Analyse des systèmes d'alimentation des troupeaux bovins laitiers et optimisation de la production laitière via des rations complètes dans la région semi-aride sétifienne

Abstract

This study aims to characterize feeding practices in dairy cattle farms in the semi-arid region of Sétif and to optimize milk production through the use of complete rations. A survey was conducted with 147 dairy farms, and an experiment was carried out at the COOPSSEL farm involving 18 dairy cows monitored during their first and second lactation. The study compared three distinct feeding regimes to evaluate their impact on various zootechnical parameters, including milk production, productive longevity, and farm profitability. The analysis of feeding practices reveals that dairy farms are heavily dependent on external supplies, indicating a low level of overall feed self-sufficiency. Grazing practices include zero grazing and semi-grazing systems. Supplementation does not address the specific needs of the cows, and only 6,8% of farmers implement feed rationing. Through a typological analysis, four classes of farming were identified: large farms with a focus on cereal production combined with dairy cattle and sheep farming; medium-sized farms combining cereal production and dairy cattle farming; small farms focused on cereal production and dairy cattle farming; and farms specializing in dairy cattle farming in a zero-grazing system. The main sources of variation are the usable agricultural area, the area allocated to forage, and the amount of concentrate distributed per cow per day. Dairy performance is considered very low. Farms view forage cultivation as a secondary activity and do not fully realize their dairy potential, remaining far from achieving the goals of an intensive and efficient system. The use of total mixed rations for dairy cows has led to better performance in both production (6 439,75 ± 347,51 kg/cow/year) and lactation persistence (92.95%), while reducing the cost of milk production compared to conventional feeding systems. These rations have helped decrease digestive disorders and maintain better stability of milk components. They have also shown favorable results in reproduction, with a higher success rate in first insemination. These results confirm the effectiveness of total mixed rations as a promising strategy to support the overall performance of dairy herds