A multi-approach study of the performance of dairy donkey during lactation: preliminary results

Abstract

Donkey milk is known for some nutritional and nutraceutical peculiarities compared to the milks traditionally used for human nutrition. Moreover although the number of studies on donkey milk production has increased the asinine species still remains little investigated. This is the first study providing a multiple assessment approach in order to extend the knowledge on the production of donkey milk, on the haematological and milk cytological parameters during the whole span of lactation. Furthermore, this study characterised the LYZ and OXT genes. Twenty two individual milk and blood samples from Amiatina donkey were taken at one, six and ten months after parturition. Milk total proteins and caseins and ash were significantly higher at the 1 month of lactation while the urea was lower (1.88% 0.95%, 0.41% and 26.08 mg/mL respectively). Whereas lactose and fat did not significantly changed and showed average values of 6.84 ± 0.145% and 0.67 ± 0.546% respectively. pH and titratable acidity were respectively higher (7.20) and lower (0.10 g/l of lactic acid) at 10th month. The mean values of somatic cell count/mL and of milk macrophages were low with maximum value at tenth month. The haematological parameters were stable during lactation except for mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration and platelet count with maximum at sixth month (respectively 20.22 pg, 36.1 g/dl, 281.16 x 109/l). This study also provides for the first time a characterisation of the LYZ gene in the Amiata donkey and describes a first polymorphism at the promoter level.Highlights This study extends the knowledge on the production of donkey milk, on the haematological and milk cytological parameters during the whole span of lactation. The results may have economic, health and social impacts since donkey milk is primarily targeted at sensitive consumers. Lysozyme polymorphisms could have association with anti-bacterial activity in milk and the inflammatory response in the mammary gland.

Keywords

• donkey milk quality
• lactation phase
• milk cytological analysis
• complete blood count
• genetic analysis