March 28, 2024

Setting growth targets for heifers: Tools to achieve return on investment

NEW PRAGUE, Minn. — Focusing on practices that help get the most out of dairy heifer investments is important for dairymen.

“Today’s replacement heifers are tomorrow’s profit generators,” said Cathy Bandyk, ruminant technical manager for AB Vista, an animal nutrition technology company. “Calves never get over a bad start or a good one.”

Dairymen can use the age at first calving or how mature the animal is at that point as metrics to measure heifer development, Bandyk said during a webinar organized by the Dairy Calf and Heifer Association.

“Age at calving is important because delaying calving from 22 to 23 months or 24 to 25 months will have increased costs,” she said. “It costs $40 per head per month and also the money tied up in the heifer is failing to produce any return for a longer period of time.”

Heifers won’t get bred if they’re not large enough or if they don’t demonstrate adequate physiological development, Bandyk said.

“We can use these two metrics to monitor how we are doing,” she said.

For a research study with beef heifers at the Meat Animal Research Center in Nebraska, heifers were developed to reach either 55% or 65% of mature body weight at 14 months.

“They saw the lighter weight animals had reduced levels of progesterone with 49.2% of the lighter animals getting pregnant in the first cycle versus 64% of the heavier heifers,” Bandyk said.

Heifers not as far along in their development have more difficulty during birth, and after they start to milk, they still need to grow.

“That takes fuel so some nutrients will go towards body growth rather than milk,” Bandyk said. “Not only does that reduce milk in the first lactation, it also reduces milk in subsequent lactations, so we’re setting a ceiling on what that animal’s production can be.”

One rule of thumb, Bandyk said, is for every 100 pounds less body weight at calving, expect 700 pounds less milk in that lactation.

“The level of maturity a heifer reaches at breeding and calving comes from a combination of how she was taken care of and what nutrition she received pre and post weaning,” Bandyk said.

“Because maturity is a combination of weight and age, if first lactation peak production is at least 75% of the mature herd peak production, you’re doing alright.”

Research at Penn State University showed for every 1 pound increase in daily dry matter intake pre-weaning, those females produced an additional 290 pounds of milk, Bandyk said.

“We’ve known for a long time that pre-weaning body weight gains more consistently influence age at puberty than post weaning, but post weaning nutrition is really important, too,” she said.

“Heifers are going through significant reproductive development at two to five months of age, including the development of follicles and endocrine axis.”

In addition to having a calf, Bandyk said, milk production is driven by the ability of the female’s mammary glands to make milk.

“That is driven by the number of milk-producing cells in the mammary gland, and that is largely set during pre-puberty growth,” Bandyk said.

“We’re also concerned about how well the cow can provide nutrients needed by the mammary gland in order to reach its potential,” she said. “That involves her capacity to not only eat enough feed, but also the ability to absorb those nutrients from the rumen.”

Dairymen should set a growth target for heifers as a percent of mature body weight.

“They should be at 60% to 65% of mature body weight at breeding and 95% at calving to avoid the need to put on additional body growth when they are milking,” Bandyk said.

She advised dairymen to monitor the ration to determine if it has the correct concentration of nutrients in proper balance to encourage intake.

“Monitor feeding behaviors because we don’t want to teach heifers bad habits,” she said. “And avoid feeding programs that encourage sorting or slug feeding.”

Two areas that really impact costs in developing heifers is managing the volume of feed and managing how well the feed is utilized, Bandyk said.

“Bunk management makes a difference to get animals to better utilize the feed they’re eating,” she said. “Animals fed at the same time every day can go a long way in minimizing problems.”

A lot of feed additives are available to add to dairy rations including bioactives such as yeast or fermentation extracts.

“Live yeast has a positive impact on the microbial population, including oxygen scavenging, pH modulation and selective competition that can enhance digestibility of feed and mitigate stress and health challenges,” Bandyk said.

“Fermentation extracts have a cascading effect on the diet when you feed them,” she said. “The greater surface area of the feed particle becomes potential adhesion sites for the microbes in the rumen to digest the feed.”

These products work to break down fiber.

“Some of the nutrients that may have been bound inside the fiber structures are now make available for digestion by the bugs,” Bandyk said.

One example of this is VistaPre-T, which is available in liquid and dry forms.

VistaPre-T was fed in a university trial to transition heifers for six weeks.

“The heifers had improved digestibility of neutral detergent fiber by over 9%,” Bandyk said. “The heifers were able to eat 2 pounds additional intake before calving and 1 pound after for a total 46 pounds in gain.”

In a trial with 320 heifers, VistaPre-T was fed for five months after the heifers were weaned.

“They saw equal gains with the control heifers, but the heifers fed VistaPre-T had a significant drop in feed intake, which saved them 10 cents per head per day,” Bandyk said.

“These tools have the opportunity to be economically important,” she said. “Select the metrics that really matter such as feed cost per pound of gain and breeding efficiency.”

For more information about AB Vista, call 888-512-2175 or go to www.abvista.com.