Relationship between udder morphology traits, alveolar and cisternal milk compartments and machine milking performances of dairy camels (Camelus dromedarius).

摘要

A total of 22 dairy dromedary camels under intensive conditions in late lactation (275+or-24 days) were used to study the relationship between external and internal udder morphology and machine milking performances. Measurements of udder and teat morphology were obtained immediately before milking and in duplicate. Individual milk yield, lag time and total milking time were recorded during milking, and milk samples were collected and analyzed for milk composition thereafter. Cisternal and alveolar milk volumes and composition were evaluated at 9 h milking interval. Results revealed that dairy camels had well developed udders and milk veins, with medium sized teats. On average, milk yield as well as milk fat and protein contents were 4.80+or-0.50 L d-1, 2.61+or-0.16% and 3.08+or-0.05%, respectively. The low fat values observed indicated incomplete milk letdown during machine milking. Lag time, and total milking time were 3.0+or-0.3, and 120.0+or-8.9s, on average, respectively. Positive correlations (p<0.05) were observed between milk yield and udder depth (r=0.37), distance between teats (r=0.57) and milk vein diameter (r=0.28), while a negative correlation was found with udder height (r=-0.25, p<0.05). Cisternal milk accounted for 11% of the total udder milk. Positive correlations were observed between total milk yield and volume of alveolar milk (r=0.98; p<0.001) as well as with volume of cisternal milk (r=0.63, p<0.05). Despite the low udder milk storage capacity observed in dairy camels, our study concluded that the evaluated dromedary sample had adequate udder morphology for machine milking. Finally, positive relationships were detected between milk yield and udder morphology traits of dairy camels.