Post-Calving Nutrition: Producers reminded to pay special attention to cattle nutrition between calving and rebreeding
At any stage in the production cycle, cows and heifers experience nutritional and environmental stressors and undergo periods of high and low nutritional demands.
While nutrition is critical for the cow herd during all of these stages, the 70- to 90-day interval between calving and breeding is quite possibly the period of greatest nutritional demand.
With many spring-calving herds already welcoming the 2025 calf crop, experts are reminding producers to pay special attention to proper nutrition for lactating females following calving and prior to rebreeding, especially in the midst of cold and snowy winter conditions.
Meeting nutritional requirements
In a Feb. 1, 2023 University of Nebraska-Lincoln (UNL) BeefWatch Newsletter, UNL Beef Systems Extension Educator Troy Walz explains energy requirements of a mature, 1,200-pound cow are relatively low at nine to 11 pounds total digestible nutrients (TDN) and two pounds crude protein (CP) per day.
In this stage of production, maintenance needs can be met by supplementing two to 2.5 pounds of a 20 to 25 percent CP source for cows grazing dormant range or low-quality forage.
However, as calving approaches, these requirements increase, peaking around 60 to 80 days postpartum with an energy demand of 15 to 16 pounds TDN per day.
It is important to note, during this time, there is a shift in the cow’s first limiting nutrient from protein to energy, Walz mentions.
UNL Beef Systems Extension Educator Meredith Bremer and UNL Cow/Calf Range Management Specialist Dr. Karla Jenkins agree.
“Both the mature cow and first-calf heifer have high energy requirements during lactation,” they explain in a UNL Extension publication dated October 2015. “If cows are turned out at pasture green-up, the grass will likely meet the energy needs of the cow. However, if peak lactation occurs before pasture turnout, supplementation must occur if the base diet is dormant range or low- to medium-quality hay. Providing a supplement high in protein and energy would be ideal.”
They note good examples of high-protein and energy sources for lactating cows include dry distillers’ grains, high-quality alfalfa and corn.
“Time of calving, age of breeding females and quality of the base diet determine if and when supplementation is necessary for a cow herd during late gestation and lactation,” Bremer and Jenkins say. “A spring-calving cow will be in late gestation – and possibly peak lactation – prior to pasture turnout in the spring, depending on calving date and forage availability. Thus, supplementation may be necessary to meet the cow’s nutritional needs.”
When it comes to creating a strategic feed and supplementation plan, Walz notes it is important producers test their forages and have an inventory of feed on hand – of both quality and quantity.
Additionally, because feed costs represent a major expense on any operation, he encourages producers to reflect on what they have available in their area and what they can actually afford.
“Realizing one cannot always afford to meet the cow’s nutrient requirements will help with a nutritional plan – putting body condition on cows when their energy requirements are the lowest and letting the cow use that body condition as an energy source when producers cannot afford to meet her requirements,” Walz states. “As such, knowing what type of supplement is needed, when it is needed and how to compare supplements based on nutrient content will help producers make better decisions on needed supplement purchases.”
Monitoring BCS
Many experts and producers agree monitoring body condition scores (BCS) of cows is one of the most effective management tools when evaluating nutritional status of the herd.
Walz recommends scoring cows in a spring-calving system at least a handful of times throughout the year, especially during late summer, fall, weaning, 45 days after weaning and 90 days before calving.
At calving, a BCS of five is recommended.
“The most economical time to put condition on thin cows is after weaning,” he says. “Ninety days before calving is the last opportunity to put condition on cows economically.”
The best way to manage BCS across the herd during cold winter months and into the spring calving season is to sort cattle into production groups based on age and BCS. This allows producers to create economical, custom dietary plans to meet differing nutritional requirements of cows in the herd.
For instance, thin cows and first- or second-calf heifers can be fed a greater quantity of feed, a higher quality of feed or supplementation mixes other cows in the herd may not need. This cuts costs and keeps pushy cows from bullying younger, thinner cows away from feed.
“Sorting cattle into feeding groups will help producers develop a feeding plan that will maintain cows in adequate body condition or provide needed weight gain for thin cows prior to and throughout the breeding season,” Walz reiterates.
Prioritizing heifers
Because heifers are still growing and simultaneously raising a calf, experts remind producers to prioritize heifer nutrition and health.
Walz notes, as calving approaches, heifers should have a BCS of six, and three weeks prior to calving, they should be separated from the main herd.
“First-calf heifers decrease their daily dry matter intake by 17 percent in the three weeks prior to calving,” Walz states. “Feeding an energy and protein-dense diet to heifers is necessary to compensate for this reduced intake at calving.”
Fellow UNL Extension Specialist Dr. Rick Rasby notes in a separate UNL publication, first-calf heifers should be consuming a diet of at least 62 percent TDN and 10 to 11 percent CP post calving.
Rasby explains winter range, grass hay or meadow hay alone will not meet a heifer’s nutrient requirements and should instead be supplemented with high-quality alfalfa, distillers’ cake or other non-bulky supplements high in energy and protein.
Bremer and Jenkins note energy and CP supplementation should continue after calving and in to the breeding season.
“A heifer is not at her mature weight prior to her first calf being born, so she will need supplemental protein and energy for muscle deposition, milk production and body condition maintenance,” they say.
“Research has shown supplementing metabolizable protein prior to calving in spring-calving heifers is needed to increase the pregnancy rate on the second pregnancy, and similar responses have been documented for supplemental energy, suggesting metabolizable protein and energy needs are hard to separate for the young cow,” add Bremer and Jenkins.
Data collected by the U.S. Department of Agriculture’s (USDA) Agricultural Research Service in Miles City, Mont. has also shown heifer rebreeding success is intertwined with how they partition nutrients immediately postpartum.
The USDA research found, in order, cattle direct nutrients to basal metabolism, activity, growth, basic energy reserves, established pregnancy maintenance, lactation, additional energy reserves and estrus cycles and pregnancy initiation.
Ultimately, this means heifers utilize nutrients for their own growth before directing them toward reproduction, resulting in an average three to four weeks longer period of postpartum anestrus than their older counterparts.
In a Feb. 25 BEEF Magazine article by Clint Peck, Ruminant Nutritionist Dr. John Paterson, says this is why it makes economic sense to have heifers on an upward plane of nutrition moving into the breeding season. He further notes, with each heat cycle missed, a beef producer can miss out on 40 pounds of gain in a heiferʼs weaned calf.
“We want heifers to be in a position after calving where they can show estrus as early as possible and rebreed on their first post-calving cycle,” Paterson says. “And each cycle missed equates to a significant amount of money left on the table at weaning.”
“First calvers represent future brood cows, and we know they require more labor and management, along with higher-quality feeds,” Rasby concurs. “But if we’ve done our homework with due diligence, they’ll reward us by being productive cows for a long time.”
Hannah Bugas is the managing editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.
