Cow-Calf Corner - The Newsletter, April 19, 2021
Forage Planning for the Next Year
Derrell S. Peel, Oklahoma State University Extension Livestock Marketing Specialist
The latest Drought Monitor shows that drought is significantly worse now than at the same time last year with 63 percent of the country now in D0-D4 categories. These drought categories can be combined into a single numerical measure of drought known as the Drought Severity and Coverage Index (DSCI), published in the Drought Monitor. The DSCI can range from 0 (zero abnormally dry or drought conditions) to 500 (100 percent D4, Exceptional Drought). The current DSCI for the continental U.S. is 169, compared to 45 one year ago. Coming summer weather raises the odds of further increases in drought. Since the Drought Monitor began in 2000, the U.S. DSCI has only reached a level of 200 for a total of 22 weeks (all in 2012 and early January 2013), with a maximum of value of 215. Drought conditions since last fall are the worst since 2013.
In any specific location, the drought situation right now will set the stage for the next year. In many parts of the country, the next two months may determine much of the forage production for the next 12 months. Regions such as the Southwest and the southern Rocky Mountains have been in drought for many months and face limited forage prospects this year unless moisture arrives very soon. For example, the DSCI in New Mexico is currently 433 and in Colorado is 301. Herd liquidation began in Colorado in 2020 with a 14.5 percent decrease in beef cow inventories last year. Additional herd liquidation in the region is likely imminent. Prevailing La Niña conditions are predicted to fade to ENSO-neutral in the next two months and the southwest region may have improved chances for precipitation this summer with the typical southwest monsoon. However, it is by no means guaranteed and may be too late to avoid drastic actions in the meantime.
In the northern plains, drought has accelerated over the winter leaving the region in critical risk of very limited forage production this year. North Dakota currently has a DSCI of 367, a record level of drought in the state. The DSCI in South Dakota is 227 in the latest report. Simultaneously, Texas has seen similar acceleration of drought and has a current DSCI of 236. These regions may produce little or no forage this year making drastic management actions likely. Herd liquidation is already occurring and may accelerate quickly in these regions.
Oklahoma and other regions in the central plains are in relatively better condition right now. The current DSCI in Oklahoma is 84, in Kansas is 36 and in Nebraska is 92. In Oklahoma, for example, the DSCI of 84 now compares to a value of 7 at the end of March, 2020, indicating that conditions are significantly worse compared to last year. The Oklahoma DSCI has increased from 52 to 84 in just three weeks, which illustrates how quickly drought can develop. These plains regions have moisture to begin early season forage growth but are vulnerable to a limited growing season if dry conditions persist or increase. In fact, the current drought advance in Oklahoma represents the fifth pulse of eastward drought advance in the past year. Fortunately, in each of the four previous occasions, the drought has receded. The current advance is at a very critical time as forage production begins and if it does not recede, may have large implications for the remainder of the year.
Producers in all drought areas need to inventory current forage and hay reserves and carefully evaluate forage production potential at this time. This will provide the basis for a drought action plan that can help guide what and when decisions must be made going forward. What happens the next couple of months may determine the resources available until this time next year.
See Dr. Laura Goodman’s Ranchers Thursday Lunchtime Webinar “Internet-Based Tools Available for Rangeland Management” OSU Extension: Internet-Based Tools Available for Rangeland Management. - YouTube
Other presentations from the Ranchers Thursday Lunchtime Webinar series “Managing Cattle and Forages in a Dry Weather Pattern” are available at: Rancher's Thursday Lunchtime Series — Beef Extension (okstate.edu)
Keeping the First Calf Heifers on Track
Parker Henley, Oklahoma State University Extension Specialist
Heifer development is one of the most substantial expenses for beef cattle operations. Time quickly gets away when you’re a cow-calf operator, but it’s essential to keep the first calf heifers on track. Heifers conceiving early in their first breeding season will have increased lifetime production and efficiency. It is critical these heifers attain enough weight to initiate their first estrous cycle before the onset of the breeding season.
Recommendations for heifer development have been focused on heifers reaching a target body weight. It’s suggested that heifers be developed to 65% of their mature body weight at the start of the breeding season. Many ranchers have not recently weighed the adult cows in their herd to know what average mature weight to expect. Therefore, most commercial ranchers underestimate the mature size and underestimate the target weights for the heifers. According to the American Angus Association, the average mature cow weight is 1200 pounds. Heifers from 1,200-pound mothers will need to weigh about 780 pounds by the start of the first breeding season. If the mature size of the herd is 1,100 pounds, then the heifers can be about 715 pounds when breeding begins. Only heifers with a potential mature size of 1,000 pounds can be expected to cycle at 650 pounds. These weights are not exact, since there is considerable variation within breeds, but the data shows large cattle must be fed for greater growth rates than smaller cattle. Since most replacements will need to gain 240 pounds between weaning and breeding, the heifers must gain around 1.5 pounds per day.
A major consideration is when to start the breeding season. Its common practice to breed heifers one month ahead of the mature cowherd. This may be a good idea if you do not have the available labor or facilities to calve both the mature cows and heifers at the same time. Also, this allows the two-year-old cow nursing their first calf to have an additional 30 days to begin cycling and breed back earlier in the next breeding season. If you choose to calve your heifers at 23 months of age instead of 24 months of age, make sure to increase the rate of gain so heifers reach 65% of mature body weight prior to breeding. This means that the spring cowherds starting their calving season in March should breed the replacement heifers around May 1st to calve in the first week of February.
Bull Breeding Soundness Evaluations
Dr. Rosslyn Biggs, OSU College of Veterinary Medicine Extension Beef Veterinarian
When selecting bulls, producers should not overlook a breeding soundness evaluation (BSE) conducted by a veterinarian before the breeding season.
Standards for breeding soundness evaluations have been established by the Society for Theriogenology (SFT), a group of veterinarians dedicated to animal reproduction. Although many may use the term “semen testing,” a breeding soundness evaluation is much more. A complete breeding soundness evaluation involves a physical examination, reproductive tract examination, and semen evaluation.
The physical examination of the bull begins with a focus on structural soundness and checking for injuries. The eyes and oral cavity are evaluated. Assessing body condition is also key. Thin bulls may not be able to maintain themselves during a physically demanding breeding season. Bulls that are fat may have difficulty adjusting to living in range conditions and are also predisposed to joint injuries.
The second component of the BSE is focused on the reproductive tract. Scrotal circumference measurements must meet established minimum requirements. Palpation of the testicles and spermatic cords along with rectal palpation of internal organs is required. Electroejaculation is the most common method used to obtain a sample for semen evaluation. It also allows examination of the penis, prepuce and scrotum for physical defects such as congenital abnormalities, warts or injury.
Semen evaluation is a microscopic examination of motility (movement) and morphology (structure) of sperm cells. These indicate the quality of the semen. Cells should move rapidly and in a linear fashion, and individual progressive motility must be at least 30%. A special stain is later added to evaluate the structure of sperm cells. Greater than 70% normal sperm must be present. The semen sample is also evaluated for other cells indicating infection.
Under the SFT classification bulls are considered:
- Satisfactory potential breeder
- Unsatisfactory potential breeder
- Classification deferred
If classification is deferred, then a producer should work with their veterinarian to reevaluate the bull. It is very important to understand that a BSE is an evaluation on the day the test was performed only, and there is no lifelong guarantee of bull fertility. Bulls should be tested at least annually. For new purchases, buyers should request documentation of the BSE.
Producers may also discuss other diagnostic testing, including sampling for infectious diseases with their veterinarian. Continued evaluation of a bull to evaluate libido and maintenance of body condition through visual observation should also occur during the breeding season.
