Calf silhouette

High Fat Feeding

The challenge

Design a milk replacer feeding schedule to maximize efficient growth while considering:

  • fat content of milk replacer
  • encourage grain intake prior to weaning
  • maintain growth rate through weaning
  • cold weather feeding implications

Using a higher milk volume feeding schedule and offering calves a higher fat content in a milk replacer does not mean that success at weaning will be compromised.  In fact, during 2015 and 2016 research trials at the Grober Young Animal Development Centre (GYADC), calves fed a 22% fat milk replacer consumed equivalent or more starter pre-weaning compared to calves fed a 17% fat formula.

Grain intake

Early solid feed intake is mandatory to establish functionality of the rumen.  In turn, significant nutritional value from solid feed may not be relied upon until rumen function and enzyme production strengthens, around week 6.  2016 GYADC research found that although calves fed a lower fat milk replacer consumed more grain during the week of weaning, the following week (post-weaning) growth rates were equivalent between both groups.  Despite different solid feed intake patterns, calves fed a 17% or a 22% fat milk replacer had strong growth rates for the 10 weeks prior to weaning and into the post-weaning period, with no slump in average daily gain seen for the 22% fat group.

Milk Replacer Week 8 Week 9

(one week prior to wean)

Week 10


Week 11


17% Fat 658g/day starter

740g/day growth

1230g/day starter

980g/day growth

2447g/day starter

1620g/day growth

3500g/day starter

1350g/day growth

22% Fat 769g/day starter

940g/day growth

1343g/day starter

960g/day growth

2303g/day starter

1180g/day growth

3073g/day starter

1340g/day growth


Feeding 750g per day of starter intake for three plus consecutive days is used as a minimum benchmark to indicate when a calf is ready for weaning.  At week 8 (two weeks prior to weaning) calves were consuming more than 750g of starter intake when fed either a 17% or 22% fat milk replacer…..even in the summer heat!!


Grober optimized their milk feeding program during the 2016 trial by providing up to 12.5L/day for the first five weeks, followed by a gradual volume reduction until weaning at week 10.  In addition, the 2014 GYADC research results showed advantages to weaning at 10 weeks compared to weaning at 7 weeks.  Allowing calves to stay on milk longer will provide additional time to consume levels of starter and forage to best maximize their rumen development before fully transitioning to solid feed, resulting in more consistent growth rates during this stressful period.


2016 GYADC trial results indicate both 17% and 22% fat milk replacer groups had equivalent body weights, calves fed the 22% fat milk replacer had significantly higher feed efficiency during weeks 1-5 (1.55 feed:gain for 22% group, 1.88 feed:gain for 17% group), further maximizing an already optimized 12.5L/day milk program.

Milk feeding schedules can be optimized with a higher energy density (fat) milk replacer and/or a higher milk allotment without negative consequences on starter intake.  Care still must be taken to ensure a slow stepdown to weaning.  Furthermore, using a higher fat milk replacer, or elevated milk allotments, have advantages during both hot and cold temperatures.  Higher feed efficiencies can be appreciated year round by providing additional energy.

Grober Nutrition

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