Water & Calf Grain
These two go hand-in-hand. Their intake ratio is 1:1. Greater water intake increases grain intake both while on milk and post-weaning. In fact, water availability and quality are major limitations to dairy farms for both calves and lactating cows. My main topic here is calf grain intake, but mention of water as a driver of grain intake is necessary. Water also is a primary component of skeletal muscle and helps maintain hydration status of the calf.
Milk is directed via the oesophical groove to the abomasum and hence does not entre the rumen. Water is directed to the rumen and aids fermentation of calf grain. A word of warning: calves drinking through feeder teats that are worn can ‘guzzle’ and have milk enter the rumen. Underdeveloped rumens have little pathogen destroying capacity and infection can establish producing scours.
After a few weeks of life, calves as monogastrics, begin developing a functional rumen. The microbial fermentation end-products (volatile fatty acids – VFAs) of consummed grain, and its weight, both contribute to starting the development of a functional rumen.
As the rumen develops, fermentation of the calf grain provides energy for rapid growth and physical development. Protein from the calf grain contributes to bacteria producing microbial protein of nearly optimal amino acid profile. The increase in microbial biomass in the developing rumen enhances immune function.
Fermentation of grain in the calf’s rumen also produces B-vitamins essential for energy metabolism and to stimulate appetite to further drive feed intake and growth. All quality calf grain mixes should contain essential minerals and trace elements for obvious reasons, but also a coccidiostat (Rumensin or Bovatec) to aid control of coccidiosis, for growth rates, immunity and susceptability to other diseases.
These essential minerals are needed for bone and skeletal growth, and calf grains with all essential minerals will allow higher growth rates. Although milk is a well balanced food, it does fall short in iron, manganese, copper, iodine, cobalt, selenium, and vitamins D & E. Supplementation through a quality calf meal ensures these mineral requirements are met.
Fermentation, apart from the above nutritional and development concerns, also produces heat for body warmth, especially through winter and exposure to wind chill.
Stimulation of cud chewing is paramount to rumen development. It produces saliva for buffering and nitrogen recycling. This increases microbial protein for absorption and a healthier rumen. Some of the fibre from calf grain escapes degradation in the rumen and is fermented in the colon. The VFA’s produced provide fuel for growth of colon cells. The colon development is also essential as it is an important site of water absorption, and hence faecal consistency.
