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Milk replacer feeding rate and fat concentration for Jersey calves

Xavier Suarez and Mark Hill for Progressive Dairy Published on 19 July 2020

It is often assumed that because Jersey cows have higher fat content in their milk, milk replacers for Jersey calves also need to be higher in fat. However, this has not been confirmed, as research in Jersey calves is limited.

In Holstein calves, researchers at Provimi have observed higher fat levels in milk replacer to reduce starter intake and calf growth. A study from Texas Tech comparing Holstein and Jersey calves suggested that Jersey calves can consume more milk per unit of bodyweight in the first two weeks of life, and another study from the same university indicated that the digestive system of 1-week-old Jersey calves is capable of digesting 1.25 pounds of milk replacer powder.

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Research from Virginia Tech suggested smaller-breed calves have higher maintenance requirements. In their research, calves fed high-protein milk replacers with either 16% or 33% fat milk replacer gained similar amounts of bodyweight when no starter was fed; however, calves fed 16% fat milk replacer grew numerically more frame and accumulated less body fat than calves fed 33% fat milk replacers. In a recent study, we fed Jersey calves either 1 or 1.5 pounds per day of milk replacer powder, calves fed more milk replacer had reduced post-weaning digestion and bodyweight gain, and frame growth was similar to 4 months old.

With the aim to better understand the effects of fat content in milk replacer at different feeding rates on Jersey calf performance and digestion, we conducted a study using 100 Jersey heifer calves. The milk replacers had 24% protein and either 24% or 17% fat and were fed at 1 pound or up to 1.5 pounds of powder per day. Calves had free access to water and a high-starch textured calf starter. Weaning occurred at 7 weeks, calves were grouped at 8 weeks by treatment and fed similarly to 4 months old.

Milk replacer feeding rate

From zero to 8 weeks (Table 1), calves fed the high rate of milk replacer consumed a total of 23 pounds more milk replacer and gained 4.6 pounds more bodyweight (7.5% greater ADG) compared to calves fed moderate amounts of milk replacer.

ilk replacer feeding rate and fat concentration of Jersey calf

Feeding more milk reduced starter intake by 15% and fiber digestibility by 18% at 3 weeks old. Fiber digestibility is an indicator of digestive system development; therefore, calves on the moderate milk replacer program had a more mature digestive system earlier in the pre-weaning period.

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Greater dry matter digestion observed for calves fed more milk was expected at 3 weeks old, as those calves were consuming 50% more milk replacer than calves on the moderate program and milk replacer is more digestible than starter. Frame growth and feed efficiency were similar between feeding rates during the first eight weeks.

In the post-weaning period (8 to 16 weeks), the bodyweight advantage for calves fed more milk in the nursery period disappeared by 16 weeks (Table 2).

Performance of Jersey calves prevously fed two milk replacer rates

Other growth parameters were also similar between feeding rates; therefore, feeding more milk did not net any growth advantage by 4 months old.

Milk replacer fat concentration

From zero to 8 weeks, calves on 24% fat milk replacer consumed 15% less starter, and their frame growth was 7% less than calves on 17% fat milk replacer. Feed efficiency tended to be 5% lower, and fiber digestibility was 26% lower for calves fed more fat in milk replacer. Growth was negatively impacted post-weaning by feeding more fat in the milk replacer, as bodyweight gain and feed efficiency tended to be lower, and bodyweight at the end of the study was 5% lower for 24% versus 17% fat.

Carry-over effects of milk or milk replacer programs during the post-weaning period are not always reported, as many studies stop measurements at weaning or shortly after; this study supports that pre-weaning feeding program evaluations should extend at least two months after weaning to understand longer-term implications of those feeding programs.

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Under the conditions of this study, feeding more milk replacer than a moderate amount did not improve Jersey calf growth to 4 months old, and adding more fat to milk replacer from 17% to 24% negatively impacted growth. These results are consistent with a tremendous amount of published, expert-reviewed research in Holstein calves when viewed relative to bodyweight. Feeding 1 pound of milk replacer to a 60-pound birthweight Jersey calf is equivalent to feeding 1.5 pounds of milk replacer to a 90-pound birthweight Holstein calf per pound of birthweight.

Feeding program economics

When looking at the economics of the feeding programs (Table 3), the program with the best return was the moderate milk replacer feeding rate with 17% fat with a $45 advantage over the program with the lowest return (high milk replacer feeding rate with 24% fat).

Economics of milk replacer feeding program to 4 months of age

On average, feed costs for the higher feeding rate program was $25 greater than the moderate program, and the value of gain over feed cost was $26 less. Even though the 24% fat milk replacer was more expensive, total feed cost only increased about $3 per calf for 24% fat as calves consumed less dry feed, but the value of gain over feed cost was $18 less than feeding a 17% fat milk replacer.

Some professionals in the field may argue that $25 more in milk replacer will pay back with more milk in the first lactation, as was theorized in a Cornell University study after they observed that calves with higher gains in the pre-weaning period (fed the same diets) produced more milk in the first lactation. However, more recent studies from Penn State and the University of Minnesota testing this theory have reported that increased growth from the liquid diet has little or no effect on first-lactation performance and that starter intake has a greater impact in improving first-lactation production.

There may be situations where extra calories from either additional milk replacer or fat intake are beneficial to calves during the first three weeks of life (winter feeding); however, measures should be taken to reduce potential negative effects this may have post-weaning. If we know that feeding more milk replacer or fat will reduce starter intake, and lower starter intake slows down rumen development, we can modify the weaning process to give calves an opportunity to make up for lower daily starter intake by keeping calves on milk longer. Another strategy would be to feed more milk replacer or fat during the first three weeks, when caloric demands are greater, but reduce amounts after 3 weeks old to improve starter intake.  end mark

Xavier Suarez, Ph.D., is a calf and heifer specialist with Provimi. Email Xavier Suarez. Mark Hill, Ph.D., is a ruminant nutritionist with Provimi.

References omitted but are available upon request. Click here to email an editor.

Take-home points

1. Feeding high versus moderate amounts of milk replacer to Jersey calves reduced starter intake in the first 8 weeks and did not improve growth to 4 months old.

2. Milk replacer with 24% versus 17% fat in moderate or high milk replacer programs reduced starter intake in the first 8 weeks and did not improve growth to 4 months old.

3. Feeding the high milk replacer feeding rate program cost $25 more than the moderate program.

4. In addition, the higher milk replacer feeding rate program did not show any additional value in gain over feed costs, as its value was $26 lesser than the moderate program. 

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