Dairy Calves
Updated: June 14, 2021
By Sarah Potts

Do pre-weaned calves need forage?

Before the 1950s, it was assumed that hay and long forages were necessary to promote rumen development in young calves. However, research conducted during the mid-to-late 1950s demonstrated the importance of grain for rumen development. The digestion of rapidly fermentable carbohydrates (i.e., grain) in the rumen generates the volatile fatty acids propionate and butyrate. Butyrate is the key to rumen papillae development, which is critical for optimal rumen function. 

These studies highlighted the significance of starter grain intake of pre-weaned calves and led to the development of the industry standard that suggests that the level of starter grain intake be considered before a calf is weaned. The current standard indicates that a Holstein dairy calf should be consistently consuming at least 2.2 pounds of starter per day before weaning. Although consumption of starter grain is crucial for rumen development, whether forage has a place in the pre-weaned calf nutrition program has been up for debate for decades.

FOCAL POINT

  • Consumption of starter grain stimulates rumen development
     
  • There is no universally accepted standard for feeding forage to pre-weaned calves
     
  • Feeding forage may improve grain intake if calves are:
    • Over 3 weeks old
    • Eating over 1 lb/d of starter grain
    • Fed a pelleted or heat-treated starter grain
       
  • Forage intake should not exceed 5 to 10% of dry matter intake

 

Currently, it is recommended to offer pre-weaned calves free-choice starter grain within the first few days of life.  However, there is no universally accepted standard for offering forage to pre-weaned calves.  Producers are often encouraged to begin offering forage around or a little before weaning.  While feeding grain is important for rumen development, intake of high levels of rapidly fermentable grain may reduce rumen pH (i.e., induce acidosis) and actually limit intake.  Because forage consumption stimulates rumination and saliva production which enhances the rumen’s buffering capacity and its ability to maintain a more consistent pH, offering forage to pre-weaned calves has been suggested as a way to mitigate the potential negative effects associated with high levels of grain consumption.

Recent research studies have investigated the effect of feeding forage on the performance of pre-weaned calves but results are highly inconsistent.  The age of the calf and current starter intake level as well as characteristics of the starter grain offered likely contribute to the large variation in responses observed in these studies. A recently published review article indicated that older calves (at least 3-5 weeks) consuming higher levels of starter grain (over 1.4 pounds per day) may benefit most from forage supplementation.  

The characteristics of the starter grain likely also contribute to the variability in the response to offering forage.  Course, textured starter grain ferments more slowly and is less likely to reduce rumen pH than finely ground, heat-treated, and/or pelleted starter.  Thus, there may be less of a forage ‘need’ for calves fed a textured starter as compared with those fed a pelleted starter.

While feeding forage apparently has potential to benefit intake of pre-weaned calves in some situations, it is important to remember that feeding too much forage can have the opposite effect.  Because forage is bulkier and contains more neutral detergent fiber (NDF), it can physically limit overall intake if consumed in excess.  To avoid this issue, forage should be fed at no more than 5-10% of the diet on a dry matter basis.

Although the practice of feeding forage to pre-weaned calves is still being debated, recent studies suggest that feeding a small amount of forage to pre-weaned calves can be beneficial under some circumstances.  Calves over the age of 3 weeks that are consuming more than 1.4 pounds of a pelleted, heat-treated, or finely ground starter grain per day are most likely to benefit from this practice.

References for Further Reading

Imani, M., M. Mirzaei, B. Baghbanzadeh-Nobari, and M.H. Ghaffari. 2017. Effects of forage provision to dairy calves on growth performance and rumen fermentation: A meta-analysis and meta-regression. 100: 1136–1150. https://doi.org/10.3168/jds.2016-11561

Suarez-Mena, F. X., T.M. Hill, C.M. Jones, and A.J. Heinrichs. 2016. Review: Effect of forage provision on feed intake in dairy calves. The Professional Animal Scientist. 32:383–388. https://doi.org/10.15232/pas.2016-01502

Van Amburg, M.E. 2017. Nutrition of the preweaned calf. In D.K. Beede (Eds.), Large Dairy Herd Management, 3rd Ed (409-419). Champaign, IL: American Dairy Science Association.

This article appears on the March 11, 2021, Volume 2, Issue 1 of the Maryland Milk Moo's newsletter.

Maryland Milk Moo's, March 2021, Vol.2, Issue 1

Maryland Milk Moos is a quarterly newsletter published by the University of Maryland Extension that focuses on dairy topics related to Nutrition and Production, Herd Management, and Forage Production. To subscribe to this newsletter, click the button below to enter your contact information.

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