Grow heifers to their potential

Elliot Block, Senior Manager, Central Technical Services, Arm & Hammer Animal Nutrition for Progressive Dairyman

Efficient heifer growth that leads to bigger heifers at an earlier age can maximize profitability on your dairy operation. The key is making sure your heifers don’t just gain weight, but achieve their genetic potential for ideal height, weight and girth so they reach breeding age earlier and enter the milking string sooner. This leads to substantial profit potential in a variety of ways.

Most progressive dairy producers already strive to calve heifers between 22 and 24 months to pay back heifer rearing costs earlier. The economics explain why.

A Penn State research study showed that reducing the age at first calving by one month nets $70 in rearing costs for each calving heifer. For a herd calving 500 heifers annually, that’s $35,000.

Getting heifers into the herd one or two months sooner allows for internal growth and discretionary culling within a herd. A dairy producer will not need to buy as many replacement animals if heifers from within the herd can start milking sooner.

Heifers that are nutritionally able to grow to their ideal size faster can be bred sooner, calve without distress and produce more milk in their first lactation. Allowing smaller heifers to catch up to the others in a group is also an advantage, as a group’s performance is more balanced and management is more seamless.

Optimize heifer growth
Producers can accomplish ideal heifer growth and capitalize on profit opportunities by putting more bacterial protein through the rumen for absorption in the animal’s small intestine. From these absorption sites the animal metabolizes the protein into amino acids to help her grow more muscle and bone, rather than fat.

Feeding a rumen fermentation enhancer can yield up to 20 percent more microbial protein production, according to Dr. Blaine Ellison, an independent dairy nutrition consultant with Calf-Vantage Feeds Inc.

Ellison worked on the development of rumen fermentation enhancers, conducting trials on farms throughout North America. He used the Cornell Penn Miner (CPM) model for dairy nutrition and fed the additive at a rate of 3 percent of dry matter intake (DMI). This is the same feeding rate recommended by nutritionists who advise using the product today.

These early trials showed a near 20 percent increase in frame growth in the heifers consuming the additive from age four months to 24 months, as compared to heifers fed identical rations without the additive. The heifers were longer, taller and had more girth, yet they were not fat, Ellison says.

By increasing microbial protein production, the additive increased bone and muscle growth without adding extra fat because the proper metabolic protein-to-metabolic energy ratio is maintained. The added protein helps heifers capitalize on the efficiencies of ruminant protein production and grow to their genetic potential. In addition, a rumen fermentation enhancer can help slow-growing heifers achieve compensatory growth, which accelerates their growth rate by more efficiently converting feed to growth so they can catch up to their peers.

Faster frame growth aids heifers in reaching breeding size faster. Once heifers are pregnant, rumen fermentation products provide them with the proper nutrients to continue to grow and maintain their lean frame so they are more likely to calve without distress and produce more milk in their first lactation.

Ellison points out that in herds where first lactation animals are not reaching their mature equivalent (ME) potential, it’s because the heifers are under-grown. Heifers with a flat lactation curve are catching up on growth during their first lactation, rather than converting nutrients to milk. They are forced to use the lactation ration, which is oftentimes the most expensive ration fed on the farm, for growth rather than production.

Enhanced growth, more milk
Heifers fed to grow to their size potential will have higher production peaks and a more normal lactation curve, Ellison asserts. It is a persistent industry-wide myth that lactation curves of first-calf heifers are flat. That doesn’t have to be the case if they grow properly.

Achieving proper heifer growth and ME milk potential has to do with “volumetrics, not just age at calving,” as shown by work done by Patrick Hoffman, dairy specialist at the University of Wisconsin-Madison. His research has shown for every 1 inch in additional height, length and hearth girth capacity, there are 20 to 25 gallons more body capacity volumetrics – 5 gallons of which is rumen capacity. Hence, a heifer 1 inch shorter than ideal has 5 gallons less rumen capacity.

A newborn calf is a long, rectangular animal, yet at 300 to 400 pounds, many heifers are “squared up,” because their growth requirements have not been addressed. Addressing growth requirements will stretch the heifer out by growing her frame. Ellison likens under-grown heifers to an under-sized flashlight with a half-discharged battery and remarks, “Then we wonder why they can’t give more milk!”

The rumen fermentation enhancer changes the protein-to-energy ratio at the absorption sites in the small intestine. The metabolic activity allows heifers to grow to their potential, having a taller, longer frame, in addition to growing mammary cells. Too much energy in the ration, Ellison points out, can cause heifers to develop short and wide frames and deposit more fat cells in the udder, which can limit future milk production.

Heifers should freshen at 85 percent of their mature size. If they are 1,500 pounds when mature, they would need to weigh 1,275 pounds at first calving. If these weights are not achieved and the heifer needs to gain weight during her first lactation, 10 pounds of milk is lost per pound of gain. If a heifer needs to gain 300 pounds of weight to reach her mature size when she is milking, 3,000 pounds of potential production will be lost in the first lactation.

A well-grown first-lactation animal will also have a better calving experience and healthier immune system. Avoiding calving problems, metabolic disorders and mastitis in the first 60 days of lactation will set the heifer up for better reproductive performance.

Make sure your heifers have proper nutrition by providing vital nutrients and essential amino acids to stimulate rumen microbial growth so they reach their ideal size more quickly and efficiently. It’s guaranteed money in the bank. PD

References omitted but are available upon request.