Effect of breed and dairy system on milk composition and udder health traits in multi-breed dairy herds

Absztrakt

The aim of the present study was to investigate the effect of breed and dairy system on milk composition and udder health (UH) traits in multi-breed dairy herds. Individual milk samples (n=1,516) were collected from 41 multi-breed herds located in Trento province (in the North-East Italian Alps). Six breeds were involved: Brown Swiss (n=661), Holstein Friesian (n=473), Jersey (n=45), Simmental (n=158), Grey Alpine (n=75) and Rendena (n=104). Four different farming systems were identified: „Original Traditional” (lactating cows that are moved to highland pastures during summer; n=9), „Traditional without summer pastures” (n=11) „Traditional with silages” (n=2), and „Modern” (n=19). Analysis of variance was performed on milk composition and UH traits using the MIXED procedure of SAS. Orthogonal contrasts were estimated between least squares means of traits for the breed and the dairy system effects. Relevant differences have been highlighted between the six breeds regarding the milk composition traits, while breed differences for UH traits were negligible. The dairy system management revealed a limited influence on all considered traits.