Accordance between measured and predicted dry matter intake in Italian Holstein Friesian cattle

In order to increase the accuracy of the current official predicted DMI (pDMI) in Italian Holstein Friesian (HF) lactating cows, a total of 352 Italian HF with direct measurements for dry matter intake (DMI) have been considered. Individual measured DMI data were compared with the individual pDMI derived from milk yield, fat content, and predicted cow body weight. DMI data of lactating cows were measured using both alkane method (296 lactating cows-UNICATT) and Roughage Intake Control system (Insentec) (54 lactating cows – Animal Production Research and Teaching Centre Lodi (CZDS) – UNIMI). Average DMI was equal to 21.90±4.22 kg/day whereas mean pDMI was 24.28±2.53 kg/day (UNICATT: 22.25±4.26 kg/day; UNIMI: 20.07±3.5). Pearson correlation between DMI and pDMI was 0.52 (P<0.01). Considering groups separately, correlations were 0.54 (P<0.01) and 0.32 (P<0.02) for UNICATT and UNIMI cows, respectively. Difference between the two groups could be related to several circumstances, including sample size, number of herds considered and DMI assessment method. Overall, results are promising, even if other prediction equations can be implemented. However, this approach can be considered a good starting point to estimate the DMI for HF cattle, at population level. Dry matter intake, being a key component of feed efficiency in dairy cattle, is an interesting new trait to consider in selection scheme for dairy cattle populations. In this regard, an Italian consortium has been created in order to build up feed efficiency critical mass data. Furthermore, this study was intended also to set up future objectives and to streamline data-collection process in future experiments.