At birth, the rumen is small, undeveloped and does not contribute to digestion. The rumen needs to develop before it can digest forages. The intake of concentrate and water are the most important factors for rumen development.
Rumen development If stimulated early on, a calf’s rumen can start to function from as early as five days of age with the majority of calves actively ruminating by 28 days of age. Consumption of concentrates and water provide the rumen microbes with the nutrients they need to grow and multiply. After three weeks of eating starter concentrate, the rumen will have enough microbes to ferment the feed to supply the calf with energy.
Calf starter should be offered from day one.
- Starter can be provided as a pellet or coarse feed and should be highly palatable to encourage early intake
- Ensure starter has adequate particle size for proper rumen development
- 3cm pellets are the most common
- Should be larger than 1.19mm in diameter to avoid ruminal parakeratosis and bloat
- Should not be powdery or dusty as this will reduce intake
- Calf nuts of 6mm are designed for feeding to calves at 12 weeks or older
- Starter should provide around 18 per cent crude protein to aid microbial growth and promote intake
Calves eat only small amounts in the first few weeks but intake begins to increase measurably around 14 days of age.
Forages are a good source of fibre which promotes the growth of the muscular layer of the rumen and helps maintain the health of the rumen lining.
In addition to starter, good quality forage should be offered as early as day 3. This should be offered on a little and often basis to ensure freshness and encourage intake.
Feed racks and buckets should be located at a height that is suitable for calves and positioned so as to reduce possibility of soiling.