Protein encapsulated fat (PEF) blends are routinely used for manufacturing calf milk replacers (MR). The use of PEF blends improves fat mixability to ensure MR when mixed and fed as a homogenous solution for neonatal calves. A new alternative PEF based on choice white grease (CWG) has been developed to improve its mixability and solubility to ensure a homogenous MR solution. The alternative PEF is hypothesized to support similar growth performance (ADG, DMI, and/or feed efficiency) of neonatal calves while potentially reducing cost. The study objective was to evaluate CWG PEF as an alternative to a standard animal-lard-tallow (ALT) PEF blend to mix a MR to be fed to Holstein calves. Forty 2- to 5-d old Holstein bull calves were blocked by BW and randomly assigned to 1 of 2 treatments (n = 20/treatment) using a Randomized Complete Block Design. Treatments were: 1) CWG used to manufacture a PEF blend, and 2) ALT used to manufacture a PEF blend. The PEF blends were then used to manufacture 2 experimental MR. Both MR were formulated to contain 22:20 (crude protein: CP:fat) with Met, Lys, Thr, Trp, and Val AA specifications and fed 2x/d along with a 22% CP mini-pelleted calf starter (CS) and free choice water. The MR were fed at 15% solids at 0630 and 1800 h fed at 0.567 kg/d for d 1-14, increased to 0.85 kg/d for d 15-35, and reduced to 1x/d at 0.425 kg/d for d 36-42 to facilitate weaning at 42 d with ad libitum CS fed for the remaining days of the 56-d study. Calves fed CWG and ALT PEF blends were similar (P > 0.10) in BW gain (37.4 and 35.9 kg for CWG and ALT, respectively), ADG (679.8 and 652.7 g/d), CS DMI intake (0.69 and 0.67 kg/d), total DMI (1.19 and 1.17 kg/d) and feed conversion (0.559 and 0.543 kg/kg). No significant differences were detected in frame gains and fecal scores among treatments. Choice white grease can be used to manufacture a PEF blend for use in manufacturing MR for feeding neonatal calves by maintaining growth performance and health at potentially lower cost.
Keywords: encapsulated fat; fat; milk replacer; protein.
© 2025, The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).