# On-farm approaches to increase whole-milk total solids: Effects on performance and health of dairy calves

## TL;DR

This study compared two methods to adjust milk solids for calves and found both effective, with a fixed dose being simpler for farm use.

## Contribution

The study introduces practical on-farm methods to adjust milk solids for calves, comparing their effectiveness and simplicity.

## Key findings

- Both fixed-dose and Brix refractometer methods improved milk solids and calf performance similarly.
- Fixed-dose feeding simplified management while maintaining health and growth outcomes.
- Serum protein levels were higher with the fixed-dose method, but overall calf health was comparable.

## Abstract

Summary: This study evaluated 2 methods for adjusting whole milk solids to 15% for feeding Holstein calves: a fixed-dose approach and daily adjustment using a Brix refractometer. Thirty male calves were assigned to one of the 2 methods and monitored for 56 days. Daily Brix adjustment improved liquid diet, protein, and lactose intake, and both methods resulted in similar calf performance and health. Both strategies were effective and practical for managing milk solids on dairy farms; however, using a fixed dose of a corrector or milk replacer simplifies the feeding routine. (Images from Freepik; macrovector and brgfx.)

Summary: This study evaluated 2 methods for adjusting whole milk solids to 15% for feeding Holstein calves: a fixed-dose approach and daily adjustment using a Brix refractometer. Thirty male calves were assigned to one of the 2 methods and monitored for 56 days. Daily Brix adjustment improved liquid diet, protein, and lactose intake, and both methods resulted in similar calf performance and health. Both strategies were effective and practical for managing milk solids on dairy farms; however, using a fixed dose of a corrector or milk replacer simplifies the feeding routine. (Images from Freepik; macrovector and brgfx.)

•On-farm approaches to increase the solids content in the liquid diet were evaluated.•A fixed dose and adjustment by Brix refractometer had similar results in calf performance.•Using a fixed dose of the product could facilitate management on dairy farms.

On-farm approaches to increase the solids content in the liquid diet were evaluated.

A fixed dose and adjustment by Brix refractometer had similar results in calf performance.

Using a fixed dose of the product could facilitate management on dairy farms.

This study aimed to evaluate the performance, metabolism, and health of Holstein calves fed whole milk adjusted for 15% TS by adding a commercial solids corrector (245 g/kg CP, 48 g/kg crude fat, 90 g/kg of mineral, and 3 g/kg of ADF) using 2 practical approaches: daily adjustment based on a Brix refractometer reading, or the addition of a fixed amount of the corrector based on mean milk solids content. Thirty newborn male Holstein calves were assigned to one of the 2 treatments: (1) fixed, in which whole-milk solids were adjusted using a fixed dose of 25 g/L, and (2) Brix, in which whole-milk solids were adjusted based on a daily Brix refractometer reading. Treatments were randomly assigned within blocks formed based on BW and birth date (2 calves per block). The experimental period lasted 56 d, during which calves were fed 6 L/d of the respective liquid diet and had free access to water and starter concentrate. Daily adjustments based on the Brix refractometer reading improved total liquid diet, as well as protein and lactose intake. However, calf performance and health indicators did not differ between treatments. Total serum protein concentration was greater in calves fed milk corrected using the fixed dose. Additionally, creatinine concentration was influenced by the interaction between treatment and age, with a trend toward greater concentrations in calves fed milk adjusted using the daily Brix refractometer reading at 2 wk of age. Overall, both strategies for increasing TS in whole milk (Brix refractometer and fixed dose) resulted in comparable performance and health outcomes and may serve as practical on-farm approaches for managing dairy calves.