE/mL). These findings suggested that microorganisms living symbiotically in kefir grains utilize nutrients from different types of milk with varying efficiency.

Molecular detection of piroplasms in domestic donkeys in Xinjiang, China.

BACKGROUND: Piroplasmosis is a common and prevalent tick-borne disease that affects equids. OBJECTIVES: To determine the infection and molecular characteristics of the piroplasms in donkeys from Xinjiang, northwestern China, we undertook a cross sectional study by collecting representative samples across several counties within the region. METHODS: A total of 344 blood samples were collected from adult domestic donkeys from 13 counties in Xinjiang. PCR was conducted to test for T. equi and B. caballi in the blood samples based on the equine merozoite antigen-1 (Ema-1) gene and the 48 kDa rhoptry protein (BC48) gene, respectively. RESULTS: Sixteen blood samples tested positive for piroplasms and the overall infection rate was 4.7% (16/344). Seven of the 13 counties were positive for piroplasms. Among the 16 piroplasm-positive samples, 15 were singly infected with T. equi with an infection rate of 4.4% (15/344), and coinfection with T. equi and B. caballi was detected in one sample (0.3%, 1/344) from Wushi. Four T. equi sequence genotypes were identified and grouped into different branches of the evolutionary trees. CONCLUSION: These findings suggest that the infection rate of piroplasms is low in domestic donkeys in southern Xinjiang and that T. equi genotypes have a regional distribution.

Effects of telemetry collars on two free-roaming feral equid species.

There are two species of free-roaming feral equids in North America: horses (Equus caballus) and donkeys or "burros" (E. asinus). Both species were introduced as domestic animals to North America in the early 1500s and currently inhabit rangelands across the western United States, Canada, and all continents except Antarctica. Despite their global distribution, little is known about their fine scale spatial ecology. Contemporary research tools to assess space use include global positioning system (GPS) tracking collars, but older models were problematic due to stiff collar belting causing poor fit. We tested modern designs of GPS collars on n = 105 horses and n = 60 burros for 4 years in five populations (3 horse, 2 burro) across the western United States, to assess whether collars posed welfare risks to horses or burros. We found no difference in survival of collared versus uncollared mares and jennies, and no difference in survival of their foals. In 4036 of 4307 observations for horses (93.7%) and 2115 of 2258 observations for burros (93.6%), collars were observed symmetrical, maintaining proper fit on the neck. Fur effects from collars (sweaty neck, indented fur, broken fur) were seen in 3% of horse observations and 25% of burro observations. Superficial effects (chafes and marks on skin surface) were seen in 2% of horse observations and 11% of burro observations; no severe effects from collars were seen. Body condition was not affected by collars; mean body condition of collared horses was 4.70 ± 0.54 (mean ± s.d) and 4.71 ± 0.65 for collared burros. Behavior results indicated minimal effects; collared horses stood slightly more than uncollared, and collared burros stood and foraged more in one population, but not in the other. For 6.3% of observations of horses and 6.4% of observations of burros, we found an effect of time wearing a collar on the cumulative sum of fur effects which increased over time (burros: rs = 0.87, P = <0.0001; horses: rs = 0.31, P = 0.002). Burros also showed an increase over time in the number of superficial effects, but horses did not. Collars occasionally moved into the wrong position, shifting forward over the ears; we observed this on 19 horses and 1 burro. Of those, most collars went over the ears in summer (n = 12). All collars were equipped with a remote release mechanism as well as a timed-release mechanism for redundancy, thus removed when observed in wrong position to avoid rubbing or discomfort. Our finding of no consequential physical effects in 98% of horse observations, and 89% of burro observations suggests the consequences of collars on free-roaming equid welfare and survival is biologically insignificant, although collars should be monitored regularly and continue to be equipped with a remote release mechanism to remove a collar if needed. With frequent welfare-driven, visual monitoring, collaring of free-roaming equids can be a safe and useful tool to increase our understanding of their spatial ecology, demography, habitat use, behavior, and interactions with other wildlife.

First identification and isolation of equine herpesvirus type 1 in aborted fetal lung tissues of donkeys.

BACKGROUND: Equine herpesvirus type 1 (EHV-1) is commonly associated with horse abortion. Currently, there are no reported cases of abortion resulting from EHV-1 infection in donkeys. RESULTS: This was the first survey-based study of Chinese donkeys. The presence of EHV-1 was identified by PCR. This survey was conducted in Chabuchar County, North Xinjiang, China, in 2020. A donkey EHV-1 strain (Chabuchar/2020) was successfully isolated in MDBK cells. Seventy-two of 100 donkey sera were able to neutralize the isolated EHV-1. Moreover, the ORF33 sequence of the donkey-origin EHV-1 Chabuchar/2020 strain showed high levels of similarity in both its nucleotide (99.7‒100%) and amino acid (99.5‒100%) sequences, with those of horse EHV-1 strains. EHV-1 Chabuchar/2020 showed significant consistency and was classified within cluster 1 of horse EHV-1 strains. Further, analysis of the expected ORF30 nucleotide sequence revealed that donkey EHV-1 strains contained guanine at position 2254, resulting in a change to aspartic acid at position 752 of the viral DNA polymerase. Therefore, these strains were classified as horse neuropathogenic strains. Lastly, a phylogenetic tree was constructed using the partial ORF68 nucleotide sequences, showing that the identified donkey EHV-1 strain and the EHV-1 strain found in aborted Yili horses in China comprised a novel independent VIII group. CONCLUSION: This study showed the first isolation and identification of EHV-1 as an etiological agent of abortions in donkeys. Further analysis of the ORF33, ORF30, and ORF68 sequences indicated that the donkey EHV-1 contained the neuropathogenic genotype of strains in the VIII group. It is thus important to be aware of EHV-1 infection in the donkey population, even though the virus has only been identified in donkey abortions in China.

Transvaginal aspiration, oocyte maturation and production of blastocysts and a pregnancy via ICSI in an endangered breed: Baudet du Poitou donkey.

Two Poitou donkey jennies were presented for clinical oocyte recovery and embryo production via intracytoplasmic sperm injection (ICSI). Both jennies underwent transvaginal ultrasound-guided follicle aspiration on two occasions. Recovered oocytes were held overnight then placed into maturation culture, using standard methods for mare oocytes. On the first replicate for both jennies, the oocytes were divided into two groups; one group was denuded and examined at 30 h culture (standard culture duration for mare oocytes) and the second was denuded and examined at 36 h culture. No oocytes with polar bodies were observed at either time. The oocytes were maintained in maturation culture until 46 h, at which time oocytes with polar bodies were observed. Semen was then prepared; oocytes underwent ICSI approximately 48 h after being placed into maturation culture. On the second replicate for both jennies, oocytes were cultured for maturation for 42 h, then denuded and subjected to ICSI at 46 h. Sperm preparation, injection and embryo culture were performed as for mare oocytes. Blastocyst rates per injected oocyte were 8/19 (42 %) overall, being 4/12 and 4/7 for the first and second TVAs, respectively. Blastocysts were vitrified. Three blastocysts were warmed and transferred to Poitou donkey jenny recipients. One embryonic vesicle was visualized on ultrasonography on embryo Day 12, which increased in size on Day 13 but was not present when examined on Day 14. These results demonstrate that oocyte recovery and ICSI are efficient for production of Poitou donkey blastocysts. To the best of our knowledge, this is the first report of production of blastocysts via ICSI in the Poitou donkey, and the first report of transfer of ICSI-produced embryos in the donkey. Further work is needed on factors affecting pregnancy after embryo transfer in the donkey.

Analysis of the Genetic Relationship and Inbreeding Coefficient of the Hetian Qing Donkey through a Simplified Genome Sequencing Technology.

The Hetian Qing donkey is an excellent local donkey breed in Xinjiang. It is of great significance to accelerate breeding and the speed of breeding and rejuvenation, as well as to understand the genetic basis of the strategies and population. This study collected a total of 4 male donkeys and 28 female donkeys. It then obtained genotype data through Simplified Genomic Sequencing (GBS) technology for data analysis. The results detected a total of 55,399 SNP loci, and the genotype detection rate of individuals was ≥90%. A total of 45,557 SNP loci were identified through quality control, of which 95.5% were polymorphic. The average minimum allele frequency was 0.250. The average observed heterozygosity was 0.347. The average expected heterozygosity was 0.340. The average IBS (state homologous) genetic distance was 0.268. ROH: 49 (homozygous fragments), with 73.47% of the length between 1 and 5 Mb. The average per-strip ROH length was 1.75 Mb. The mean inbreeding coefficient was 0.003. The 32 Hetian green donkeys could be divided into six families. The number of individuals in each family is significant. To sum up, the Hetian Qing donkey population has low heterozygosity, few families, and large differences in the number of individuals in each family, which can easily cause a loss of genetic diversity. In the subsequent process of seed protection, seed selection should be conducted according to the divided pedigree to ensure the long-term protection of the genetic resources of Hetian green donkeys.

Limited herbivore migration during the Last Glacial Period of Kenya.

Eastern Africa is home to the largest terrestrial migrations on Earth. Though these migratory systems have been well studied for decades, little is known of their antiquity and evolutionary history. Serially sampled strontium stable isotopes (87Sr/86Sr) from tooth enamel can be used to track migration in mammals. Here we analyse 87Sr/86Sr for 79 bovid and equid individuals representing 18 species from four localities in Kenya to characterize prehistoric migratory systems during the Last Glacial Period (115-11.7 ka). Of the species analysed, 16 lack definitive evidence for migration, including blue wildebeest (Connochaetes taurinus), Thomson's gazelle (Eudorcas thomsonii) and plains zebra (Equus quagga), which are long-distance migrants today in the Greater Serengeti Ecosystem and historically in the Athi-Kapiti Plains. Only two species, the extinct wildebeests Rusingoryx atopocranion and Megalotragus sp., were migratory. These findings suggest a possible alternative narrative about ecosystem dynamics during the Last Glacial Period and shed light on the behaviour of both extant and extinct species at this time. In particular, these results indicate that migratory behaviour in extant species either emerged during the Holocene or was more spatiotemporally constrained in the past. Our results contribute to a growing body of evidence suggesting that the structure and function of geologically recent large mammal communities in eastern Africa differed considerably from those observed in the present day.

Double-Tube Multiplex TaqMan Real-Time PCR for the Detection of Eight Animal-Derived Dairy Ingredients.

Milk and dairy products represent important sources of nutrition in our daily lives. The identification of species within dairy products holds importance for monitoring food adulteration and ensuring traceability. This study presented a method that integrated double-tube and duplex real-time polymerase chain reaction (PCR) with multiplex TaqMan probes to enable the high-throughput detection of animal-derived ingredients in milk and dairy products. The detection system utilized one pair of universal primers, two pairs of specific primers, and eight animal-derived specific probes for cow, buffalo, goat, sheep, camel, yak, horse, and donkey. These components were optimized within a double-tube and four-probe PCR multiplex system. The developed double-tube detection system could simultaneously identify the above eight targets with a detection limit of 10-0.1 pg/µL. Validation using simulated adulterated milk samples demonstrated a detection limit of 0.1%. The primary advantage of this method lies in the simplification of the multiplex quantitative real-time PCR (qPCR) system through the use of universal primers. This method provides an efficient approach for detecting ingredients in dairy products, providing powerful technical support for market supervision.

Impact of pH modification of the empirically used tobramycin ophthalmic solution on MIC90 concentration in tears and aqueous humor of donkeys (Equus asinus).

BACKGROUND: Commercial tobramycin ophthalmic solution is frequently used empirically to treat ocular disorders in equines, despite being primarily formulated for use in humans. It has been noted that tobramycin MIC90 concentration (minimal inhibitory concentration to 90% of microbial growth) rapidly declined following topical administration. It is hypothesized that adjustment of the pH of the empirically used tobramycin ophthalmic solution -prepared for human use- with the pH of the tears of donkeys, could increase the bioavailability of the drug and subsequently improve its penetration to the aqueous humor. Therefore, this study aimed to evaluate the impact of pH adjustment of the empirically used tobramycin ophthalmic solution on MIC90 concentration in tears and aqueous humor of donkeys (Equus asinus). The study was conducted on six (n = 6) clinically healthy donkeys. In each donkey, one eye was randomly selected to receive 210 µg tobramycin of the commercial tobramycin (CT) and used as a positive control (C group, n = 6). The other eye (treated eye) received 210 µg of the modified tobramycin ophthalmic solution (MT) (T group, n = 6). Tears and aqueous humor samples were collected 5-, 10-, 15-, 30- min, and 1-, 2-, 4-, and 6 h post-instillation. RESULTS: Modifying the pH of the empirically used commercial tobramycin ophthalmic solution in donkeys at a pH of 8.26 enhanced the drug's bioavailability. The MIC90 of the most hazardous bacteria isolated from equines' eyes such as Pseudomonas aeruginosa (MIC90 = 128 µg/ml) and Staphylococcus aureus (MIC90 = 256 µg/ml) was covered early (5 min post-instillation) and over a longer period in donkey tears (239-342 min) and aqueous humor (238-330 min) with the modified tobramycin solution. CONCLUSIONS: Adjustment of the pH of the commercial tobramycin ophthalmic solution, empirically used by veterinarians to treat donkeys' ophthalmic infections at a pH of 8.26, isotonic with the donkeys' tears pH, resulting in higher concentrations of tobramycin in tears and aqueous humor for a longer time.

De novo transcriptome assembly database for 100 tissues from each of seven species of domestic herbivore.

Domesticated herbivores are an important agricultural resource that play a critical role in global food security, particularly as they can adapt to varied environments, including marginal lands. An understanding of the molecular basis of their biology would contribute to better management and sustainable production. Thus, we conducted transcriptome sequencing of 100 to 105 tissues from two females of each of seven species of herbivore (cattle, sheep, goats, sika deer, horses, donkeys, and rabbits) including two breeds of sheep. The quality of raw and trimmed reads was assessed in terms of base quality, GC content, duplication sequence rate, overrepresented k-mers, and quality score distribution with FastQC. The high-quality filtered RNA-seq raw reads were deposited in a public database which provides approximately 54 billion high-quality paired-end sequencing reads in total, with an average mapping rate of ~93.92%. Transcriptome databases represent valuable resources that can be used to study patterns of gene expression, and pathways that are related to key biological processes, including important economic traits in herbivores.

Dynamic alterations of flavor, functional nutrients, and microbial community during fermentation of different animal milk kefirs.

Kefir is a traditional dairy beverage, usually made from cow or goat milk fermented with kefir grains, and has many health benefits. To elucidate the fermentation patterns of animal milk kefirs during the fermentation process and find the optimal milk types, cow, camel, goat, and donkey milk were fermented with kefir grains for 0, 1, 3, 5, and 7 days. Volatile and non-volatile metabolites and microbial changes were dynamically monitored. The results showed that volatile flavor substances were massively elevated in four kefirs on days 1-3. Lipids and carbohydrates gradually decreased, while amino acids, small peptides, and tryptophan derivatives accumulated during fermentation in four kefirs. Besides, four kefirs had similar alterations in Lactobacillus and Acetobacter, while some distinctions existed in low-abundance bacteria. Association analysis of microorganisms and volatile and non-volatile metabolites also revealed the underlying fermentation mechanism. This study found that appropriately extending the fermentation time contributed to the accumulation of some functional nutrients. Furthermore, goat and donkey milk could be the better matrices for kefir fermentation.

Ultrasonography of the normal donkey tarsus (equus asinus).

Tarsal joint illness is a frequent source of hind limb lameness due to the complex anatomy of the region and the presence of numerous bony and soft tissue structures. Proper lameness diagnosis aims to discover the structure provoking lameness. Ultrasonography documents valuable information of soft tissues and characterizes soft tissue injuries that have heretofore been difficult to obtain either noninvasively or via radiography. The objectives of the current study were to develop and describe a standardized ultrasonographic protocol for investigation of the tarsal region in donkeys. The donkey tarsal anatomy was investigated in 5 cadavers and the tarsi of 11 healthy lameness free adult donkeys were echographically investigated. The dorsal, plantar, lateral and medial aspects of the tarsal region were substantially evaluated at four anatomical landmarks in both the longitudinal and horizontal planes using a multi-frequency 5-12 MHz linear transducer. Sonoanatomy of the extensor and flexor tarsal tendons, collateral and plantar ligaments, and synovial pouches was delineated and described. Systematic echography of the tarsal region allowed accurate localization and thorough exploration of various soft tissues of clinical interest in the donkey tarsus. Sonograms provided in this study should serve as a reference database for tarsal ultrasonography in clinical circumstances.

Pharmacokinetics and tissue residues of albendazole sulphoxide and its metabolites in donkey after intramuscular injection.

BACKGROUND: Various anti-parasitic drugs are used to control donkey parasitic diseases. The abuse of donkey drugs leads to the disposition of residues in the edible parts of treated donkeys. OBJECTIVES: The aim of this study was to (1) analyse the pharmacokinetics of ABZSO to serve as reference for the dosage regimen in donkey; and (2) calculate the withdrawal times of the ABZSO in the tissue of the donkey. METHODS: The concentrations of ABZSO and its metabolites in plasma and tissues were determined using high-performance liquid chromatography with an ultraviolet detector. Pharmacokinetic analysis was performed by the programme 3p97. RESULTS: The plasma concentrations of ABZSO and ABZSO2 concentration-time data in donkey conformed to the absorption one-compartment open model. The t 1 / 2 k e ${{{t1}} \!\mathord{/ {\vphantom { {2{{k}_{\mathrm{e}}}}}}}}$ of ABZSO was 0.67 h, whereas the t1/2 k e was 12.93 h; the Cmax and the Tp were calculated as 0.58 µg mL-1 and 3.01 h. The Vd/F of ABZSO was estimated to be 10.92 L kg-1; the area under the curve (AUC) was 12.81 µg mL-1 h. The Cmax and AUC values of ABZSO were higher than those of ABZSO2; however, t1/2 K e and Vd/F were lower. Other pharmacokinetics parameters were similar between the two metabolites. CONCLUSIONS: The results revealed that ABZSO2 was the main metabolite of ABZSO in donkey plasma. The concentrations of ABZSO and its chief metabolite (ABZSO2) were detected in liver, kidney, skin and muscle; however, ABZ-SO2NH2 was only detected in liver and kidney. The results also revealed that the depletion of ABZSO and its metabolite in donkey was longer, especially in skin.

Determinants of microbiome composition: Insights from free-ranging hybrid zebras (Equus quagga × grevyi).

The composition of mammalian gut microbiomes is highly conserved within species, yet the mechanisms by which microbiome composition is transmitted and maintained within lineages of wild animals remain unclear. Mutually compatible hypotheses exist, including that microbiome fidelity results from inherited dietary habits, shared environmental exposure, morphophysiological filtering and/or maternal effects. Interspecific hybrids are a promising system in which to interrogate the determinants of microbiome composition because hybrids can decouple traits and processes that are otherwise co-inherited in their parent species. We used a population of free-living hybrid zebras (Equus quagga × grevyi) in Kenya to evaluate the roles of these four mechanisms in regulating microbiome composition. We analysed faecal DNA for both the trnL-P6 and the 16S rRNA V4 region to characterize the diets and microbiomes of the hybrid zebra and of their parent species, plains zebra (E. quagga) and Grevy's zebra (E. grevyi). We found that both diet and microbiome composition clustered by species, and that hybrid diets and microbiomes were largely nested within those of the maternal species, plains zebra. Hybrid microbiomes were less variable than those of either parent species where they co-occurred. Diet and microbiome composition were strongly correlated, although the strength of this correlation varied between species. These patterns are most consistent with the maternal-effects hypothesis, somewhat consistent with the diet hypothesis, and largely inconsistent with the environmental-sourcing and morphophysiological-filtering hypotheses. Maternal transmittance likely operates in conjunction with inherited feeding habits to conserve microbiome composition within species.

Comparison of different cryoprotectants for freezing donkey (Equus asinus) semen.

The aim of this study was to evaluate two cryoprotectants, dimethylformamide (DMF) and methylformamide (MF) in two concentrations (5 and 7 %) in vitro in donkey semen using a rapid freezing technique and the effect on pregnancy rates in mares. Twenty-four ejaculates from 8 jacks (n = 8; r = 3) were divided into 4 extenders: BotuSemen Gold with 5 % or 7 % MF and 5 % or 7 % DMF, all containing 11 % lactose, 20 % egg-yolk and 0.5 % Equex. Post-thaw evaluations included: sperm motility, membrane function and acrosome status. A linear mixed effect model was used to test the effect of different freezing media on semen parameters. No differences were observed between the 4 freezing media used, for any of the seminal parameters (P > 0.05). However, samples with 5 % DMF showed the highest percentages of sperm with acrosomes and functional membranes (DMF: 5 %: 53.67 ± 22.01; 7 %: 33.92 ± 23.4; MF: 5 %: 44.5 ± 20.46; 7 %: 38.75 ± 27.4) (Data: mean ± SD; P > 0.05). Hence, thirty mares were inseminated: 15 with 5 % DMF and 15 with 7 % DMF. The pregnancy rate was 46 % (7/15) and 0 % (0/15) using the extender with 5 % or 7 % DMF, respectively (P = 0.003). To conclude, the use of 5 % or 7 % of MF or DMF did not affect the in vitro parameters. Despite the lack of differences in vitro with the two DMF concentrations, in vivo results only showed pregnancies when using 5 % DMF. Thus, the results of this study demonstrate the importance of accompanying in vitro semen evaluations with studies that evaluate post-insemination pregnancy rates.

Characterization of lipids and volatile compounds in boiled donkey meat by lipidomics and volatilomics.

Lipids are crucial substances for the formation and retention of volatile compounds (VOCs). The lipid and VOC profiles of boiled donkey meat were investigated by lipidomics and volatilomics. In total, 4277 lipids belonging to 39 subclasses were identified, comprising 26.93% triglycerides (TGs), 15.74% phosphatidylcholins (PCs), and 9.40% phosphatidylethanolamines. The relative percentage of TG in the meat significantly decreases (p < 0.001) from 0 to 40 min, after which there is no significant change, whereas PCs, sphingomyelins, and methyl phosphatidylcholines (MePCs) show the opposite trend. TG(16:1_18:1_18:2) and TG(16:0_16:1_18:2) appear to be key lipids for retaining VOCs in boiled donkey meat. Furthermore, PC(18:3e_16:0) and MePC(31:0e) were found to be potential markers for discriminating donkey meat. A total of 83 VOCs were detected, including 25.30% aldehydes, 18.07% hydrocarbons, 14.46% ketones, and 13.25% alcohols. Eleven characteristic VOCs with relative odor activity values >1 were identified as the predominant flavor compounds in boiled donkey meat, mainly hexanal and 1-octen-3-ol. Of the 258 differential lipids, 72 of them, especially polyunsaturated-fatty acid-rich lipids, are the main contributors to the formation of VOCs. Together, the key lipids for retention and formation of VOCs in donkey meat were revealed, providing a theoretical basis for VOC regulation.

The behavior and welfare of neglected species: some examples from fish and mammals.

Animal welfare is the state of an animal's body and mind and the level to which its requirements are satisfied. Animal welfare is affected by human decisions and actions. Numerous decisions concerning animals are driven by human desires to enhance their own lives, and some of these decisions may be influenced by self-interest or a strong emphasis on economic factors. How to assess the welfare state of animals is a central issue in animal welfare science. Two critical questions can be used to address animal welfare: first, is the animal healthy, and second, does the animal have what it needs? Both of these questions can potentially be answered using the study of animal behavior. The development of behavioral methodologies is crucial for evaluating welfare in contexts where concern for animal welfare is often highest, such as on intensive modern farms and sites where working animals are used. Herein, we discuss animal welfare by focusing on some of its major concepts and explanations. Later, to illustrate key aspects of animal welfare, we chose to examine the information that is available for some 'neglected' livestock species, which are commercially important on a global basis and found in large numbers: buffaloes (Bubalus bubalis), camels (Camelus dromedarius), donkeys (Equus asinus), mules (Equus asinus × Equus caballus), and lumpfish (Cyclopterus lumpus). We chose these species because there are major ongoing concerns about their welfare, and more research is required to help solve the various problems. Overall, there are strong imbalances in terms of the species that are usually studied in terms of animal welfare research, and we call for greater attention to those that have traditionally been neglected.

The interaction between seminal plasma, sperm, and endometrium in inter- and intra-species breeding in equids.

In brief: In some instances, extra-species breeding in equids is more successful than intraspecies breeding; however, little is known about the immunomodulatory effect of donkey semen and seminal plasma on the mare's endometrium. This study compared the mare uterine inflammatory response during extra- and intraspecies breeding. Abstract: Anecdotal experience suggests horse mares have less post-breeding inflammation and better fertility when bred with donkeys. This study aimed to compare the post-breeding inflammatory response of mares exposed to donkey and horse semen and seminal plasma and evaluate the proteome and metabolome of donkey and horse sperm and seminal plasma. Uterine edema, intrauterine fluid accumulation, polymorphonuclear neutrophils on cytology, and concentrations of progesterone, and pro- and anti-inflammatory cytokines (IL1A, IL1B, IL4, IL6, CXCL8, IL10) were assessed pre- and post infusion of semen and seminal plasma (donkey and horse). The metabolome and proteome were analyzed by LC-MS/MS. Mare cycles bred with horse semen had a greater progesterone concentration than those bred with donkey semen at 8 days post ovulation (P = 0.046). At 6 h post infusion, the inflammatory response due to the donkey semen tended to be lower (P = 0.074). Donkey seminal plasma had anti-inflammatory properties compared to horse semen and seminal plasma, as determined by fewer neutrophils on uterine cytology (P < 0.05). Horse semen resulted in greater concentrations of IL6 and lesser concentrations of IL1B (P < 0.05). PGE1, PGE3, and lactoferrin concentrations were significantly more abundant in donkey sperm and seminal plasma. Prostaglandins play an important role in immunomodulation and might contribute to the response triggered in interspecies breeding. In conclusion, breeding horse mares with donkey semen induces similar post-breeding endometritis as observed with horse semen. Donkey seminal plasma results in a lower post-infusion inflammatory response compared to other combinations in the immediate post-breeding.