Planned and Impulse Heifer Breeding

Derrell S. Peel, Oklahoma State University Extension Livestock Marketing Specialist

 

The January Cattle report from USDA-NASS has included the inventory of beef replacement heifers since 1920. The latest USDA Cattle report pegged the January 1, 2024 beef replacement heifer inventory of 4.86 million head, down 1.4 percent year over year. However, the latest report revised the initial estimates of the 2023 inventory from 5.16 million head down to 4.93 million head. This means that the 2024 beef replacement heifer total is down 11.4 percent from 2022. With the revisions, the 2023 inventory, along with the 2024 beef replacement heifer inventory are below 5 million head and are the smallest January 1 inventories since 1950.

 

Since 2001, USDA has provided an additional breakdown of beef replacement heifers into the number expected to calve (bred heifers) and the residual of heifers retained for breeding. This emphasizes that the replacement heifer total consists of heifers from two different calf crops: coming two-year-olds that will calve this year and yearling heifers, from last year, in development for breeding (Figure 1).

 

Figure 1. Heifers held as Beef Cow replacements

The average number of beef heifers calving since 2001 has been 3.46 million head, an average of 11.1 percent of the beef cow inventory. This compares to the average herd culling rate (beef cow slaughter as a percent of the beef cow inventory) of 10.0 percent over the same period. Year by year the relative percentages of heifers calving and cow culling determines whether the beef cow herd increases or decreases. The inventory of bred heifers for 2024 is the smallest in data available since 2001.

 

Yearling heifers saved for breeding this year become bred heifers next year. However, on average, the calculated yearling heifer total is only 64 percent of the bred heifer total for the following year. The remaining 36 percent of bred heifers is assumed to be impromptu heifer breeding in the previous year in which producers decide to breed heifers not previously identified as replacement heifers. These extra heifers bred are presumed to be sourced from the other heifer inventory. This means that planned heifer breeding accounts for roughly two-thirds of heifers calving with the remaining one-third the result of impulse (unplanned) heifer breeding (Figure 2).

 

Figure 2. Beef Replacement Heifers expected to calve

 

Not surprisingly, impulse heifer breeding is more variable than planned heifer breeding. Statistically, impulse heifer breeding is about 80 percent more variable than planned heifer breeding. Therefore, impulse heifer breeding plays an important role in the dynamics of cattle cycles. For example, in the cyclical herd expansion from 2014 to 2019, impulse heifer breeding was the first to expand, increasing in 2014 by three times more than planned heifer breeding. As herd expansion slowed near the 2019 peak, impulse heifer breeding decrease first and more rapidly compared to planned heifer breeding. The data available now allows a more detailed accounting of heifer breeding and quantifies commonly described behavior when producers decide to increase or decrease heifer breeding in an impromptu manner.

 

The 2024 inventory of bred heifers is down 1.9 percent year over year and consists of yearling heifers bred last year, which was down 15.1 percent year over year and a 27.3 percent increase in extra heifers bred (impulse breeding). In other words, while planned heifer breeding decreased to a record low level (data back to 2001), impulse breeding of heifers increased sharply in 2023, nearly offsetting the decrease in planned heifer breeding. Is this increase in impulse heifer breeding the first sign of industry attempts to begin herd expansion? Maybe...although it is not clear yet. When both planned and unplanned heifer breeding are increasing it will be more certain what producers' intentions are. It will depend on evolving producer expectations as well as weather that will determine what is possible in 2024 and beyond. Stay tuned.

 

 

When to Assist with Calving

Mark Z. Johnson, Oklahoma State University Extension Beef Cattle Breeding Specialist

 

There are three stages of bovine parturition. Stage 1, dilation of the cervix is variable in length and can occur over hours or days. During Stage 1, you may or may not notice a mucus string hanging from the vulva, cows with less appetite or cows separating themselves from herd mates. Stage 2 is the delivery of the calf. Stage 2 officially begins with the appearance of the placenta (water bag) at the vulva. Deciding when/if to provide assistance to a female is based on what you observe at the onset and during stage 2 of the birth process. Stage 3 is the delivery of the placenta or afterbirth, typically happening within a few hours after delivery of the calf. Understanding the birth process, the normal timelines associated with Stage 2 and what a normal presentation of the calf fetus looks like are all critical in making the judgement call of when to offer assistance during calving. Intervening in the calving process too soon or too late can lead to a bad outcome. Unusual disturbance or stress too early in the process can slow down contractions and delay calving. Don't jump the gun! Give the natural birth process time to run its course before intervening. By that same token, waiting too long to assist can lead to weakened or dead calves.

 

When to Assist?
"Start your clock" at the appearance of the water bag at the beginning of Stage 2. Normally, at this point, the fetus has entered the birth canal, a portion of the water bag can be observed and the heifer/cow is usually lying down. Uterine contractions occur every couple of minutes and are accompanied by contractions of the diaphragm and abdominal muscles. Surrounded by the water bag, the calf's front feet and possibly nose are beginning to protrude from the vulva. After the nose is exposed, the dam exerts maximum straining to push the shoulders and chest through the pelvic girdle.

 

Once the shoulders have passed, the abdominal muscles of the calf relax and its hips and legs extend back to permit easier passage of the hip region. At this point, the water bag has ruptured and the calf is calf is normally free of fetal membranes, because they remain attached to the cotyledons of the uterus. This ensures an oxygen supply for the calf during birth. Upon passing though the vulva, the umbilical cord breaks, respiration begins, filling the lungs with air and the lungs become functional.

 

Although the time intervals presented here may vary among types and breeds of cattle, and among individuals of the same breed, most recent research indicates healthy heifers, calving for the first time and with a normal presentation of the calf should calve unassisted within 60 minutes of the appearance of the water bag. Healthy cows with normal calf presentation typically calve in less than 30 minutes after the onset of stage 2.

 

Deciding when to offer assistance is a judgment call and good judgement is the result of experience. Obviously when we come upon a heifer or cow with the front feet and nose of the calf showing, and water bag ruptured but don't know how long they have been trying, it can lead to anxious moments. When cows are lying down and having contractions and no water bag or calves feet can be seen, it can be a sign of an abnormal presentation or a very large calf. When you don't know when stage two started, or it is apparent no progress is being made, or all signs are normal but the timelines mentioned are expiring, you will need to conduct a vaginal exam to determine what is going on and if help is needed.
Reference: The 3 Stages of Bovine Parturition

 

 

How much water do cows really need during cold weather?

Dana Zook, NW Area Livestock Specialist

 

It's no surprise that the main topic of conversation in the winter is how to help cows maintain condition through cold temperatures. Supplementation and feeding are always on producers' minds, but one often overlooked topic during cold weather is water. How much water do cows really need during cold weather?

 

Growing up in Nebraska, our cows were always grazing crop residues during the winter and there was rarely a natural water source. Because of this, water was hauled. Some Oklahomans look at me aghast when I tell them this, but I can honestly say it was just part of the job. Instead of supplementing cows with feed most of the winter, we hauled water.

 

A fact of beef production is that decreased temps increase the need for additional energy. This extra energy often comes in the form of dry feeds such as hay, byproduct cubes, or commodity blends. Water is essential to helping cows digest this additional feed. Limiting water will in turn compromise feed intake and make it very hard for cows to maintain weight. Another factor that affects water need is the stage of production. The need for water will increase with the demands of production. For example, lactating cows will require more water than pregnant, dry cows. Water intake data collected by OSU and other research institutions has provided baseline water intake data for all production stages of cattle so that people hauling water or building new water infrastructure can estimate total water needs by cattle.

 

So how much water do they need? Water requirement guidelines are listed in OSU factsheet AFS-3299 "Estimating Water Requirements for Mature Beef Cows". This factsheet reports 1300-pound cows experiencing 40°F require approximately 9-15 gallons of water daily. The lower end of that scale would apply to open or pregnant, non-lactating cows while the upper limits apply to lactating cows.

 

Further research evaluating this range of water intake is currently being collected by Dr. Dave Lalman and his research team. In the current study, 5-year-old cows weighing an average of 1363 pounds with calves at side have been consuming an average of 15 gallons since mid-November. Consumption by the calves is included in this average but Dr. Lalman said it would be accurate to assume they are drinking 1-2 gallons of this total amount. That brings up a good point about the importance of water for calves. To ensure calves get enough to drink, fill tanks high enough so shorter animals can reach the water level. Natural water sources should be chopped so that calves can access the water source safely.

 

Water is usually a "hot weather" topic, but its importance should not be overlooked in the winter. Dehydration is an added stress for cows in cold weather. Help cows deal with winter stress and maintain their body condition by ensuring they have adequate water.

 

 

The Simple Economics of Extended Wheat Grazing and Why it's a Bad Idea

Eric A. DeVuyst, Professor and Rainbolt Chair, Department of Agricultural Economics, Oklahoma State University

 

With the current above average temperatures, first hollow stem in wheat pastures will likely be here earlier than is usual. So, it's a good time to look at the benefits and costs of grazing wheat past first hollow stem. Let's start with the research.

 

There are two Oklahoma studies that looked at the impact of extended wheat grazing on wheat grain yield. Fieser et al. (2006) looked at grazing stockpiled wheat forage, where Redmon et al. (1996) looked at wheat pasture that was grazed over the winter months. So, when looking at Fieser et al., the results show far less wheat loss from extended grazing. Meaning, if wheat pastures have been grazed over the winter months or are behind normal growth, Redmon et al. results are where we should focus.

 

In Table 1, wheat yield losses are given as a percentage of wheat yield. Assuming 35 bushel wheat grain yield (without extended grazing), one day of extended grazing is a loss of 1.75 bushels. At $6 per bushel, that's $10.50 per acre in lost grain. Next, let's calculate the value of one day of extended stocker grazing. Assuming a stocking rate of 0.64 head per acre, $1.80 value of gain, and 3 pounds per day gain, one day of extended grazing generates $3.46 per acre in added revenue. The difference in returns per acre from one day of extended grazing is -$7.04 per acre. The losses increase quickly as extended grazing continues. By just three days past first hollow stem, extending grazing has a net return (value of stocker gain less wheat grain loss) of -$21.13 per acre. At seven past first hollow stem, the loss is over $45 per acre. This is before charging opportunity cost to the stocker enterprise.

 

The results are robust to changes in wheat prices and stocker gains. If wheat price is $6 per bushel, the stocker value of gain would need to be $5 per pound to roughly breakeven on extended grazing. Alternatively, at $1.80 value of stocker gain, wheat price would need to be about $2 per bushel to roughly breakeven on extended grazing.

 

The economics are clear: don't graze past first hollow stem if you intend harvest wheat grain.

 

Table 1. Wheat yield grain yield loss from extended grazing*

*Derived from Redmon et al. (1996).

 

References

Fieser, B.G., G.W. Horn, J.T. Edwards, and E.G. Krenzer, Jr. "Timing of Grazing Termination in Dual-Purpose Winter Wheat Enterprises." The Professional Animal Scientist 22(2006):210-216.

 

Redmon, L.A., E.G. Krenzer Jr., D.J. Bernardo, and G.W. Horn. "Effect of Wheat Morphological Stage at Grazing Termination on Economic Return." Agronomy Journal 88(1996):94-97.

 

 

Rancher's Thursday Lunchtime Series