A comparative analysis of dairy production systems: Milk production tiers and their impact on dairy calf and heifer cost of production in Brazil.

The objective of this study was to estimate the costs associated with raising dairy calves and heifers in Brazil during 2021. Additionally, it sought to determine the average number of lactations that heifers should remain in the herd to cover their production costs, analyzing data from 311 dairy farms in Minas Gerais. These farms were categorized into 3 milk productive tiers based on daily milk production per cow: lower production tier (LOW) 12.0 L/cow per day (7.4-14.5 L/cow per day); intermediate production tier (INT) 18.0 L/cow per day (14.6-22.5 L/cow per day), and upper production tier (UPP) 26.7 L/cow per day (22.6-32.0 L/cow per day). Mean comparisons were performed using the GLIMMIX procedure of SAS. The main cost factors were feed, labor, and machinery, which together accounted for 83.0%, 85.0%, and 83.0% of the total costs for LOW, INT, and UPP tiers, respectively. The cost of raising a heifer from birth to calving tended to be lower for INT tier ($1,821.40 ± $44.35) and higher for LOW tier ($2,006.40 ± $62.52), whereas UPP tier had a cost of $1,884.60 ± $62.52, which was similar to both LOW and INT tiers. To cover their production costs, the average number of lactations that cows should remain in the herd was 3.98 (1.33-9.33) lactations for the LOW tier, 2.64 (1.33-6.33) lactations for the INT tier, and 1.64 (0.66-3.66) lactations for the UPP tier. Dairy farms with lower production have higher costs for rearing calves and heifers due to prolonged development and delayed age at first calving, largely due to less efficient growth, feeding and reproduction methods. Feed was the main cost, followed by labor and machinery. Improving genetics and management or purchasing better genetic animals can reduce costs and increase productivity, especially on farms with limited resources.