Absorption of short-chain fatty acids, sodium and water from the forestomach of camels

Distribution characteristics of gastric mucosal colonizing microorganisms in different glandular regions of Bactrian camels and their relationship with local mucosal immunity

Bactrian camels inhabiting desert and semi-desert regions of China are valuable animal models for studying adaptation to desert environments and heat stress. In this study, 16S rRNA technology was employed to investigate the distribution characteristics and differences of mucosal microorganisms in the anterior gland area, posterior gland area, third gland area, cardia gland area, gastric fundic gland area and pyloric gland area of 5-peak adult healthy Bactrian camels. We aimed to explore the possible reasons for the observed microbial distribution from the aspects of histological structure and mucosal immunity. Bacteroides and Fibrobacteria accounted for 59.54% and 3.22% in the gland area, respectively, and 52.37% and 1.49% in the wrinkled stomach gland area, respectively. The gland area showed higher abundance of Bacteroides and Fibrobacteria than the wrinkled stomach gland area. Additionally, the anterior gland area, posterior gland area, third gland area, and cardia gland area of Bactrian camels mainly secreted acidic mucus, while the gastric fundic gland area mainly secreted neutral mucus and the pyloric region mainly secreted a mixture of acidic and neutral mucus. The results of immunohistochemistry techniques demonstrated that the number of IgA+ cells in the anterior glandular area, posterior glandular area, third glandular area, and cardia gland area was significantly higher than that in the fundic and pyloric gland area (p < 0.05), and the difference in IgA+ between the fundic and pyloric gland area was not significant (p > 0.05). The study revealed a large number of bacteria that can digest and degrade cellulose on the mucosa of the gastric gland area of Bactrian camels. The distribution of IgA+ cells, the structure of the mucosal tissue in the glandular region, and the composition of the mucus secreted on its surface may have a crucial influence on microbial fixation and differential distribution.

Effects of wheat bran replacement with pomegranate seed pulp on rumen fermentation, gas production, methanogen and protozoa populations of camel and goat rumen using competitive PCR technique: An in vitro study

BACKGROUND

Microbial populations in the rumen play an essential role in the degradation of Cellulosic dietary components and in providing nutrients to the host animal.

OBJECTIVE

This study aims to detect the effect of pomegranate seed pulp (PSP) on rumen fermentation, digestibility and methanogens and the protozoa population (by competitive polymerase chain reaction [PCR]) of the camel and goat rumen fluid.

MATERIALS AND METHODS

PSP was added to the experimental treatments and replaced by wheat bran (0%, 5% and 10%). Rumen fluid was collected from three goats and two camels according to the similarity of sex, breed, origin and time and used for three gas production studies. DNA extraction was performed by the RBB + c method, the ImageJ programme calculated band intensities (target and competing DNA), and line gradients were plotted based on the number of copies and intensity.

RESULTS

Our result showed that diets did not significantly affect the methanogen and protozoa population. Animal species affected microbial populations so that both populations in camels were less than goats. The production of gas and volatile fatty acids was not affected by diets. These two parameters and NH3 concentration and methane production in goats were higher than in camel. The pH of digested dry matter and microbial protein in camels was higher than in goats.

CONCLUSIONS

Therefore, the competitive PCR technique is an effective method for enumerating rumen microbiota. This supplementation can be considered a strategy to achieve performance and environmental benefits.

Compartment 1 acidosis associated with hemorrhagic diathesis causing mortalities among racing camels in Oman

Camels are adapted to digestion of dry rough forages for their nutrition, and sudden change to highly digestible feed during the racing season causes digestive disorders. The current study investigated the cause of death among racing dromedary camels within 3-7 days following a sudden onset of fever ≈ 41 °C, colic with tarry feces, and enlarged superficial lymph nodes. Marked leukopenia, low RBC count and thrombocytopenia, deranged liver and renal function tests, and prolonged coagulation profiles were reported. Compartment 1 fluid revealed a pH of 4.3-5.2 with absence or few ciliated protozoa and Gram-positive microbial flora. Widespread petechial to ecchymotic hemorrhages were observed in various organs including the gastrointestinal tract (compartment 3 and colon), lungs, and heart. Fibrin thrombi in arterioles, capillaries, venules, and medium-sized veins were observed especially in the pulmonary interstitium, submucosa of the large intestine (ascending colon), deep dermis, and renal cortex. Furthermore, widespread hemorrhages and necrosis were constant histopathological lesions in parenchymatous organs. Based on clinical signs, hematology, blood biochemistry, and gross and microscopical findings, the cases were diagnosed as compartment 1 acidosis associated with hemorrhagic diathesis and endotoxicosis. Finally, compartment 1 acidosis associated with hemorrhagic diathesis is a serious fatal disease on the Arabian Peninsula in racing dromedaries causing multi-organ dysfunction and coagulopathy and disseminated hemorrhages.

Regional and Seasonal Variability of Mineral Patterns in Some Organs of Slaughtered One-Humped Camels [Camelus dromedarius] from Saudi Arabia

Camel products are receiving great interest worldwide because of their high functional properties and nutritive values. Therefore, this study was focused on the variation of copper [Cu], zinc [Zn], manganese [Mn], selenium [Se], iron [Fe], iodine [I], and some heavy metals, cobalt [Co], lead [Pb], and cadmium [Cd], in the blood and tissues of slaughtered camels from five regions in Saudi Arabia [SA] during the summer and winter seasons, because environmental factors vary from region to region. Whole blood, meat, liver, rumen fluid, and rumen tissues were collected from the slaughterhouse in each region during the two seasons. Moreover, samples were prepared and analyzed for trace mineral and heavy metal concentrations using ICP-MS. The data were statistically analyzed as part of a complete randomized design and correlation analysis for season and location using SAS. The findings revealed a pattern in the minerals, with Ca being the only mineral that was unrelated to other minerals in the liver. For lead and cadmium, our mean value in liver [0.40 µg/g] was below the limit of the EU standard for cadmium [0.50 µg/g], while in meat and liver, lead contents [1.62 µg/g and 2.57 µg/g, respectively] were above the limit of the EU standard [0.10 and 0.20 µg/g, respectively]. For meat, the significantly highest positive correlations were observed between P and Mg [R² = 0.928], Fe and Mn [R² = 0.860], and Co and Mn [R² = 0.821]. For rumen tissues, P and Mg were highly correlated [R² = 0.958] as well as Zn and Mg [R² = 0.857], Zn and P [R² = 0.836], and Fe and Ca [R² = 0.802]. As a result, a region and season reflect variations in mineral concentrations in SA during the summer and winter seasons. Further intensive research is needed to investigate the minerals' biological mechanisms in camels under different environmental conditions.

Effect of diet supply on milk production and weight performances of she-camels

The milk productivity improvement of she-camels requires a good feeding program that should indicate appropriate foods, required quantities, and how and when to distribute them. The aim of this study was to explore the interactions between milk productivity and body variations of dairy camels in response to experimental dietary treatments. The camels received a new diet every 15 days approximately, with higher rate of concentrates and high energy concentration. Results showed that diets with high energy or protein density, UFL (forage unit for milk production), and nutrient waste stimulated the development of body weight at the expense of milk production (p <0.05). Therewith, the inadequate supply of feeds rich in fermentable carbohydrates such as dates (p <0.01) or corn (p <0.05) compromised milk productivity level in favor of ADG (average daily gain) and body reserves deposit. Increasing the level of roughage feed intake had a positive effect on milk production (p < 0.05). According to the results, it is recommended in the feeding of dairy she-camels to maintain a minimum level of roughage at more than 60%. In addition, it is necessary that the energy density (DER) be in the order of 0.91-1.17 maximum (0.78 UFL/kg.DM-dry matter). Taking into account famous nitrogen recycling mechanisms of camels, the protein supply of diets does not seem useful to overcome 63 g PDI/kg.DM (PDI protein digestible in the intestine).

Characterizing rumen microbiota and CAZyme profile of Indian dromedary camel (Camelus dromedarius) in response to different roughages

In dromedary camels, which are pseudo-ruminants, rumen or C1 section of stomach is the main compartment involved in fiber degradation, as in true ruminants. However, as camels are adapted to the harsh and scarce grazing conditions of desert, their ruminal microbiota makes an interesting target of study. The present study was undertaken to generate the rumen microbial profile of Indian camel using 16S rRNA amplicon and shotgun metagenomics. The camels were fed three diets differing in the source of roughage. The comparative metagenomic analysis revealed greater proportions of significant differences between two fractions of rumen content followed by diet associated differences. Significant differences were also observed in the rumen microbiota collected at different time-points of the feeding trial. However, fraction related differences were more highlighted as compared to diet dependent changes in microbial profile from shotgun metagenomics data. Further, 16 genera were identified as part of the core rumen microbiome of Indian camels. Moreover, glycoside hydrolases were observed to be the most abundant among all Carbohydrate-Active enzymes and were dominated by GH2, GH3, GH13 and GH43. In all, this study describes the camel rumen microbiota under different dietary conditions with focus on taxonomic, functional, and Carbohydrate-Active enzymes profiles.

Modes of genetic adaptations underlying functional innovations in the rumen

The rumen is the hallmark organ of ruminants and hosts a diverse ecosystem of microorganisms that facilitates efficient digestion of plant fibers. We analyzed 897 transcriptomes from three Cetartiodactyla lineages: ruminants, camels and cetaceans, as well as data from ruminant comparative genomics and functional assays to explore the genetic basis of rumen functional innovations. We identified genes with relatively high expression in the rumen, of which many appeared to be recruited from other tissues. These genes show functional enrichment in ketone body metabolism, regulation of microbial community, and epithelium absorption, which are the most prominent biological processes involved in rumen innovations. Several modes of genetic change underlying rumen functional innovations were uncovered, including coding mutations, genes newly evolved, and changes of regulatory elements. We validated that the key ketogenesis rate-limiting gene (HMGCS2) with five ruminant-specific mutations was under positive selection and exhibits higher synthesis activity than those of other mammals. Two newly evolved genes (LYZ1 and DEFB1) are resistant to Gram-positive bacteria and thereby may regulate microbial community equilibrium. Furthermore, we confirmed that the changes of regulatory elements accounted for the majority of rumen gene recruitment. These results greatly improve our understanding of rumen evolution and organ evo-devo in general.

Comparison of the nutritional value and fatty acid composition of milk from four South American camelid species

The nutritional value, whey protein, and the fatty acid (FA) composition of milk from four South American camelids (SAC) (vicuna, Vicugna vicugna (Molina, 1782); alpaca, Vicugna pacos (Linnaeus, 1758); guanaco, Lama guanicoe (Müller, 1776); llama, Lama glama (Linnaeus, 1758)) were evaluated and compared with milk from old-world camelids. Samples were collected from healthy animals from the northwest (llama, alpaca, and vicuna) and Patagonia (guanaco) areas of Argentina. Gross composition of milk from SAC showed a higher protein, lactose, and lipid content than camel milk. Serum albumin and α-lactalbumin were the dominant whey proteins, followed by immunoglobulin G (IgG). The FA profile showed from 4:0 to 24:0 FA, with a high level of conjugated fatty acid (CLA; 1.05–1.64 g/100 g of FAME) and its precursor, vaccenic acid. Desaturase activity of C16 and CLA was quite similar between species but was significantly different for C14. Camelid milk showed a lower atherogenicity index than ruminant milk. This is the first time that a comparative study involving four species of SAC was carried out to contribute to the general knowledge of the physiology of new-world camelids. Their milk was determined to be of high nutritional quality, allowing it to be considered an alternative food item for humans in the semi-arid region of South America.

Characterizing the bacterial microbiota in different gastrointestinal tract segments of the Bactrian camel

The bacterial community plays important roles in the gastrointestinal tracts (GITs) of animals. However, our understanding of the microbial communities in the GIT of Bactrian camels remains limited. Here, we describe the bacterial communities from eight different GIT segments (rumen, reticulum, abomasum, duodenum, ileum, jejunum, caecum, colon) and faeces determined from 11 Bactrian camels using 16S rRNA gene amplicon sequencing. Twenty-seven bacterial phyla were found in the GIT, with Firmicutes, Verrucomicrobia and Bacteroidetes predominating. However, there were significant differences in microbial community composition between segments of the GIT. In particular, a greater proportion of Akkermansia and Unclassified Ruminococcaceae were found in the large intestine and faecal samples, while more Unclassified Clostridiales and Unclassified Bacteroidales were present in the in forestomach and small intestine. Comparative analysis of the microbiota from different GIT segments revealed that the microbial profile in the large intestine was like that in faeces. We also predicted the metagenomic profiles for the different GIT regions. In forestomach, there was enrichment associated with replication and repair and amino acid metabolism, while carbohydrate metabolism was enriched in the large intestine and faeces. These results provide profound insights into the GIT microbiota of Bactrian camels.

Comparative analysis of fecal microbial communities in cattle and Bactrian camels

Bactrian camels may have a unique gastrointestinal (GI) microbiome because of their distinctive digestive systems, unique eating habits and extreme living conditions. However, understanding of the microbial communities in the Bactrian camel GI tract is still limited. In this study, microbial communities were investigated by comparative analyses of 16S rRNA hypervariable region V4 sequences of fecal bacteria sampled from 94 animals in four population groups: Inner Mongolian cattle (IMG-Cattle), Inner Mongolian domestic Bactrian camels (IMG-DBC), Mongolian domestic Bactrian camels (MG-DBC), and Mongolian wild Bactrian camels (MG-WBC). A total of 2,097,985 high-quality reads were obtained and yielded 471,767,607 bases of sequence. Firmicutes was the predominant phylum in the population groups IMG-Cattle, IMG-DBC and MG-WBC, followed (except in the Inner Mongolian cattle) by Verrucomicrobia. Bacteroidetes were abundant in the IMG-DBC and MG-WBC populations. Hierarchical clustered heatmap analysis revealed that the microbial community composition within the three Bactrian camel groups was relatively similar, and somewhat distinct from that in the cattle. A similar result was determined by principal component analysis, in which the camels grouped together. We also found several species-specific differences in microbial communities at the genus level: for example, Desulfovibrio was abundant in the IMG-DBC and MG-WBC groups; Pseudomonas was abundant in the IMG-Cattle group; and Fibrobacter, Coprobacillus, and Paludibacter were scarce in the MG-WBC group. Such differences may be related to different eating habits and living conditions of the cattle and the various camel populations.

Transfer of blood urea nitrogen to cecal microbial nitrogen is increased by fructo-oligosaccharide feeding in guinea pigs

The present study was conducted to determine the mechanism by which nitrogen (N) availability is improved by fructo-oligosaccharide (FOS) in guinea pigs. Adult male guinea pigs were fed a commercial pellet diet (50 g/day) with either 5% glucose or 5% FOS for 7 days in individual metabolism cages. After 7 days of feeding the diet, (15) N-urea was administered intravenously 1 h before slaughter under anesthesia. The amount and concentration of total, protein, bacterial, ammonia and urea N and the (15) N atom % excess were measured in blood, liver, gut contents and urine. The (15) N atom % excess of total and protein N, and the amount of total, protein and bacteria N and (15) N in the cecum were significantly increased by the consumption of FOS. Furthermore, the concentration and amount of short-chain fatty acids were significantly increased by the consumption of FOS. In contrast, the amount of urinary (15) N was significantly decreased by the consumption of FOS. These results suggest that consumption of FOS increases transfer of blood urea N into the large intestine for bacterial N synthesis, which is subsequently re-absorbed by cecotrophy, and contributes to the increase of N utilization in guinea pigs.

Molecular diversity of the foregut bacteria community in the dromedary camel (Camelus dromedarius)

The molecular diversity of the foregut bacterial community in the dromedary camel (Camelus dromedarius) in Central Australia was investigated through comparative analyses of 16S rRNA gene sequences prepared from the foregut contents of 12 adult feral camels fed on native vegetation. A total of 267 full-length 16S rRNA gene clones were examined, with 151 operational taxonomic units (OTUs) identified at a 99% species-level identity cut-off criterion. The prediction of actual diversity in the foregut of the dromedary camel using the Chaol approach was 238 OTUs, while the richness and evenness of the diversity estimated using Shannon index was 4.84. The majority of bacteria in the current study were affiliated with the bacterial phylum Firmicutes (67% of total clones) and were related to the classes Clostridia, Bacilli and Mollicutes, followed by the Bacteroidetes (25%) that were mostly represented by the family Prevotellaceae. The remaining phyla were represented by Actinobacteria, Chloroflexi, Cynophyta, Lentisphaerae, Planctomycetes, Proteobacteria and Sphirochaetes. Moreover, 11 clones of cultivated bacteria were identified as Brevundimonas sp., Butyrivibrio fibrisolvens, Prevotella sp. and Ruminococcus flavefaciens. The novelty in this foregut environment is remarkable where 97% of the OTUs were distantly related to any known sequence in the public database.