Does the aridity of Algerian steppe affect the Ewe's raw milk quality?

Abstract

The microbiological and physico-chemical quality of milks varies from bioclimatic stage toanother. The latest has significant effect on Total Bacterial Count (TBC), Total and Fecal Coliforms(TC and CT) and reduction time (P<0.001). The effect is highly significant for TBC, faecalStreptococci (P< 0.01) and significant only for Yeasts (P<0.05). No effect was observed for othermicrobiological variables. The variability of the chemical composition is significant for density andprotein (P<0.05), highly for pH, Dornic acidity, freezing point and solids-non-fat (P<0.01). Lactose,fat and total solids are independent. The semi-arid zone contains milks with a high density, weakfreezing point and less loaded on TBC, TC, FC and Moulds. They are rich in protein, fat and totalsolids. They differ from those other zones by the highest frequency of faecal Streptococci and absenceof Staphylococcus aureus. The inferior-arid includes the poorest in protein, fat, total solids, solidsnon-fat and lactose. It contains the most acidic milks (lowest pH and highest acidity), the less densitymilks and having the highest freezing point and it had the most loaded on TBC, TC, FC and Moulds.However, there are less milk loaded in Yeast and distinguished by the absence of faecal Streptococciand Brucella. The middle and superior arid reassemble milks with same characteristics andintermediate between the two stages. It seems that the milks which come from superior arid are richerin fat. These two zones are differentiated by the level of presence of E. coli, S. aureus and Brucella.The superior-arid combines milks with the highest count of Yeast and mostly contaminated withanaerobic sulfito-reducing.