Monday, 13 May 2019

Rearing calves, the essentials

Key Points 

1. CMR is a premium milk replacer 
2. it is formulated to provide the correct balance of nutrients(including energy, protein, macro and micro minerals and vitamins) required for rapid growth and development of young calves
3. It is manufactured using quality ingredients and meets comprehensive European animal feed manufacturing standards 
4. Added probiotics and prebiotics help support gut health and improve digestion 
5. CMR is a cost effective, safe, consistent and balanced alternative to whole milk 

The objective of any calf rearing operation is to optimise early growth and development while supporting early rumen development and minimising any incidence of disease or poor health. For dairy heifers it is essential that skeletal development and lean tissue deposition are maximised and the potential for excessive fat deposition in the body and mammary tissue are avoided.

Successful calf rearing begins straight after birth with adequate intake of good quality colostrum an essential factor in ensuring the calf receives a good supply of antibodies, energy and protein. It is considered best practice to feed new born calves 10 percent of their bodyweight (e.g. 4l for a 40kg calf) of “gold” colostrum within the first 6 to 12 hours of life (Vermunt, J. 2002. Calf rearing Part 1: Principles of calf rearing from birth to weaning. Vetscript 15(4): 4-6.). For best results, this should be administered in two or three smaller feeds (e.g. two feeds within the first 12 hours of life). After this, calves should be fed colostrum for at least the first four days of life. Although gut closure occurs within the first 24 hours after birth, and calves are no longer able to absorb the antibodies present in colostrum, the high fat content provides a valuable source of energy for the young calf. Colostrum is also rich in essential high quality protein, vitamins and minerals.

If calves are to make a successful transition from liquid feeds to a fibrous grass-based diet, and avoiding a post-weaning growth check, encouraging early rumen development is essential. Unlike the adult dairy cow, the young neonatal calf is essentially a monogastric (simple stomached animal) unable to effectively digest high fibre feeds. Development of rumen begins with ingestion of microbes into the rumen and establishment of a functioning microbial population. Supporting the development of this microbial population by providing a grain based hard feed from 4 days old and always providing cool, clean and fresh drinking water for calves is key to early rumen development.

The differences in the number and size of rumen papillae, and the colour of the rumen wall, can easily be seen in these three calves - especially with the milk & grain diet. Photos courtesy Penn State University

Choosing a whey based milk replacer, such as Ravensdown CMR, that encourages early hard feed intake is one way of supporting early rumen development. Unlike whole milk or casein based CMR, whey based milk replacers do not form a curd in the abomasum and are more rapidly digested. This means that calves start to feel hungry sooner than they would if fed whole milk and start looking for and eating other food sources at an earlier age.

When choosing a calf starter feed look for a high quality grain based feed which contains good quality protein sources such as soyabean meal, canola and peas. Because young calves only eat a small amount of meal, choose a nutrient dense feed with at least 18% (DM) crude protein. RavCalf 20 is formulated to provide a rich source of carbohydrates essential for early rumen development and a range of essential amino acids, the building blocks of protein, required by the young monogastric calf.

Ensuring clean fresh water is always available is essential for rumen development as both milk and milk replacer, when fed correctly, by-pass the rumen.