Effet du stade de lactation sur la qualité physico-chimique de lait de vache

Abstract

This thesis examines the effect of lactation stage on the physicochemical quality of cow's milk, focusing on the biological and physiological variations that influence milk composition. It begins with an in-depth review of mammary gland anatomy, the lactation cycle, and the hormonal processes that trigger and regulate milk secretion. The study then presents the various intrinsic (breed, age, lactation stage) and extrinsic (feeding, season, milking hygiene) factors influencing milk production and milk quality, particularly in terms of fat, protein, pH, acidity, specific gravity, and mineral composition. An experimental portion was conducted on milk samples collected at different stages of lactation. The results show that lactation stage significantly affects milk fat, protein, acidity, and specific gravity. Milk from early and late lactation has different physicochemical characteristics compared to mid-lactation milk, which has important implications for the health and nutritional quality of the milk produced. This thesis emphasizes the importance of rigorous herd and lactation cycle management to ensure quality milk production, suitable for human consumption and the dairy industry.