Impact de l’incorporation de grains de tournesol dans la ration sur la qualité du lait de la race bovine locale Brune de l’Atlas.

Abstract

This study focuses on improving the performance of the local Brune de l'Atlas cattle breed, found in the El Kalaa region of Algeria, through the optimization of its diet. The experiment involved adding sunflower seeds to the diet of ten cows to assess the impact on milk quality. The results reveal a marked improvement in physicochemical quality: the lipid supplementation enables significant levels of fat (3.28%), protein (4.025%), and a total solids content of 13.09% to be achieved. This more concentrated milk offers superior processing characteristics. From a microbiological standpoint, although a slight increase in bacterial load was noted (5.5 vs. 5.2 Log CFU/mL), the product remains fully compliant with hygiene and food safety standards. Analysis of the ten isolated lactobacillus strains shows a predominantly homofermentative profile, ensuring rapid and stable acidification (pH 4.6 after 24 hours). Furthermore, the marked lipolytic activity of strains LT3 and LT6 suggests strong potential for the development of the aromatic qualities of derivative products. Finally, this nutritional strategy improves cheese yield, reaching 256.54 g, thanks to better water retention and reduced syneresis. The inclusion of sunflower seeds represents a sustainable and effective solution for maximizing the genetic potential of the Brune de l'Atlas. By simultaneously addressing the nutritional richness of the milk, microbiological safety, and the efficiency of cheese processing, this feeding protocol opens up concrete prospects for the enhancement of local livestock systems and the production of high-quality traditional dairy products.