Energy Inputs and Needs: Impact on Milk Production and Body Reserves in Dairy Cows

Abstract

Algeria is a major importer of milk and dairy cows, with the Holstein and Monbéliarde breeds being the most common. Adapting these cows to their new environment poses a significant challenge in maintaining their original performance. This research aims to determine how feed input and milk production relate to body condition score (BCS) and energy reserves. Over three lactation periods, two flocks of dairy cows, 20 Prim’Holstein (PH) and 20 Montbéliarde (MB), pregnant at 5.6 ± 0.4 (PH) and 5.5 ± 0.4 (MB) months, were monitored under the same rearing conditions. The staple diet consisted of barley silage, green clover, grain barley, and wheat bran, with concentrate consumed twice daily during the milking period. Throughout three lactation periods, the state of body reserves deteriorated gradually, reaching BCS values below 2. In the first lactation, milk production was 4,211 ± 340 kg for MB and 3,965 ± 328 kg for PH, 5,024 ± 360 kg (MB) and 4,660 ± 420 kg (PH) in the second lactation and 5,700 ± 530 kg (MB) and 5,180 ± 400 kg (PH) in the third lactation. During the first week of lactation, the energy needs coverage rates for PH and MB were only 70 % and 77 %, respectively, while on the 30th day they were 66 % and 74 %, respectively. The balance between needs and inputs is restored at 120 %, starting on the 90th day of lactation. This energy deficit was recurring in both breeds and occurred during subsequent lactation.