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Heifer Development

Dr. Patsy Houghton sees heifers as a mixed blessing. In fact, she has thought of little else but heifers 365 days of the year for the past 20 years.

Houghton is the owner and general manager of Heartland Cattle Company (HCC), the first professional heifer development centre in the U.S., which she and two former partners established near McCook, Nebraska in 1990.

Though heifers represent the future profitability of a cow herd, she recognizes that the practicalities of managing heifers alongside the mature cow herd are a challenge and oftentimes an inconvenience for many beef producers given that replacement heifers won’t provide any return to the operation for at least 2-1/2 years.

Clients come to HCC for various reasons. Many don’t have the labour and/or feed to economically get heifers off to a good start. Others prefer to put their time and resources into their mature cow herd or other farming enterprises. Some have made the decision to concentrate on raising feeder cattle and purchase bred replacement heifers or young cows rather than trying to produce both maternal and red meat yield genetics.

To date, HCC has turned over nearly 75,000 artificially inseminated (A. I.) bred heifers for customers in 31 states, weaned and started approximately 130,000 calves, finished out more than 75,000 head and participated in 40 research projects.

Houghton was recently in Saskatchewan to share some of her tips for developing replacement heifers with producers at provincial workshops. Her overarching message was that proper heifer development involves much more than proper nutrition.

“Producing high-quality, consistent beef for consumers is the end goal of any cattle production system, but you can’t have production without reproduction — the cow has to have a calf,” Houghton stresses. It starts with selecting genetically superior, fertile heifers that have the ability to excel at raising calves in your environment and will be economical to retain in the cow herd for at least 10 problem-free years.

“If you get the genetics right on the front side, everything else will fall into place,” she says. HCC’s average annual customer retention rate of more than 97 per cent is proof that her clients agree with her strategy. Benchmarking clients’ productivity at the start and ongoing cow herd consultation to measure improvement through the years have shown an eight per cent improvement in the second-calf rebreeding rate across herds and locations for heifers developed at HCC compared with heifers previously raised on their home ranches. Proper management from weaning to first breeding improves the retention rate of second and third calvers in the mature cow herd as evidenced by the fact that the longevity of the professionally developed heifers averages 10-plus years versus less than seven years for ranch-raised replacement heifers.

SELECT THE RIGHT GENETICS

Fertility is the top priority. Houghton selects for fertility by tightly controlling nutrition and placing pressure on length of the breeding season. HCC uses estrus synchronization and A.I. in its breeding program with no natural service at all. Some clients want to place very high selection pressure on fertility by culling any heifers that don’t conceive within 15 days of the first service, while others — often those with fewer replacement prospects — may want to extend the breeding period to 30 or 45 days.

“Pregnancy is the goal, but not at the expense of selecting and managing for sound production traits,” she explains. Early removal of sub-fertile heifers reduces the overall cost of developing replacement heifers and improves cash flow because you will be able to market the culled heifers in a timely manner.

Start by selecting only early-born heifers as replacement prospects. Age at first conception is more critical than body condition score (BCS) in achieving a high first-service conception rate. “It doesn’t matter whether a heifer has adequate flesh — if she is too young to be cycling she won’t get pregnant,” Houghton explains. One or two months can make all the difference. HCC has observed a reduction of five to 15 per cent in first-service conception rates for 12-month-old heifers versus that for the ideal age of 14 months.

Next, look at frame size. Year after year, HCC results show heifers of medium frame size for their biological type have the highest fertility. Taller, larger-framed heifers within a biological group will have an extended growth curve and tend to take longer to reach puberty.

Also consider frame size relative to predicted mature weight to select replacement heifers that will mature into cows that match your available feed resources. For example, a high-quality cow with an expected mature weight of 1,150 pounds should have a very moderate frame score of four when using the U.S. scale of one to nine, Houghton explains. In comparison, a frame-six replacement heifer with the same expected mature weight will be a hard-fleshing, light-muscled, inefficient cow.

FEED AND HEALTH MANAGEMENT

Heifers should be limit fed a high-roughage diet to reach 60 per cent of their mature body weight at first conception. Some producers prefer to develop heifers to 50 to 55 per cent of their mature body weight. Houghton agrees a restricted feeding program places more selection pressure on fertility, however, pregnancy rates will likely be 10 to 15 per cent lower than for heifers developed to 60 per cent of their mature body weight at first conception. Furthermore, pregnancy rates can fall to unacceptably low levels if lighter-weight heifers encounter extreme weather conditions. Regardless of the feeding regime prior to breeding, experts agree that heifers should receive a nutritional program to achieve 80 to 85 per cent of their mature body weight by first calving.

HCC targets a BCS of 5.5 to 6.0 (U. S. scale of one to nine) at the time of first breeding. When they compare weights with visual BCS, heifers grown out to about 50 per cent of their expected mature weight generally have a BCS of mid-to high four, while those developed to 60 to 65 per cent of their mature weight have a BCS of 5.5 to 6.0.

Developing heifers to a BCS of 5.5 to 6.0 provides for a margin of safety should they face severe weather challenges during pregnancy, Houghton explains. Developing heifers to a lesser body condition increases the likelihood of calving difficulty, weak calves, dead calves and poor breed-back.

On the other end of the spectrum, fertility will fall off signifi- cantly if heifers are overfed and the BCS rises above 6.5. Houghton would rather see heifers carry a little less condition (high-four BCS) 90 to 120 days before breeding and increase their plane of nutrition just before breeding to reach a BCS of 5.5 to 6.0. This strategy will provide the best value per dollar spent by improving fertility while not overspending on feed.

BREEDING PROGRAM

A soundness exam 35 to 45 days prior to breeding will help to identify which of your early-born, medium-frame heifers are the top replacement prospects. HCC’s pre-breeding soundness exam includes reproductive tract scoring (RTS), BCS, pelvic measurements, body weight, frame score and a functional soundness evaluation. HCC’s records show the culling rate prior to breeding ranges from three to nine per cent. The most common reasons for culling are small pelvic areas and infantile reproductive tracts along with various functional soundness problems.

RTS involves an internal exam to evaluate ovarian and uterine horn development. HCC’s scoring system is slightly different from that developed by university systems. Houghton wants to see an RTS of 4-4, which indicates the heifer is reproductively normal and actively cycling. A heifer with an infantile RTS of 2-2 may simply be too young to breed and may be suitable to market to a producer with a later breeding season. An older heifer with infantile RTS likely has a hormonal imbalance and will never conceive. An RTS of 3-3 reflects a heifer that is normal but pre-pubescent, needing just a little more time to mature. Estrus synchronization will often kick-start puberty in these heifers.

Pelvic measurements are useful to sort out bottom-end heifers that will experience calving difficulty because their birth canals are too small. HCC uses a Rice Pelvimeter to measure the width and height of the birth canal. Heifers with pelvic areas measuring less than 160 square centimetres are culled. Recording pelvic areas can also help track sire lines that propagate potential pelvic-area problems in their daughters. Breed associations express this trait in their expected progeny differences as “daughter’s first-calf calving ease” or “maternal calving ease.”

Functional soundness evaluations include checking the eyes, teeth and jaw, feet and legs, and udder conformation, all of which are important to longevity.

Heifer temperament is also an important consideration since quiet heifers are known to have improved fertility, immune response and performance. The crew at HCC spends a lot of time and effort working with and exercising heifers so they are quiet and easy to handle when they leave the program.

Biosecurity is non-negotiable, Houghton states. HCC conducts a complete modified-live vaccination program along with internal and external parasite control. All heifers are ear notched and tested for persistently infected bovine viral diarrhea to ensure that no positive females will be returned home or introduced into a buyer’s herd.

Estrus synchronization results in an earlier average conception date within a defined breeding season. When used in conjunction with proven, superior A.I. sires you can expect heavier calves with greater uniformity at weaning than you would get from natural matings using young, non-proven bulls. HCC uses a synchronization method whereby synthetic progesterone is provided to the heifers at a rate of 0.5 mg/ head/day for 14 days followed by an injection of prostaglandin 19 days later. Ninety to 95 per cent of the heifers will be in estrus (heat) two to four days later. Visual heat detection is used and heifers are serviced approximately 12 hours after estrus is observed.

Houghton says you should expect 65 to 70 per cent of heifers to conceive on their first service to high-accuracy, multiple-trait A.I. sires. Breeding heifers at least 21 days in advance of the mature cow herd will give them additional time to rebreed and increase their rate of retention as young cows. Pregnancy testing heifers 45 to 90 days post-breeding will allow you to identify and quickly market any open heifers.

Research from Kansas State University and HCC indicates the weaned calf crop averages seven per cent higher than the U.S. industry average when heifers receive proper nutrition and are bred using estrus synchronization and highly proven, multiple-trait A.I. sires. Estrus synchronization and A.I. also decrease a rancher’s labour requirements by shortening the calving period, simplifying subsequent nutrition, health and marketing programs, as well as simplifying pasture management by eliminating the need for “heifer” bulls.

Hybrid vigour is free for the taking without necessarily sacrificing consistency and uniformity when you follow a well-planned crossbreeding program. Houghton says crossbred calves exhibit improved fertility, growth, longevity and immune response. For example, the industry average first-service conception rate (FSCR) is 60 per cent, whereas the HCC yard average FSCR is 71 per cent and the HCC crossbred heifer average FSCR is 78 per cent. Likewise, the pregnancy rates are 79, 91 and 96 per cent respectively.

Part of the reason for improved fertility in crossbred heifers is likely due to fewer genetic defects resulting in abnormal embryos that slough off. Matings between animals with closely related genetics can result in defects when two recessive genes combine. An increase in early embryonic death is a consequence of the narrowing genetic pool for beef breeds in the ongoing effort to gain consistency.

“Crossbreeding provides a quick fix to this problem, improving the rancher’s bottom line through increased fertility and longevity with no additional inputs,” Houghton adds. “Whenever fertility can be increased by five to seven per cent by simply applying an easy management procedure such as crossbreeding, it deserves serious consideration.”

When all goes according to a well-devised plan, you can expect heifers to calve unassisted at 22 to 23 months of age and provide optimal milk production (based on your grass resources) to raise healthy, high-quality calves for 10 years or more in a cost-effective management system.

For more information visit www.heartlandcattle.com, or contact Houghton at 308-345-4524 [email protected]

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