Conception Influenced Most By Management, Environment
Recent research documents what most producers have suspected.
That is that environment and management are the primary factors
affecting conception rates (see figure 1).
Figure 1
That’s why in an article in the October 2001 Holstein World,
Dr. Kent Weigel, genetics specialist from the University of
Wisconsin, reminded dairy producers to keep fertility measures
and information in the proper perspective.
"Conception rates are a problem on many farms, and this trait has
a high economic value," Weigel said. "But reliability of male and
(especially) female fertility evaluations will be low, and we can’t
forget about the other traits that pay the bills, like milk, protein,
udders, feet and legs, somatic cell scores, and productive life."
When primary selection traits between bulls are equal, then looking
at fertility measures is a small detail that may help gain a percentage
or two in conception rate, advises Mel DeJarnette. In these situations,
producers can trust the SUPERIOR SETTLER™ designation - a mark of higher
fertility given only to sires that excel in both laboratory analysis and
field-based non-return data - as a reliable secondary selection criterion.
Stacking the Odds
By Mel DeJarnette,
Select Sires Reproduction Specialist
"If it weren’t for bad luck, I’d have no luck at all." I’m sure there
are few of us who haven’t used this phrase at one time or another.
Although many things in life occur purely by chance or luck, I’m
convinced that when it comes to getting cows bred, we make our own luck.
Fertility of any animal at any point in time is a summation of the
effects of all prior experiences. From conception until death, regardless
of age or lactation, what happened yesterday can be just as important as
what happened today in determining the fertility potential of each animal.
The only way to successfully maintain high levels of reproductive efficiency
is through a sound reproductive management program that attends to the
multitude of environmental factors affecting fertility and "stacks the odds"
in your favor.
Nutrition
A sound nutrition program is your number one tool:
- Feed heifers to reach 65% of their mature weight by the time they
are bred at 14-months-of-age.
- Use body condition scoring to monitor nutrition. Make sure all animals
calve with body condition scores of 3 to 3.5.
- Minimize body condition loss in the stressful early postpartum period.
- Avoid excessive weight gain during late lactation.
Cow Comfort
Maintaining cow comfort is important to both production and reproduction.
- Keep housing facilities clean and comfortable with regular manure
removal and bedding changes.
- Design facilities to maximize ventilation and air flow during the
summer and heat retention during the winter (northern tier states).
- Cool, clean water should always be available.
- Avoid overcrowding.
Heat Detection
Heat detection programs are another important tool to stack fertility
odds in your favor. The most important aspect of a heat detection program
is to have one. Too many producers have no structured or scheduled heat
detection program. All employees are told to watch cows while performing
their other duties. Results with this method are usually less than optimal,
as each employee assumes that others are catching cows in heat and their
individual contribution doesn’t mean much in the big scheme. In the end,
more assuming is done than heat detection.
Good heat detection management will stack fertility odds in your favor:
- Designate the heat detection responsibility to only one or two employees,
however, make sure all employees help out with heat detection and know what
signs they should watch for.
- Use some type of heat detection aid to help catch those animals who may
only stand for a short period of time (Chalking, KAMAR, BOVINE BEACON).
- Make sure to have a designated heat detection period that is scheduled
at the appropriate times (early morning & late afternoon) and for the
appropriate duration (20-30 minutes). Time spent heat detecting while
milking, feeding or scraping pens does not count.
- Properly designated incentive programs will encourage not only good
heat detection by employees, but result in good breeding efficiencies as
well. The rewards, however, must be based on a) getting cows pregnant with
b) a low number of services and c) within an optimal time frame.
Herd Health Program
- Like heat detection programs; have one.
- Work with your veterinarian to vaccinate for diseases relevant to your area.
- Isolate new animals entering your herd and any animals who develop an illness.
- Schedule regular veterinary visits with appropriate fresh cow checks.
- Good nutrition programs are essential for proper immune system function.
Semen Handling & A.I. Techniques
- Make sure the person inseminating your cows is following recommended
procedures for straw retrieval and thawing. Thaw Select Sires straws in 95°F water.
- Keep unused straws low in the tank’s neck tube during straw retrieval.
- Think "Clean" throughout retrieval, thawing, gun loading and insemination.
- Protect semen from extreme temperature changes after thawing.
- Deposit semen in the uterine body.
Bull Selection
Use Select Sires SUPERIOR SETTLERs to maximize conception potential.
However, remember that when using A.I. bulls who have been screened
for semen quality, fertility will not differ more than 10-15% from the
highest to the lowest fertility individuals. If you have been using
average fertility bulls, sire selection cannot be expected to change
conception rates more than a few percentage points. Because of many
environmental and management factors, individual herds range from 20%
to 70% in conception rates. Using high fertility bulls will help take
you in the right direction, but no bull can change a 20% herd to a 70% herd.
Today’s fertility level is, in part, a reflection of what happened yesterday,
and tomorrow’s will be a reflection of what happened today. Each and every
detail is important each and every day. Reproductive management programs
designed with these points in mind will "stack the odds" for optimum conception
in any herd of cattle.
®BOVINE BEACON is a registered trademark of Omniglow Corp., W. Springfield, Mass.
®KAMAR Kamar Inc., Steamboat Springs, Colo.
™SUPERIOR SETTLER is a trademark of Select Sires Inc.
To order product contact:
Select Sires Inc., 11740 U.S. 42 North, Plain City, Ohio 43064 / Phone: (614) 873-4683 Fax: (614) 873-5751
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