3 tips to enhance post-weaning heifer nutrition
A strong heifer nutrition program is a multi-phase process geared toward optimizing animal growth and development. While there’s no one-size-fits-all program every farm or calf ranch must adopt, the most successful heifer raisers have a few things in common, including:
They feed high-quality feedstuffs.
They feed to maximize productivity.
They don’t feed too much forage too soon.
They keep accurate health and growth records for each animal, especially cases of scours and pneumonia.
In addition, successful operations monitor and measure performance throughout the heifer-rearing process. This enables them to make informed career decisions for each animal at points that enhance economic investment and return on that investment.
Use the following tips to get the most from your heifers’ nutrition program.
1. Avoid post-weaning lag
Many calf-raising programs experience a “lag phase” when calves are moved from the hutches to group pens. But those that require calves to consume about 6 to 8 pounds of calf starter grain mix per day before leaving the hutch experience less lag and often see better performance during the transition to groups.
To further improve performance, wait to introduce hay in the ration until the animals are in group pens for a week or two. Begin including forages in the ration at 3 percent and increase in post-weaning diets to about 20 to 25 percent by the time the animals have a fully developed rumen (about 440 pounds).
That’s because when calves are properly weaned at 6 or more weeks old, their rumen walls are only moderately developed. The diet of these young calves should be formulated to maximize rumen development, note experts at Penn State University.
It usually takes four to six months before the rumen becomes large enough in relation to the animal’s body to handle high-forage, high-volume diets.
Just as with pre-weaning starter grain mixes, optimal grower grain mixes contain:
Highly palatable and digestible sources of plant protein, including metabolizable protein
Vitamins and minerals
Refined functional carbohydrates
High-quality hay, as appropriate
In addition, make sure heifers have plenty of access to free-choice clean, fresh water. This factor should be of primary consideration throughout the animal’s life.
Consider the initial group size as well, as smaller groups translate into less stress. Groups of 10 to 20 head per pen on large operations seem to work well. Keep in mind not all heifers like to eat in lockups, so it is a good idea to provide some starter grain mix inside the pen to encourage intake.
In addition, a dry, draft-free bedded area is required to assure calves lie down. Temperature, moisture, hair coat and wind velocity have a large impact on daily maintenance requirements – and average daily gain. Keep this in mind as you work with your nutritionist and adjust the ration throughout the year as necessary.
2. Maximize the grower phase
From the time heifer calves are weaned until they reach about 450 pounds, it’s highly possible to achieve average daily gains of 2 to 2.75 pounds per day or even more. To make sure performance is on track, weigh calves as they leave individual hutches or pens and again at 150 to 160 days old, if possible.
This information will help measure total cost per pound of gain and aid in feedstuff sourcing decisions.
Again, this is not the time to skimp on feed quality. While it’s tempting to include lower-digestible ingredients to decrease ration cost, the potential dip in weight gain is not equivalent to the up-front cost savings. In addition, higher feed conversion rates with higher-quality feedstuffs do not economically support a decision to switch to lower-quality substitutions.
Nor is this the time to feed too much forage to save on grain cost. Research at Purdue University showed feeding higher grain levels to post-weaned dairy heifers can improve growth and can actually decrease the cost of gain over higher-forage diets.
In addition, the findings reinforced that heifers fed high grain levels can be negatively impacted by abrupt changes to higher-forage diets, with the heifers on the 80-20 grain-to-forage treatment showing a definite decline in intake when they were switched to a 40-60 diet, from which it took some time to recover. Results indicate average daily gain dropped from 2.29 pounds per day to 1.72 pounds per day after the dietary switch.
Also closely monitor health events. Increased incidence of pneumonia, for example, can be a diagnostic red flag indicating diets are energy-deficient, which can impede immune system support.
Adequate growth during this phase means heifers achieve height and weight goals in a timely fashion and are ready for breeding at the optimal time. Movement to the breeding pen must be based primarily upon accurate hip heights and bodyweight measurements, with age as a secondary parameter.
The recommendation is to breed heifers at about 55 percent of the dam’s mature bodyweight.
That means Holsteins should be 51 to 52 inches at the hip before entering the breeding pen. It is recommended you do not breed Holstein heifers before 10 months old, even if they have achieved the hip height and weight targets. In well-managed programs, approximately 20 percent of heifers will be of adequate size by 10 months old.
Jerseys should be about 650 pounds and greater than 40 inches at the hip. Wait to breed these heifers until they reach 9 months old.
3. Upgrade the breeding phase
This stage offers one more chance to positively affect heifer development through nutrition.
Once the heifer has been confirmed pregnant, the objective is now to maintain growth of about 1.9 pounds per day or more without adding too much condition. They are not yet lactating cows, so rations should not be too high in energy.
As animals approach their move to the close-up pen, aim for about 22 pounds of dry matter intake for Holsteins and about 17 to 18 pounds for Jerseys.
Also, formulate close-up rations to provide adequate levels of metabolizable protein. Holstein heifers should receive about 1,350 grams of metabolizable proteins per day and about 1,100 grams per day for Jerseys.
The fetus and mammary gland are developing at a very fast rate as the end of gestation nears, resulting in increased requirements for metabolizable protein and energy, while dry matter intake is declining. The heifer also has requirements for its own maintenance and growth as well as the immune systems of both the fetus and dam.
When requirements for metabolizable protein and energy are not met, the animal begins to mobilize protein and fat.
Note the most common mistake in this phase is not having springing heifers on the close-up diet for more than 28 days before calving.
Therefore, it’s important to calculate days with calf for each animal. Move heifers to the close-up pen before they reach 250 days with calf.
With each of these parameters, monitor variation as well as averages so you can tweak your program as needed while keeping heifer development on track.
Lastly, keep in mind heifer development is essential and should be considered an opportunity, especially since input costs require intense management.
High-quality feedstuffs, average daily gain and feed efficiency data are required to make management decisions that yield the best return on your heifer development dollars.