Harlan Ritchie Symposium Highlights
By: Dr. Emily Taylor
David Lalman – Mature Cow Size and Impacts on Cow Efficiency.
Dr. Lalman began the Harlan Ritchie Symposium discussing the changes in cow efficiency due to mature cow size. While frame size has stayed constant, overall mature cow weight has continued to increase. This includes an increase in expenses required to maintain the larger females (about 10%). Producer profit will decrease if calf value does not accompany the increased cow size. Dr. Lalman discussed how weaning rate, stayability, reproductive performance and lifetime productivity is impacted by these changes. Data presented suggests that increases in cow weight has a negative impact on weaning rate, stayability and lifetime productivity. However, days to calving and age-adjusted weaning weight were positively correlated.
Dr. Lalman also discussed carcass weight as it relates to cow size. One study found there was a strong correlation between cow size and carcass weight – carcass weight drives finishing phase profitability. However, Dr. Lalman made a point that with all the implants and fine-tuned feedlot management – why do we need larger cows to get larger carcasses? It seems unnecessary to increase annual cow costs for the purpose of increasing carcass weight.
Travis Mulliniks – Impacts of dam age and milk production on cow/calf profitability.
Dr. Mulliniks began his discussion by making the point that production efficiency in the cow herd is limited by reproduction. Reproductive performance is 5x more economically important, however, it seems we are chasing weaning weights. It is important to note that calf body weight only influences profitability 5% and so we are increasing costs associated with cow weight and not being profitable. Dr. Mulliniks addressed this issue by targeting the young calving females (2-3 years of age). These females are at a disadvantage because they not only are expected to maintain a pregnancy and lactation period, they are also still trying to maintain their body weight while growing. This is consistent in most cow herds across the country.
Cull rate of young females can be large if they are mismanaged early on. Dr. Mulliniks suggests putting more emphasis on these females. Heifer development is one of the largest costs on a cow/calf operation. Losing these females as 2, 3 or 4 year olds heavily impacts production profitability. Driving the improvement of long-term profitability will be done by addressing young cow challenges.
Dr. Mulliniks also discussed how we are selecting for milk production and it is negatively impacting the young cow. We are feeding females to produce an overabundance of milk that the calf cannot consume. Data was presented that weaning weight did not differ between a low, moderate or high lactating female. Reproductive performance is also negatively correlated to higher milk production.
Overall, resources should be used to address the partitioning of nutrients in the young female. Moving nutrients from milk production will help her manage body weight and rebreeding.