Chances are, if you are feeding milk replacer, you know there are benefits from not feeding whole milk. Less bacteria, a more consistently balanced diet for the calf, etc. But you also know milk replacer can be expensive. And above that, not all milk replacers are the same! A conventional milk replacer is either 22/20 or 20/20 (meaning 22% protein and 20% fat, dry matter basis), or an accelerated milk replacer (closer to 28% protein and 20% fat). Different milk replacer protein and fat levels are reflected in the price, but each has its advantages.
Either way, your goal is going from this:
(Courtesy of Katie Kubacki Photography)
….as soon as possible. And the best way to do that is a calf that grows quickly, and efficiently. After all, milk, either from a bag or from the tank, can add up in terms of cost! Keep in mind that we want growth from muscle and bone (PROTEIN), and not fat deposition. We know that too much fat deposition will limit the amount of milk the animal is capable of producing when she calves.
Let’s start with the types of milk replacer to feed. Keep in mind that this blog doesn’t touch on ingredients, just protein and fat amount provided. This post will talk about conventional or accelerated.
Like I mentioned earlier, conventional means around 20-22% protein and 20% fat on a dry matter basis. There is a reason that conventional milk replacers cannot be fed at a high rate. As a calf grows, it requires protein for muscle growth, and the proportions of protein:fat in this sort of milk replacer mean that merely increasing the amount fed will mean that protein is actually limited in the diet and fat deposition will occur. Instead, conventional programs should be used at more modest feeding levels (but above 10% of the birth weight of the calf when offered in liquid), and promote grain intake. The extra protein provided by grain will increase body weight gains. There are many ways to increase starter grain intake, but that’s a topic for another time!
The purpose of accelerated milk replacer is simple: more nutrients from milk. A beef calf has unlimited access to milk (generally), and this form of milk replacer, while it doesn’t allow free choice milk, packs more nutrients into the same volume of milk. A calf is extremely efficient at converting nutrients from milk into energy, so usually the idea of feeding this milk replacer is to capitalize on early life efficiency. In order to do so, it is recommended to feed calves in a “step-up” sort of program, where they receive a medium amount of milk (~ 1.5 lbs of milk replacer a day) for the first 10-14 days of life, after which the milk is increased to closer to ~2 lbs per day.
A caution!! You cannot cheat the system! This program was designed to provide more nutrients and more overall milk to the calf. Yes, it is more costly, but the point is the calf is extremely efficient in converting milk replacer nutrients to growth, so the value is there. But if think you can get away with feeding this milk replacer in lower amounts, think again! Opposite of the conventional feeding system, feeding an accelerated milk replacer in low amounts will actually provide excess protein to the calf because the energy is limiting, and the calf cannot use the protein and it will leave the body in urine! After how much you paid for this milk replacer, I’m sure you don’t want to see it being thrown out with the straw!
A draw back of the increased milk feeding is a slower start on starter grain intake. A calf with a full stomach of milk will have less desire to explore for new feeds. This is why it is essential to ensure calves on this program have begun to eat grain before weaning! It takes about 3 weeks after grain intake begins for the rumen and gastrointestinal system to be developed enough to handle energy from solid feeds alone.
As you can tell, there is a lot that goes into feeding calves. This doesn’t even begin to cover milk replacer ingredients, cold or heat stress, breeds of calves (Jerseys especially), when to wean, how many times to feed, etc. What are your thoughts?