We deliver a piece of paper that has been meticulously assembled to change your calves’ destiny. There is no doubt in our minds that you feel the same way and deliver this ration perfectly. Or will you? … Or can you?
Perfection is unattainable
It can be discouraging to consider all the areas that add variation to our nutrition programs. While some sources of variation can be controlled – or at least limited – in several cases, we can’t control them. Even if we can do something about variation, the cost required to address it may not justify the marginal improvement.
If variation is a given, is assembling rations even a worthwhile activity? The answer is: unequivocally yes. Research has recognized that cattle allowed free-choice access to unmixed dietary components are at greater risk of subclinical acidosis.
Additionally, there is evidence that cattle consuming a TMR have higher average daily gains and trend toward improved feed conversions compared to self-fed cattle. There is, no doubt, value in a well-mixed ration.
To help clarify the issue, we could assume there are three different rations: one on paper, one in the mixer and another in the bunk. Understanding some of the control points will help limit variation.
The paper ration
Controlling variation always starts with the available ingredient inputs. Nutritionists should consider several factors regarding ingredients, including: inventory and inclusion rate, storage method, how the combinations of ingredients affect performance and how long ingredients will last.
Inventory/sampling
Assessing ingredient quantities and quality is the first step in improving ration consistency. This is important in determining what to sample and the frequency with which it’s done.
When considering a TMR, it is easy to deduce that the ingredients with the highest inclusion rate have the greatest likelihood of impacting the variation of the ration. It’s then important to consider just how variable that ingredient may be.
When evaluating hay, take 10 to 15 core samples to account for variation, separating each cutting, field and load. Ensiled feeds can vary because of changes in field sources and storage stability. Be sure to sample across the entire face and consider repeating periodically through feedout.
Balancing rations
Most rations will first be balanced on a cost basis for a given set of nutrient specs. The computer is less intuitive when it comes to considering what mix of ingredients makes a high-quality ration that mixes well and is palatable.
Some of the things often overlooked are having sufficient moisture in the ration, particle sizes of the ingredients and the order that the nutritionist recommends the ingredients are loaded for a particular mixer. The first barrier to proper rations in the mixer and in the bunk is a well-formulated ration on paper.
The mixer ration
The loading and mixing procedures are where our most visible sources of variation will show up. It is unreasonable to think that the exact amount of each ingredient is loaded exactly as prescribed every time. While some of the variables can be hard to control, things like sequencing and mixing offer an opportunity to reduce variability.
Managing ingredient variability
Ingredients that are exposed to the environment have a greater likelihood of deviating from sampled nutrient and moisture specs. This is especially important for ingredients that have been exposed to precipitation while in storage.
Following batching instructions for these ingredients would most likely lead to underfeeding for the targeted dry matter intakes.
The process
It is important to recognize that different types of mixer wagons will require unique sequencing and mixing times to limit the variation of the final TMR. It is important to communicate with the manufacturer regarding recommendations for sequencing.
Also, mixing time should be optimized, as both under- and over-mixing are sources of variation.
Regardless of the type of mixer you have on your operation, keeping them in good repair is important to proper ingredient distribution. Also, one of the most common mistakes is overfilling mixer wagons beyond capacity.
Overfilling can create areas that are not capable of being distributed throughout the mixer; these are known as dead spots.
The bunk ration
The ultimate test on the procedures that have been followed is evaluating our end-users. The goal has been to achieve a targeted level of performance and health across a pool of animals that, even in the steadiest group of calves, are a gathering of individuals.
It is imperative to provide an evenly distributed, heterogenous mix that allows equal access to all calves.
The ration
Under the perfect circumstance, a calf will consume the same nutrients, vitamins, trace minerals and medication in each bite. Just as importantly, it should be a ration that is palatable and appropriate for the stage of production.
If there are issues with palatability, particle size or conditioning, it must be communicated so the appropriate adjustments can be made. Additionally, it is this stage that must be monitored to determine the appropriate level of dry matter intake to target.
Ration distribution
All is for naught if insufficient bunk space or an unevenly distributed ration is provided. It’s been observed in lactating cows that a reduction in bunk space can lead to a reduction in milkfat. This is indicative of changes to their feeding pattern and the potential negative effects it has on fiber digestibility.
This variability in backgrounding or growing yards provides an opportunity to sort the ration and can lead to inconsistent gains or even digestive upset.
Summary
Lastly, it is important that communication exists among all three processes. Information should move back and forth, from the nutritionist to the feeders and back the other way.
Because we are dealing with constant variability in feedstuffs, animals and environmental conditions, we must be adaptive. We can accept that perfection is unattainable, but that does not mean we should quit striving for it. 
PHOTO: Different types of mixer wagons will require unique sequences and mixing times to limit variation of the final TMR. Photo by Staff.
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Tyler Melroe
- FBeef Nutritionist
- Hubbard Feeds
- Email Tyler Melroe
