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JULY 2019
Animal Health Focus
JULY 2019
Animal Health Focus
Impact of nutrition on
animal health
Cathal Cassidy, InTouch feeding specialist, Alltech Ireland, examines the impact
of nutrition on the health of the dairy herd
On any farming enterprise, healthy animals are core to
an e cient and profitable business. They also help to
reduce labour created by issues that may occur. Like any
problem, prevention is better than reaction, and keeping
animals healthy and productive is no di erent. Two
main areas that help to prevent any animal health issue
are: implementing a herd health plan in conjunction
with your vet -- covering everything from a vaccination
programme to biosecurity -- and, just as important,
animal nutrition.
Getting animal nutrition correct will not only lead to
healthy animals but also highly productive ones as
well. Animal nutrition can help in areas such as rumen
health, animal immunity and metabolic issues, which
all have their associated e ects on animal health and
Rumen health
The stomach (rumen) of any ruminant animal works like
their engine, converting the fuel (feed) into performance
(milk or meat), and keeping it working e ciently is key
to driving animal performance. The main challenge to
this e ciency is acidosis. Rumen acidosis is a metabolic
disease appearing as acute rumen acidosis, but more
often as the sub-acute form (SARA). It occurs when
there is an increase in the amount of acid in the rumen
due to animals rapidly digesting feeds that are high in
starch or sugars, such as cereal grains (barley, wheat),
beet or lush grass. This drop in rumen pH caused by the
build-up of acid results in damage to the rumen wall,
leading to animals being less able to absorb the nutrients
from the feed and thus a production drop. The majority
of this damage is irreversible, resulting in poor thrive and
production throughout the life of the animal. Several
studies have shown that 1926 per cent of all dairy cows
su er from SARA, and on the beef side, it causes major
limitations when building cattle up on concentrates
during their finishing period.
Signs of acidosis include:
Bubbles on dung.
Loose manure.
Cows swishing their tails (due to passing acidic
Cud balls in cubicles or pens.
Increased lameness levels.
Less than 80 per cent of animals lying down
observed chewing the cud.
Depressed demeanour.
Links to a drop in milk butterfat.
The basis of preventing acidosis is to reduce the build-
up of acid causing the drop in rumen pH. There are a
few solutions for this that can be used in conjunction
with one another to reduce acid-load, including:
Increasing fibre intakes.
Using feed additives, such as a live yeast product,
along with best-practise management advice.
Feeding high starch and sugar diets as part of a total
mixed ration (TMR).
Ruminants naturally have a way of controlling rumen
pH through rumination. Rumination is the process by
which ruminants digest their feed by chewing the cud.
The saliva they produce during this process has a natural
bu ering capacity in the rumen, which helps control
the acid level. This rumination process is triggered by
physical fibre in the diet, which stimulates the inside
of the rumen, causing the animal to chew the cud and
produce saliva. Therefore, increasing the fibre content
of the diet will increase rumen pH and reduce the risk of
acidosis. While straw is the best source of physical fibre,
products such as soya hulls and beet pulp can also be
sources of digestible fibre. For grazing animals, make