Effects of water deprivation on urea metabolism in camels, desert sheep and desert goats fed dry desert grass

Nutritional factors affecting camel (Camelus dromedarius) milk composition

Saharan population in Algeria still depending on bovine milk, which suffers from serious constraints undermining its sustainability. Camelus dromedarius milk has experienced growing demand following the emerging market requirements for livestock production and dairy farming over the past decade. The present work aimed at analysing the effect of nutritional regime on milk quality. The differences in pH, Acidity D°, Ash and Fats were significant. The pH was negatively influenced by the intensification conditions such as the much higher use of concentrates. The major constituents of milk were strongly and positively correlated with barley, wheat bran, TN/Kg.DM (Total Nitrogen/ Kg. Dry Matter), Kg.DM, Concentrates and daily watering. The results showed that a good energy-protein balance around 73 g PDI/UFL (Protein Digestible in the Intestine/Energetic Forage Unit for milk production) was beneficial for a better milk protein ratio. The use of corn, soybeans, palm dates and VM-premix (Vitamin Mineral) supplementation were also favourable to the synthesis of fats. Crude fiber and cell walls were better valued in the synthesis of fats with the availability of concentrates and the increasing of TN /Kg.DM and VM-premix rate in dietary regime. The vitamin C content elevate following high ratio of UFL /Kg.DM and PDI/UFL. For thus, the influence of nutritional status can lead to major improvements that need also more advanced and detailed studies.

Camel Proteins and Enzymes: A Growing Resource for Functional Evolution and Environmental Adaptation

In less agroecological parts of the Asian, Arabian, and African deserts, Camelus dromedarius play an important role in human survival. For many years, camels have been employed as a source of food, a tool of transportation, and a means of defense. They are becoming increasingly important as viable livestock animals in many desert climates. With the help of camel genetics, genomics and proteomics known so far, this review article will summarize camel enzymes and proteins, which allow them to thrive under varied harsh environmental situations. An in-depth study of the dromedary genome revealed the existence of protein-coding and fast-developing genes that govern a variety of metabolic responses including lipid and protein metabolism, glucoamylase, flavin-containing monooxygenase and guanidinoacetate methyltransferase are other metabolic enzymes found in the small intestine, liver, pancreas, and spleen. In addition, we will discuss the handling of common medications by camel liver cytochrome p 450, which are different from human enzymes. Moreover, camels developed several paths to get optimum levels of trace elements like copper, zinc, selenium, etc., which have key importance in their body for normal regulation of metabolic events. Insulin tolerance, carbohydrate and energy metabolism, xenobiotics metabolizing enzymes, vimentin functions, behavior during the rutting season, resistance to starvation and changes in blood composition and resistance to water loss were among the attractive aspects of camel enzymes and proteins peculiarities in the camels. Resolving the enigma of the method of adaptation and the molecular processes linked with camel life is still a developing repository full of mysteries that need additional exploration.

Nitrogen recycling via gut symbionts increases in ground squirrels over the hibernation season

Hibernation is a mammalian strategy that uses metabolic plasticity to reduce energy demands and enable long-term fasting. Fasting mitigates winter food scarcity but eliminates dietary nitrogen, jeopardizing body protein balance. Here, we reveal gut microbiome-mediated urea nitrogen recycling in hibernating thirteen-lined ground squirrels (Ictidomys tridecemlineatus). Ureolytic gut microbes incorporate urea nitrogen into metabolites that are absorbed by the host, with the nitrogen reincorporated into the squirrel's protein pool. Urea nitrogen recycling is greatest after prolonged fasting in late winter, when urea transporter abundance in gut tissue and urease gene abundance in the microbiome are highest. These results reveal a functional role for the gut microbiome during hibernation and suggest mechanisms by which urea nitrogen recycling may contribute to protein balance in other monogastric animals.

Effect of Different Watering Regimes in Summer Season on Water Intake, Feed Intake, and Milk Production of Marecha She-camel (Camelus dromedarius)

Simple Summary

Camel livestock is a significant sector of agriculture in Pakistan. Punjab Marecha is the camel breed more diffuse for their production characteristics. In fact, this camel breed is well adapted to the desert ecosystem, tolerating elevated temperatures and dehydration. This study aimed to evaluate the effect of water deprivation on milk production performance in Marecha camels during the summer. Twelve she-camels in the early lactation stage were included. After seven days, camels were divided into three groups: Group 1 (G1) having access to water once a day, Group 2 (G2) having access once every 4 days, and Group 3 (G3) having access once every 6 days. Milk production and daily dry matter were decreased in camels deprived of water for 6 days. The results of the current study suggest that the camel is a productive animal even when subjected to water deprivation; however, its feed intake and milk production are decreased.

Abstract

Twelve lactating healthy Marecha she-camels in the early lactation stage during the summer at Camel Breeding and Research Station Rakh-Mahni (Pakistan) were included. All animals were fed with Medicago sativa and Cicer arientinum ad libitum and divided into three groups in relation to the access to water, after a period of seven days of adaptation to experimental conditions. Group 1 (G1) was considered as control having access to water once every day; Group 2 (G2) had access once every 4 days, while Group 3 (G3) had access once every 6 days. The duration of the study was 60 days with an adaptation period to experimental conditions of 7 days before the onset of the study. Dry matter intake (DMI) was calculated on a dry matter basis. On average the ambient temperature and relative humidity during the trial were 39–41 °C and 55–63%, respectively. The DMI, water intake, milk production, and body weight changes were affected (p < 0.001) during various watering regimes. The mean values of water intake were found to be 82.94 ± 1.34 L higher in G3 than G1 and G2.

A sensitive and high-throughput fluorescent method for determination of oxidase activities in human, bovine, goat and camel milk

Milk oxidases are an integral part of milk immune system, and good indicators for milk thermal history. Current assay methods for milk oxidases are either insensitive, tedious or not cost-effective. In this study, a high-throughput fluorescence assay method for determination of xanthine oxidase (XO) and polyamine oxidase (PAO) activities in milk samples was developed. The hydrogen peroxide generated by XO catalysed oxidation of hypoxanthine, and PAO catalysed oxidation of spermine, was coupled to horseradish peroxidase conversion of Amplex® Red (1-(3,7-dihydroxyphenoxazin-10-yl)ethanone) to the fluorescent product resorufin. The assay was highly sensitive, with limits of detection of activity in milk being 3 × 10^-7 and 7 × 10^-7 U/mL for XO and PAO, respectively. Intra-run and inter-run results showed good assay repeatability and reproducibility. The assay was successfully applied to survey the XO and PAO activities in human, bovine, goat and camel milk samples, and it can be readily adapted for measurements of other oxidase activities.

Small Ruminants: Farmers' Hope in a World Threatened by Water Scarcity

Simple Summary

Water is one of the most important nutrients to livestock. It is so essential that more than half the volume of the animal's body is water. However, its availability is threatened by the irreversible changes in climate, which has culminated into reduced rainfall in most regions of the world. Such an increasing threat to regular water supply, and by extension to food security and livelihood has forced a shift from large to small ruminant production, especially in regions experiencing low rainfall, with farmers taking advantage of their adaptive process and efficiency of water use. Small ruminants, especially desert goats, can adaptively survive in water-limited areas while trekking long distance in search of feed and they will regain any weight loss at the next watering point. Further research is needed on adaptive indigenous breeds of small ruminants since tolerance to water scarcity is breed dependent, so that improvements can be made through effective selection and breeding program.

Abstract

The availability and sustainability of suitable and good quality drinking water is a global concern. Such uncertainties threaten livestock production with an attendant ripple effect on food security. Small ruminants, including sheep and goats, appear to be promising to smallholder farmers in solving this problem because of their ability to survive in water-limited areas and harsh environment when compared with large ruminants. Their small body size is also seen as an advantage, because less water will be required for proper digestion and feed utilization. Therefore, this review will provide information regarding the adaptive responses of small ruminants on thermoregulation, blood metabolites, immune status, drug pharmacokinetics, reproduction and hormonal indices during the period of water stress. Adaptable and indigenous breeds are known to be more tolerant to water stress than selected breeds. A drop in feed intake and weight reduced respiratory rate and increased concentration of blood metabolites are the general effects and/or observations that are encountered by small ruminants during the period of water stress. The concept of water tolerance either as deprivation and/or restriction of indigenous and adaptable breeds of small ruminants is gaining ground in research studies around the world. However, more research, however, seeking to explore water tolerance capacity of adaptable breeds especially in arid and water limiting areas are still needed.

From Desert to Medicine: A Review of Camel Genomics and Therapeutic Products

Camels have an important role in the lives of human beings, especially in arid regions, due to their multipurpose role and unique ability to adapt to harsh conditions. In spite of its enormous economic, cultural, and biological importance, the camel genome has not been widely studied. The size of camel genome is roughly 2.38 GB, containing over 20,000 genes. The unusual genetic makeup of the camel is the main reason behind its ability to survive under extreme environmental conditions. The camel genome harbors several unique variations which are being investigated for the treatment of several disorders. Various natural products from camels have also been tested and prescribed as adjunct therapy to control the progression of ailments. Interestingly, the camel employs unique immunological and molecular mechanisms against pathogenic agents and pathological conditions. Here, we broadly review camel classification, distribution and breed as well as recent progress in the determination of the camel genome, its size, genetic distribution, response to various physiological conditions, immunogenetics and the medicinal potential of camel gene products.

Proteomics of old world camelid (Camelus dromedarius): Better understanding the interplay between homeostasis and desert environment

Life is the interplay between structural–functional integrity of biological systems and the influence of the external environment. To understand this interplay, it is useful to examine an animal model that competes with harsh environment. The dromedary camel is the best model that thrives under severe environment with considerable durability. The current proteomic study on dromedary organs explains a number of cellular mysteries providing functional correlates to arid living. Proteome profiling of camel organs suggests a marked increased expression of various cytoskeleton proteins that promote intracellular trafficking and communication. The comparative overexpression of α-actinin of dromedary heart when compared with rat heart suggests an adaptive peculiarity to sustain hemoconcentration–hemodilution episodes associated with alternative drought-rehydration periods. Moreover, increased expression of the small heat shock protein, α B-crystallin facilitates protein folding and cellular regenerative capacity in dromedary heart. The observed unbalanced expression of different energy related dependent mitochondrial enzymes suggests the possibility of mitochondrial uncoupling in the heart in this species. The evidence of increased expression of H+-ATPase subunit in camel brain guarantees a rapidly usable energy supply. Interestingly, the guanidinoacetate methyltransferase in camel liver has a renovation effect on high energy phosphate with possible concomitant intercession of ion homeostasis. Surprisingly, both hump fat tissue and kidney proteomes share the altered physical distribution of proteins that favor cellular acidosis. Furthermore, the study suggests a vibrant nature for adipose tissue of camel hump by the up-regulation of vimentin in adipocytes, augmenting lipoprotein translocation, blood glucose trapping, and challenging external physical extra-stress. The results obtained provide new evidence of homeostasis in the arid habitat suitable for this mammal.

Urea nitrogen salvage mechanisms and their relevance to ruminants, non-ruminants and man

Maintaining a correct balance of N is essential for life. In mammals, the major sources of N in the diet are amino acids and peptides derived from ingested proteins. The immediate endproduct of mammalian protein catabolism is ammonia, which is toxic to cells if allowed to accumulate. Therefore, amino acids are broken down in the liver as part of the ornithine-urea cycle, which results in the formation of urea - a highly soluble, biochemically benign molecule. Mammals cannot break down urea, which is traditionally viewed as a simple waste product passed out in the urine. However, urea from the bloodstream can pass into the gastrointestinal tract, where bacteria expressing urease cleave urea into ammonia and carbon dioxide. The bacteria utilise the ammonia as an N source, producing amino acids and peptides necessary for growth. Interestingly, these microbial products can be reabsorbed back into the host mammalian circulation and used for synthetic processes. This entire process is known as 'urea nitrogen salvaging' (UNS). In this review we present evidence supporting a role for this process in mammals - including ruminants, non-ruminants and man. We also explore the possible mechanisms involved in UNS, including the role of specialised urea transporters.

Antioxidant levels in tissues of young and adult camels (Camelus dromedarius)

In this study, we measured the concentration of some antioxidant substances in erythrocytes hemolysate, liver, kidney and brain in young and adult camels. It has been found that the activity of the antioxidant enzymes glutathione peroxidase (GSH-Px), catalase (CAT), superoxide dismutase (SOD) and the concentration of glutathione, ascorbic acid and alpha-tocopherol are high in both young and adult camels. GSH-Px and CAT activities were higher in adult camels than in the young whereas no significant difference in the activity of SOD between young and adult camels was noticed. Glutathione was present in all tissues studied. Ascorbic acid was found to have significantly higher values in young camels. From this study it could be concluded that, as in other mammals, camel tissues contain a powerful antioxidant system. The liver has the highest contents of antioxidants and antioxidant enzymes indicating that it plays an important role in pro-oxidants detoxification. Age has a variable effect on the antioxidant system in camels.

Feed intake, forestomach fluid volume, dilution rate and mean retention of fluid in the forestomach during water deprivation and rehydration in camels (Camelus sp.)

Camels were deprived of water for 11 days. Before and during water deprivation and during rehydration changes in body weight, feed and water intake were measured. Using the liquid marker Cr-EDTA forestomach fluid volume, mean fluid retention and fluid dilution in the forestomach were estimated. At the eleventh day of water deprivation hay intake had decreased to only 9.6% of controls, dilution rates had decreased to 31%, mean retention time of fluid in the forestomach had increased to 189%. At the end of dehydration flow of saliva of 2 l/h mainly contributed to the still rather high dilution rates. Thereby buffering capacity and flow of fluid into the forestomach for microbial digestion as well as the outflow from the forestomach were maintained. At the beginning of rehydration camels drank 97 l within a few minutes, and animals thereby replaced all the water lost. Following this first huge water intake water is rapidly absorbed from the forestomach, and forestomach volume decreased again to dehydration values. At the third day of rehydration control values were reached again. Although feed intake decreased dramatically during water deprivation, functions of the forestomach can be maintained sufficiently mainly due to saliva inflow. This explains the mostly rapid recovery of camels when water is available again.

Effects of water and feed restriction on body weight change and nitrogen balance in desert goats fed high and low quality forages

The effects of water and food restriction on feed utilization, body weight changes and nitrogen balance were investigated in Sudanese desert goats given high or low quality forage. Nine male goats were employed in a 3x3 Latin square design where they were subjected to three treatments: ad libitum water and feed, ad-libitum feed/restricted water, and ad libitum water/restricted feed. These treatments were repeated using lucerne or sorghum hay. For both feed types dry matter intake (DMI) was not affected by treatments. Water intake decreased with feed restriction in goats fed sorghum hay. The ratio of water intake to DMI increased with lucerne hay compared to sorghum hay in both the control and feed restricted group. Water consumption increased with lucerne compared to sorghum hay. Body weight losses were more pronounced with water than with feed restriction but were less severe with lucerne than sorghum hay. Interactions due to treatment and feed type were significant for water intake and body weight change. With lucerne hay, except for crude protein (CP), nutrient digestibility improved with water restriction. Feeding sorghum hay, there were no effects on digestibility except for crude protein (CP) that was reduced with water restriction. Crude fiber (CF) and nitrogen free extract (NFE) digestibility increased with feed restriction in animals on sorghum hay. For all groups, CP digestibility was better with lucerne than sorghum hay. Interactions of the main effects were significant for all apparent digestibility coefficients as well as total digestible nutrients. The treatments did not have significant effects on nitrogen balance, however, nitrogen intake, retained or excreted in faeces was higher with lucerne than sorghum hay. It may be concluded that subjecting animals to water or feed restriction will have a more deleterious effect on feed utilization and nitrogen balance when using a low than a high quality forage.

Contributions of microbes in vertebrate gastrointestinal tract to production and conservation of nutrients

The vertebrate gastrointestinal tract is populated by bacteria and, in some species, protozoa and fungi that can convert dietary and endogenous substrates into absorbable nutrients. Because of a neutral pH and longer digesta retention time, the largest bacterial populations are found in the hindgut or large intestine of mammals, birds, reptiles, and adult amphibians and in the foregut of a few mammals and at least one species of bird. Bacteria ferment carbohydrates into short-chain fatty acids (SCFA), convert dietary and endogenous nitrogenous compounds into ammonia and microbial protein, and synthesize B vitamins. Absorption of SCFA provides energy for the gut epithelial cells and plays an important role in the absorption of Na and water. Ammonia absorption aids in the conservation of nitrogen and water. A larger gut capacity and longer digesta retention time provide herbivores with additional SCFA for maintenance energy and foregut-fermenting and copoprophagic hindgut-fermenting species with access to microbially synthesized protein and B vitamins. Protozoa and fungi also contribute nutrients to the host. This review discusses the contributions of gut microorganisms common to all vertebrates, the numerous digestive strategies that allow herbivores to maximize these contributions, and the effects of low-fiber diets and discontinuous feeding schedules on these microbial digestive processes.

Metabolic profiles and risks of diseases in camels in temperature conditions

A survey of 65 female camels has been conducted over a 1-year period in France to determine their metabolic profiles and to study the correlations between this profile and the feeding and health status in temperate conditions. The following parameters were measured: protein (albumin, globulin, total protein), urea, glucose, free fatty acid, liver enzymes (GLDH, GGT, GOT), minerals (Ca, Mg, Cu, Zn) and ceruloplasmin. The values obtained were similar to those reported in desert areas throughout the world, but the standard deviation was generally higher. This important variation might be due to the large variability of feeding conditions: albumin (36.4 +/- 4.7 g/l), total globulin (32.7 +/- 5.1 g/l), total protein (69.2 +/- 6.1 g/l), urea (30.0 +/- 14.8 mg/100 ml), glucose (111.0 +/- 12.2 mg/100 ml), FFA (0.15 +/- 0.15 mmol/l), GLDH (5.8 +/- 10.8 IU/l), GGT (10.1 +/- 5.8 IU/l), GOT (48.1 +/- 14.3 IU/l), calcium (10.2 +/- 6.5 mg/100 ml), magnesium (2.6 +/- 0.3 mg/100 ml), copper (65.4 +/- 20.2 micrograms/100 ml), zinc (34.6 +/- 7.8 micrograms/100 ml), ceruplasmin (41.4 +/- 2.6 UO). The season, the mineral supplementation and the health status had a significant effect on the metabolic profile of the she-camels.

The Arabian race camel normal parameters--I. Haemogram, enzymes and minerals

1. Racing camels' (Camelus dromedarius) normal blood parameters were determined in Al-Ain, U.A.E. The parameters were: packed cell volume, haemoglobin, total red and white blood cells, the activities of glutamate oxaloacetate (GOT), creatinine kinase (CK), gamma-glutamyl transferase (gamma-GT) and CK muscle-brain isoenzyme and the concentrations of creatinine, urea, total protein, albumin, calcium, magnesium, phosphorus, sodium, potassium, zinc, copper and iron. 2. Most blood parameters were found to differ from those of other domestic animals and from non-race camels. 3. The data are discussed in relation to the management system practised.

Effect of dehydration on feed intake and dry matter digestibility in desert (black Bedouin) and non-desert (Swiss Saanen) goats fed on lucerne hay

Food consumption decreases with the lengthening of the period of dehydration in both breeds in a similar manner. However, in comparison, the Saanen goats reduced their dry matter intake and consequently their water intake much more than the Bedouin goats. Apparent digestibility of dry matter increased significantly in both breeds during dehydration, the response being larger in the Saanen goats. Bedouin goats are capable of maintaining during 3 days of dehydration a level of consumption which is well above their maintenance requirements while the Saanen goats consumed only the amount of feed which is needed to satisfy their maintenance requirements.