If not for an Easter freeze, research fields at the recent field day at the Livestock and Forestry Branch Station in Batesville, Ark., would have been much greener.
“We have here a demonstration on four practices usually implemented at this time of year when forages begin to green up,” said Shane Gadberry, Arkansas Extension cattle specialist whose primary responsibility is ruminant nutrition. “Some may not have such greenery available yet and are in a situation like we’re standing in right now — predominantly dormant bermudagrass — unlike the cattle across the road grazing on fescue.
“March surprised us this year. Bermudagrass wanted to begin growing, but Mother Nature caught up with us. The recent cold spell set forage production back.”
For the Batesville station demonstration fields, Gadberry’s objective was to “identify any benefit to supplemental feeding of these fall-calving cows. To compare the scene to your operation, you need to consider the cattle’s stage of production, body condition score and the quality of forage (hay versus pasture).
“From there, is supplemental feeding required? What type of supplements? Is there a protein deficiency, an energy deficiency, a combination? Also find out the level of supplementation needed to overcome that deficiency.
“In times like these — with drought and the impact of ethanol on the grain and byproduct feed markets — can you supplemental feed economically?”
Gadberry worked in four adjacent fields studying various setups with dormant bermudagrass and hay or grazing spring pasture. In cases with warm season pastures, producers normally end up feeding hay four to six months of the year.
When it comes to winter feeding, the researcher first goes to the field and has a good look around. “If you walked into this field, one of the first things you’ll notice is a bale of hay in the center. How does this field differ from the field beside us? We have some feed troughs in this field. There are none on the other side.”
One field of cattle was supplemented beginning in mid-February.
Another observation: this field has hay only and the next field has green fescue. However, the forage in the fescue field is short because of the recent cold spell coupled with 1.5 inches of March rain. Even though it’s been available, the cattle on that field haven’t eaten a lot of hay.
“They’ve consumed about half the hay of the cattle on dormant bermudagrass. The cattle on dormant bermudagrass consumed 13 or 14 bales. Cattle in the fescue field consumed seven bales since February.”
If you look at the fescue field, it may appear there’s enough forage to supply those cattle daily nutritional requirements.
“The forage is pretty short in the fescue field. How many cows are standing around that hay bale? Not many. Yesterday morning, all those cattle were grazing — none were standing at the hay rings. On this side of the road, all the cattle were gathered at the hay rings.
“This is a common observation this time of year. When pastures begin to green, cattle quit consuming hay. They’ll often lose body weight as a result because forage quantity is more limiting than forage quality.
“Of forages in Arkansas — particularly where we’re feeding hay — about 70 percent that go through the forage testing lab in Fayetteville don’t meet the energy requirements for lactating beef cattle. As a result, we see in most hay feeding situations that forage quality is the most limiting factor compared to forage quantity.”
The second thing Gadberry points to are the five-month-old calves.
“So, these cattle are lactating but not at the front-side of the lactation curve when nutrients requirements are greatest. They’re on the backside of that curve.”
Theoretically, to maintain good body condition, the cattle need about a 55 percent digestible diet for energy.
As for protein requirements, “we tend to overemphasize that here in the state. If you’re doing a decent job of fertilizing hay crops, even if you don’t harvest in a timely manner, we don’t see a lot of protein deficiencies in the state. Only about 40 percent of tested forages are deficient in protein.”
Considering peak requirement is two months after calving, a 15-pound peak milk production only requires about a 10 percent protein diet. “That isn’t very high.
“Many times we emphasize protein supplementation when we should be shifting some economics to supply supplemental energy. That would do a better job of maintaining cattle’s body conditions.”
Back in January, Gadberry pulled hay samples for testing. Depending on the lot, it came back between 6 percent and 10 percent protein.
“So we did come up a little short on protein. Our goal was to have a 55 percent TDN (Total Digestible Nutrients) diet. The energy (reading) came back at 48 percent. So there’s a real shortage in energy from this hay.”
What impact would corn gluten feed provide as a combination of supplemental protein and energy? The corn gluten pellets run about 21 percent protein and about 80 percent TDN.
Researchers “started supplementing the cow herd on this herd at 5 pounds of corn gluten feed per cow, per day. The cows on the other side of the fence continued to receive hay only.
“One of the first measured responses: those that were being supplemented lost just as much body weight as those that weren’t supplemented. On average, they lost about 60 pounds. That’s not uncommon under a supplemental feeding program. There are a lot of factors that can come into play (beyond just the supplemental feeding).”
One is the environment. When the weather changes, “we might try to feed to adjust for it, but we don’t have a strong understanding of how to precisely fix it.”
A second factor is feeding for lactation. “We must estimate if the cows are producing 10, 15 or 20 pounds of peak milk. As their milking ability increases, so do their protein and energy requirements.”
When evaluating your feeding situation, check the digestibility of the hay. If there are many stacked “fecal pats” in a field “that’s one indication forage digestibility isn’t extremely high.”
Next, check the body condition scores. Generally, 75 pounds of body weight loss is equivalent to “a loss of one body condition score. These cattle lost about 60 pounds. The ideal body condition score at calving is 5 to 6. That score will help minimize negative impacts on a cow’s energy reserves on her breed-back for the following year. Most of these cattle will score an average of 6.”
Then, put the picture together. “We’ve got a group of cows with a diminishing lactation requirement. Their calves will be weaned in about a month.
“On top of that, they’ve got excess body condition and they’ve already been bred as a fall calving group.”
So, why did both groups lose such body weight?
“Partly, when you work with a small group of animals in a demonstration without a lot of repetition, those things can pop up. But also, the calves are four or five months old. They’re at the age now where they’ll steal some of the feed.
“When we look at the performance of the calves, their weight helps explain where that feed was going. Here, the calves exposed to corn gluten feed gained about 1.5 pounds per day. (In an adjacent field with no supplemental feeding) they gained 1.3 pounds per day.”
So was the supplementation worth it?
“Well, we’ve got calves with 10 pounds more body weight. Put the prices to it, and supplementing didn’t pay in this situation. Results may have differed if we were working with a spring calving herd in moderate body condition.”
If growing forage continues to remain unavailable and “we continue to feed lower-quality hay, one option we could consider is early weaning these calves — and it’s a real option, especially when we get into a drought with a spring-calving herd. A cow’s nutritional requirement drops drastically at weaning. That’s because the calves have been pulled off, there isn’t a suckling influence and milk production ceases.”
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