Dairymen balance their feed budgets on pennies. Ingredients are often pulled from a ration based on the perceived cents per cow it could save the bottom line. Feed refusals, too, fall victim to this mindset. In an effort to reduce the amount of feed that is "wasted" on a daily basis, some producers have chosen to feed to a slick bunk. This choice isn't always advantageous, though. Providing dairy cattle with unlimited access to high-quality feed over the course of the day is the best way to promote maximum feed intake and improve milk production, noted Alanna Kmicikewycz, a Ph.D. candidate at Penn State University.
While it is not advantageous to feed to an empty bunk, having large amounts of refusals is also not economical. "Increasing the amount of dry matter refused by one percentage point often costs five to six cents per cow per day, which amounts to approximately $20 per cow per year," added Kmicikewycz.
There are indirect expenses associated with excessive feed refusals, too. When cows are offered a TMR with a high proportion of dry forage, sorting often occurs more extensively, resulting in possible health problems. Furthermore, when feed is restricted, ruminal pH can rise. A high pH inhibits lactate utilizing rumen bacteria, leaving the cow more susceptible to acidosis.
It is often recommended to target 2 to 4 percent refusals for the fresh group; 1 to 3 percent for high groups and 0.5 to 3 percent for late-lactation groups, said Kmicikewycz. "If feed refusals are similar in composition to the original TMR offered, you can go for the lower end of the targets. If feed refused is vastly different, you should shoot for the higher end," she continued.
Kmicikewycz then highlighted approaches that should and should not be taken to use feed refusals and minimize waste:
- Remixing the refusal into the new TMR batch or delivering the new TMR over refusals for the lactating herd has been practiced but is highly discouraged. This approach can lead to problems that will cost more than the feed refusal itself.
- Refusals also should never be fed to prefresh or fresh cows. Cows at this stage are vulnerable to metabolic diseases. Feeding refusals that are variable in nutrient content or contain mycotoxins can impact the cow's immune system and exacerbate health problems.
- Refusals can be fed to older heifers, steers or other beef cattle.
- Discard all refusals. It is best to dispose feed that is spoiled and highly sorted.
The author, Amanda Smith, is an associate editor and an animal science graduate of Cornell University. Smith covers feeding, milk quality and heads up the World Dairy Expo Supplement. She grew up on a Medina, N.Y., dairy, and interned at a 1,700-cow western New York dairy, a large New York calf and heifer farm, and studied in New Zealand for one semester.
