Chronic subclinical mastitis reduces milk and components yield at the cow level

Autor(es)

Martins, Larissa ^[1] ; Barcelos, Melina Melo ^[1] ; Cue, Roger I. ^[2] ; Anderson, Kevin L. ^[3] ; Santos, Marcos Veiga dos ^[1] ; Goncalves, Juliano Leonel ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Vet Med & Anim Sci, Dept Anim Nutr & Prod, BR-13635900 Quebec, SP - Brazil

^[2] McGill Univ, Dept Anim Sci, Ste Anne De Bellevue, PQ H9X 3V9 - Canada

^[3] North Carolina State Univ, Coll Vet Med, Dept Populat Hlth & Pathobiol, Raleigh, NC - USA

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF DAIRY RESEARCH; v. 87, n. 3, p. 298-305, AUG 2020.
• Citações Web of Science: 0

Resumo

We evaluated the effects of chronic subclinical mastitis (CSM) caused by different types of pathogens on milk yield and milk components at the cow level. A total of 388 Holstein cows had milk yield measured and were milk sampled three times at intervals of two weeks for determination of SCC and milk composition, and microbiological culture was performed. Cows were considered healthy if all three samples of SCC were <= 200 000 cells/ml and were culture-negative at the third milk sampling. Cows with one result of SCC > 200 000 cells/ml were considered to suffer non-chronic subclinical mastitis whereas cows with at least 2 out of 3 results of SCC > 200 000 cells/ml had CSM. These latter cows were further sorted according to culture results into chronic negative-culture or chronic positive-culture. This resulted in four udder health statuses: healthy, non-chronic, chronicNC or chronicPC. The milk and components yields were evaluated according to the udder health status and by pathogen using a linear mixed effects model. A total of 134 out of 388 cows (34.5%) were chronicPC, 57 cows (14.7%) were chronicNC, 78 cows (20.1%) were non-chronic and 119 cows (30.7%) were considered healthy, which resulted in a grand total of 1164 cow records included in the statistical model. The healthy cows produced more milk than each of the other groups (+2.1 to +5.7 kg/cow/day) and produced higher milk component yields than the chronicPC cows. The healthy cows produced more milk than cows with chronicPC caused by minor (+5.2 kg/cow/day) and major pathogens (+7.1 kg/cow/day) and losses varied from 5.8 to 11.8 kg/cow/day depending on the pathogen causing chronicPC mastitis. Chronic positive-culture cows had a reduction of at least 24.5% of milk yield and 22.4% of total solids yield. (AU)

• Processo FAPESP: 14/17411-6 - Impacto econômico e perfil de agentes etiológicos da mastite bovina
• Beneficiário: Marcos Veiga dos Santos
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/23613-8 - Impacto da mastite subclínica sobre custo de produção e qualidade do leite em rebanhos leiteiros
• Beneficiário: Juliano Leonel Gonçalves
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 15/04570-1 - Impacto da mastite subclínica sobre custo de produção e qualidade do leite em rebanhos leiteiros
• Beneficiário: Juliano Leonel Gonçalves
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 15/00142-5 - Produção e composição do leite em vacas com mastite subclínica causada por Streptococcus ambientais
• Beneficiário: Larissa Martins
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica