I*'
Larry W. Spect
Dairy Science Extension
Penn State
Bovine Leukocyte Adhesion Deficiency [BLAD] is a
genetic defect that surfaced in the past ten to fifteen
years in the Holstein breed. The mode of inheritance
is similar to that of the "red factor" in Holsteins.
Animals are either normal [do not have the recessive
gene that is responsible for the defect], or are
"carriers" [have one defective gene but appear
normal] or have two copies of the recessive which
permits the defect to be expressed. Carrier animals
transmit the gene to their offspring one-half the
time. Mating two carrier animals will, on average,
produce one normal [non-carrier] calf, two
"carriers" and one calf afflicted with the problem. In
the latter case, such calves usually die shortly after
birth because their immune system is compromised.
Those that survive are weak and small.
UNIVERSITY PARK (Centre Co.)
Old buildings can be used to raise
dairy replacements successfully or
they can be a continuous drain on
resources and result in health and
growth problems.
Whether a brand new pole barn or a
remodeled 1825 bam, the require
ments for raising healthy dairy
replacements are the same.
The bam must provide adequate
grouping, excellent year-round venti
lation, continuously available frost
proof water, good observation of all
animals, easy mechanical cleaning for
all groups without excessive moving
of animals, and convenient access to
appropriate feeds.
Determining the true value of an
Congratulations
Dairy of Distinction
Award Winners
Keep Your Cows Producing
Over the Hot Summer Months
and Cut Feed Costs and Increase Profits
at the Same Time with TMR out of the...
*~R/SSLER~}
TMR MIXERS & FEED CARTS J
yy if ■/
STATIONARY MIXER MOBILE TMR FEED CARTS
11 sizes available 6 sizes available
Indlori Supplement
Some Tips On Remodeling For Calves, Heifers
Mobile Round-Bale
Fed Carts Available
i linciitw FaMffi&T Saturday, 7ufr' if, HDtt
BLAD And Milk Production
Controlling the spread of this defect in the breed is
fairly simple. Just do not breed carrier animals to
each other. A more extreme step is to not use BLAD
carriers as parents of the next generation. The major
AI units have taken two steps to control its spread..
First, by testing and culling nearly all of the bulls
that are carriers. Less than 10% of the bulls in active
AI service are carriers. Secondly, all young bulls
slated for progeny testing are checked and the
carriers are culled. These steps have reduced the
incidence of BLAD carriers in regular service. Such
action, initiated five-six years ago has markedly*
reduced the incidence of carriers to almost nothing
and has the potential to eliminate it from the male
side of the pedigree in AI bred catde.
A number of well respected bulls have been carriers
of BLAD. Carlin-M Ivanhoe Bell, well known as a
sire of high production, and a number of his sons
existing building is difficult. Evert pro
fessionals have trouble identifying all
the hidden costs in renovation. When
the farmer tries to do this there are
additional considerations.
“That’s the first bam grandpa built
when he came here” or “But I put a new
roof on the bam 12 years ago.” These
can be valid reasons for keeping a
building. They can also cloud a realis
tic evaluation of the building’s value.
Why is the building available in the
first place? Was it unsuitable for
everything else so now we’ll try it for
heifers? Are the ceilings too low to get
power equipment in?
The most important consideration
when evaluating an existing building
for remodeling is location. Remember
Dairy
of M
Distinction
"®J.
the first three rules in real estate for
determining value are location, loca
tion, and location.
The same is true for a bam. No
amount of money short of moving the
structure can truly make up for a bam
that is in the wrong place.
• Location. Is access to the existing
structure adequate for cleanout and
delivery of feed and bedding? For ani
mal traffic to and from pastures? For
needed utilities? For proper animal
care and regular observation? Does
this location fit into a logical long
range plan for replacement housing? Is
this location on the farm better suited
for other uses, such as shop, storage,
garage, open space?
If the building stands the location
S
Dairy ▲
of fll
Distinction
F.M. BROWN'S SONS , INC.
Manufacturer of High Quality Feeds
Balance, for Your Dairy Farms Needs
|JL Mllkmmtw ||
1 M BROW'S
tIS FLEx-pmmUL A 11 j
lIS Feeds
) I lu »»u»l*lnS iWuutiim, i
Salutes
Dairy of Distinction
Award Winners
For Promoting the
High Quality Standards of
MILK
are carriers. According to Michael Cowen ot
Genetic Visions, 23% of the young Holstein bulls
sampled in AI in 1989 were carriers. The figure is
near zero today.
Because a number of bulls that carried BLAD were
near or at the top of the list of potential mating sires,
some people wondered if BLAD was linked to yield
and if the removal of such bulls would slow genetic
gain. Genetic Visions and the USDA Animal
Improvement Programs Lab have cooperated in
studying the question. Sons of four Holstein bulls
that were carriers were divided into two groups,
carrier and non-carrier. The comparison showed no
difference between the two groups for yield traits.
The conclusion was that removal of BLAD carriers
from breeding programs would not slow genetic
progress for milk production.
test, it’s time to do a closer analysis.
Items to consider include ventilation,
floor plan restrictions, and structural
condition.
• Ventilation. Can the building be
opened up to provide adequate year
round natural ventilation, or is a more
costly mechanical ventilation system
required? If you cannot realistically
provide a good healthful environment
year-round, don’t renovate.
• Layout. The same rules for good
layout for animal traffic and chore pat
terns should be applied to existing
buildings as to new ones. Can a good
floor plan be established around exist
ing poles and walls? Can frostproof
water be installed? What’s the cost to
(Turn to Pago 30)
&