Malnourished vs. Overconditioned: Body Condition Scoring
For ranchers, your cow herd health and well-being directly correlate with your calf production parameters and your profitability. Assessing your cow herd throughout the year will allow you to obtain the desired body condition at different stages of production to enhance production efficiency. These assessments are a management tool for evaluating the net energy reserves and the nutritional program. Some tools that can be used are body weight, body condition scoring, and ultrasound for these assessments. For this blog post, I am going to focus on body condition scoring or BCS.
BCS is a subjective or hands-on method of determining the amount of fat an animal is carrying. Understanding the risks this fat content can have on a cow can lead to increased rebreeding ability, decreased dystocia and calving complications, etc. Different breeds of cattle deposit fat differently. For example, British and continental beef breeds deposit excess fat subcutaneously (externally). In contrast, dairy breeds tend to deposit this excess fat internally (mesenteric). These fat stores are essential for cattle in times of reduced nutrition. These fat stores will be broken down to meet nutritional requirements. Undernourished cattle will have very little fat reserves and therefore, the body will resort to breaking down proteins to meet these requirements. This will cause further muscle depletion in these already undernourished animals. With over-conditioned cattle, there are plenty of fat stores to meet nutritional needs, however, there are other risks that could be financially catastrophic to a cow-calf operation. Overweight cattle are consuming much more than their body requires, resulting in unnecessary feed costs and these fat deposits increase the risk of calving complications. BCS directly correlates with the length of postpartum anestrous as well. This is the period between calving and rebreeding where the cow is not experiencing estrous cycles. Cows need to be bred 80 to 85 days after calving in order to maintain a one-year calving interval. Estrus is exhibited sooner in cows with ample energy reserves when compared to malnourished cows.
The BCS system varies between the US and Canada. The US uses a 9-point system and Canada uses a 5-point system, with both systems using 1 as thin and emaciated cattle. There are 6 key areas of the body where body condition is assessed. 1. the back, 2. the tail head, 3. the pins, 4. the hooks, 5. the ribs, and 6. the brisket (as illustrated below). It is important to note that this is a subjective scoring system that only looks at fat reserves, not gut fill, hair coat, or body weight (as this fluctuates with fetal growth). Considering a cow's age, breed, production stage and frame size are critical in BCS assessments. The ideal BSC for cows is 2.5 to 3, with some variation depending on the stage of production.
The Scottish System (Lowman et al. 1976)
- Visually prominent hip bones, tail head, and ribs
- Individual short ribs are fairly sharp to touch
- No fat around the tail head
- Often severely emaciated and weak
- Individually identify short ribs by touch(rounded not sharp)
- Some tissue cover around the tail head, over hip bones, and flank
- Individual ribs are no longer obvious
- Spaces between spinal processes are less pronounced
- Need firm pressure to feel short ribs
- Degree of fat cover on either side of tail head which can be easily felt
- Slight "rounds" of fat cover around tail head (soft to touch)
- Short ribs cannot be felt, even with firm pressure
- Folds of fat beginning to develop over ribs and thighs
- Bone structure is no longer noticeable ("blocky" animal)
- Tail head and hip bones almost completely buried in fat
- Folds of fat apparent over ribs and thighs
- Short ribs completely covered by fat
- Animal's mobility impaired
Managing BCS does not happen overnight. For small to moderate frame cows, 1 BSC is equal to about 60-80 lbs of BW and that number increases for larger-frame cows. Therefore, consulting with a nutritionist throughout the year can prevent BCS from varying from 2.5-3. Strong mineral programs and adequate protein and energy supplementation throughout the year will prevent the need for these major weight increases or decreases to meet the desired BCS. It is always easier to maintain than correct.