In every drought cycle, some producers have an earlier end to the drought than others, and some are more severely affected by drought than others. As producers liquidate productive cows due to drought, there is an opportunity to ship in cows with high-quality genetics that otherwise would be in the prime of their productive life.
But often, these cows have been held on to for too long by a producer waiting for the “ranch-saving rain” that never materialized, with too little grass and little to no hay or feed in reserve. It is hard to turn loose genetics we have been building and working toward for years, so you can understand the thought process. Nevertheless, these cows have become too thin and weak to survive a severe weather event, let alone be productive. However, with the proper management, these cows can be a massive benefit in building a cowherd for your future or a windfall for short-term gain if sold when the market correction occurs (it always does).
There are reasons why these cattle are cheap:
• Thin cows have less cold tolerance. Cows in good condition can withstand temperatures below 32 F reasonably well, thin cows with a thin haircoat may have a lower critical temperature of around 40 F. For every degree below the lower critical temperature, energy requirements increase by 1%. A winter storm hitting thin cows with little protection can be a disaster.
• Thin cows have more problems calving. This is especially true for heifers. It takes a lot of energy to expel a fetus, and new heifers often run out of power before the process is even getting going. If we take too dramatic of steps to improve the condition of the cow, we can influence the size of the calf.
The rule of thumb is nutrition on a third-trimester cow can increase the calf weight by 10%. This is not usually a problem for a mature cow or a well-developed heifer in good condition. A 10-pound heavier calf can be a disaster for a 750 lb. weak, thin heifer.
• Thin cows have weaker calves. Calves born from assisted births are usually weaker and take longer to get up and start nursing. Both the cow and the calf are exhausted. This will delay the uptake of colostrum, which has huge effects on the health and resilience of the calf.
Undernutrition during fetal development limits production of fat in the calf, especially the essential brown adipose tissue needed for quick energy early in life. If calving happens during a cold winter storm, the calf may wind up laying in the cold wind and freezing to death.
• Thin cows produce less (and weaker) colostrum. As mentioned above, colostrum is essential for early passive immunity transfer from the cow to the calf. Maternal antibodies in our research often are still found in the calf for up to 4 months. Calves that get limited or no colostrum shortly after birth are less resilient to disease, more likely to succumb to scours or respiratory disease before weaning and have more health issues throughout production.
• Thin cows have problems rebreeding. Research at Oklahoma State University (OSU) from the ’80s and ’90s has shown us the importance of body condition at calving on post-partum interval and rebreeding success. Cows with a body condition score (BCS) 3 have been shown to have a 20-day longer postpartum interval and 20% lower pregnancy percentage than a cow with a BCS 5 (90 days to first breeding vs. 60 days, and 60% pregnancy vs. 80% pregnancy). Cows that needed assistance during calving also had lower rebreeding percentages.
Cows calving in thin body condition have also been shown to have improved pregnancy rates when they are increasing in body condition before breeding. Increasing body condition during lactation is not easy and is expensive because of large increases in protein and energy requirements, but it can be done in the right situations.
Savvy operators can manage through these challenges and have successful outcomes with these challenging sets of cows. Having a clean calving pasture with plenty of cover from the weather that is handy to the working facilities is a must. Adding flesh to thin cows post-calving is not easily done using hay and supplement. We have had much greater success putting young pairs on high-quality wheat pasture or limit feeding a high concentrate total mixed rations to cows than trying to supplement along with even good quality hay. — Paul Beck, OSU Extension beef cattle nutrition specialist
