IN THIS ISSUE: |
CURRENT ISSUES IN HEIFER GROWTH
REMEMBER, IT’S A SYSTEM |
One of the “felt” lessons learned early by most dairy nutritionists is that too much information often leads not to better choices, but to paralysis by analysis. Take heifers. Such a conflict-generating wealth of research into their nutritional needs conducted during the last decade could explain the continuing inability to really break through the traditional barriers to growing either cheaper or better heifers, says Cornell’s Dr. Mike Van Amburgh. Some of the issues and paradoxes include:
EVEN THE ASSUMPTIONS AREN’T SAFE TO ASSUME.
Consider for instance the “considerable
body of research” that’s been generated to
support the universal consensus that
high rate of gain hurts mammary development
and thus, lactation yields. Dr. Van
Amburgh’s group started feeding heifers
at 100 pounds either high- or restrictedenergy
diets, to gain either 1.4 or 2.1
pounds daily, serially slaughtering them
at 110-pound increments through about
770 pounds. Results showed neither diet
nor body weight had any significant
effect on mammary tissue characteristics
or development. Pre-puberty mammary
development still appears to be dictated by
age and not energy intake, per se.
The research into mammary development
and nutrient intake has demonstrated
responses that have varied from
as much as a 60 percent difference in
mammary development in some studies
to none in those like Dr. Van Amburgh’s.
The variability can be explained by:
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how you define and measure mammary development
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differences in how you define “rapid” gain
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differences in genetics and mature size
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heifer ages or time on treatment
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dietary differences like the quantity of energy fed and the quality of protein used.
TRUST THE NEW GROWTH MODELS, BUT VERIFY.
Revisions made in NRC 2001 made our
ability to balance energy and protein
in the rapidly growing animal better
than ever. Still (without indulging in
the popular pastime of NRC criticism),
Dr. Van Amburgh says it’s important to
remember models are usually designed
to be fail-safe.
“On the farm,” he says, “the real answer comes
down to the need to meet a requirement.” Meeting
that requirement usually doesn’t get us near
optimizing dietary protein. Because the efficiency
of dietary nitrogen for growth decreases dramatically
as requirements are met, there remains
much room for removing inefficiency from the
system, he believes. Also, heifers tend to suffer
from too much of a good thing when they’re fed
high-quality forages to refusal, which reduces
efficiency.
With almost 400 head of research heifers serially
slaughtered between his group and that of
Dr. Jim Drackley at Illinois, our ability to more
aggressively pursue efficiency is getting better.
Dr. Van Amburgh is also in the process of work
in coordination with West Central to develop
starter programs that better meet the ruminal
and intestinal protein needs of the fast-growing
heifer, including appropriate levels of undegradable
protein. Much work remains to be done in
that area. Our understanding of the energy and
protein exchanges—both within the rumen and
to the animal during the period of rumen development—
remains inadequate to fully exploit
both the health and growth potential of the calf.
THE NUTRITIONIST’S ROLE.
The long and short remains
that success still depends on judgments made in the
field. Nutritionists can play a key role in advocating
among their clients for better measurement.
Despite heifer costs consuming up to a fifth of
every production cost dollar, enough of that followup
on management changes is still not being done
now. There’s still a lot of opportunity to put tapes to
work on dairies raising heifers.
“Milk production and cow body condition can
be measured every day,” he says. “But how many
people actually measure the change that occurs
when a starter ration is changed? Growth is an
essential component of the dairy, yet many of us in
the industry have had little training or background
in applied aspects of animal growth.”
CONSULTANT’S CORNER
HEIFER TECHNOLOGY
Akira Saito, DVM, Zen-Raku-Ren, National Federation of Dairy Co-operative Associations,
Tokyo/San Francisco
Among the Japanese dairies served by our producer cooperative, Zen-Raku-Ren, the
main factors affecting farm income related to replacement programs do not differ
greatly from the challenges faced by dairy producers in the United States:
- health and mortality
- development of the mammary gland
- age at first calving and cost of raising
- body size at calving
- dry matter intake
- foot and circulatory system development
- achieving full genetic potential
Our strategy in order to manage those challenges is two-fold: first, improve
basic management techniques; second, apply advanced technology atop that basic
technique. One example of that advanced technology is the use of SoyPLUS® in
development rations. ZRR started importing SoyPLUS to Japan in 1997, based on
West Central’s good research history and the product’s consistent quality. Our own
in-house research has shown adding a source of rumen-undegradable protein with a
good intestinal digestibility has helped us achieve our heifer-growing goals. SoyPLUS
provides a palatable bypass protein with an excellent amino-acid profi le in our prepubescent starter/grower diets. In addition to its obvious uses as a protein supplement
for high-producing cows during lactation and transition, SoyPLUS has also become an
important component of ZRR’s calf starter and young-heifer growing ration.
BEYOND BYPASS
SOYPLUS® AND HEIFER GROWTH
Penn State University professor of dairy science Dr. Judd Heinrichs randomly assigned 78 young dairy heifers to starters containing one of three protein sources:
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control with solvent soybean meal
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corn distillers and cottonseed meal in combination
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SoyPLUS
All diets were isonitrogenous and isocaloric, formulated to contain 18 percent crude protein and either 36 percent or 45 percent bypass protein.
His results showed body weights were significantly greater for the calves fed SoyPLUS. Also, calves fed SoyPLUS outperformed the other calves in the important frame-development indicators. Similar trials to update the value of intestinally digestible bypass protein to improve the efficiency of heifer evelopment are now in progress by Cornell professor Dr. Mike Van Amburgh. Results will be reported as soon as they are available.
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QUALITY CORNER
TYPICAL SOYPLUS UREASE VALUE?
Urease is one of the most common laboratory methods used to determine whether soy products have been properly cooked for nonruminant uses. Typical urease values for SoyPLUS, measured
as pH change, are 0.02 to 0.03 units.
In addition to in-house NIR monitoring, we send check samples to Woodson-Tenent Laboratories in Des Moines. Samples are also analyzed for bypass protein at Cumberland Valley Analytical Services in Hagerstown, Md., using an in situ method. April to July 2005 results show:
The new Labconco Digital Chloridometer we’ve added to the new SoyChlor® plant permits hourly analysis to ensure a constant chloride level. June through August results show:
FROM THE MATERNITY PEN
DRY COW LIGHT MANIPULATION
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GET A METER, USE IT
Offering metered lighting spotchecks to clients can
make a good value-added service for nutritional consultants.Dr. Dahl, reviewing his latest findings at this year’s American Dairy Science Association annual meeting in July, showed that a cycle of 16 hours of darkness followed by eight hours of light for the 60-day dry period improves milk production in the following lactation, compared to cows given either a reverse cycle of light/dark or left to natural ambient light cycles.
Dr. Dahl suggests these pointers for client dairies interested in implementing the practice:
- Any well-ventilated facility can work to limit photoperiod, as long as you can control light. Cows being held in darkness shouldn’t be exposed to any artificial light during the dark hours.
- Infrared lighting that provides 1 to 2 foot candles can be used to handle and observe cows in the dark hours.
- Any type of lighting appears to work
for the lighted hours, so the choice
should be dictated by cost efficiency
and intensity of light at cow level.
That intensity will be based on how
high the facility’s structure dictates
lights must be mounted. Ambient
light can be used, as long as it’s
intense enough. - Light intensity during the lighted hours should be 15 foot candles at 3 feet from the stall floor. Place lights so that intensity level gets dispersed over as uniform an area as possible.
- Although controlling light for just the 21 days before calving causes a similar response to doing so for the entire 60-day dry period, the response is less consistent when only done for 21 days, Dr. Dahl says.
- The dry-period light response also appears to work in heifers during their last 60 days of gestation, he says.
BETTER HEALTH, AS WELL?
Work reported by Dr. Dahl’s group at Illinois showed a small group of cows
treated with short day photoperiod during the dry period had numerically—
though not statistically significant—improved indicators of general reproductive
health. Cows in a short-day photoperiod also averaged an SCC of 250,000,
compared to 650,000 for cows given long lighting.
WEST CENTRAL HAPPENINGS
WEST CENTRAL DONATES BIODIESEL FOR HURRICANE CLEAN-UP
As the clean-up from Hurricane Katrina continues in the Gulf, West Central is doing what it can to assist the ravaged area. The needs in the area are many and immediate; the ways a company can assist in the efforts are numerous. As one of the country’s leading producers of soy biodiesel, West Central donated more than 6,500 gallons of fuel to help move clean-up equipment, supplies and people in and out of the affected areas.
This biodiesel donation will be distributed with the help of The Veggie Van Organization and The Federation of Southern Cooperatives. The Veggie Van Organization is a non-profit advocacy group based in Venice, Calif. The Federation of Southern Cooperatives is a cooperative working with those affected by the hurricane, primarily in rural Mississippi and Louisiana. The Federation of Southern Cooperatives has a 35-year history of successfully providing self-help economic opportunities and hope for many low-income communities across the South.
The effects of this hurricane have impacted the entire country. Cooperative organizations throughout the United States are stepping up to contribute to the relief efforts. West Central is proud to be able to do its part in assisting with this huge rebuilding process.
