“The Influences of age on lactation length and milk yield in Kenana and Butana cows. ” (1990) The Sudan Journal Of Animal Production المجلة السودانية للانتاج الحيواني, 3(3), pp. 88–96. Available at: https://sud-jap.sd/Journal/index.php/sjap/article/view/64 (Accessed: 26 October 2026).