Metagenomic analysis of bacterial community composition in Dhanaan: Ethiopian traditional fermented camel milk.

This study was conducted to evaluate the safety and bacterial profile of Dhanaan (Ethiopian traditional fermented camel milk). The composition of the microbial community in Dhanaan samples was analysed by a metagenomic approach of 16S rRNA gene amplicon sequencing. Metagenomic profiling identified 87 different bacterial microorganisms (OTUs) in six samples analysed. Although the Dhanaan samples contained various lactic acid bacteria (LAB), they also all contained undesirable microorganisms in large proportions. The following LAB genera were identified: Streptococcus, Lactococcus and Weissella. One Streptococcus species represented by OTU-1 (operational taxonomic unit) was found in all Dhanaan samples and the dominating species in four out of six samples. This common isolate was found to be closely related to S. lutetiensis and S. infantarius. Undesirable microorganisms from genera such as Escherichia, Klebsiella, Enterobacter, Acinetobacter and Clostridium were, however, also frequent, or even dominant in Dhanaan samples. Thus, this calls for a change in the Dahnaan manufacturing practice to an improved and safer production system. Starter cultures suitable for Dhanaan production might be developed from the Streptococcus, Weissella and Lactococcus microorganisms identified in this study. However, further safety evaluation and technological characterization need to be conducted on strains defined by OTU-1, OTU-2, OTU-3, OTU-8 and OTU-35 before they can be used as food grade starter cultures.

Processing Challenges and Opportunities of Camel Dairy Products.

A review on the challenges and opportunities of processing camel milk into dairy products is provided with an objective of exploring the challenges of processing and assessing the opportunities for developing functional products from camel milk. The gross composition of camel milk is similar to bovine milk. Nonetheless, the relative composition, distribution, and the molecular structure of the milk components are reported to be different. Consequently, manufacturing of camel dairy products such as cheese, yoghurt, or butter using the same technology as for dairy products from bovine milk can result in processing difficulties and products of inferior quality. However, scientific evidence points to the possibility of transforming camel milk into products by optimization of the processing parameters. Additionally, camel milk has traditionally been used for its medicinal values and recent scientific studies confirm that it is a rich source of bioactive, antimicrobial, and antioxidant substances. The current literature concerning product design and functional potential of camel milk is fragmented in terms of time, place, and depth of the research. Therefore, it is essential to understand the fundamental features of camel milk and initiate detailed multidisciplinary research to fully explore and utilize its functional and technological properties.

Defining weaning age of camel calves in Eastern Ethiopia.

This experiment was conducted with the aim to define the weaning age of camel calves managed with pastoral farmers in eastern Ethiopia. Twenty camel calves (11 males and 9 females) were randomly assigned into five blocks based on their birth date. Calves within a block were further assigned to one of the four Treatments (T1, T2, T3, and T4). Calves in T1, T2, and T3 were weaned at 6, 8, and 10 months of age and supplemented with concentrate from weaning up to 12 months of age, respectively. They were supplemented with a mixture of noug seed (Guizotia abyssinica) cake and wheat bran at a ratio of 40% and 60%, respectively. Calves in T4 (control) were weaned at 12 months of age, hence were not supplemented with concentrate. Calves in all treatment groups browsed natural vegetation for 8 hours a day. Post weaning performance was evaluated for all calves at 14 months of age. The mean daily concentrate intake was significantly higher (P < 0.001) in the dry season compared to the wet season. Daily weight gain was significantly (P < 0.001) affected by treatment, sex of calves, and season of birth. Calves supplemented with concentrate gained relatively more weight (P < 0.001) than calves not supplemented. Calves born during the short rainy season gained more weight than those born during the short and long dry season. Three calves died, two from T3 and one from T4. From the study it was concluded that weaning calves at 8 months of age and supplementing with concentrate to the age of 12 months of age resulted in good post weaning growth rate and survivability of calves.