Discriminant milk components of Bactrian camel (Camelus bactrianus), dromedary (Camelus dromedarius) and hybrids

In Kazakhstan, the cohabitation of Bactrian camels, dromedaries and their hybrids is a common feature even within farms. The physico-chemical composition of 147 milk samples from 57 Bactrians, 70 dromedaries and 20 hybrids was determined. The samples came from 4 different regions and were collected at 4 different seasons within a year. Compared with dromedary, Bactrian camel milk had significantly higher fat (6.67 vs. 5.94%), vitamin C (177 vs. 152 mg.L(-1)), calcium (1.30 vs. 1.16 g.L(-1)) and phosphorus (1.07 vs. 0.91 g.L(-1)). The iodine index value was significantly higher in dromedary (16.69) than in Bactrian milk (14.99). To distinguish Bactrian milk from dromedary milk, a discriminant analysis was carried out after discarding seasonal and regional variability. The discriminant parameters were phosphorus (linear discriminant coefficient = -1.00), pH (-0.408), vitamin C (-0.377) and fat content (-0.226), in higher concentrations in Bactrian than in dromedary milk. The iodine index (0.287) was higher in dromedary milk. After quadratic discriminant analysis, milk composition can predict species, with 75.4% well-classed. The milk composition of the hybrids was intermediary but with a low discriminant power.