Profitability on your ranch depends on reproduction. To sustain a calf year after year, cows must maintain body condition scores and be cycling 40-60 days postpartum and rebred by days 80-85.
Healthy cows that are ready for breeding season should be at a body condition score of 5. Anything lower than a 3 or 4 and cows often stop cycling, extending the calving season and disrupting profits with no calves or lighter calves.
It is important to note that breeding season preparations should start at weaning by evaluating your herd’s body condition and increasing the energy content of forages for optimal scores.
However, in emergencies, there are three ways to get lower body condition cows cycling for breeding season.
1. 48-hour Calf Removal
According to the University of Nevada, the hormonal processes of lactation and nursing directly influence the start of a cow’s estrus cycle or her first heat. The stimulation a cow receives from a nursing calf, along with her nutritional status, determines how long until she starts cycling post-calving.
Calf removal for 48 hours just prior to the breeding season has been proven to work by removing the stimulus of the calf being nursed. This triggers hormones in the cow to start cycling.
Note that this strategy can also be used on cows with a higher body condition score to get their cycles synchronized. This removal method has also been shown to increase pregnancy rates of herds sooner.
However, the downside of this strategy is that it will inevitably put extreme stress on the calf. Calves will likely not eat during this time. Beef producers must be set up with proper fencing (to hold back the cow) and facilities to house the calf while trying to get them to eat.
2. Early Weaning
When body condition scores are at a 4 or lower, early weaning is often suggested, rather than 48-hour removal. This allows cows to start focusing nutrients on themselves instead of lactation, since milk is the biggest pull of nutrients that stops a cow from cycling.
This strategy takes a 60-90-day old calf and completely separates them from the cow. According to North Dakota State University, studies show that early weaning can help improve pregnancy rates and allow cows a greater opportunity to rebreed in the early days of breeding season.
The downfall to this strategy is it requires more attention to calf health and nutrition. Young newly weaned calves require more supervision and accrue higher feed costs to background.
3. Bypass Protein Supplementation
Another method for adding body condition to a cow is by using bypass protein supplementation or crude protein. Crude protein has two-parts.
Protein is a crucial nutrient for rumen microbes and low values will impact their ability to break down forage and extract nutrients. However, rumen microbes are only able to break down a portion of the crude protein supplied in a diet. This portion is called rumen degradable protein (RDP). This protein has been shown to improve intake, and available energy. However, in early lactation this increase in energy would almost certainly go to milk production and not actually help put body condition on the cow.
The other protein in crude protein is rumen undegradable protein (RUP) and is not digested by the microbes in the rumen. Instead, this protein bypasses the rumen and provides more available protein to the animal itself.
The goal of this strategy is to limit the magnitude of weight loss and supply more available protein to the cow with bypass protein. Studies show that pregnant beef cows supplemented with RUP or bypass protein had reduced weight loss. This means body condition scores were maintained during calving for better and faster rebreeding.
Keep in mind that excess protein of any kind can do more damage than good if not properly formulated to animal requirements. Animals excrete extra protein through ammonia, and this process takes energy adding causing cows to lose weight instead of gain weight. Always consult with a ruminant nutritionist before implementing.