The aim of this study was to validate selected precision livestock farming (PLF) methods of nutrition and feeding management of high-yielding Holstein dairy cows. In a feeding trial with 36 dairy cows, the effect of replacing 0.1 kg of sodium bicarbonate in the control total mixed ration (TMR-C) with 1 kg of wheat straw in the experimental total mixed ration (TMR-S) on the physiological status of cows and the amount of milk produced (milk yield, MY) was investigated. Feed intake time (FT), as measured using tensometric feed troughs (TFT), was significantly longer with TMR-S (188 min) than with TMR-C (157 min). Differences between TMR-C and TMR-S were not significant for FT or rumination time (RT), as measured by a sensor in the collar (VSC). There was only a weak correlation between the two technologies (TFT vs. VSC) for FT (r = 0.27). Differences between TMR-C and TMR-S were not significant for values measured in rumen fluid (pH, acid and ammonia levels) nor for values measured by sensors in the milking parlour (MY, fat and protein percentage of milk). Milk analysis in the laboratory showed that the cows fed TMR-C had higher urea (26.6 vs. 22.7 mg/100 ml) and free fatty acid (0.87 vs. 0.33 mmol/100 g) levels in milk. Moderate correlations were between TMR intake and MY (r = 0.55); between MY and milk fat (r = –0.46); between milk fat and milk protein (r = 0.63); and between milk fat and milk protein measured by sensors and in the laboratory (r = 0.47 and r = 0.42, respectively). In view of the above results, further research and data validation for each technology are needed.