What is it?
One purpose of this article series is to show how the simple technique of body condition scoring (BCS) can contribute significantly to good husbandry and management of dairy cows.
This will help to ensure that the cow is in the correct condition for each stage of her annual cycle and that appropriate dietary changes can be made in order to correct any deficiencies.
Why do body condition scoring?
- Body condition indicates how much stored energy a cow has for future use. BCS can help you track energy balance and understand production and reproductive performance.
- The most common body condition scoring system ranks cows from one to five with a score of one being thin and a score of five being obese. It was developed at Virginia Polytechnic Institute and State University, USA. Areas to evaluate when body condition scoring include hooks, pins, tailhead, and the ligaments around these bones.
- Body condition of feeding groups should be evaluated. It will reflect the true energy content of the diet.
- Cows should be scored at calving during their first postpartum exam, when bred, when checked for pregnancy, some time during late lactation and at dry-off.
An evaluation of body condition can help you understand the past nutritional status of your cows and why your milk production and reproductive performance results are good or bad. It will also show you some of the challenges to come. Body condition is an indication of how much energy a cow has stored for future usage. Body condition scoring was developed to help farmers and nutritionists more definitively assess and track body condition. This is very important because the monthly changes in body condition tend to be more highly correlated with health, productivity, and reproduction than a cow’s actual body condition on any particular day.
How to do body condition scoring
You use sight and touch to evaluate the amount of fat covering the loin, rump and tail head with a score from one to five. The most critical areas to be evaluated are the hook and pin bones, the ligaments going to the hook and pin bones from the spine and the tail head. Studies show that the amount of fat at these points on the body is related to the amount of fat inside the cow. Body condition scoring is better for monitoring body energy reserves than body weight. Body weight can change due to changes in body fat, frame size, gut size and udder size.
|Body condition score
||Vertebrae at the middle of the back
||Rear view (cross section) of the hook bones
||Side view of the line between the hook and pin bones
||Cavity between tail head and pin bone Rear view and Angeled view
|1. Severe under-conditioning
|2. Frame obvious
|3. Frame and covering well
|4. Frame not as visible as covering
|5. Severe over conditioning
Source (adapted from): A.J. Edmondson, I.J. Lean, C.O. Weaver, T. Farver and G. Webster. 1989.
A body condition scoring chart for Holstein dairy cows. J. Dairy Sci. 72:68- 78.
BCS = 1.5
This cow is too thin and is hopefully rarely seen on a farm. This cow will not milk well or reproduce. This cow probably isn’t healthy. The vertebrae, short ribs, hooks, pins, and tail head are very sharp and visible. One-half of the length of the transverse processes is visible. The ligaments are easily seen. The area around the tail head and the dish of the rump (thurl) are very dished. There are folds of skin seen between the tail head and pins.
BCS = 2
This cow is very thin, causing low milk production and poor reproduction. Health may be OK. The spine and short ribs can be easily seen, but the individual vertebrae are not really apparent. The short ribs appear scalloped. The upper surfaces of the short ribs can be felt. One-half to a third of the length of the transverse processes is visible. The hooks and pins stand out. No fat can be felt on the pin bones. The ligaments are sharp and easily seen. The areas around the tail head and the thurl area are very dished. There are folds of skin between the tail head and pins.
BCS = 2.5
It is a reasonable goal not to have more than 10 percent of the herd scoring 2.5 or less. This is the lowest acceptable condition score. A cow with a score of 2.5 has vertebrae showing but they cannot be seen as individual bones. The short ribs can be counted but are not scalloped. One-third to a quarter of the length of the transverse processes is visible. The ligaments are easily seen but not as sharp as with a BCS of 2.0. Both the hooks and pins are angular but some fat can be felt on the pin. The areas around the tail head and thurl are dished.
BCS = 3.0
This cow could be a healthy, high-producing cow. But, if a cow calves in at a score of 3.0 or less, she may not have enough body fat to use for high peak milk production and to carry her through until dry matter intake increases. At this score, the dish of the rump (thurl) is at the transition between looking like a “U” and looking like a “V”. Any cow under a BCS of 3.0 has a thurl area looking like a “V”. The backbone can be seen but the individual vertebrae are rounded. Covering the short ribs is half to one inch of flesh. Less than quarter the length of the transverse processes is visible. There is fat covering the ligaments but they are still obvious. The hooks and pins have some fat that can be felt. The area around the tail head is dished but no folds of skin are seen.
BCS = 3.5
Dry cows and calving cows should have a body condition score of 3.5. On this cow, fat can be felt on the backbone, short ribs, and ligaments. The hooks and pins are rounded. No individual transverse processes can be seen. The thurl is somewhat dished. The coccygeal (tail head) ligament is barely visible but the sacral ligament can still be seen. The area around the tail head is rounded and filled in but not fat.
BCS = 4.0
Cows calving in at this condition will eat less, lose more weight and have more metabolic problems. This cow’s back is flat because fat has filled it in. The short ribs can not be seen individually but they can just barely be felt. The hooks and pins are obviously fat. The “U” between the hooks and pins is very flat with no depression. The ligaments cannot be seen. The area around the tail head is filled in and folds of fat are seen.
BCS = 5.0
This cow is extremely fat and will have metabolic and breeding problems. The backbone and short ribs cannot be seen and are hard to feel. The hooks and pins are buried in fat and hard to feel. The thurl is totally filled in. The tail head is buried in fat.
Target body condition scores for milking cows:
(Source: Jan Hulsen, Cow Signals)
Recommendations for BCS management
It is recommended that cows be scored at calving, during their first postpartum exam, when bred, when checked for pregnancy, some time during late lactation and at dry-off. Nutritionists feeding groups of cows should determine the average BCS of each feeding group. Body condition should be the final word on the energy content of the diet, rather than the computer predicted energy value of the ration. If the cows are too thin during early lactation, adjust the energy content of the diet upward and focus on ways to increase dry matter intake. Determine if metabolic problems are extreme and may be causing the weight loss. Late lactation cows use energy for body reserves more efficiently than dry cows (75 percent vs. 60 percent efficiency). So it is recommended that cows be put on condition during mid to late lactation (after 75 to 100 days in milk) and achieve the desired calving BCS of 3.5 at that time, rather than during the dry period. If cows are too heavy in late lactation, reduce the energy content of the diet immediately rather than putting them on a diet during the dry period.
When feeding cows as a group, it is important that the group have a fairly uniform BCS. If they do not, there is most likely a problem. Perhaps some cows are experiencing severe metabolic problems which reduce dry matter intake early in their lactation. Perhaps cows are not being fed a true total mixed ration (TMR). For example, cows may be sorted or they are being offered hay separately. Perhaps there are hoof and leg problems that limit some cows from getting to the feed bunk. There may be severe reproductive problems that causing some cows to stay in a particular group longer than they should – they will be getting fat while others in the group are milking well and getting the nutrients that they need. If the group is not uniform, it is difficult to design the ration to feed all cows properly. Most likely, the compromise will have to be that some cows do not receive a ration with adequate nutrient density while others get too much. The cows receiving too much will get fat and waste consumed nutrients.
For more information on cow nutrition and TMR, look in the Topics section>>
We know that a significant amount of the energy a high-producing cow uses to make milk in early lactation comes from her body fat reserves. Weight losses of one to one-and-a-half kilograms per day, are not uncommon during the first 100 days in milk. Forty-five grams of mobilised fat can support about three kilograms of milk. Many herds will average 0.5 body condition loss by 30 days in milk. A good goal is not to exceed 0.5 body condition loss during that time. It is critical that cows do not exceed one point of body condition loss by 30 days in milk. Cows with excessive body condition losses will have irregular heats, longer time to first ovulation and may fail to conceive. These cows will also be less persistent in milk production.
Cows with a BCS over 3.75 at two weeks prior to calving are more prone to having depressed intakes, weight loss, fatty liver, ketosis, high non-esterified fatty acid (NEFA) levels, calving and reproductive problems. When a cow loses body fat reserves, especially two weeks before and after calving, the liver takes up fat and processes it. Fatty liver and ketosis can then develop. In a Michigan study, eight percent of dry cows with a BCS of less than 4.0 had health problems while 17 percent of cows with a BCS of more than 4.0 had health problems. In another study, cows that had a BCS of 4.0 or greater at dry off were 2.5 times more likely to have reproductive problems.
Even if one could avoid the health and reproductive problems associated with fat cows, it is inefficient to put excessive weight on (>3.75 BCS) during late lactation and the dry period, then have to take it off after calving. It takes energy for the cow to process body fat and then to mobilise it for later use.
It is not recommended to put over-conditioned cows on a diet at dry-off due to the risk of fatty liver. It is inefficient but acceptable to put body condition on during the dry period if it is needed to achieve a BCS of 3.5 at calving. Total body weight should increase during the dry period regardless of body condition because the calf developing inside the cow will gain 45 to 68 grams per day.