Every dairy farm produces a quantity of milk which is not suitable for sale. With the rising cost of milk replacers, many producers are looking toward utilization of waste milk as a source of nutrition for their calves. Before making this management decision, several important factors should be considered:
- “Waste” milk comes from fresh cows and those treated with antibiotics. It frequently has a high bacteria count and may contain disease organisms not favorable to calf health. It is not known what the influence of antibiotics from treated cows does to calf health.
- Several field studies in California, North Carolina and Wisconsin have shown both quality and quantity of waste milk varies considerably. Fat varied from 1.5% to 5.0% and protein from 2.7% to more than 5.0%. One 1,200-cow commercial dairy tracking their waste milk supply for a seven-month period found supply varied from a low of 100 lbs. to a high of over 800 lbs. per day. This supply did not necessarily align with the population of milk-fed calves.
- Milk needed for the preweaned calf enterprise varies by the intensity of feeding program. More biologically normal feeding programs recommend feeding over 2 lbs. of milk solids (2 gallons of milk) per day. This would require sourcing 160 lbs. per day from waste milk for every 10 calves. Producers should seriously consider the effectiveness of their herd health program if there is this much “waste” milk available on a daily basis.
It is strongly recommended that any farm considering the use of waste milk purchase an on-farm pasteurizer. Remember to consider cost of purchase of the equipment and associated infrastructure as well as daily operating costs. A spreadsheet developed at Penn State and Virginia Tech enables one to estimate total operating cost for various calf feeding systems.
- There are a number of very effective pasteurizers that are well suited for heating waste milk to a sufficient temperature to destroy known disease organisms. However, field studies of on-farm pasteurizers reveals failure to reach sufficient temperature and time of heating is not uncommon. Routine testing of pasteurizers is advised.
- A well-managed waste-milk feeding program can provide desirable nutrients to calves. However, it’s not as easy as one might imagine. Variation in quality and quantity must be considered as well as the risks of disease transfer from equipment not functioning as desired. Operation and maintenance of a pasteurizer system requires additional skilled labor. In most cases, strategies must be developed to supply needed milk solids when quantities of waste milk are inadequate. Using saleable milk rapidly escalates calf-feeding costs. Strongly consider all costs in using waste milk in comparison to use of a high-quality milk replacer, which can supply nutrients more consistently as well as valuable additives to enhance nutrition and animal health.