Particle size distribution of total mixed rations fed to Italian Mediterranean buffaloes measured by the PSPS: impact on milk quality and digestibility

Abstract

Buffalo breeding in Italy is becoming increasingly economically attractive, with milk production in the Lazio region growing by 15% since 2004. However, the optimal physical characteristics of total mixed rations (TMR) have not been thoroughly investigated. This lack of research suggests the need for greater attention to the physical characteristics of diet, which, combined with its chemical properties, may negatively impact milk yield (MY) and milk quality (MQ), as seen in dairy cows. Therefore, the objective of this study was to assess the effect of diet composition, with a particular focus on the physical component, on MY and MQ, and apparent digestibility (AD) of dairy buffaloes. The study was conducted on 10 dairy buffalo farms in Amaseno valley (Italy). Monthly samples of TMR, faeces, and bulk milk were collected over a 12-month period, alongside interviews with farmers to gather information on MY and diet composition. The results revealed a high variability in the physical-chemical composition of diets across farms, attributable to differences in feeding management practices. Both chemical and physical component were found to be associated with MY, MQ and AD changes. A ration poor in roughage and rich in concentrate negatively affected MQ showing lower milk fat, and higher somatic cells count and milk urea, while a greater presence of coarse particles and high fibre were associated with lower MY. Nevertheless, coarse particles and aNDF were positively associated with milk clotting parameters and aNDF digestibility. Our study emphasised the high importance of fibre for improving MQ of dairy buffaloes.