The aim of this work was to study the suitability of camel milk for the production of dairy products by lactic acid fermentation. Sixty strains of lactic acid bacteria (LAB) were isolated from camel milk. The strains were tested for their acidification activity, ability to use citrate, exopolysaccharide production, lipolytic, proteolytic activities and resistance to antibiotics. Ten strains were investigated for their ability to metabolize carbohydrates and that resulted in the identification of 5 Lactococcus lactis, 1 Lactobacillus pentosus, 2 Lactobacillus plantarum, 1 Lactobacillus brevis and 1 Pediococcus pentosaceus strains. Two strains of Lactococcus lactis SCC133 and SLch14 were selected to produce traditional Tunisian fermented dairy products (Lben, Raib, Jben cheese and Smen). These strains were chosen based on their acid production capacity and their ability to produce a high yield of biomass.

The transformation of camel milk into cheese is an operation considered very delicate because of several difficulties encountered in achieving coagulation. The present study aims to improve coagulation abilities of camel milk using enzyme extracts from pineapple, kiwi, and ginger. Our results concerning the characterization of the enzymatic extract showed an extraction yield that varies according to the type of extract (pineapple: 75.28% ± 4.59, kiwi: 63.97% ± 5.22, and ginger: 28.64% ± 1.47). The optimum coagulation conditions of the 3 types of extract were as follows: for pineapple: pH = 5 and temperature = 45°C; for kiwifruit: pH = 6.6 and temperature = 40°C; and for ginger: pH = 6.6 and temperature = 45°C. A fresh cheese was made from camel milk with a particular nutritional quality and consistency. The kiwi proteases displayed chymosin-like properties and thus hold the best potential for use as a milk coagulant in cheese production.

The objective of this work is to formulate a starter lactic seen application camel milk to prepare fermented product yoghurt. Lactic acid bacteria isolated from camel milk has different characterization tests and selection: morphological study, catalase test, gram stain, use of citrate, acidifying power, lipolytic power and proteolytic power. These tests have to choose the strains: 1, 4, 5, 6, 7, 8, 9 and 10 which has ΔpH ≥ 0.3U after 6h as the most acidifying and EPS producing strains. All the strains showed a proteolytic activity with zone diameters and proteolysis was between 15 and 21mm. In addition, these lactic acid bacteria were considered low lipolytic but all having antimicrobial activity against 11 pathogenic strains. Then freezedried lactic acid bacteria were prepared from these strains starters (1, 4, 5, 6 and 9). These were used to inoculate three types of milk after pasteurization, using each time a combination of two strains. These strains were applied to goat, camel and cow's milk for the preparation of yoghurt. The monitoring of these fermented products shows the combinations of strain nº1 with strain nº6 in the goat milk and cow milk certainly give us the desired product (yogurt). Because of pH, titratable acidity and viscosity seem so similar to those of natural yoghurt.

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Native genetic resource of goats is a pivotal source for meat and milk in southern Tunisia. Feeding is one of the most important activities of goat husbandry. Perceptions on the role of native feed resources for growth and carcass characteristics have not been well studied. Therefore, the present study was designed to help understand and to compare the influences of local forage resources (grass hay, dried olive leaves, Stipa tenacissima and oat hay) on growth performance and carcass characteristics of kids. The kids with the age of 4 months (average live bodyweight of 15 ± 58 kg) were selected for the study. The three study groups in the 90-day trial were as follows: Group C, where animals received oat hay only (control), Group OL, where animals received olive leaves (dried) + S. tenacissima and Group GH, where animals received grass hay. A daily allowance of commercially available concentrate (305 g DM/day) was offered to all groups (making about half of the total DM intake). At the end of the experiment, all animals were slaughtered. Statistical analysis showed that total DM intake was lower (P < 0.001) in C group (490.77 g) than the other two groups having similar DM intake (619.22 and 589.28 g for OL and GH, respectively). Average daily gain was comparable for the three groups (38.33, 40.71 g and 39.52, respectively, for C, OL and GH), with similar final liveweights. Cold carcass weight and carcass yield were not affected by diet treatment. Diet had no significant effect on individual organ weights and carcass composition. The use of the local forage resources evaluated in this trial could be used for the local goat population without loss of productivity when they make up about half of the diet along with a concentrate feed.

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Context The food security of Tunisia is dependent on utilising all of its resources effectively to feed the population. Rangelands used for grazing are subject to continuous degradation, which reduces the availability of feeds to livestock. In the oasis regions, this constraint is attenuated by the systematic use of various by-products of the palm grove. There is a need to constantly search for alternative feed resources to support ruminant-livestock farming in arid regions and, therefore, the products of desert oases need to be exploited Aims The present work aimed to determine the effect of the use of local resources of oases on feed intake and milk quality of goats. Methods Twenty-four indigenous lactating goats were used to investigate the effect of the substitution of the concentrate feed with alternative feed obtained from oases in Tunisian arid zones. The three study groups in the 60-day trial were as follows: the first group received 0% date waste (WD) + 100% concentrate (CON) + oaten hay; the second group received 50% WD + 30% alfalfa cork (AC) + 20% CON + alfalfa hay; and the third group received 50% WD + 50% AC and no CON + alfalfa hay. Key results Feed intake was higher in Group 2 (1167.10 ± 42.8 g DM/day) than in Groups 3 and 1 (1028.9 ± 68.9 and 856.04 ± 58.9 g DM/day respectively. Average daily milk production did not differ among the groups. Dietary fat and crude protein were not affected by the type of ration. The concentrations of saturated fatty acids were similar in the milk of the three groups. In the three groups studied, the ratio n6:n3 (12.80, 8.80 and 6.77) was higher than the recommended value (&lt;5) for human consumption. Conclusions The use of WD did not affect milk production but it improved the nutritional quality of milk, especially the composition of fatty acid (ratio n6/n3). Implications The use of alternative resources in goat feeding, such as WD and alfalfa cork, can replace the use of market feeds and decrease the costs of animal feed.

The aim of this work is to study the effect of lactation stage and camel farming system on microbiological, physicochemical parameters, and identification of lactic acid bacteria (LAB) of camel milk. Samples were collected from four camels in semi-intensive system and four camels in intensive system. Microbiological and physicochemical parameters were analyzed. Furthermore, to study the effect of lactation stage, samples were collected from three camels and followed during a period of 10 months of lactation from parturition. LAB were isolated from this sample and identified by biochemical methods. The difference between the physico-chemical characteristic basis of camel farming system are not statistically different except fat. The microbiological analysis showed a significant difference in total mesophilic bacteria, yeast, and molds and total coliform between intensive, semi-intensive, and extensive system. The difference between physicochemical and microbiological characteristics basis of lactation stage are statistically significant. In the intensive system, they were identified the same genre of bacteria: Lactococcus lactis, but in semi intensive system, we found different species of LAB. Eight of LAB identified as different Lactococcus or Lactobacillus was isolated in colostrums. The diversity of LAB was affected by lactation stage and farming system.