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LIVESTOCK MATTERS
16
SPRING 2014 ISSUE
LAMB ING
Assuming all has gone well at lambing
and a healthy lamb flock has been turned
out, the two main problems seen in
growing lambs are parasite burdens and
nutritional deficits.
Nematodirus battus is high on the list of
suspects when it comes to scouring lambs,
alongside high Trichostrongyle counts and
Coccidia. N. battus has a direct life-cycle
from one year’s lamb crop to the next via
weather resistant eggs that remain on the
pasture over winter. Lambs should not be
turned out onto pasture grazed by last
year’s lamb flock if possible and regular
faecal worm egg counting should be
performed to assess worm burden and
monitor wormer efficacy. A free parasite
forecast is available on the NADIS website
and is well worth reading whilst you have
lambs at pasture.
Coccidiosis is a significant disease that is
often overlooked on smaller sheep units but
is well worth considering when dealing
with scouring lambs. It is usually seen in
lambs 4-6 weeks old, often in groups of
later lambs, and particularly if stocking
density is high or hygiene in the shed
(or around feeders in the field) is poor.
Coccidiosis is caused by two specific
strains of Eimeria species which are
parasites that live inside cells in the lamb's
gut. They multiply within the lining of the
gut and cause considerable damage to the
intestine. This loss of gut lining causes a
profuse diarrhoea and affected lambs will
often look dull and anorexic, often with
abdominal pain and straining. Severely
affected cases may have secondary
bacterial infection in the intestine and there
may be blood in the diarrhoea. Adult
sheep are unaffected by coccidia, as
immunity is strong, however they are the
main reservoir of infection to lambs,
shedding higher numbers of coccidial
oocysts in their faeces around lambing.
Early lambs will only be exposed to low
numbers and will gain strong immunity by
eight weeks, however coccidia numbers
will multiply up, leaving large numbers on
the ground for the naïve later lambs, which
may succumb to disease. Concurrent
infection with Nematodirus is often seen
and may mean that only low levels of
coccidia are needed to cause clinical
disease. Treatment of severely affected
lambs includes administering anti-coccidial
drugs, injectable sulphonamides (off-licence)
and fluid therapy as directed by your vet.
Coccidia are resistant to many commercial
disinfectants, however there are several
effective products available that clearly
state suitability for use against coccidia.
Prevention involves improving hygiene and
reducing stocking density, as well as turning
out later born lambs onto ground not
previously grazed by early born lambs.
Anti-coccidia (coccidiostat) medications are
available that can be added to creep feed,
however they will prevent any natural
immunity building up, so that lambs will
be fully susceptible as soon as medication
is stopped.
Nutrition of ewes and lambs after turnout is
just as important as worming protocols, and
simply turning everything out onto ‘lush’
spring grass invariably isn’t quite enough.
Ewes must be supplemented with sufficient
feed to sustain milk production for the
growing lamb, whilst creep feed must be
available in sufficient amounts to maximise
growth rates. After discounting parasites
and under-nutrition as a cause of poor
growth, looking at trace element
deficiencies is the next step. The easiest
way to do this is by blood sampling a
representative group of 10 lambs from the
flock to look at blood plasma values for
copper, cobalt and selenium/Vitamin E as
a starting point. As well as hindering
growth, trace element deficiencies can
predispose lambs to secondary diseases.
There are many ways of supplementing for
trace elements, including boluses, licks,
injectables and feed additives. It should be
pointed out however that a great many
farmers are spending huge sums of money
on unnecessary supplements, touted by
manufacturers as ‘essential’ and it is well
worth knowing what trace elements are
required (if any) before blanket
supplementation. Boluses and injectable
vitamins are the only way of guaranteeing
correct dosages are administered if a
deficiency is found. It is important to note
that sheep (particularly Texels) are
susceptible to copper toxicity and care
should be taken not to overdose with
copper supplements.
Cobalt
deficiency signs:
l
Loss of appetite
l
Slowed growth
l
Watery eyes
l
Anaemia and anorexia in severe cases
Copper
deficiency signs:
l
Loss of wool crimp
l
Swayback in young lambs
l
Slowed growth
l
Anaemia and fragile bones in
severe cases
Selenium
deficiency signs:
l
Stiff lamb disease (white muscle disease)
l
Sudden death of young healthy lambs
l
Slowed growth
l
Increased numbers of barren ewes
After turnout
Clostridial disease can be an issue on some farms, with pulpy kidney
and lamb dysentery claiming a few lambs each year on many
unvaccinated farms. Ewe vaccination with a combination clostridia/
pasteurella vaccine 4-6 weeks prior to lambing will protect the ewe
for 12 months, and lambs for 12 weeks from Clostridial diseases, and
Pasteurella for four weeks, providing they receive colostrum from
the ewe. It is recommended that lambs be vaccinated from 12 weeks
for continued protection.
As well as the direct benefits of
fewer lamb losses, ensuring lambs
get off to a healthy start will pay
dividends in the longer term. This can
be seen as improved feed conversion
of growing lambs, decreased time
to slaughter weight and improved
fertility of replacement ewe lambs,
to name but a few.
To fully assess the management
practices and disease risk on your
own farm it is important that you
contact your own XLVets practice
and your vet will devise a specific
flock health plan, tailored to your
own circumstances.
Lamb showing signs of abdominal discomfort