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.

What are the challenges for implementing an "organic label" to camel milk?

Increasing demand for camel's milk worldwide occurred in the context of the development of the organic sector in agriculture. The implementation of an organic label for camel milk has never been established. However, the creation of such a label faces to important challenges that are investigated in the present paper. Indeed, although camel milk conveys the image of a "natural product" issued from remote places, the risk of being produced in contaminated areas (mining activities, oil extraction) cannot be neglected for grazing animals. Moreover, the management of veterinary drugs for prevention or curative treatment can lead to the presence of residues in milk, especially in camel species with different pharmacokinetics, although similar instructions than for cow milk are used. Moreover, the lack of international standards regarding both composition and hygienic rules, the risks of adulteration, and the necessity to use specific indicators or analytical procedures adapted to the behavior of camel milk, have to be taken in account in the establishment of the specifications for the camel milk producers through the world.

Domestication of the Dromedary Revisited and Its Consequences for Legislation as to Keeping Livestock or Pet Animals.

Being in an advanced stage of domestication is a newly proposed requirement to decide which animals can be safely kept by humans. Dutch legislators were the first to apply it and other European countries may be tempted to adopt a similar approach. Unexpectedly, the Dutch assessors considered the dromedary (Camelus dromedarius) as being insufficiently domesticated and this species will therefore no longer be able to be kept as a production animal from 2024 onwards. In a recent publication on this topic, we showed that the domestication of the dromedary is actually very advanced. In this paper, we apply the same criteria that were used by the Dutch assessors to determine the degree of domestication, taking into account the most recent scientific developments in this area, even though it should be noted that these criteria have neither been peer-reviewed, nor published in an international scientific journal. For the sake of comparison, and in order to validate the procedure, we also applied these criteria to the house cat. The results confirm that the dromedary is highly domesticated, but also that the house cat (Felis silvestris catus) is at most semi-domesticated. Obviously, we agree with the decision of the Dutch legislators to place the house cat on the positive list, but our analysis demonstrates that this was decided on false grounds. Our analysis makes it clear that the requirement of being in an advanced stage of domestication is not suitable. Instead of maintaining this requirement, we recommend implementing evidence-based, peer-reviewed methods to decide which animals can be kept by humans, and to include species specific-guidelines in the legislation on how this can be achieved safely.

Some Variation Factors of Freezing Point in Camel Milk.

The freezing point degree of milk (FPD) is a classical indicator of cow milk quality. In camel milk, few references are available in the literature regarding the main factors of variation. In the present paper, two methods of FPD determination were used: the Reference method (RM) (using Cryostar) and the Express method (EM), using a milk analyzer (Milkoscan-FT1). The RM was used to determine FPD in 680 bulk raw or pasteurized camel milk samples. Regarding EM, 736 individual milk samples, 1323 bulk samples, 635 samples of pasteurized milk and 812 samples of raw milk used for cheese making were available. The variability of FPD was investigated according to month, lactation stage, milk composition, milk production and microbiological status. Correlations between methods were explored. FPD was highly correlated with most of the milk components and tended to decrease in cases of high contamination by coliforms or high total flora count. However, the weak significant correlations between the two methods indicated the necessity to specifically calibrate an automatic milk analyzer for camel milk.

Phenotypic biodiversity characterization of dromedary camels and hybrids in Kazakhstan.

Kazakhstan is one of the rare camel countries with rich camel biodiversity where different dromedary camels, Bactrian camels, and hybrid types are cohabiting at the same territories during centuries. Several data on phenotype biodiversity of local camels are available, mostly published during Soviet Union time using few body quantitative measurements. Unfortunately, those data are not sufficient to place the local breeds among the world camel population. The aim of this study was to describe detailed phenotype parameters of dromedary camels and hybrids in Kazakhstan and to compare our animals with the other camel populations in the world. As the whole, six camel farms were visited, located in different regions of southern Kazakhstan. In total, 185 female camels (Aruana breed camels and hybrids) were described by the phenotype questionnaire. There was a significant effect of "breed" on the different parameters except udder depth and body length. Most of the measurements were lower in Aruana compared to hybrids. The discriminating factorial analysis confirmed the clear separation between the breed based on their body measurements with a total of 95% of well-classed. The main discriminating parameters (allowing distinguishing the populations) were in the order: (i) the length of the head, (ii) the neck length, (iii) the neck circumference, (iv) the teat length, and (v) the udder length.

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.

Refining the Camelus dromedarius Myostatin Gene Polymorphism through Worldwide Whole-Genome Sequencing.

Myostatin (MSTN) is a highly conserved negative regulator of skeletal muscle in mammals. Inactivating mutations results in a hyper-muscularity phenotype known as "double muscling" in several livestock and model species. In Camelus dromedarius, the gene structure organization and the sequence polymorphisms have been previously investigated, using Sanger and Next-Generation Sequencing technologies on a limited number of animals. Here, we carried out a follow-up study with the aim to further expand our knowledge about the sequence polymorphisms at the myostatin locus, through the whole-genome sequencing data of 183 samples representative of the geographical distribution range for this species. We focused our polymorphism analysis on the ±5 kb upstream and downstream region of the MSTN gene. A total of 99 variants (77 Single Nucleotide Polymorphisms and 22 indels) were observed. These were mainly located in intergenic and intronic regions, with only six synonymous Single Nucleotide Polymorphisms in exons. A sequence comparative analysis among the three species within the Camelus genus confirmed the expected higher genetic distance of C. dromedarius from the wild and domestic two-humped camels compared to the genetic distance between C. bactrianus and C. ferus. In silico functional prediction highlighted: (i) 213 differential putative transcription factor-binding sites, out of which 41 relative to transcription factors, with known literature evidence supporting their involvement in muscle metabolism and/or muscle development; and (ii) a number of variants potentially disrupting the canonical MSTN splicing elements, out of which two are discussed here for their potential ability to generate a prematurely truncated (inactive) form of the protein. The distribution of the considered variants in the studied cohort is discussed in light of the peculiar evolutionary history of this species and the hypothesis that extremely high muscularity, associated with a homozygous condition for mutated (inactivating) alleles at the myostatin locus, may represent, in arid desert conditions, a clear metabolic disadvantage, emphasizing the thermoregulatory and water availability challenges typical of these habitats.

Blood Trace Element Status in Camels: A Review.

Trace minerals play an important role in animal health and productivity. They are involved also in many physiological activities, and their deficiency causes a variety of pathological problems and metabolic defects, reducing consequently the animal productivity. The demand for animal products in semi-arid areas is rapidly increasing, and the supply is still below the required level, partially due to low animal productivity. Camels (Camelus dromedarius and Camelus bactrianus) are considered one of the main sources of healthy, high-quality meat and milk for human consumption within most of the countries in the semi-arid regions. Despite their efficient adaptation to their environment, camels can suffer from the growth retardation of newborns, low feed efficiency, anemia, poor fertility, poor reproduction and many other metabolic disorders. It is well known that trace mineral deficiencies and trace mineral toxicities can influence camels' production and reproductive efficiency, as well as many aspects of their growth and metabolism. Evaluating the trace minerals status of camels and their variability is an obvious step toward improving camels' productivity and health. Thus, the present article reviews the data regarding the status of trace minerals (copper, zinc, iron, selenium, manganese, cobalt, iodine, fluorine, molybdenum, sulfur, bromide and nickel) in camel blood and their physiological variability, with a focus on their deficiency and toxicity effects.

Development of a control strategy towards elimination of Trypanosoma evansi infection (surra) in camels in Africa.

With an increasing worldwide population that presently exceeds 38 million, camels are important source of meat, milk, and transportation of goods, in many regions of the world. Camels are particularly critical in the northern parts of Africa, above the tsetse belt. However, camel breeding areas are expanding into southern areas, under the pressures of global warming, leading to increasing risk of acquiring parasitic infections in these non-traditional ecotypes. Common biting flies (tabanids, stomoxyine flies, and Hippobosca camelina) act as mechanical vectors, resulting in exposure to trypanosomosis (Trypanosoma evansi; Surra) and high camel morbidity and mortality. In these regions, complicating infections with other Trypanosoma may also occur, particularly Trypanosoma vivax. In many modern camel-breeding areas, human populations are living under political upheaval (terrorism, riots), poverty, and precarity (drought, climate modification). Hence, control and/or elimination of Surra in camels would be beneficial to the economies of these populations. Due to the relatively straightforward epidemiology (single parasite with seasonal transmission in a single host species), control of Surra in Africa is affordable and should be based on implementing: (1) national veterinary services capabilities; (2) efficient diagnosis and control methods; (3) joint integrated control of Surra, gastrointestinal helminthoses (mainly haemonchosis), and sarcoptic mange. We propose that methods to control two economically-critical disease problems, gastrointestinal parasitosis and sarcoptic mange, will support improved Surra control in camels. Aided by decision-makers and donors, elimination of Surra could improve camel health and productivity, and stabilize camel-rearing in regions of the world that suffer from political instability and global warming pressures.

Camel milk composition by breed, season, publication year, and country: A global systematic review, meta-analysis, and meta-regression.

Camel milk consists of an essential macro/micronutrient for human nutrition in the arid and urban regions. This review study aimed to use meta-analysis statistical techniques for assessment and correction of publication bias, exploration of heterogeneity between studies, and detailed assessment of the effect of a comprehensive set of moderators including breed, season, country, year of publication, and the interaction between composition elements. This could provide a single synthesis of the camel milk composition to warrant strong generalizability of results, examine variability between available studies, and analyze differences in camel milk composition among different exposures. Such a finding will aid future researchers and health professionals in acquiring a more precise understanding of camel milk composition and drawing more clinical implications. Six searching databases and bibliographic were used including PubMed/MEDLINE, ScienceDirect, Springer, EBSCOhost, Scopus, and Web of Science from January 1980 to December 2021. The DerSimonian-Laird estimator was used to create the current random-effects meta-analysis. This systematic review and meta-analysis included a total of 7298 camel milk samples from 23 countries. This review comprises 79 studies published in the English language on or after 1980, including a subgroup of 117 analyses consisting of seasons, sub-breeds, and countries. The contents of macro/micronutrients in camel milk were identified as follows: protein, 3.17%; fat, 3.47%; lactose, 4.28%; ash, 0.78%; and total solids, 11.31%; calcium, 112.93 mg/100 g; iron, 0.45 mg/100 g; potassium, 116.13 mg/100 g; magnesium, 9.65 mg/100 g; sodium, 53.10 mg/100 g; zinc, 1.68 mg/100 g; vitamin C, 5.38 mg/100 g; vitamin A, 0.36 mg/100 g; vitamin B1 ,0.05 mg/100 g; vitamin B2 , 0.13 mg/100 g; vitamin B3 , 0.51 mg/100 g; vitamin B6 , 0.09 mg/100 g; and vitamin B12 , 0.0039 mg/100 g. Our meta-regression analysis found that fat and total solids were statistically significant moderators of protein; moreover, total solids content is a statistically significant moderator of fat. Discrepancies observed in camel milk profiles are dependent upon several factors, including number of included studies, number of samples, different analytical techniques, feeding patterns, camel's breeds, geographical locations, and seasonal variations.

The Flourishing Camel Milk Market and Concerns about Animal Welfare and Legislation.

The worldwide dromedary milk production has increased sharply since the beginning of this century due to prolonged shelf life, improved food-safety and perceived health benefits. Scientific confirmation of health claims will expand the market of dromedary milk further. As a result, more and more dromedaries will be bred for one purpose only: the highest possible milk production. However, intensive dromedary farming systems have consequences for animal welfare and may lead to genetic changes. Tighter regulations will be implemented to restrict commercialization of raw milk. Protocols controlling welfare of dromedaries and gene databases of milk-dromedaries will prevent negative consequences of intensive farming. In countries where dromedaries have only recently been introduced as production animal, legislators have limited expertise on this species. This is exemplified by an assessment on behalf of the Dutch government, recommending prohibiting keeping this species from 2024 onwards because the dromedary was deemed to be insufficiently domesticated. Implementation of this recommendation in Dutch law would have devastating effects on existing dromedary farms and could also pave the way for adopting similar measures in other European countries. In this paper it is shown that the Dutch assessment lacks scientific rigor. Awareness of breeders and legislators for the increasing knowledge about dromedaries and their products would strengthen the position of dromedaries as one of the most adapted and sustainable animals.

New animal-based measures to assess welfare in dromedary camels.

Reliable and measurable animal-based measures (ABMs) are essential for assessing animal welfare. This study aimed at proposing ABMs for dromedary camels identifying their possible associations with management. Data were collected at a permanent camel market; a total of 76 pens and 528 camels were evaluated. ABMs were collected for each welfare principle (i.e., good feeding, good housing, good health, appropriate behavior), while resources or management-based measures were collected at three levels of investigations (animal, herd, or caretakers). Associations were calculated by generalized linear models. Body condition score and thirst index (ABMs of good feeding) resulted negatively associated with short caretaker's experience, dirty bedding, limited shaded space, feeding and water space, and space allowance (P < 0.05). Resting behaviors and restricted movements (ABMs of good housing) were associated with short caretaker's experience, dirty bedding and water, rationed water distribution, water points in the sun, and presence of hobbles (P < 0.05). Disease, injury, and pain induced by management procedures (ABMs of good health) were negatively associated with short caretaker's experience, presence of hobbles, limited space allowance and shaded space, dirty bedding, and feeding and watering practices (e.g., frequency of distribution, resource quality, location of the troughs; P < 0.05). Response to approaching test and aggressivity (ABMs of Appropriate behavior) were negatively associated with limited space allowance, shaded, feeding and water space, and rationed water distribution (P < 0.05). Overall, the proposed ABMs seems to be appropriate indicators of welfare consequences in camels being able to identify factors related to housing and management practices that may impair or improve camel welfare.

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).

Recent Advances in Camel Milk Processing.

Camel milk is a newcomer to domestic markets and especially to the international milk market. This recent emergence has been accompanied by a diversification of processed products, based on the technologies developed for milk from other dairy species. However, technical innovations had to be adapted to a product with specific behavior and composition. The transformation of camel milk into pasteurized milk, fermented milk, cheese, powder, or other products was supported, under the pressure of commercial development, by technological innovations made possible by a basic and applied research set. Some of these innovations regarding one of the less studied milk sources are presented here, as well as their limitations. Technical investigations for an optimal pasteurization, development of controlled fermentation at industrial scale, control of cheese technology suitable for standardized production, and improvements in processes for the supply of a high-quality milk powder are among the challenges of research regarding camel milk.

Seroprevalence and risk factors for Trypanosoma evansi, the causative agent of surra, in the dromedary camel (Camelus dromedarius) population in Southeastern Algeria.

Surra, caused by Trypanosoma evansi, is a re-emerging animal trypanosomosis, which is of special concern for camel-rearing regions of Africa and Asia. Surra decreases milk yield, lessens animal body condition score and reduces market value of exported animals resulting in substantial economic losses. A cross-sectional seroprevalence study of dromedary camels was conducted in Algeria, and major risk factors associated with infection were identified by collecting data on animal characteristics and herd management practices. The seroprevalence of T. evansi infection was determined in sera of 865 camels from 82 herds located in eastern Algeria using an antibody test (card agglutination test for Trypanosomiasis - CATT/T. evansi). Individual and herd seroprevalence were 49.5% and 73.2%, respectively, indicating substantial exposure of camels to T. evansi in the four districts studied. Five significant risk factors for T. evansi hemoparasite infection were identified: geographical area, herd size, husbandry system, accessibility to natural water sources and type of watering. There was no association between breed, sex or age with T. evansi infection. Results of this study provide baseline information that will be useful for launching control programmes in the region and potentially elsewhere.

First report of Chlamydophila abortus infection in the dromedary camel (Camelus dromedarius) population in eastern Algeria.

Chlamydiosis is caused by an obligate intracellular gram-negative bacterium of the genus Chlamydophila which is a zoonotic pathogen. The objectives of the study were to identify the seroprevalence of antibodies against Chlamydophila abortus in dromedary camel herds from four districts in eastern Algeria, as well as to estimate the association between seroprevalence and certain factors present at the animal and herd levels. Blood samples were collected from a random sample of animals within each of 82 camel herds. Serum samples were subjected to a C. abortus ELISA test, and association between the presence of antibodies and potential risk factors was estimated. Animal and herd seroprevalence were 2.5 % and 15.8 %, respectively, indicating substantial exposure of camels to C. abortus in the four districts studied. Age, breed, and sex did not influence seroprevalence in tested animals. Based on the univariate analysis, contact with sheep and goats, contact with other camel herds, and histories of abortion were major risk factors for infection. By using multivariate analysis, contact of camels with sheep and goats and with others camel herds, through shared grazing or watering points, were important factors for transmission of chlamydiosis with an odds ratio of 3.3 and 9.4, respectively. At the herd level the introduction of purchased animals was the major risk factor. This baseline information will be highly useful for launching C. abortus control programs in the region and potentially elsewhere.

Correction to: Camelids: new players in the international animal production context.

In the originally published version of the article, Figure 4 image has an error. Corrected Fig. 4 is shown below.