The Nine-Point Body Condition Scoring (BCS) System for beef cattle provides valuable insights into how body condition impacts cow productivity. Understanding this system, along with effective management strategies and the optimal use of body condition scoring, offers a practical approach to improving the efficiency of beef production. This module explores how to apply this knowledge to enhance production outcomes and herd management.

Body Condition Scores Reflect Body Fat

The beef cow has the ability to store energy that exceeds her current nutrient requirements in the form of fat, so that she can draw on it at some future point when requirements exceed the nutrients supplied by her diet. This stored fat has the dual role of leveling out the peaks and valleys of a seasonal feed supply and insulating her against the effects of severe cold weather, thus reducing heat loss. The amount of fat associated with each BCS as a percent of empty body weight is shown in Table 1.

As a rule of thumb, one BCS equates to about 75 pounds of live weight in cows that are weighed full or unshrunk. Thus, a 1200-pound BCS 4 cow would be expected to weigh 1275 pounds at BCS 5 and 1350 pounds at BCS 6. These weight changes do not include weight of the fetus, fetal membranes or fetal fluids, which in total amount to about 1.7 times the fetus weight.

The bottom line is that substantial amounts of nutrients are required to elevate a cow herd one full BCS (75 pounds and 4 % fat) and this is increasing difficult after calving during lactation.

Grouping Cows by Body Condition

The ideal BCS for mature cows (4 years +) prior to spring calving should be 5 and is one condition score higher for first calf two-year-old heifers. The higher condition score is warranted for the younger females because after calving they are still growing while suckling a calf plus preparing for rebreeding.

It's much easier to get condition back on cows economically before calving because the nutrient requirements are lower compared to after calving. Two feeding groups prior to calving is often good strategy; one for mature cows in good condition (BCS 5) and a second group for thin cows (BCS 4). Often the thin cows are three-year-olds, pregnant with their second calf, and are thin because they lost body condition while nursing their first calf and didn't recoup their lactation weight loss in the fall after weaning. It may be possible to feed the thin cows with the first calf two-year-olds because the objective for both groups is weight gain while objective in mature cows in good condition is simply to maintain weight and condition. Also, the feedstuffs used for bred heifers is generally more energy dense (high quality hay, grain, corn silage, grain by-products, etc.) as opposed to the common foodstuffs used to feed mature cows in good condition (winter range, hay, crop residue). If mature cows are consistently appearing in the ''thin group'' a thorough re-evaluation of the breeding management program is in order. It could be the genetic production level of the cows simply doesn't fit the feed resource.

Developing Feeding Programs to Increase Body Condition

In order to increase body condition, the ration must meet the nutrient requirements for protein, minerals and vitamins; but exceed the requirement for energy for a given stage of production. Thus, to increase body condition, more energy must be fed, and in a dense enough form that the cow has the capacity to consume it on a daily basis.

Management practices which allow cows to gain body condition by grazing would always be more desirable than feeding harvested forages; however, striving for a BCS greater than 6 for mature cows by either route would likely not be economical.

When developing feeding programs, remember that as cows near calving nutrient requirements increase in percent of the ration and in total pounds, It is wise to feed lower quality forages in mid-gestation and save higher quality forage for late gestation and after calving. Lactating cows, for example, may not have enough capacity to consume enough low-quality forage to meet their needs.

Table 2 below shows the partitioning of energy needed for a mature cow throughout the production year. Note that maintenance energy drops and energy for lactation ceases at weaning and that energy for fetal growth accelerates rapidly in late gestation. This table is only appropriate for 17.6 pounds of milk at peak production (about 50-80 days post- calving) and additional energy for maintenance and lactation would be required for high milking cows due to larger visceral organ size. Also of importance is the relatively low energy demand of the fetal calf in the first and second trimester of gestation. The post-weaning period thus becomes the logical target to increase body condition of cows because that period (September-October-November in this case) represents the cow's lowest nutrient demand.

Table 3 below shows the amount of energy in megacalories (Mcal = one million calories) required to change body condition of cows. For example, if the goal was to increase the body condition of an 1100 pound cow from a BCS 4 to a BCS 5, the cow would need a total of 207 Mcal of energy beyond her daily maintenance needs found in Table 2. This 207 Mcal of additional energy could be supplied by an energy dense feedstuff such as dried distillers grains (Table 4 below) which has 1.22 Mcal of NE per pound. If 3 pounds of distillers grains were fed, it would take about 57 days to elevate the cow's body condition from a BCS 4 to a BCS 5. The cow would have to gain about 1.32 pounds per day to achieve this change in body condition (75 pounds divided by 57 days = 1.32 pounds per day).

Table 4 lists some common feedstuffs and their respective Net Energy for maintenance.

Feedstuffs listed other than the grains have less energy and would require larger amounts to be fed in order to affect a change of one BCS. Alfalfa hay, for example, fed at 5 pounds per day beyond daily maintenance needs, would require 69 days of feeding to change the cow mentioned above from a BCS 4 to a BCS 5. Thus, energy density of the feed used is a factor in feeding cows to change body condition. Energy dense feeds such as grains or grain by-products will usually be required fewer days to change BCS and less energy dense feeds will need more days to change BCS so plan accordingly. Your ability to change body condition in a short period (50 to 60 days) using forage may be a challenge because the animal can consume a certain amount of feed daily. It would be a challenge for a 1,200 to consume 40 lb dry matter of a diet of average quality grass hay and alfalfa.

Time Of Calving and Time Of Weaning

The choice of calving season in relation to peak forage production for a given location is critical to the cost of maintaining adequate body condition on mature cows. Calving too soon before peak forage production leads to the use of more harvest forage and drives up total feed cost. Calving about two weeks ahead of available grass up to four weeks after first grass growth would substantially reduce harvested feeds fed to cows and also substantially reduce labor at calving and early calfhood health problems. Such systems can result in lighter calves at weaning and to optimize profit, calves ownership needs to be retained for some time after weaning. The advantage of a late-spring or early-summer calving program is to force the cow to graze for most, if not all of her needs and avoid harvested feeds being fed to the cow. A Nebraska study, using four years of data, indicates March calving cows were fed 3,182 pounds of hay per year while June calving cows were fed 30 pounds of hay per year.

June-calving cows were fed on average 23 pounds more of a protein supplement than March calving cows to maintain body condition. Strategic planning of the nutritional program for young cows when the calving season is moved to a later date is essential.

Adjusting the weaning date, particularly for first-calf two-year-olds, can be used to allow for lactating two-year-olds to graze their way back to a higher body condition prior to winter. Weaning calves at 120-150 days can give these females a real opportunity to recover body condition so they won't be so thin as three-year-olds.

Summary

Take time to record body condition scores well ahead of calving with particular attention to age groups of your cows. Plan a sound nutritional program with an eye toward optimizing profit. Keep an open mind for ideas such as early weaning or calving season adjustments, but ask lots of questions and get documentation before implementing. Body Condition Scores are simply a tool that help you or your customer do a better job of producing beef.