Pak Dairy Info - Body Condition Scoring (BCS)


Body Condition Scoring

Importance in Dairy Animals

Body condition scoring is a subjective method for estimating the quantity of subcutaneous fat in specific anatomical regions on a live animal. Actual body condition scores (BCS) and changes in scores over time enable the farmer/supervisor to estimate the impact of various management practices, especially the efficiency of nutrition on reproduction, production of milk and on health. Scoring body condition enables farmers to estimate and compare the body conditions in various production groups and how much body tissue is lipolized during the transition period . Thus, body condition scoring is an important tool in daily management of dairy animals.

Methodology

Body condition is scored on a scale of 1 to 5. In dairy animals, a change in BCS is related to both liveweight change and a change in body tissue reserves. A score of 1 indicates severe underconditioning and a score of 5 is assigned to very obese animals. Quarter and half scores, sometimes expressed as pluses and minuses can be added to refine scoring system.

With one system, relevant parts of back and rump of the dairy animal are palpated to determine the amount of fat tissue covering these areas. With another system, the same relevant parts of the animal are visually appraised. In scoring body condition, particular attention is given to tissue covering the vertebral spinous processes and transverse processes of the lumbar vertebrae, tuber coxae (hooks), tuber oschii (pins), and tissue depressions between the backbone and the hook and pin bones. Also, the slope between hook and pin bones and the hollowness between tailhead and pin bones are evaluated. All these areas must be considered for each animal. Using 1 or 2 areas can be misleading. For accurate scoring, animal must be standing. Frame size, breed, stage of lactation, milk production level, and health status must be ignored for accurate scoring.

In short, it can be stated that score 1 represents animals that are emaciated with a skinny and bony appearance. A high producing, early lactation animal should have a score not lower than 2.5. A buffalo or cow with a score of 2 or lower in early lactation indicates a shortage in dry matter/energy intake at an earlier stage. A milking buffalo or cow in good condition is represented by score 3. Dry dairy animals should score 3.25 to 3.5. Score 4 represents an overconditioned animal. A score of 5 makes a dairy animal a prime candidate for fat cow syndrome. Body condition scoring should be performed every 4 weeks for dry animals and every 4 to 6 weeks after calving. Young stock should be scored at regular intervals of 2 months. Condition can change very rapidly around puberty. Therefore, this time period should be monitored carefully. Pregnant heifers from about 2 months before parturition can be scored at the same time as dry animals. BCS should be recorded on recording sheets. This offers opportunity to follow condition scores of individual buffaloes/cows over time. BCS of individual animals during the dry period should be put on the examination list within the frame work of herd fertility programme. Clinical findings can be related with changes in body condition.

Recommended Body Condition Scores in Dry Period and Various Lactation Stages

Dry Period:
Dairy animals with extreme condition scores at calving are at a higher risk of increased health problems, reproductive disorders, and lower peak and lactation yields. Animals that calve with low condition scores (less than 3.0) received inadequate energy during late lactation and/or during the dry period. Such animals show a suboptimal peak yield with a good persistency. Additional energy intake may be necessary to achieve maximum production in thin animals. One has to realize that body cannot be easily, nor rapidly adjusted during a normal dry period length. During this period, an increase of 0.5 in BCS is the maximum that can be reasonably achieved. Animals that calve with a BCS higher than 3.5 indicate that energy intakes were too high during late lactation and/or the dry period.

Generally, an overconditioned animal is at an increased risk of calving problems, reduced feed intake, severe condition loss, and a complex of metabolic, digestive, reproductive, and infectious diseases. Overconditioned animals often have a history of diseases in previous lactation such as mastitis or infertility and are often dried off early, leading to extended dry periods which may result in a vicious circle. Most of these problems can be avoided in the future, if dairy animals are fed balanced late-lactation and dry-animal rations. It is not advisable to reduce body weight during the dry period. This will lead to mobilization of fat from body tissues, deposition of fat in the liver, and all the associated metabolic problems. Thus, it is important for the dairy farmer to strike a balance between allowing animals to be too fat or too thin at calving and also to monitor body condition changes after calving in order to feed them properly.

Early Lactation:
It is recommended that animal in early lactation should not lose more than 0.75 unit of condition score. The target score in this period is between 2.5 and 3.0. Dairy animals that lose 1.0 or more BCS are at an increased risk of metabolic problems and reproductive inefficiency. High producing animals under excellent conditions of management may drop a full condition score without any problem. BCS should not drop after 4 weeks. In healthy animals it will take about another 8 weeks (12 weeks postpartum) before BCS will start improving under normal feeding regimes and adequate nutrient balance. The greatest challenge in early lactation is to maximize dry matter intake so that body condition changes and negative energy balance will be minimized. Ideally, a dairy animal should not lose more than 0.75 of a score unit over the first 30 days of lactation. Animals that have lost more than 1 condition score and are not producing to their potential are not receiving or utilizing enough energy or are experiencing increased incidence of metabolic problems. Feeding management must then be evaluated along with dry matter and water intakes, including the quality of feedstuffs. If BCS change is less than 0.5 units in the first 4 weeks of lactation, animals may not be producing to their potential, nutrient balance and feeding management should be evaluated.

Mid-Lactation:
By 12 weeks postpartum, buffaloes and cows should begin to replete body tissue reserves. At this time, a gradual increase in BCS should be observed. The target score level is 2.75 and 3.25. If BCS is not increasing at this time then animals are not receiving adequate energy and the cause should be investigated. If BCS is greater than 3.5, energy intake needs to be reduced to avoid overconditioning and subsequent fat dairy animal problems.

Late Lactation:
During this stage, BCS should be approaching 3.5 (the recommended BCS at dry-off). This is the most economical time to replete body tissue reserves, because metabolic demands are the lowest. The energy demands of milk production are lower, while the metabolic demands of the developing foetus are not yet elevated. Animal should not be allowed to become overconditioned nor should they be denied the opportunity to adequately replete body tissue reserves. Either condition will influence productivity in the next lactation. In high producing herds and those milked 3 times daily or utilizing bovine somatotropin, a change in grouping strategy may be required to properly manage body condition.

Research findings and field data suggest that the degree of changes in body condition after calving influence health, reproduction, and productivity in dairy animals more than the BCS at calving. Current body condition scores reflect previous energy balance, whereas changes in body condition after calving may be associated with a higher incidence of fatty liver, impaired fertility, and other health problems.