Cattle Newsletter – October 2020

Topic: Body Condition Scoring | Author: Ben Bennett, DVM

In this monthly newsletter, we wanted to cover the importance of body condition scoring (BCS) cattle. Some of you may have heard us present on this topic recently at the Park Co. Farm Bureau meeting. For those of you that were able to attend, we hope that this newsletter adds to our conversation. For those who were not, we hope you find it interesting and informative and we look forward to the conversations to come.

All figures described are shown on the final pages of this document.
In animals, body condition scoring is a numeric scale used to record the amount of energy stores that an individual possesses. In cattle, we use a 1 to 9 scale. A cow with a BCS of 1 is one that is physically weak due to malnutrition and is on the brink of death. While a cow with a BCS of 9 is extremely obese, has large amounts of fat in its tail head, brisket, and flank and will struggle to travel much territory. To properly body condition score an animal there are different locations to assess. These locations include the ribs, tail head, flank, brisket, spine, pelvis, and a few more. When obtaining a body condition score, it is important to assess multiple of these locations and not make a judgement from just one. Please refer to Figure 1 for a full list of assessment criteria for the different locations.

The goal of monitoring body condition in cattle throughout the year is to find the optimal, most economical way to ensure that cattle are a body condition 5 to 6 at the time that they calve. If this is achieved, then it is proven that this is the top indicator that an individual will remain on a 1-year calving interval. Meaning that if she calves early this year, she is more likely to remain calving early the next year. A graph from one study (Wiltbank, J.N., 1983) (Figure 2) shows the time that it takes cows in different body conditions to return to cycling after calving. For this, the goal is for a cow to return to cycling, thus able to be bred, within 80 days of having her calf. This is because 80 + 283 ( the average cow gestation period) = 363 (i.e. 1 year). When we look at figure 2, we see that the cattle were grouped into a very low BCS group (BCS 1-3), a low BCS group (BCS 4), and an adequate BCS group (BCS 5-6). Only about 60% of the cattle in  the very low BCS group were cycling by the desired 80 days post calving. Even yet, only an additional 20% were cycling by 120 days post calving. That means that of the cows that calved early on March 1st this year, more than 20% of them would fall behind and not calve until after April 1st next year. In today’s market, that lost month of growth could cost you $90+ per calf. If we then look at the low and adequate BCS groups, things are a little more optimistic. At 80 days post calving, the low BCS group is around 85% cycling and the adequate BCS group is around 98%. Where we see a big difference is if we are wanting to move our late calving cows up in the calving season for subsequent years. If a cow calved on April 1st this year, but we would rather her calve on March 1st, we need her to start cycling sooner than 80 days post calving. When we look again at figure 2, we see that at 60 days post calving, the low BCS group only has about 60% of the cows cycling while the adequate BCS group has 90+% of them cycling. If we can get a late calving cow pregnant on that first cycle, then that would advance her calving date up from April 1st to March 10th. Then with one more year, we can likely get her to calve at the desired March 1st.

Secondly, when cows calve at an adequate body condition of 5 to 6, they produce higher quality colostrum that is denser with antibodies, and thus their calves are healthier. As I am sure many are aware, pneumonia is the costliest disease to the beef industry as a whole, but scours is the costliest disease to the cow-calf sector. In most cases, scours is due to either environmental issues, or failure of the calf to receive adequate passive transfer of immunity from its dam’s colostrum. When assessing a calf’s IgG (antibody) concentration in its blood, the gold standard is for it to be greater than 2000 mg/dL. As we can see in figure 3, as a cow’s BCS at calving rises, so does the level of antibodies in its calf’s blood; and visa versa. At a BCS of 3, a cow is just barely providing enough antibodies in its colostrum to reach that desired 2000 mg/dL of IgG at 24 hrs of life. If we are able to keep that cow at a BCS of 5 to 6 when she calves, then the passive transfer of IgG to her calves is almost 20% better, allowing her calf to achieve a concentration of almost 2400 mg/dL. Long story short, when a cow is at a body condition 5 to 6 at calving, the level of antibodies passed along to her calf will, on average, be significantly higher and her calf therefore healthier.

So, when is the ideal time to body condition score cattle? At Mountain Valley Veterinary Services, we recommend to body condition score a representative sample of your herd at 4 points throughout the year. If we start from the point necessary to ensure that we are preparing the cattle to calve at a BCS of 5 to 6, we first recommend recording BCS as the grass dries up in the summer. This is the point at which the level of nutrition that the environment provides starts to decline, and thus we may need to start supplementing the cows. More often than not at this time, since the cows are coming off a period that they had been consuming nutritious, green grass they will be in an adequate body condition. By taking a BCS at this time though, it gives us a reference for if the cows have maintained that condition, or lost some between then and the next time that we record a score; at preg check. By noting the difference in BCS from when the grass dried up until preg check, we are able to roughly predict if the cow will be at an adequate BCS at calving. If we realize that the group is losing weight a little too quickly, this is a great time to start supplementing the herd to maintain the condition that they have. Economically, it is better to maintain condition coming off grass, than to have to put condition back on right before calving. Following preg check is an ideal time to add condition if needed. For many operations, the calves have been weaned by this point, so the cow no longer has to provide milk and energy to them. Also, if a spring calving herd and preg checking in September/October, we are still in the second trimester of pregnancy. It is ideal to add condition at this time, since about 2/3 of fetal growth occurs in the 3rd trimester. Because of that fact, it can be very costly to add condition to a cow in the 3rd trimester. So much of her energy is going toward growing the calf inside her, that it can become quite expensive if we have to provide enough nutrition for her to put on condition as well. Please refer to the next page to see the forms that we at MVVS use to collect pregnancy and body conditions data on cows as we ultrasound throughout the fall. Next, we recommend taking body condition scores 45 to 60 days before calving. By doing it then, it gives us one more opportunity to adjust the plane of nutrition to ensure that the cows will calve at a BCS of 5 to 6. Lastly, we recommend recording body condition scores at calving. Many producers already keep a calving record book, so simply adding a column to record BCS would be quick and easy to do. Recoding this allows us to see if we reached our goal so that we can make informed decisions about things to change or not for next year.

So in conclusion, adequate body condition at calving has been long proven as one of the top indicators of a cow’s reproductive performance. To maintain that cow on a 1-year calving cycle, you need to ensure that she is a BCS 5 to 6 at the time of calving. This will not only help maintain her 1- year cycle, but will also optimize the health of her calves. By intentionally monitoring body condition at strategic points throughout the year, we can ensure a BCS of 5 to 6 at calving in the most economical way possible.
– Thanks for reading and as always, please let us know if you have questions or concerns about what we have discussed. –

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