Why is it important to know the nutritional quality of your hay or forage? It’s because the nutritional status of your cows during the last trimester of pregnancy and right after calving largely determines the success of your ranch.
But numbers on a lab analysis only get you so far. When you’re getting ready for calves to hit the ground, assessing the nutritional status of your cows is important. The best way to do that is to determine a body condition score (BCS) on your animals, and the best way to determine a BCS is just by looking.
The reason why you hear so much about BCS, says Warren Rusche, South Dakota State University Extension cow-calf field specialist, is because it works. “The best indicator we have for the nutritional status of a beef cow is her body condition,” he says.
Managing body condition in the last three months leading up to calving is important for two big reasons, he says:
• Thin cows tend to produce poorer-quality colostrum with lower levels of immunoglobulins. They also tend to have calves that take longer to stand and are less able to produce enough body heat to maintain their temperature under cold conditions.
• Cows that are thin at calving are less likely to breed back in the first 21 days of the breeding season and are more likely to be open in the fall.
According to Eldon Cole, University of Missouri Extension beef specialist, body condition scores range from 1, which is very thin and weak; up to a 9, which is overly fat/obese. “The mid-range 5s and 6s are good targets to aim for at calving for mature cows. First-calf heifers should be in a 6 or possibly 7 BCS if you expect them to come into estrus after calving in a time frame so they’ll have about a 12-month calving interval,” he advises.
A 6 BCS cow, heifer or bull should have no visible ribs or backbones showing. There should be some fullness in the brisket and plumpness on either side of the tail head. “The 5 BCS animal is obviously thinner and you’ll be able to detect a bit of rib showing in the last pair or two. Compared to the 6 animal of the same frame and type, this animal will weigh 80-100 lbs. less. This lower weight represents reduced fat,” Cole says.
“If you can see more than one or two ribs and the outline of the spine is visible, that cow is below the optimum BCS of 5,” Rusche adds.
“You don’t want the 5 animal to drop another 80 lbs. or so as it will drop into the 4 BCS range,” Cole says. “The 4s definitely show multiple ribs, backbone and the loin edge will show a lack of covering. A 4 cow is acceptable if they’ve just weaned a calf and have time to add the 80 lbs. back before calving with good nutrition. Adding weight is a challenge if the weather is cold, rainy, snowy, muddy, etc.”
Other factors that retard weight gain are low-quality hay, no pasture, parasites both internal and external, old age, poor teeth and chronic health problems, he says.
“To add weight to an otherwise healthy animal takes very good hay and plenty of it. If hay is limited as well as pasture, resort to 2-5 lbs. per day of high-energy concentrate feed,” Cole says.
“Some of you may even have small-grain pasture, wheat, rye or barley that with adequate growth is an excellent protein and energy source. If possible, limit the cows’ time on the pasture to 3-5 hours per day, which extends the usefulness of the small grain as a supplement.”
Body condition influences not just the size of the check from the 2015 calf crop, but the 2016 calf crop as well, Rusche says. “That’s the reason for the focus on BCS, because body condition can have such a sizeable impact on a rancher’s bottom line.”
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