Normally this is the time of year that our winter
small grain pastures are getting ready to make significant growth and bloat
should be on our minds from a management stand point. Of course now days what is normal.
Let’s keep an open mind and pray a lot, so in the near future I can be
writing articles that reflect, due to recent rains and favorable growing
conditions producers need to be aware of the potential for bloat in
cattle. To top it off because of the
rains producers are actually getting excited about putting out fertilizer. All of these things are very good but at the
same time be prepared for your pastures to become too high of quality and cause
some potential for bloat in your cattle.
The following information can be very useful for Wise County beef
producers about bloat from Ted McCollum III, PhD, PAS-ACAN, Extension Beef Cattle Specialist, Texas
AgriLife Extension Service, Amarillo, Texas If we receive the favorable weather
we need.
Foamy or
frothy bloat reduces performance and can potentially lead to death of
cattle. Frothy bloat occurs when the
gases normally produced during ruminal fermentation cannot be expelled from the
rumen by eructation (belching). At the
onset of bloat, cattle may cease eating and the bloat may dissipate. As the severity of bloat increases, the rumen
becomes more distended and the level of discomfort increases. If no intervention occurs, death can result
from respiratory distress and heart failure.
Anytime cattle are consuming highly
digestible feedstuffs and forages the potential for frothy bloat exists. Carbohydrates and soluble proteins from these
feeds are rapidly degraded and fermented in the rumen. Slime-producing bacteria
that degrade soluble proteins and small feed particles produce a slime that can
develop into a stable, proteinaceous foam.
Mineral composition of the forage may also affect the stability (surface
tension) of the foam. Bloat occurs when
the gases produced by the fermentation become trapped in this foam and cannot
be expelled.
Frothy
bloat on pasture is usually associated with actively growing, highly digestible
forages that contain low fiber and relatively high crude protein (and soluble
protein) levels. Among these forages are
small grain forages and legumes such as alfalfa and red and white clover.
The
occurrence of bloat is affected by a number of factors – soil fertility,
climatic conditions, stage of plant development, grazing management, and animal
predisposition – among others. Because
of the multiple factors, reducing or preventing bloat may require multiple
management approaches on a single operation and, the success, or lack thereof,
of a preventative measure can vary from year-to-year and
operation-to-operation.
Soil
fertility practices may influence the incidence of bloat on small grains
pastures. Work in the Rolling Plains
suggests that high, single applications of N on wheat increases the potential
for bloat. This and management history
on fields may partially explain why bloat outbreaks may occur on some fields
but not on others in the locale.
Stage of
plant development affects the concentration of carbohydrates and soluble
proteins that can provoke bloat. This
again may partially explain why bloat outbreaks may occur on some fields but
not on others in the locale. The forage
may be at different stages of development as influenced by planting dates,
moisture conditions and other factors affecting growth.
Small
grains bloat is typically a problem in the late winter/early spring when the
forage is coming out of winter dormancy.
Occasionally fall/winter bloat can be a problem. With legumes, bloat risk changes with stage
of plant development. For instance,
bloat risk on alfalfa decreases as the plant matures and blooms. Knowing when bloat risk increases and
subsides during the grazing season aids the timely application of prevention
practices.
For
pastures containing bloat-provocative legumes, it is recommended that the
legumes comprise no more than 50% of the forage mix. An alternative is to plant adapted legumes
that are less bloat provocative.
Grazing
programs should focus on turn-out practices and forage availability. Prior to turning cattle onto pasture ensure
that the cattle are full. This will tend
to limit immediate grazing activity and forage consumption. Likewise, if cattle are managed under a
rotational grazing scheme, judiciously manage forage availability. Moving cattle from pastures with a limited
forage supply (and hence limited consumption) to fresh paddocks with an
abundant supply (and hence increased consumption) may predispose the cattle to
bloat. Adjust the rotation so cattle are
not rotated from a limited forage supply to an abundant forage supply.
During
bloat risk periods, providing access to hay or other forages may reduce the
occurrence of bloat. Assuming the cattle
will consume the hay/forage, consumption of the bloat-provocative forage may be
reduced and hence reduce the risk of bloat.
Poloxalene
(Bloatguard) is a mild detergent that reduces the foam in the rumen and hence
can reduce the incidence of bloat. The
product is available in different forms – blocks, mineral supplements, liquids,
top dresses. To be effective, the cattle
must consume a sufficient amount of poloxalene daily. Poloxalene in a self-fed form will probably
never totally prevent bloat because of the variation in daily consumption by
individual animals. Hand feeding
poloxalene in a larger volume of feed will increase the consistency of daily
intake.
Surfactants,
anti-foaming agents, have been used successfully in some grazing situations. In
order for surfactants to be effective, they must be consumed on a daily basis.
Water treatments are effective as long as the treated water is the only source
of water and the surfactant concentrations are maintained.
Ionophore
feed additives may also aid in bloat prevention. Microbial gas production in the rumen is
reduced by ionophore consumption. Studies on irrigated wheat in New Mexico
demonstrated that Rumensin dramatically reduced the incidence and severity of
bloat. Ionophores can be delivered in
blocks, mineral supplements, pelleted supplements and mixed feeds. As noted with poloxalene, these feed
additives will not totally eliminate bloat.
In addition to aiding with bloat prevention, the ionophores will improve
daily weight gain.
Anecdotal
data suggests that salt (sodium) consumption may reduce incidence of
bloat. A survey of Oklahoma producers
indicated that bloat incidence was lower when salt was available to cattle. Remember
that complete mineral supplements for cattle contain salt. Oklahoma data has also shown that cattle
grazing wheat and consuming a complete mineral balanced for wheat pasture gain
more rapidly than cattle consuming salt alone and inclusion of Rumensin further
improved gains. So offering a mineral
supplement provides a means of delivering salt as well as an ionophore, both of
which may help reduce bloat prevalence, as well as improving performance.
Some
cattle are predisposed to bloat. This
may reflect physiological differences, differences in ruminal microbial
populations, differences in forage selection and forage intake, or other
factors. If animals are chronic
bloaters, the best approach is to remove them from the group.
The only
100% effective means of stopping bloat is to remove the cattle from the bloat
provocative pasture.
Several
factors, acting in combination or individually, can lead to a bloat
problem. No one single management
practice will be completely effective all of the time. Knowledge of when bloat occurs and why it
occurs can help in developing and implementing a management plan to reduce the
occurrence.
