16 December 2014

2 minute read

Ensuring milk-replacer reaches the calf's digestive system can be complicated by mixing solutions with "soft" water, according to a Land O'Lakes nutrition expert .

Water is softened by sodium, with too much sodium causing toxicity, Dr Tom Earlywine is telling farmers.

Beware of Mixing Milk Replacer

The ingredients in the milk replacer selected to feed preweaned calves receive a lot of water, writes Dr Earlywine for the North Dakota State University newsletter Dairy Connection.

Young calves do not tolerate poor water quality well. Water quality can affect mixed milk-replacer quality, mixed electrolyte solution quality, calf water consumption and starter intake, calf health, rumen development, and the effectiveness of cleaners and disinfectants.

One common error in water management is using sodium chloride-softened water to reconstitute milk replacer.

Water quality can affect the quality of mixed milk replacer and mixed electrolyte solutions, and calf water consumption and starter intake. Photo courtesy of J.W.Schroeder

Do not do it! In typical softeners, sodium replaces the hardness minerals to soften the water, and this can lead to sodium toxicity for calves, writes Mr Schroeder.

While some testing guidelines indicate that 2,000 parts per million (ppm) of sodium in water is safe for cattle, those numbers do not apply to young calves.

Calves can tolerate only 50 ppm of sodium. Soft water often exceeds that threshold. Thus, using soft water to reconstitute milk replacer would compound the problem because of the sodium already in milk replacer.

Calves also are sensitive to excessive levels of iron, manganese, magnesium, sulfur and microbial contamination.

The best advice: Get a calf-suitability test of the water delivered to preweaned calves, including the water source used to mix milk replacer.

When submitting water samples for analysis, ask for an assessment of:

• Total soluble salts or total dissolved solids, which measures the salinity or amount of soluble salts in water, including calcium, magnesium, sodium, chloride and sulfate salts
• Hardness – calcium, magnesium, iron, zinc and manganese all affect water hardness
• All of the individual minerals listed in total dissolved solids and hardness tests
• pH
• Nitrates
• Copper
• Phosphorus
• Microbial contaminants such as coliforms, E. coli and salmonella