Body condition scoring: A tool to assist in managing cows through the winter
By Shelby Rosasco
With producers facing higher feed costs and limited feed availability due to continuing drought conditions, planning winter feeding strategies will be important to optimize utilization of feed resources and cow performance. Understanding the nutritional requirements of the cowherd, as well as the quality and quantity of forage resources can assist in developing a plan for managing cows through the winter.
Body condition scoring
Body condition scoring (BCS) can be a valuable tool producers can utilize in preparing for winter and spring calving. BCS provides a consistent, systematic way to quantify energy reserves in beef cattle.
Changes in muscle and fat reserve can be visually evaluated using the BCS system and utilized as an indicator of the nutritional status of the animal. The BCS system utilizes a scale of one through nine, with a BCS of one being an extremely thin and emaciated animal, a five being ideal or moderate and a nine indicating an obese animal.
Management decisions made throughout the year, especially during the winter and spring, can directly impact success during the breeding season. The body condition of a cow or heifer at calving and breeding can have significant effects on reproductive performance and efficiency.
Specifically, BCS at calving can impact the postpartum interval or the length of time between calving and resumption of estrous cyclicity.
Body score and calving intervals
To maintain a 365-day calving interval, cows need to rebreed within 80 to 85 days after calving, meaning they need to have resumed cyclicity within 60 days after calving. In addition to the stress of uterine involution and repair of the reproductive tract, fetal development and lactation increase nutritional demands. Inadequate nutrition and/or low body condition during this important production period can inhibit animal performance and increase the postpartum interval.
Previous research has shown thin cows, at a BCS of three, had a postpartum interval of roughly 90 days, whereas cows at a BCS five and six had postpartum intervals of approximately 60 and 52 days, respectively.
With weaning wrapping up and winter weather starting, now would be a good time to evaluate the BCS of the cowherd. Most spring calving herds are approaching the last 90 days before calving, which is the last chance to economically increase cow BCS prior to calving.
In general, a cow must gain 75 to 100 pounds to increase one BCS, not including the weight of a gestating calf and the associated fluids. Therefore, if a cow is currently at a BCS three after weaning and the producer wants her to be a BCS five at calving, she needs to gain approximately 175 pounds. By knowing how much she needs to gain and the number of days until calving producers can calculate an expected average daily gain to achieve the targeted BCS goal.
Winter weather, as well as feed availability and quality, can make adding additional body condition prior to calving challenging. After calving, increasing body condition may require large amounts of high-quality feeds to meet increased nutrient requirements due to lactation.
Winter feeding strategies
Assessing the BCS of the cowherd can also help determine winter feeding and supplementation strategies. Consider sorting and managing the cowherd based on their nutritional needs. Young cows have additional nutritional requirements attributed to growth on top of nutritional requirements related to gestation and fetal development.
Thin cows with a BCS less than four may also have additional nutritional needs to maintain or increase body condition during winter weather conditions. Body condition will impact the lower critical temperature (LCT) of cows, with thinner cows having a higher LCT.
Cows in an optimal body condition score – BCS five to six – are better able to withstand adverse weather conditions due to additional body reserves and will have a lower LCT.
Sorting thin and young cows into a separate group can allow for more strategic supplementation and optimize utilization of forage resources.
When developing a plan for supplementing or feeding cows through the winter, it is important to know the quality of crude protein and energy content of the feed. Total digestible nutrients (TDN) with crude protein (CP) can range in forage resources, ultimately impacting the rate at which animals are fed or supplemented and resources needed to feed animals through the winter.
Testing forage resources can allow for strategic supplementation of cattle and avoid over- or underfeeding cattle. Hay quality can be impacted by a number of factors including growing conditions and timing of harvest. This means last year’s hay will not be an indicator of the quality of this year’s hay, even if sourced from the same location.
Additionally, testing hay to determine CP and TDN can allow producers to sort hay based on quality, as well as determine if additional supplementation is necessary. In addition, matching forage resources based on quality for each management group may help minimize costs.
Obtaining a nutrient analysis of forage resources will allow producers to have the ability to dial in nutritional management of the cowherd which will help to ensure cows maintain body condition.
Producers should consider utilizing BCS as a guide to proactively monitor the cowherd through the winter and spring to help ensure cows are in good condition heading into the breeding season next year.
Moreover, knowing the quality of forage resources, as well as taking an inventory of forage resources based on quality will allow producers to create a plan for managing the cowherd this winter.
Additional information on BCS and a Three-Step Body Condition Scoring Guide can be found at wyoextension.org/publications/html/B1294/.
Shelby Rosasco is the University of Wyoming (UW) Extension beef specialist and an assistant professor at the UW in the Animal Sciences Department. She can be reached at email@example.com or 307-766-2329.