6 Questions and Answers About Rumen Development in Calves
By Kevin Miller Ph.D. MS Biotec September 10, 2014 | 7:16 pm EDT
Q: What does the rumen need to begin to develop and function?
A: Microbes, water and solid feed are three important components of rumen development. Microbes from the environment are introduced into the rumen shortly after birth. The microbial population grows and diversifies as the calf begins to consume solid feeds and water. Water provides an ideal environment for microbial fermentation. Feed is used as a substrate by microbes to produce volatile fatty acids, which provide energy for the calf to grow, and play a major role in rumen development. Butyrate, and to a lesser extent propionate, supply energy for the growth of papillae – the finger-like projections responsible for absorption of nutrients from the rumen.
Q: How does my milk/milk replacer feeding program affect rumen development?
A: A conventional feeding program – one that limits the amount of milk or milk replacer given to calves daily – is designed to encourage calf starter intake and rumen development, allowing calves to be weaned as soon as possible. In contrast, feeding a higher plane of nutrition pre-weaning can decrease starter intake and slow rumen development because of the higher volume of liquid fed. The tradeoff is that this approach has been shown to enhance calf growth and milk production when these animals enter the milking herd.
Q: Does the composition of my calf starter impact rumen development?
A: Yes, highly palatable concentrate-based diets result in optimal rumen development. Both grain type and its processing method impact the rate at which the rumen develops. Although forages stimulate the musculature and volume of the rumen, as well as help maintain papillae health, they may limit intake. Forages also have limited efficacy for stimulating papillae development. Therefore, limit or delay feeding forages until the rumen has reached adequate development, which occurs when the calf is consuming about 4-6 pounds of feed daily. Other dietary ingredients, such as molasses, may increase starter intake by increasing diet palatability and reducing dustiness of the diet.
Q: What tools can I use to improve rumen development?
A: Sodium butyrate and some direct-fed microbials have been effective at increasing rumen development. Adding sodium butyrate to a calf starter increases the supply of butyrate available to the rumen papillae. Direct-fed microbials can increase calf starter intake, thereby increasing volatile fatty acid production. They also can alter rumen fermentation, increasing butyrate and propionate production.
Q: What are the economic benefits of improving rumen development?
A: Due to the high cost of milk and milk replacer, enhancing rumen development is important. It can decrease weaning age, lower feed cost and reduce labor needed for calves in individual housing. Proper rumen development also can offset a performance slump post-weaning. Whatever your calf-rearing program is, discuss with your nutritionist how it impacts rumen development. This can be an effective starting point for implementing changes that improve rumen development and your profitability.
Research citations available upon request
Editor's note: This article appeared in the September 2014 issue of Dairy Herd Managment magazine.