04/05/2026
Let's talk calf nutrition - the goals in rearing dairy and poddy calves are different to the goals for rearing with cow/calf units. Milk feeding of calves costs money in labour, time and medications. Not to forget the significant costs of milk powder if you're not on a dairy farm.
The goal for hand reared calves is transitioning the calf from a pre-ruminant (reliant on milk) to a ruminant, able to efficiently utilise concentrates and roughage to continue to grow. Calf rearing and weaning practices should be based around growing and developing the calf's rumen to enable it to thrive following weaning.
Calves with poorly developed rumens are likely to regress in body condition and growth rates post weaning, and are more likely to become immunocompromised due to stress. The rumen requires both roughage and grain to develop properly, these should be introduced with water from day 1.
Really high growth rates can be achieved in the short term on milk and concentrates alone, or even on just high volumes of milk. However, the calf's long term growth rates, especially post weaning, will be reduced.
Getting technical: concentrates are broken down into volatile fatty acids (VFAs) which stimulate development of the rumen papillae (imagine a s**g pile rug, the papillae increase the surface area for nutrient absorption). However, without roughage these papillae can become thickened and keratinised which will then reduce absorption of these VFAs. As VFAs are part of the end product of digestion that stimulates the rumen papillae (from the breakdown of concentrates) then the lack of roughage will inhibit further development of rumen papillae. The roughage is also developing the rumen as a whole, in terms of size of the rumen, correct pH/internal environment. So, whilst a concentrate fed calf will have a high number of rumen papillae, and a roughage fed calf will have a large rumen you need both roughage and concentrates to develop a large rumen with good pH (roughage) and well-developed rumen papillae (concentrates).
This will lead to a calf that is able to thrive and continue to excel even with early weaning practices. The calves in this video were weaned from milk at 7-8 weeks of age and are 11 weeks old in the second half.
