IntroductionOxidative stress, resulting from environmental changes, significantly affects female fertility. Developing a mouse model to study oxidative stress lays the groundwork for research into human reproductive health and livestock fertility.Materials and methodsIn this study, we established and evaluated an oxidative stress model by administering hydrogen peroxide (H2O2) to mice. ICR mice of similar age (7–8 weeks old) and average body weight (31.58 ± 1.12 g) were randomly assigned to four groups (A, B, C, and D). Group A served as the control and was injected with a saline solution, while groups B, C, and D received saline solutions containing 0.75%, 1.50%, and 3.0% H2O2, respectively, over one week. We measured the body weights of all mice before and after the experimental period.Results and discussionOur findings showed that the average body weight of mice in groups A and B increased, while groups C and D experienced weight loss. Group C showed a significantly lower average weight gain compared to groups A and B, and group D exhibited an even more pronounced reduction in weight gain. Although group D had a high mortality rate, there was no significant difference in mortality rates among groups B, C, and D. Serum malondialdehyde (MDA) content increased with higher concentrations of H2O2, with a significant difference noted between groups C and A. Catalase (CAT) activity in group B was significantly higher than in group A, while superoxide dismutase (SOD) activity in group C was notably elevated compared to groups A and B. Conversely, glutathione peroxidase (GSH-Px) activity in group C was significantly lower than in both group A and group B. Hematoxylin and eosin (HE) staining revealed changes in ovarian morphology and follicle dynamics. The percentage of atretic follicles in group C was significantly higher than in the control group, and group D had a significantly lower total number of healthy follicles compared to the untreated group. Increased H2O2 content resulted in a reduction of ovary size and an irregular appearance in group D.ConclusionBased on our findings, treatment with 1.50% H2O2 effectively established an oxidative stress model in mice within 1 week. This model serves as a valuable reference for future clinical studies on oxidative stress and reproductive disorders in female animals and humans.

IntroductionThe number of the large-scale donkey breeding farms in China has increased dramatically. However, information regarding the situation of a Chinese donkey population under large-scale donkey breeding farms is limited. MethodsThis survey report was conducted using questionnaires online to investigate the current situation of the donkey original breeding farms in China, in terms of donkey stock, local breeds, reproductive parameters, growth and lactation performance, and future perspectives. China has developed the donkey reserve system based on national, provincial and non-governmental (self-own) donkey original breeding farms. ResultsIn the present study, a total of 38 donkey original breeding farms concentrated in Northern of China were studied, and 52% of them keep their donkeys with a stocking density of 100-500 donkeys. China is rich in various local donkey breeds, and 16 local donkey breeds including large-sized, medium-sized and small-sized breeds were collected in our survey. Dezhou donkey are prevalent with a percentage of more than 57% of the total donkeys, while the Cullen donkeys belong to small-sized donkey breeds are scare. The reproductive efficiency and donkey productivity were different across donkey farms, indicating potential differences in management and breeding practices between different donkey original breeding farms. The artificial insemination has been performed in these donkey farms with an average proportion of 73%. Regarding the donkey productivity, the national and provincial donkey original breeding farms showed a higher birthweight and fat content in donkey milk than self-own farms. Furthermore, our results indicate that the donkey breeds with different body size also have important influence on the reproduction parameters and donkey productivity, with the large-sized donkeys had better performance compared to the small-sized donkeys. DiscussionIn summary, our survey provided valuable baseline information on the situation of donkey population dynamics in the donkey original breeding farms. However, further study is required in the future to investigate the factors such as donkey health care, management and nutrition during breeding, fattening and lactation that influence donkey productivity under large-scale farm systems.

IntroductionThe Dezhou donkey, a prominent Chinese breed, is known for its remarkable size, rapid growth, and resilience to tough feeding conditions, and disease resistance. These traits are crucial in meeting the growing demand for Ejiao and donkey meat. Yeast polysaccharide (YPS), a functional polysaccharide complex known for its immune-enhancing and growth-promoting properties in livestock and poultry, remains relatively understudied in donkeys.ObjectivesThis study aimed to investigate the impact of YPS supplementation on lactating and growing Dezhou donkey jennies and foals.Materials and methodsTwelve 45-day-old Dezhou donkey foals and their jennies, matched for body weight and age, were randomly allocated to two dietary groups: a control group receiving a basal diet and an experimental group receiving the basal diet supplemented with 10 g/pen of YPS. The experiment was conducted over a 23-day period, during which donkey foals and lactating jennies were co-housed.Results and discussionThe findings revealed that YPS supplementation had no adverse effects on milk production or composition in Dezhou donkey jennies but significantly increased feed intake. Additionally, YPS was associated with increased plasma glucose and creatinine concentrations in foals, while tending to decrease alkaline phosphatase, white blood cell count, red blood cell count, and hemoglobin levels (p < 0.10). Immune indices demonstrated that YPS supplementation elevated the levels of immunoglobulin A (IgA) and immunoglobulin G (IgG) in jennies (p < 0.05) and increased complement component C4 concentrations in foals (p < 0.05). Moreover, YPS positively influenced the fecal microbiome, promoting the abundance of beneficial microorganisms such as Lactobacillus and Prevotella in donkey foals and Terriporobacter and Cellulosilyticum in jennies, all of which contribute to enhanced feed digestion. Additionally, YPS induced alterations in the plasma metabolome for both jennies and foals, with a predominant presence of lipids and lipid-like molecules. Notably, YPS increased the concentrations of specific lipid metabolites, including 13,14-Dihydro PGF2a, 2-Isopropylmalic acid, 2,3-Dinor-TXB2, Triterpenoids, Taurocholic acid, and 3b-Allotetrahydrocortisol, all of which are associated with improved animal growth.ConclusionIn conclusion, this study suggests that dietary supplementation of YPS enhances feed intake, boosts immunity by increasing immunoglobulin levels, stimulates the growth-promoting gut microbiota (Lactobacillus and Prevotella), and exerts no adverse effects on the metabolism of both Dezhou donkey jennies and foals.

为了解规模化饲养条件下驴的繁殖性能,以山东地区规模化养驴场为调研对象,采用调查问卷与实地调研相结合的方法调查分析13家规模化养殖场德州驴的繁殖率,对比分析自繁自养模式与专业繁育模式的能繁母驴繁殖率差异.选取自然交配繁殖记录齐全的山东省德州市某规模化驴场,通过分析繁殖记录获取德州驴(三粉驴和乌头驴)的初配日龄、初次产驹天数、妊娠天数及空怀间隔等繁殖性能指标.结果显示:自繁自养模式驴场的母驴繁殖率多为30％～50％,专业繁育模式的能繁母驴繁殖率显著高于自繁自养模式(P＜0.05).对繁殖记录进行统计分析发现,三粉驴的初配日龄、初次产驹天数、妊娠天数和空怀间隔均小于乌头驴,其中空怀间隔差异最明显,最高相差48 d;三粉驴的平均妊娠天数为(362.3±0.3)d,且随着胎次的增加呈现逐渐增加的趋势.结果表明,山东地区规模化驴养殖场的德州驴繁殖率较低,空怀间隔较长,导致母驴的繁殖周期较长,繁殖性能整体表现较低.

Background Previous studies have shown that the protein kinase cGMP-dependent 2 (PRKG2) gene is associated with dwarfism in humans, dogo Argentines, and Angus cattle, as well as with height and osteoblastogenesis in humans. Therefore, the PRKG2 gene was used as the target gene to explore whether this gene is associated with several thoracolumbar vertebrae and carcass traits in Dezhou donkeys.Results In this study, fifteen SNPs were identified by targeted sequencing, all of which were located in introns of the PRKG2 gene. Association analysis illustrated that the g.162153251 G > A, g.162156524 C > T, g.162158453 C > T and, g.162163775 T > G were significantly different from carcass weight. g.162166224 G > A, g.162166654 T > A, g.162167165 C > A, g.162167314 A > C and, g.162172653 G > C were significantly associated with the number of thoracic vertebrae. g.162140112 A > G was significantly associated with the number and the length of lumbar vertebrae, and g.162163775 T > G was significantly associated with the total number of thoracolumbar vertebrae.Conclusion Overall, the results of this study suggest that PRKG2 gene polymorphism can be used as a molecular marker to breed high-quality Dezhou donkeys.

Grape seed proanthocyanidin (GSP) contains polyphenolic bioflavonoids ubiquitously found in the lignified portions of grape seeds from the winery and distillery industries, as an antioxidant. To explore its potential as a rumen modifier in methanogenesis inhibition, a 2 × 5 factorial experiment was conducted to determine the effect of GSP at 0, 15, 30, 60 and 120 mg/g of substrate on the rumen fermentation and methanogenesis of two representative total mixed rations (HY, a diet for high-yield (>2 kg/d) lactating cows, and LY, a diet for low-yield (<25 kg/d) lactating cows). By using the MIXED procedure, after a 48 h in vitro rumen incubation, increasing the GSP addition linearly decreased the in vitro dry matter digestion (IVDMD) and slowed down the rates of ration fermentation (RmaxS, g/h) and kinetic gas production (RmaxG, mL/h), with the decreases being more pronounced in the LY than HY group (p < 0.05). The GSP addition decreased hydrogen recovery (2Hrec) and altered the fermentation gas composition. The molar CH4 proportion was significantly reduced with both 60 and 120 mg GSP addition (p < 0.01). The total volatile fatty acid production was linearly decreased with the increasing GSP addition (p < 0.01). In addition, the GSP addition significantly decreased the ratio of methanogens to total bacteria (p < 0.05), and the reduction was notably greater in the HY than in the LY substrate (45.3% vs. 15.2% decrease), although the diversity of rumen methanogenic archaea was not affected in either the HY or the LY group. Bioinformatic analysis illustrated that the rumen archaeal community was predominated by a Methanobrevibacter genus (>72.5%), followed by Methanomassiliicoccus (>20.9%) and Methanosphaera (>1.0%). Methanobrevibacter could play an important role in methanogenesis in the presence of GSP, though it is usually considered to be the main hydrogenotrophic methanogen. In brief, the GSP addition presented high potential as a rumen modifier to mitigate methanogenesis by decreasing the ratio of methanogens to total bacteria. Methanobrevibacter could play an important role in methanogenesis in the presence of GSP. However, a relatively low administration level of GSP should be taken into consideration in order to obtain its inhibitory effect on CH4 emission, with a minimal negative effect on rumen digestion and fermentation.

Dezhou donkey is one of the excellent large donkey breeds in China. In our study, eight microsatellite markers were used to genotype from each of three populations of Chinese Dezhou donkeys: 67 individuals in Liaocheng (pop1), 103 individuals in Binzhou 1 (pop2), and 102 individuals in Binzhou 2 (pop3), in order to study the genetic diversity of these populations. A total of 213 alleles were detected, and the PIC results showed that eight loci were all highly polymorphic. The means of Ho and He of pop2 were the highest, which were 0.646 and 0.717, respectively. The PCoA analysis demonstrated that the samples from three conservation farms were mixed together. The phylogenetic tree showed that pop 2 and pop 3 were closely related. The phylogenetic tree results clustered that 272 donkeys were divided into six groups. AMOVA analysis showed that the genetic variation was mainly concentrated within the population and the genetic differentiation among the populations was low. Fst values between populations also indicated that genetic differentiation between populations was too small to be considered. This indicated a low probability of inbreeding within the population. And this also showed that the conservation and breeding of Dezhou donkeys in recent years have achieved excellent results. The investigation of genetic diversity in three Dezhou donkey original breeding farms can provide reference data for the selection and breeding of excellent breeds of Dezhou donkey.

IntroductionA better understanding of the microbiota community in donkey foals during the weaning transition is a prerequisite to optimize gut function and improve feed efficiency. The objective of the present study was to investigate the dynamic changes in fecal microbiota in donkey foals from pre-to post-weaning period.MethodsA total of 27 fecal samples of donkey foals were collected in the rectum before morning feeding at pre-weaning (30 days of age, PreW group, n = 9), dur-weaning (100 days of age, DurW group, n = 9) and post-weaning (170 days of age, PostW group, n = 9) period. The 16S rRNA amplicon sequencing were employed to indicate the microbial changes during the weaning period.ResultsIn the present study, the cessation of breastfeeding gradually and weaning onto plant-based feeds increased the microbial diversity and richness, with a higher Shannon, Ace, Chao and Sobs index in DurW and PostW than in PreW (p < 0.05). The predominant bacterial phyla in donkey foal feces were Firmicutes (>50.5%) and Bacteroidota (>29.5%), and the predominant anaerobic fungi and archaea were Neocallimastigomycota and Euryarchaeota. The cellulolytic related bacteria including phylum Firmicutes, Spirochaetota and Fibrobacterota and genus norank_f_F082, Treponema, NK4A214_group, Lachnospiraceae_AC2044_group and Streptococcus were increased from pre-to post-weaning donkey foals (p < 0.05). Meanwhile, the functions related to the fatty acid biosynthesis, carbohydrate metabolism and amino acid biosynthesis were significantly enriched in the fecal microbiome in the DurW and PostW donkeys. Furthermore, the present study provided the first direct evidence that the initial colonization and establishment of anaerobic fungi and archaea in donkey foals began prior to weaning. The relative abundance of Orpinomyces were the highest in DurW donkey foals among the three groups (p < 0.01). In terms of archaea, the abundance of Methanobrevibacter were higher in PreW than in DurW and PostW (p < 0.01), but the abundance of Methanocorpusculum were significantly increased in DurW and PostW compared to PreW donkey foals (p < 0.01).DiscussionAltogether, the current study contributes to a comprehensive understanding of the development of the microbiota community in donkey foals from pre-to post-weaning period, which may eventually result in an improvement of the digestion and feed efficiency in donkeys.

随着现代农业的发展,驴的传统役用功能大大降低,逐渐向产皮、产肉、产奶以及休闲娱乐方向转变,驴产品的消费需求也不断扩大.然而,在自然本交条件下,由于驴的妊娠期长、发情持续时间长、受孕率低和产驹率低,驴的繁殖效率表现不高,驴存栏量不断下降.近年来,随着驴的规模化养殖逐渐兴起,驴精液的冷冻保存、人工授精和胚胎移植等高效繁殖技术也逐步应用于驴的生产实践.深入开展驴的繁殖生理特征及繁殖生物学技术的应用研究,对于提高驴的繁殖效率、实现驴的快速扩繁以及遗传改良具有重要意义.本文重点综述了相关驴繁殖生理特征与驴繁殖生物学技术应用的研究进展,为有效提高驴的繁殖效率及研究应用提供参考.

Donkey hindgut is an enlarged fermentative chamber that harbors a highly complex and extremely abundant community of anaerobic bacteria. It can be divided into two different ecological sites: liquid (Lq) phase and adherent fraction (Ad) colonized by bacteria. However, the Ad bacteria have not previously been specifically collected or directly compared with the Lq bacteria. In the present study, the digesta collected from the caecum, ventral colon and dorsal colon of nine Dezhou donkeys was separated into Lq and Ad fractions. The bacterial community structure was comparatively determined using 16S rRNA gene sequences by Illumina MiSeq. The Ad bacteria had a higher bacterial diversity than Lq bacteria due to the higher Chao and ACE index (p < 0.05). The predominant bacteria at the phylum level were Firmicutes (55.4~74.3%) and Bacteroidota (13.7~32.2%) for both the Lq and Ad fraction. The relative abundance of Bacteroidota, Spirochaetota, Fibrobacterota and Patescibacteria in the Ad fraction was greater than Lq (p < 0.05), suggesting that bacteria associated with feed particles were mainly responsible for plant fiber degradation. At the genus level, the abundance of Lactobacillus in Lq was greater than that in the Ad fraction (p < 0.05), indicating that the bacteria in the Lq fraction were better at hydrolyzing readily fermentable carbohydrates. PICRUSt showed that the activities of enzymes related to fiber degradation in the Ad fraction were also greater than Lq. In addition, the hindgut region also had a significant effect on the bacterial community composition. The relative abundance of Rikenellaceae_RC9_gut_group, Clostridium_sensu_stricto_1, Christensenellaceae_R-7_group and norank_Bacteroidales_BS11_gut_group was increased (p < 0.05) along the donkey hindgut. In summary, the present study provides evidence that bacteria adherent to plant biomass were different to those in the liquid phase within the donkey caeco-colic digesta, and bacteria associated with feed particles may mainly be responsible for plant fiber degradation.

异位酸主要指异丁酸、异戊酸、2-甲基丁酸和戊酸,属于短链挥发性脂肪酸.异位酸对于反刍动物瘤胃内的纤维降解菌具有促进作用,能够提高饲料纤维的降解消化率;异位酸还可以促进瘤胃内支链氨基酸的生物合成,进而提高微生物蛋白的合成;而且异位酸能够抑制脲酶,增加瘤胃内非蛋白氮的利用和机体内氮的留存,提高动物的增重性能;此外,异位酸还可以促进瘤胃内乙酸的生成,进而提高反刍动物的产奶量及乳脂率.本文旨在阐述异位酸对反刍动物瘤胃消化代谢及其对产奶量、动物增重等生产性能的影响,以期为异位酸在反刍动物生产实践中的合理利用提供科学理论依据.

农业农村部2021—2035全国畜禽遗传改良计划指出:畜禽种业是畜牧业发展的根基,是畜牧业核心竞争力的重要体现.在"三品一标"行动方案中,品种培优居于首位.山东省是驴产业发展强省,全国90％的阿胶产自山东,具有阿胶、驴肉、驴奶、化妆品和保健品等完整的产业链条.德州驴是我国五大大型驴品种之一,随着政府支持力度的加强,德州驴的养殖逐渐向规模化、标准化和产业化方向发展,并且发挥了支持医养健康,特色文化振兴的良好作用.驴是单胎动物,生长周期和妊娠期长,而我国地方驴的品种数量和产业规模均位居世界首位,但国内外仍没有一个驴的培育品种出现.因此,加大驴的种质资源保护力度,尽快启动遗传改良工作具有重要意义.

硝基化合物是指化学结构中含有硝基(-NO2)官能团的化合物.黄芪、冠花、木兰属等牧草植物中含有的天然硝基化合物(3-硝基丙醇和3-硝基丙酸)以及化学工业合成的硝基化合物(硝基烷烃、硝基乙醇、3-硝基酯-1-丙醇等)均能够高效抑制瘤胃发酵甲烷的生成,而其自身能够被瘤胃微生物所代谢利用.本文重点围绕硝基化合物的分类及其脱毒机制方面的研究进展进行了综述.

本试验旨在比较分析德州驴盲结肠食糜液中纤维降解酶活性以及挥发性脂肪酸(VFA)的含量.采集9头德州驴的盲肠、腹结肠和背结肠食糜液样品,经4层纱布过滤后,通过分光光度计法测定羧甲基纤维素酶(CMCase)、微晶纤维素酶(AVI)、木聚糖纤维素酶(Xlyse)、阿魏酸酯酶(FAE)和乙酰酯酶(AE)活性,此外,使用气相色谱法测定VFA含量,每个指标3个平行.结果表明:CMCase、AVI与Xlyse活性在驴盲肠、腹结肠和背结肠食糜液中依次增加(P<0.05),而FAE活性在驴盲结肠间无显著差异(P>0.05).驴背结肠食糜液中AE活性显著高于盲肠与腹结肠(P<0.05).乙酸摩尔比例在驴盲肠、腹结肠和背结肠食糜液中依次显著增加(P<0.05),丙酸摩尔比例依次降低(P<0.05).而且驴结肠食糜液中支链VFA含量显著高于盲肠(P<0.05).综上所述,本研究明确了驴盲结肠食糜液具有较高的催化水解饲料细胞壁半纤维素与木质素分子间酯键连接的FAE和AE活性,随着驴后肠段逐渐后移,驴盲肠、腹结肠与背结肠食糜液中乙酸摩尔比例依次增加,丙酸摩尔比例依次降低.

Wulong geese are renowned for their egg-laying and reproductive abilities. This work investigated the potential of using body size traits in the selection and breeding of high-yielding Wulong geese. A total of forty 479 day-old female geese (high-yielding geese, n = 20; low-yielding geese, n = 20) were selected to evaluate the relationship between body weight, body size trait indicators, serum reproductive hormones, and biochemical indicators. The results showed that serum estradiol (E2), glucose (GLU), and triglyceride (TG) concentrations, together with pubic spacing and abdominal circumference were significantly higher in high-yielding geese (P < 0.01), whereas the opposite was true for neck circumference, neck length, and tibial circumference. In addition, the serum testosterone (T) concentration and body weight were higher in high-yielding geese (P < 0.05). Neck circumference and neck length were negatively correlated with E2 and TG (P < 0.01); while pubic spacing and abdominal circumference were positively correlated with E2, GLU, and TG (P < 0.01), the highest correlation coefficient was 0.777 between TG and pubic spacing; T was also strongly associated with neck circumference (P < 0.01). In conclusion, high-yielding Wulong geese can be selected through neck circumference, neck length, pubic spacing, and abdominal circumference.

The number of thoracolumbar vertebrae is a quantitative trait positively correlated with the economic traits of livestock. More thoracolumbar vertebrae individuals could genetically be used to improve the livestock population, as more thoracolumbar vertebrae means a longer carcass, which could bring more meat production. Nuclear receptor subfamily 6 group A member 1 (NR6A1) is considered a strong candidate gene for effecting the number of vertebrae in livestock. The purposes of this study are as follows: (a) Analyzing the effect of TLN variation on body size and carcass traits of Dezhou donkey; (b) Studying the distribution of seven single nucleotide variants (SNVs) in NR6A1 gene of Dezhou donkey; (c) Exploring the relationship between latent SNVs and TLN, the body size and carcass traits. We examined the thoracic and lumbar vertebrae number and seven SNVs in NR6A1 gene of 455 Dezhou donkeys, and analyzed the relationships between them. Five types of thoracolumbar combinations (T17L5 (individual with 17 thoracic and five lumbar vertebrae) 2.4%, T18L5 75.8%, T19L5 1.1%, T17L6 11.9%, and T18L6 8.8%) of Dezhou donkeys were detected in this study. For one thoracolumbar vertebra added, the body length of Dezhou donkey increases by 3 cm and the carcass weight increases by 6 kg. Seven SNVs (g.18093100G > T, g.18094587G > T, g.18106043G > T, g.18108764G > T, g.18110615T > G, g.18112000C > T and g.18114954T > G) of the NR6A1 gene were found to have a significant association with the TLN, body size and carcass traits of Dezhou donkey (p < 0.05), respectively. For instance, g.18114954C > T is significantly associated with lumber vertebrae number, the total number of thoracolumbar, and carcass weight, and individuals with TT genotype had significantly larger value than CC genotype (p < 0.05). Using these 7SNVs, 16 different haplotypes were estimated. Compared to Hap3Hap3, individuals homozygous for Hap2Hap2 showed significantly longer length in one thoracic spine (STL), the total thoracic vertebrae and one thoracolumbar spine. Our study will not only extend the understanding of genetic variation in the NR6A1 gene of Dezhou donkey, but also provide useful information for marker assisted selection in donkey breeding program.

In donkeys, the gestation period is a dynamic and precisely coordinated process involving systemic and local alterations. Both the gut microbiota and its link with blood metabolites are thought to play significant roles in maintaining maternal health and supporting fetal development during the gestation period. This study was conducted to evaluate gut microbiota changes and the correlation with plasma metabolites in Dezhou donkeys during the gestation period. The donkeys were divided into the four following groups according to their pregnancy stages: the non-pregnant (NP), early stage of pregnancy (P1), middle stage of pregnancy (P2), and late stage of pregnancy (P3) groups. A total of 24 (n = 6 per group) samples of donkey feces and plasma were collected. The results showed that the diversity (Shannon index) of fecal bacteria significantly increased throughout the gestation period. The phyla Spirochaetota and Fibrobacterota varied significantly according to the stages of pregnancy (p < 0.05). At the genus level, the abundance of Treponema in pregnant donkeys was greater than that in non-pregnant donkeys (p < 0.05), and the genus Streptococcus reached its maximum abundance in the P2 period (p < 0.05). The abundance of Ruminococcaceae_NK4A214_group and norank_f_norank_o_WCHB1-41 linearly increased with the progression of pregnancy (p < 0.05). In addition, the host plasma metabolome was altered significantly during the gestation period. Testolic acid, estradiol-17beta 3-sulfate, equol 7’-o-glucuronide, equol 4’-o-glucuronide, estrone, estrone 3-glucuronide, and estradiol were the most significant differential enriched metabolites, and they increased gradually as gestation progressed. The altered metabolites were mainly enriched in pathways matched to bile secretion, ABC transporters, amino acid metabolism, protein digestion and absorption, mineral absorption, fatty acid degradation, glycerophospholipid metabolism, and steroid hormone biosynthesis. We also found a significant correlation between the shifts in donkey fecal bacteria and changes in the host metabolism. In summary, this study provided systematic data on the fecal bacterial changes and host plasma metabolism of donkeys throughout pregnancy. The results indicated that host–bacteria interactions during the gestation period influence the host metabolism. These interactions benefit the pregnant donkeys by providing a sufficient supply of nutrients and energy for fetal growth and maternal health.

Equines and ruminants have evolved as grazing herbivores with specialized gastrointestinal tracts capable of utilizing a wide range of fibrous feeds. In China, agricultural by-products, including corn straw, wheat straw, peanut vine, wheat husk, rice husk, and grass hay, have been extensively included in both equine and ruminant diets. These plant materials, which are composed predominantly of cellulose, hemicellulose, noncellulosic polysaccharides, and lignin, are largely undegradable by equines and ruminants themselves. Their breakdown is accomplished by communities of resident microorganisms that live in symbiotic or mutualistic associations with the host. Information relating to microbial composition in the hindgut and rumen has become increasingly available. Rumen fermentation is unique in that plant cell wall breakdown relies on the cooperation between microorganisms that produce fibrolytic enzymes and that ruminant animals provide an anaerobic fermentation chamber. Similar to the rumen, the equine hindgut is also an immensely enlarged fermentative chamber that includes an extremely abundant and highly complex community of microorganisms. However, few studies have characterized the microbial functions and their utilization process of lignocellulosic feeds within the equine hindgut. The process of understanding and describing plant cell wall degradation mechanisms in the equine hindgut ecosystem is important for providing information for proper feeding practices to be implemented. In the present study, we gather existing information on the rumen and equine ecosystem and provide scientific insights for understanding the process of plant cell wall breakdown within the hindgut. (c) 2022 Elsevier Inc. All rights reserved.

Dezhou donkey, divided into Wutou and Sanfen strains, is one of the largest local breeds in China, famous for its tall and muscular body. Information regarding the growth and development indicators in Dezhou donkeys is limited. The present study explored the growth and development pattern of body weight (BW) and body mea-surements in the growing Dezhou breed donkey. The linear and non-linear models fitted the growth curve for Dezhou donkeys, and the stepwise regression equations for estimating BW were also developed. Both the birth weight and body height (BH) of Wutou were greater than Sanfen donkey (P < 0.05). With the age and BW increasing, the body measurements, including BH, body length (BL), thoracic girth (TG) and cannon bone girth (CG), increased accordingly. The Brody model was selected as the best model for fitting the growth curve with the highest R-2 (0.991) and lowest AIC (2418.7) and RMSE (5.12). The parameter 'k' of the Sanfen donkey was lower in comparison with the Wutou donkey, suggesting that Wutou achieved asymptotic weight earlier than the Sanfen donkey. The stepwise regression analysis was conducted to obtain the best prediction equations for BW of Dezhou donkeys from body measurements: 1.34 x TG + 0.59 x BH + 0.45 x BL + 2.45 x CG -170.3 (R-2 = 0.962, P < 0.01). In summary, the present study provided evidence that the growth rate of the Wutou donkey is faster than that of Sanfen, and both of them fitted the Brody growth curve from birth time to 18-month-old.

Due to its similarity with human milk, donkey milk is gaining interest as a nutritional milk source. The aim of current study was to compare the difference in the milk composition and metabolites of two Dezhou donkey strains (SanFen and WuTou). The results showed that fat, total solids, and solids-not fat of SanFen milk were higher than WuTou milk. Then we further identified the metabolites in the donkey milk by untargeted metabolomics using LC–MS, and showed that 49 significantly different metabolites between two milk samples were detected. 36 metabolites in the SanFen were significantly higher (p < 0.05), while 13 metabolites were significantly lower than the WuTou (p < 0.05). The results indicated that some different metabolites, such as l-glutamate, and l-glutamine, glucose, and choline, might be ascribed to the genetic differences of the two Dezhou donkey strains. The significantly different metabolites (SDM) were mainly enriched in arginine biosynthesis, d-glutamine and d-glutamate metabolism, alanine, aspartate and glutamate metabolism, and starch and sucrose metabolism. This is the first comparative study performed in SanFen and WuTou and indicates that stains differentially affect the milk composition and metabolites. Furthermore, the SDM and metabolic pathways at least partly explore the regulation mechanisms related to different milk quality and lactation traits between two donkey strains.