Spring calving is here for many cow-calf producers. Jill Larson discusses how the nutritional requirements of a cow change after calving and why cow body condition is vital for the health of her calf.
Tom: I’m Tom Martin and we’re talking with Jill Larson, Nutritionist with CRYSTALYX® Brand Supplements. Jill grew up on a livestock farm in south-central Minnesota as a sixth-generation livestock producer. She holds a Master’s [degree] in Ruminant Nutrition. The research she conducted for her M.S. degree focused on developmental and fetal programming in beef cattle, specifically, the impacts of maternal nutrition on both the cow and her calf. The focus of our conversation today is looking at those impacts of cow nutrition, and the importance of a spring calving nutrition program. Thanks for joining us, Jill.
Jill: Yes, thank you.
Tom: So, spring calving time is here. Tell us about the importance of cow nutrition during this particular time of year.
Jill: Many are in the midst of calving or will soon be starting and for many of our registered herds they are well underway. On my last podcast, I talked about the importance of cow nutrition during gestation and the impacts that it has on her calf. That is an important phase in her production cycle and an important time to make sure the cows are getting the nutrition they need. Hopefully, cows have been well-prepared for the changes they will face upon calving and into lactation during what is their highest nutritional requirement time of year.
Once her calf hits the ground, the demand for high-quality colostrum and for lactation comes into full-swing. And for the cow herd, [this involves] a substantial increase in the demand for proper nutrition to meet those needs, especially with an increase in demand for energy and crude protein.
Tom: You mentioned colostrum. How does the cow’s nutrition and management impact colostrum production and, ultimately, her calf?
Jill: As most producers know, once the calf is born, getting colostrum into its system is crucial for its immune system, [primarily because the calf is] not [yet] fully-developed when it hits the ground. Colostrum contains many antibodies and immunoglobulins that are essential to protect that calf from diseases.
For many years, the rule of thumb was to get colostrum into the calf within the first 24 hours, but looking at the estimated time points, only 10-percent of those necessary proteins are absorbed in that 24-hour span. So, maybe a better rule of thumb should be within the first six hours after birth, while the intestine is still very efficient in allowing those large proteins to be absorbed before it starts to close.
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So, this timing is crucial; the transition from colostrum to milk also occurs during this time frame and [the calf is] going from 22-percent solids in colostrum to about 12-percent in normal whole milk. Along with the age of the cow and the breed, nutrition leading up to calving also has a huge impact on colostrum quality and also the quantity.
Studies have shown that cows in poor body condition and also [those that are] overly-conditioned have less nutritious colostrum and produce less total volume of milk as well. Additionally, there is research looking at both calves and lambs which have indicated that if the cow or the ewe is deficient in nutrients during gestation, her calf or lamb will have a slower time getting up and will take longer to actually consume that needed colostrum.
And, in colder climates this can have a huge impact on calf survival as well. So, it is important for cows to be in appropriate body condition at calving for colostrum quality, for calf vigor and also to practice good management, including having a clean, dry area out of the wind for that calf to get off to a good start.
Tom: How do the nutritional requirements of a cow change after calving to keep up with the demands of her calf at her side?
Jill: The lactation phase is the most nutritionally-stressful time for the cow. During peak lactation — around two months post-calving — the average beef cow produces around 20 pounds of milk each day, and milk contains a high concentration of protein; therefore, the cow’s protein requirements increase.
So, for example, for a 1300-lb. cow milking 20 pounds per day, the crude protein requirements from that last one-third of gestation into lactation jumps from about two pounds to three pounds of crude protein each day. Also, energy expressed as total digestible nutrients or TDN, which may be familiar to some, follows that same trend as protein requirements during lactation. And the demand for energy for lactation is at an all-time high post-calving.
So, for that same 1300-lb. cow, her energy requirements from gestation to lactation will jump from nearly 14 pounds to 18 pounds of energy per day. And, for those first- and second-calf heifers, they also require more energy compared to more mature cows because they need that additional energy for growth in addition to maintenance and lactation. And so, inadequate energy during that late part of gestation and from calving to rebreeding can lead to poor rebreeding performance.
Not only does age impact a spring calving cow’s nutrient requirements post-calving, but so does the size of the animal and milk production. Now, larger cows, in terms of body weight, have greater protein and energy requirements compared to smaller cows, as well as high-milk-producing cows. The changes in cow type through genetic selections have a big impact on the overall nutritional requirements of a beef cow herd.
Tom: How does forage intake impact and change how much a cow needs during lactation?
Jill: Forage intake will vary based on the forage quality. When poor-quality forages are fed, you will see lower intake levels because the rate of passage through that rumen is much lower due to the slower rate of fermentation.
As the quality of forage increases, that rate of passage will also increase through the rumen and, to a point, forage intake will increase. Typically, we estimate that cows will eat, you know, between 2- and 2.5-percent of their body weight per day, but this estimate can increase or decrease based on the quality of forage. So, knowing the quality of your forage will have a direct impact on knowing how much your cow herd will require and what kind of supplementation is necessary during the calving season and beyond to be sure that she is meeting her nutrition and those requirements.
Tom: In a cow-calf operation, the time it takes for a cow herd to get bred back is what drives profitability for the operation the next year. How can farmers and ranchers tell if they’re meeting the nutrient requirements of their cows during this time of year [in order] to have these good conception rates?
Jill: So, the transfer of nutrients from the cow to the calf, both during gestation and after calving through lactation, really can drain a cow’s nutrient reserves. After the cow has calved we expect her to recover quickly and be bred back to calve again in a timely rate to keep that 365-day calving interval.
The breed-back period is a huge driver to the cow calf producers’ profitability and it’s not a time to really cut corners on your nutrition program. A good way to gauge if your nutrition program is on target and [to] achieve those timely breed-back periods is [to] evaluate your cow’s body condition. Data has shown that cows should be in a body condition score of 5 to 5.5 based on the 10-point scale at the time of calving, and gaining weight after calving in order to have a successful breed-back period.
If cows are losing body condition, you may need to increase that energy and [the] crude protein levels you’re delivering to your cows in order to keep up with the demands of lactation.
Tom: So, Jill, how can CRYSTALYX Brand Supplements help improve the nutrition of spring calving beef cows?
Jill: Supplementation during this time of year, before spring growth in our pastures, is key for cows to consume the proper nutrients they need. CRYSTALYX Brand Supplements can improve forage digestibility [and]can provide a complete mineral package that’s important for milk production and for reproductive success. It can also improve immune function and overall gut health. So, products such as the Breed-Up® product line of CRYSTALYX can help improve cow-calf performance during the demanding time of year.
Tom: That’s Jill Larson. She is a nutritionist with CRYSTALYX Brand Supplements. And, we thank you for joining us, Jill.
Jill: Thank you.