Technology-driven improvements in dairy calf and heifer management: performance and economic impacts

• Ano de defesa: 2024
• Autor(a) principal: Silva, Luís Henrique Rodrigues
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa; Zootecnia
• Palavras-chave em Português: Bovinos de leite - Criação - Aspectos econômicos; Bovinos de leite - Criação - Métodos estatísticos; CIENCIAS AGRARIAS::ZOOTECNIA::PRODUCAO ANIMAL
• Link de acesso: https://locus.ufv.br/handle/123456789/33567; https://doi.org/10.47328/ufvbbt.2024.832

This study aimed to investigate how productive tiers on dairy farms impact the rearing and production costs of dairy calves and heifers in Brazil and estimate the payback timeline in average number of lactations. Data were gathered from 311 dairy farms in Minas Gerais, classified into three milk productive tiers based on average milk production: low (LOW) at 12.00 L/cow/d (7.36 -14.50 L/cow/d), intermediate (INT) at 18.00 L/cow/d (14.60 – 22.50 L/cow/d), and high (UPP) at 26.70 L/cow/d (22.60 – 32.00 L/cow/d). Statistical analyses were conducted using the GLIMMIX procedure in SAS Studio®, considering P-values < 0.05 as statistically significant and values between 0.05 and 0.10 as indicative of trends. The study found the Holstein breed was prevalent in UPP systems, while a Holstein × Gyr crossbreed animals were more prevalent in the LOW and INT tiers farms. The LOW and INT farms, characterized by more extensive rearing practices, had lower total milk outputs, larger grazing areas, and less intensified facilities. These conditions resulted in inferior performance metrics such as lower average daily gain (LOW: 0.41 ± 0.01 kg/d; INT: 0.51 ± 0.01 kg/d; UPP: 0.60 ± 0.01 kg/d) and delayed age at first calving (LOW: 35.6 ± 0.50 months; 29.9 ± 0.35 months; UPP: 26.0 ± 0.50 months). Consequently, the cost of raising a heifer from birth to first calving was highest in LOW farms at approximately US$ 2,006.4 ± 62.52, compared to US$ 1,821.4 ± 44.35 in INT and US$ 1,884.6 ± 62.52 in UPP. Feeding, labor, and machinery costs were the primary expenses, accounting for over 83, 85 and 83% of total costs across for LOW, INT e UPP respectively. The payback time based on expected production for a heifer need to remain in the herd was 3.98, 2.64 and 1.64 lactations for the LOW, INT and UPP tiers. This analysis underscores the significant influence of a farm's milk productive tiers on both performance and economic outcomes in dairy calf and heifer rearing. Farms with lower milk productive tiers incurred higher costs due to less efficient animal performance. The findings highlight the critical role of targeted investments to enhance efficiency and in dairy operations. Keywords: dairy farms; economic efficiency; farm management; calf; heifer.