Performance, Health, and Behavioral Responses of Pre-Weaned Calves to Different Liquid Diets and Physical Forms of Starter

This study examines the critical role of whole milk or milk replacer as a liquid diet (LD) with 15% solids in combination with different physical forms of starter as a solid diet (SD), on performance, health, and behavior of pre-weaned calves. Sixty male Holstein calves were used in a 2 × 2 factorial design, and randomly distributed into the following treatments: Whole milk powder diluted to 12.5% of solids and enriched with 25 g/L of milk replacer to achieve 15% solids, associated with either micropelleted stater (WM+micro) or texturized stater (WM+text); milk replacer diluted to 15% solids associated with either micropelleted stater (MRmicro) or texturized stater (MRtext). Starter intake and, consequently, total DMI were higher in the MRtext treatment compared to WM+micro. Calves fed texturized starter showed higher DMI, starter intake time, and rumination time. Calves in the WM+Text group showed greater ADG compared with MR treatments, regardless of starter type. Calves fed WM+ presented a lower number of days with fecal score ≥2, and the first day of diarrhea occurred at older ages. Calves fed MR showed more health challenges but similar feed efficiency with WM+, while texturized starter increased intake, eating duration, and rumination compared with micropelleted starter.