Katherine Research Station
PO Box 1346, Katherine NT 0851
Phone (08) 8973 9739
Fax (08) 8973 9777
Krs.DPIF@nt.gov.au
ISSN 0394-9823
www.dpif.nt.gov.au
EDITION 322 — January 2015
Wet season phosphorus – Why? When? Who? How much?
Whitney Dollemore, Pastoral Production Officer, Katherine
A key profit driver for a majority of properties in the Katherine region is to maximise reproductive
performance of their breeder herds. Body condition score (BCS) has a great impact on the ability of a
cow to conceive, grow a calf, successfully produce a weaner and reconceive. Nutrition is intrinsically
linked to BCS and so maximising nutrition at the time of greatest demand will enable preservation of
BCS resulting in a higher weaning rate.
Acute phosphorus (P) deficiency can be identified by obvious signs of stiffened gait or peg leg, bone
chewing (increasing the risk of botulism) leading to increased mortality, depraved appetite (pica) which
includes chewing of rocks, dirt, wood, bones or hair (pica will also occur if an animal is sodium or
potassium-deficient) or fragile bones often breaking easily. Chronic phosphorus deficiency, which is
rarely diagnosed, is a significant factor affecting the reproductive performance of breeder herds as over
70% of rangelands across northern Australia are severely phosphorus deficient. It is extremely
important economically because it is difficult to identify, manifesting as reduced performance
(growth/reproduction). During the wet season energy and protein in pastures are in sufficient quantities
to meet animal requirements but phosphorus is not and becomes the limiting nutrient. In order to
maximise good quality pasture during the wet season, supplying additional phosphorus to meet the
needs of the animal will aid to preserve a body condition score for re-conception or to maximise
compensatory growth.
Phosphorus supplementation of breeding animals is hard to justify when an immediate increase in
production is not observed in a commercial situation. Breeding animals do have storages of
phosphorus in bone which can be mobilised in times of dietary restriction. However, a 400kg cow has
only 600g (20-30%) of phosphorus that can be mobilised from bone. If the animal is lactating, during
the first four weeks
she will use 10g
Contents
phosphorus per day
Wet season phosphorus – Why? When? Who? How much?
1
(300g) and over
Beetaloo rotational grazing field day
3
another eight weeks
she will use 5g of
DPIF annual bull sale results
5
phosphorus per day,
Buyer’s market
6
the remainder of her
Resources to get you started burning your bushes
9
body reserves.
Some phosphorus
Share your knowledge, promote your invention
9
will be supplied by
Who’s the money maker? Identifiying bull reproductive performance indicators
10
the pasture
Greener pastures call Grant’s name
12
however, in regions
of acute phosphorus
Movement restrictions (Banana Freckle)
13
deficiency including
Animal Health News
14
most of the NT,
Round the Region
21
extra phosphorus
Pastoral Market Update
22
will be required via
supplementation.
Katherine Rural Review
Page |1
What is the required amount of supplement for a lactating breeder?
A calculation based on a 400 kg lactating breeder, maintaining weight over the dry season has the
following phosphorus (P) requirements:
1.6gP/L milk produced x 5L milk = 8gP/d + 9gP/day to maintain weight = 17gP/d
A standard black speargrass (Heteropogon contortus) pasture has on average 0.66gP/kgDM. If an
animal consumes 3% of their body weight in dry matter per day, this cow will consume 12kgDM/day.
0.66gP/kgDM x 12kgDMI = 7.92gP/day
If the requirement for P is 17gP/day and it consumes 7.92gP/day from pasture that leaves a deficit of
9gP/day. So, expanded to 1,000 breeders for 6 months (Nov-Apr):
1000 breeders x 9gP/hd/day = 9000g/d = 9kg/d x 183 days = 1,647kg of P for the wet season
If the lick was straight Kynofos which has 21% phosphorus, than the amount of Kynofos required to
provide 1,000 breeders with enough P for the wet season is:
1,647kgP x 21/100 = 7,843kg = 8 tonne @ a consumption of 42g/breeder/day
However, if the P in a lick mixture is supplied by Kynofos, and the Kynofos makes up 40% of the lick:
21% x 40% = 8.4%P in the lick, therefore, 1647kgP x 100/8.4 = 19607kg = 20 tonne of lick @
consumption of 107g/breeder/day
The benefits of wet season phosphorus supplementation have been outlined in the MLA publication –
Phosphorus management of beef cattle in
Without P
With P
Northern Australia, as a 10% increase in
weaning rate, a 15kg/year increase in live
GM/10,000 AE
$866,100
$965,800
weight gain and a 2% reduction in breeder
mortalities.
GM/AE
$86.61
$96.58
Currently, a wet season phosphorus loose
lick mix (50% salt, 40% P and 10% Gran
GM difference/AE
$9.97
am) is estimated at $955/tonne delivered to
Katherine. Using Breedcow, the gross margins on adding phosphorus supplementation to a standard
dry season lick supplementation regime is shown in the adjacent table. According to this analysis
additional supplement cost can be recovered in two years. The economic and production benefits from
phosphorus supplementation are shown in case studies of properties across northern Australia in the
aforementioned MLA publication available at: http://www.mla.com.au/Publications-tools-andevents/Publication-details?pubi d=6024.
Although feeding phosphorus in the wet season is the most cost effective supplementation strategy,
further minimising costs could be achieved by also segregating animals according to their phosphorus
requirements. For example, keeping growing animals together, heifers separate to the breeder herd or
separating breeders according to the predicted time of calving/lactation. Phosphorus supplementation
is most important for late pregnant heifers and cows, growing stock and lactating cows. Other
strategies to minimise cost may include, not feeding lick to breeders (three years of age or older) that
will not lactate in the current year or selecting for a cow with a moderate frame size, therefore lower
requirements for phosphorus.
Supplying phosphorus supplements to stock will increase the amount of pasture eaten by each animal
and so it is important to calculate stocking rates correctly based on an increase in dry matter intake of
10-30% (Jackson et al. 2012).
Reference:
Jackson, D., Rolfe, J., English, B., Holmes, W., Matthews, R., Dixon, R. M., Smith, P., and MacDonald, N. (2012). "Phosphorus management of beef cattle in
northern Australia", I. Partridge, (ed.). City: Meat and Livestock Australia Limited: Sydney.
Katherine Rural Review
Page |2
Beetaloo Rotational Grazing Field Day
Jane Douglas, Pastoral Production Officer, Tennant Creek
On the 10th of September 2014, the Rotational Grazing
Field Day was held at Beetaloo. Forty-two participants
travelled from all over, Darwin to Alice Springs,
Queensland, NSW and even Tasmania; just to see
what was being done on the Barkly.
Participants met up at the Beetaloo homestead for
morning tea, general introductions and a quick overview
of the project. Everyone then convoyed out to the
Peabush site, stopping off along the way to see the
cattle in the rotation before lunch was served in the
paddock.
After lunch, Dionne Walsh (DPIF) discussed the
pasture sampling that is being conducted, and Jon
Hodgetts (NRM) spoke on behalf of Desert Wildlife
Services about the fauna surveys. The real discussion
came via talks by Jane and Scotty Armstrong about the
management, infrastructure and development that have
taken place across the property. John Dunnicliff also
joined in with an informal panel discussion to round out
the day.
Scotty Armstrong giving some insight on the
development at Beetaloo
After purchasing Beetaloo, Mungabroom and OT
Downs, the Dunnicliffs and Armstrongs had noticed that the traditional set stocking regime was
impacting on land condition and animal performance. At this time, there were about 40 waters across
the three properties. In order to realise the carrying capacity and production potential of the leases, a
substantial infrastructure development program has been undertaken. There are now almost 600
waters and thousands of kilometres of new fencing and polypipe on the properties.
Set stocked area
Adjacent rotation paddock
The set stocked areas tend to have higher levels of defoliation compared to the adjacent rotation paddocks,
illustrating the issue that the development program is addressing.
The Armstrong and Dunnicliffe families believe that this development will:
 increase herd productivity
 improve and maintain land condition
 maintain biodiversity values within a productive native pasture ecosystem
 increase water use efficiency
Katherine Rural Review
Page |3
The family believes that in order to achieve development of this scale, both forward planning and
flexibility are essential. Know what you want to achieve in the long run, but be willing to change things
along the way in order to reach the final goal.
Scotty prefers the simple set up, with the water lines connecting a series of tanks and bores on loop
systems, allowing for storage and backup water supplies.
The Rotational Grazing Pilot has been collecting data on pasture and cattle performance, as well as
fauna surveys, for a couple of years. At this stage it is still too early to say how the environmental and
animal performance outcomes of the system compare to traditional grazing practices. Stay tuned for
future results!
Bulls surrounding one of the hundreds of new tanks covering the property
Participants at the field day listen to Dionne Walsh, Rangelands Program Coordinator with DPIF, as she discusses the
findings from the annual pasture sampling
Katherine Rural Review
Page |4
DPIF Annual Bull Sale Results
Whitney Dollemore, Pastoral Production Officer, Katherine
It was a year of change for the annual DPIF Selected Brahman and Composite bull sale. There was a
lot more advertising and promotion this year along with a leap into the world of online livestock
auctions. On September 26th DPIF held their first online bull auction with the assistance of Elders
Katherine and AuctionsPlus. AuctionsPlus is like eBay for livestock.
The sale had full clearance with the average
Breed
Average Price
Number of
prices shown in the table below. There has
Animals
been very positive feedback about the
process of the online auction, it was said to
Composite
$944
25
be “very easy and convenient”. Other features
Selected Brahman
$1,052
46
that people liked were that the process is
transparent and is available to a wider
All
$1,014
71
audience either through their local stock
agent or at home online. Given the positive feedback, we will continue to use this service.
The bulls were available for viewing at the NT Field days at KRS (Sep 18 & 19). There were questions
asked about the bull’s body condition as they were in much lighter condition than animals at a typical
bull sale where they have been fed grain and protein supplements. There were also questions about
the “ability of these Select Brahman and composite bulls to do the job when they are in condition score
three and have come from Douglas Daly”. Although these bulls are located at Douglas Daly Research
Farm, for the 18 months of their life they have been restricted to native pastures (see photographs
below). While the bulls were given mineral supplementation (eg. lick blocks) they never received any
supplementary feeds. Semen testing shows whether bulls are producing sperm and DPIF has been
successfully using these bulls
for many years.
The native pastures the Selected Brahman Sale bulls have been running on at
Douglas Daly Research Station for the past 18 months
A Selected Brahman bull at 18 months of age (left), the same Selected Brahman bull
at four years of age (right)
Katherine Rural Review
These bulls are sold at 18
months of age and coming
solely from native pasture it is
possibly the ugliest stage of a
bull’s life; a bit like a teenager
that can’t eat enough to fill out
and has pimples and a terrible
haircut. The two photos below
and to the left show what they
will grow up to look like, but are
looks the important part?
Another question could be, “will
this bull produce daughters that
are adapted to the NT
environment and will produce a
calf each year, a calf that
grows well as a steer or
reproduces as a bull or heifer?”
The following independently
written article by Don Nicol,
Beef Genetics specialist,
independently examines some
of these questions.
Page |5
Buyer’s market
This article has been independently written by well known genetics specialist, Don Nicol, Brisbane
It’s bull-selling season again and on Friday 26th September there was a Brahman bull sale in the
Northern Territory. There was no fanfare from the sale; no breed records were broken – no photos of
proud purchasers of the top price bull or from the contented vendors.
Perhaps that was because the average price for 46 Brahman bulls sold was $1052 and the top price
was $1300. It was however a total clearance — a good result for this season in particular.
So, another bull sale passes into oblivion, on to the next one…
However to my mind this particular bull sale begs a deeper analysis than just a bull sale with a
particularly low sale average. It was the annual DPIF Selected Brahman bull sale, available nationally
on Auctions Plus by simultaneous live auction.
You see; based on objective data, amongst the offering of 46 bulls, two bulls were in the top 1% of the
breed, four in the top 5%, seven in the top 7% and nine in the top 15% of the breed.
By top of the breed I am referring to the Jap Ox Index that combines the genetic merit (EBVs) or
otherwise for the genetic growth and fertility potential of each bull. The good genes it will pass on to its
progeny in terms of higher weaning rates and weaning weights.
So if there were 22 bulls on offer in the top 15% of the breed why were there no big bids, why such a
poor interest in the top bulls? Why did the top price bull, Lot 30, which sold for $1300, have figures that
were below breed average when there were all those bulls with top numbers on offer?
Were there mitigating circumstances?
Yes, there were mitigating circumstances. The bulls, although with 30 years of performance recording
behind them, were NOT stud registered. That’s perhaps the first strike against them.
The spring born 2012 bulls ranged between 192 and 320 kg liveweight. That was the next strike
against these rising two-year-old bulls. They had got by on what was available in the paddock with lick
but without improved pastures, grain, pellets or a protein meal. This was clearly reflected in the “unstudlike” photos available in the catalogue. What wasn’t apparent was that they had been deliberately
run on the toughest country to help identify the bulls that perform best under harsh conditions and to
“bring the cream to the top”.
They may not look as though they could work and their size could have been another factor. Well, full
fertility data was available on all bulls and it
was clear that with a reasonable spring and
early summer they would work well.
They must have been lacking in breed
characteristics! Well that was likely another
factor, the breeders had been concentrating on
selection for animals with early puberty, fast rebreeding on the second calf and much less on
breed characteristics like colour, spots, hump
shape and the like. DPIF have been careful to
select for tight sheaths and scrotal
circumference and semen morphology, but not
colour.
Why no competition for the best bulls?
There were a few sheets of numbers that told how each animal ranked genetically with its herd mates
and their comparison to Brahmans around Australia. The two or three columns of EBVs ranking the
bulls for Days to Calving fertility and scrotal circumference may have been too complicated for people
Katherine Rural Review
Page |6
to take in. If they had just looked at the Indexes reported for each bull they would have had an easy
guide to rank the bulls on a single number. Surely not that difficult…
Bull buying
I think most bull buyers are really looking to buy a bull that will improve the ‘looks of my herd’. Some
might say you couldn’t judge these DPIF bulls properly, presented in such light condition – “You can’t
see their potential to what they will grow out to”. “If these bulls had been fed and sold at around 600kgs
then we could have seen their true potential to improve the herd”.
Phenotype versus genotype
The truth is that most bull buyers are more interested in phenotype (genetics + feed + environment)
than they are in genotype.
The genotype is the genetic makeup of an animal separated from feed and environment, usually
reported as an Estimated Breeding Value (EBV). When we know the genotype or EBV of an animal we
also know that half its EBV will be passed on to its progeny.
In the case that all we have is the phenotype we don’t know what will be passed on genetically.
Nutrition does not affect a bull’s genotype. By feeding you will increase liveweight, eye muscle area or
scrotal circumference but you won’t increase his transmitting ability for superior genes.
Fat bulls versus bulls in their working clothes
I definitely think the light condition of the bulls would have put buyers off.
How many times have I heard commercial producers say we don’t want fat bulls but then go and buy
amongst the fattest in the offering. With a fat bull it covers a range of faults but mainly the purchase of
a fat bull is in the belief that this new bull will improve the herd. “His progeny will grow out like him as I
see him in the ring today”. “Nobody will criticize me for buying a fat bull, because they are all doing it
too”.
That’s why we have bulls on sale with excess backfat, excess fat in the scrotum, swollen hocks,
inability to walk – and these are bulls that may have to go out to work on speargrass…
So where from here?
It is clear to me that if the vendor puts another $1000 in feed into each bull it would take the weights up
nearer 600kgs on average, enough to show the bulls off as to their ‘sire potential’ to improve the looks
of a herd. At Rockhampton 800kgs would be nearer the mark. Putting $1000 of feed into each bull will
expand the phenotypic difference; it will make the colour stand out more, the muscle will be more
visible, buyers will be proud to take them home. Nobody will criticise you taking home a well-fed bull.
So where’s the problem?
Well the truth is, $1000 of feed won’t change the genetic potential of a bull one iota. The genes he
passes on won’t improve the looks of the herd because of the extra feed.
Tailpiece
The Northern Territory beef industry has been doing it tough in recent years with plenty of external
shocks.
Bull selection, however, is one thing that is under a producer’s control and if genetically superior bulls
are purchased their effect on the herd is additive, cumulative and permanent. What other
improvements on a place are permanent?
It is not too late to throw out your long-held beliefs of what a bull should ‘look’ like and buy genetics that
will improve your herd for the long-term.
Katherine Rural Review
Page |7
For many crossbreeding will be an option. However cross breeders ignore the numbers at their peril.
The EBV gains from a superior merit bull from any breed or performance-recorded composite are
additional to the hybrid vigour gains.
Proven genetics
The DPIF have proven that genetics in their selected Brahman herd are superior at the commercial
herd level, plus they are selected in the NT environment. These facts are indisputable. How much more
will it take for producers to be convinced?
But wait there’s more…
By now some of you might be wondering just what kind of an animal do these ‘breedleading’ Brahman
bulls grow out to?
Well get ready for it because below is a photo of a mature October 2007 Brahman born bull that is a
“breedleader”.
Before you look at him I must give you some information on him:
 He has been fully-performance recorded in BREEDPLAN
 He is in the top 10% of the breed for 600-Day growth EBV
 He in the top 1% of the breed for scrotal size
 He is in the top 10% for Days to Calving, the female fertility EBV
 He is however in the bottom 10% for Eye Muscle Area EBV (will you pick that from his photo?),
but…
 He is in the top 1% for Rump Fat EBV.
Adding up his genetic merit for each trait and balancing for each trait’s relative economic importance
puts him at +$52 for the Jap Ox Index compared to the breed average of $22. That incidentally puts
him in the top 1% of the breed for that index. It means, compared to a breed average bull, he will put
$15 added genetic value into each successful mating he has. The calculation is $52-$22= $30/2=$15.
You divide the difference between the two bulls’ Selection Indexes by two because each sire
contributes only a random half of its genes to its progeny.
But wait there’s even more…
Horn: incorrectly registered as ‘horned’ on
visual phenotype when he was young, they are
actually scurs (a different gene to the poll
gene). The Horn-Poll DNA Test indicates that
his genotype is heterozygous polled, i.e. he
carries one copy of the polled and 1 copy of the
horn gene and should throw about 50% polled
calves when mated to horned cows.
Additional comments: He has demonstrated
good ‘calf-getting ability’ when used in multi-sire
mating groups. Very quiet nature backed up by
a strongly favourable Flight-time EBV.
© Breedlink September 2014
Published with the permission of Don Nicol,
This Selected Brahamn bull is in the top 1% for the breed
Breedlink.
according to the Jap Ox Index
Katherine Rural Review
Page |8
Resources to get you started burning your bushes
Robyn Cowley , Senior Rangelands Officer, Katherine
A recent webinar on why and how to apply fire to
manage woody cover on grazed lands, with lessons
from the Kidman Springs fire experiment (21 years
old this year) is now available for everyone to view
at the following link: http://bit.ly/1x3Qm2w, titled
“Burn your bush before it bites back - Lessons from
the Kidman Springs fire trials 1993-2013”.
There is also further information about the Kidman
Springs fire experiment and links to fire publications
including NT fuel load and fuel curing photostandards, on the future Beef website at http://bit.ly/1r4zuWR.
If you still can’t get enough, I also recommend viewing another fire webinar by Col Paton from
Queensland DAFF http://bit.ly/1zDK7BP. For QLD yield photo-standards see http://bit.ly/1C8CeDH.
And for the geeks, a scientific paper on the first 20 years of the Kidman Springs fire experiment is
available here http://bit.ly/1wRcQRe.
Happy burning.
Share your knowledge, promote your invention
The Australian Rangeland Society is currently seeking potential speakers for the ARS Conference
being held in Alice Springs in April 2015.
The conference theme is Innovation in the Rangelands, featuring sessions on pastoral management,
water sharing, adaptation and resilience, leadership and relationships, and more. One session that may
be of particular interest to pastoralists is the poster session, Innovation and Invention in the rangelands,
where delegates are able to present or physically demonstrate a product, invention or technology that
they have developed or adapted.
Contributors to this session are required to supply an abstract for the conference proceedings which
are currently being accepted up until February 2015.
Any persons managing land are encouraged to participate, particularly beef producers. Interested
parties are encouraged to explore the ARS Conference website: arsconference.com.au or contact
Jodie Ward (Jodie.Ward@nt.gov.au) for assistance.
Katherine Rural Review
Page |9
Who’s the money maker?
Trisha Cowley & Whitney Dollemore, Livestock Industry Development, Katherine
Reproductive performance is a key profit driver in northern Australia, with plenty of room for
improvement. While nutritional management is key, genetics also definitely play a major role. The Beef
CRC III research program found that the heifer fertility traits, age at puberty, and time to resume cycling
after calving were highly heritable in Brahmans and Tropical Composites. Furthermore, these two traits
were strongly genetically correlated to lifetime reproductive performance, meaning that heifers who
reached puberty at a younger age and reconceived earlier after their first calf, tended to have more
calves in their lifetime. Hence by selecting superior heifers for these traits, you are also selecting those
who will be superior breeders over their lifetime. Sires have the largest influence on the genetic
direction of a herd, so selecting superior sires is also critical.
Show them what your daddy gave you!
As an example of the role that genetics play, we compared heifer progeny performance of two
Brahman bulls who were used in the Beef CRC III research program. Each bull sired about 20
daughters whose calving performance was recorded for six matings on Belmont Research Station near
Rockhampton in Central Queensland. As Table 1 below shows, these two sires produced daughters
who performed very differently!
Table 1: Some bulls breed much more fertile daughters
Sire
Reproductive Trait
Lancefield 4999M
Belmont 79/96
Maiden heifer pregnancy rate
94%
86%
Percent of first calf heifers cycling prior to
weaning
92%
19%
First calf heifer pregnancy rate
67%
17%
Average lifetime weaning rate
82%
62%
How do you know he is made of the right stuff?
We want to select bulls who will produce more fertile daughters, but we can’t wait until he has sired 20
daughters who have calved several times before we decide if he’s good enough to buy! So how do we
know who’s got the goods at two years old? Estimated Breeding Values (EBVs) are estimates of
differences in an animal’s genetic merit based on the animal’s pedigree, own performance, and that of
its recorded relatives. They provide the best basis for comparison of the genetic merit of animals reared
in different environments and under different management systems, by making adjustments that
account for these factors. For example, Sire A may be producing females on the A property which have
a 90% weaning rate, but it is in premier country and the cows are fed molasses at calving to increase
reconceptions. In comparison, Sire B is producing females on another property in poorer country where
the cows are not provided any extra feedstuff but are weaning 80%. You can’t compare the weaning
rates between these two properties to determine which sire has a better genetic merit for fertility. And
this is where EBVs offer the advantage, because they remove the effects of nutrition and only compare
differences due to genetics.
Days to calving (DTC) EBVs provide the best estimate of an animal’s genetic merit for fertility. Variation
in DTC EBVs reflect differences in the time taken for females to conceive after the joining period.
Animals which calve earlier and more often have lower, more negative DTC EBVs. Scrotal size EBVs
are also important. Let’s compare our two sires.
Katherine Rural Review
P a g e | 10
Table 2: Group BREEDPLAN EBVs for Lancefield 4999M
September 2014 Brahman GROUP BREEDPLAN
Birth Wt.
(kg)
Mature
Scrotal
200 Day 400 Day 600 Day
Cow Wt. Size
Wt. (kg) Wt. (kg) Wt.(kg)
(kg)
(cm)
Days
to
Carcase
Calving Wt. (kg)
(days)
Eye
Muscle
Area
(sq.cm)
EBV
+0.6
+13
+24
+40
+11
+4.1
-20.9
+14
-2.2
Acc
91%
93%
94%
95%
93%
77%
83%
91%
85%
Breed Avg. EBVs for 2012 Born Calves
EBV
+2.7
+18
+25
+34
+40
+0.4
+0.9
+21
+2.4
Table 3: Group BREEDPLAN EBVs for Belmont 79/96
September 2014 Brahman GROUP BREEDPLAN
Birth
Wt.
(kg)
200
Day
Wt.
(kg)
400
Day
Wt.
(kg)
600
Day
Wt.
(kg)
Mat.
Cow
Wt.
(kg)
Scrotal
Size
(cm)
Days Carcase Eye
to
Wt.
Muscle
Calving (kg)
Area
(days)
(sq.cm)
EBV +1.0
+15
+12
+23
+15
+2.2
+10.2 +4
+3.4
Acc
94%
96%
96%
94%
90%
85%
91%
88%
+21
+2.4
95%
Breed Avg. EBVs for 2012 Born Calves
EBV +2.7
+18
+25
+34
+40
+0.4
+0.9
Because you want a shorter period between calves, this means that negative DTC EBVs are better, as
this means cows calve earlier. Hence, the DTC EBVs are confirming the raw data shown in Table 1 –
Lancefield 4999M is a superior sire for fertility. As a general rule of thumb, 1 unit difference in a DTC
EBV is equal to 1% different in weaning rate. While there is a 20% different in weaning rates between
the female progeny of these two bulls,
there is a 31.1 unit difference in their
DTC EBV.
Show me the money!
What about a dollar value difference
between these bulls? Selection
indexes take into account each EBV
and provide a ‘balanced’ view of the
animal, depending on the particular
market and production systems. They
relate to short term profit generated
by a sire through the sale of his
progeny, and the longer term profit
generated by his daughters. The Live
Export Selection Index was
developed in the NT by Katherine and Figure 1. Importance weighting of factors that were incorporated into
the Live Export Index.
Barkly producers, so is the most
Katherine Rural Review
P a g e | 11
locally relevant. Figure 1 shows the relative importance given to different traits when designing the Live
Export Index.
Lancefield 4999M has a Live Export Selection Index value of +$64, while Belmont 79/96 has one of $8, compared to the breed average of +$19. Admittedly Lancefield 4999M has better growth EBVs as
well, which will also increase his index value. However, the heaviest weighting in the Live Export
Selection Index is on the DTC EBV.
The Bottom Line
Buying bulls with superior fertility genetics will influence your bottom line, by breeding daughters who
have more calves in their lifetime. While other traits need to be considered when selecting bulls (i.e. he
has to be quiet and structurally and reproductively sound), it is obvious that these two bulls differ
greatly in the value that they would bring to your herd. Select bulls with larger, more positive Scrotal
Size EBVs and lower, more negative Days to Calving EBVs – it’s worth it!
Acknowledgements: Thanks to David Johnston from AGBU, Armidale, for providing the data on which
to base this article.
Greener pastures call Grant’s name
On the 12th of November the Plant Industries
Development team farewelled Technical Officer Grant
Cutler. Grant had been with us at first as a work
placement student in 2012 working on aerobic rice trials
and returned again in 2013 working on diversification
projects like peanut variety trials, lucerne persistence
trials, fodder beet trials, and more rice trials—all the while
studying for his bachelor’s degree in agriculture with the
University of Queensland. He was also a valued team
member in the Action on the Ground project and the
Mango Irrigation Deficit Trial in Calypso Mangoes (in
conjunction with QDAFF).
Grant was well known for his sense of humour and hard
work. We would quite often hear in the Plant Industries
building about his desire to “go play with his nuts”…
Peanuts that is! His dog, Molly, was quite cherished here at work being the pseudo Plant Industries
mascot who was always up for pats and tummy rubs.
Grant is beginning the next stage of his career working with irrigation in cotton in the Goondiwindi area.
We wish him all the best in his future endeavours.
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Leptospirosis
Wet and humid environments
are the perfect breeding
grounds for a number of
bacteria, Leptospira is one
such bacteria. Leptospira is
the bacteria responsible for
Leptospirosis, a contagious
disease that has the ability to
infect animals and also
cause serious diseases in
humans. Animals infected
can include pigs (domestic
and wild), cattle, sheep, rats,
goats and horses. The
strains commonly found in
cattle are Leptospira
hardjobovis and Leptospira
pomona.
The disease can be spread
through urine, or at birth or
abortion, resulting in the
contamination of water, feed,
pastures and soil. Once in
the environment, the bacteria
are able to infect animals and
humans through damaged
skin or the membranes lining
the nose, eyes or mouth.
Clinical signs in cattle will
vary depending upon the
strain of the disease. In
general, signs associated
with Leptospirosis include
weak newborns, fever,
infertility, mastitis, jaundice,
depression and anorexia.
Abortion ‘storms’ may also
be seen in cows that are
greater than five months
pregnant. Abortions may
occur weeks after initial
symptoms, or even in the
absence of symptoms.
It is important to note that it is
not only cattle that have
recovered from Leptospirosis
that are capable of spreading
Katherine Rural Review
the disease. Cattle that have
not shown any symptoms
can be carriers and are
considered to be a high risk
source of infection for both
animals and humans.
Once exposed, cattle that
recover from the disease will
develop immunity to that
specific strain of leptospirosis
for periods of up to seven
months. Calves may also
acquire temporary immunity
through the colostrum of
vaccinated or previously
infected cows.
Vaccination is not a common
procedure on NT properties,
however in individual herds
leptospirosis can cause
severe economic losses.
Options are available in the
form of ‘7 in 1’ vaccines
which cover L. hardjobovis
and L. pomona, and bivalent
leptospirosis vaccines. As L.
pomona is normally
associated with contact with
the urine of pigs and rats,
reducing the pig population is
also an important
management strategy.
Blood samples are the most
practical means of confirming
whether stock have
Leptospirosis. Ideally, blood
samples will be collected
twice with the second set of
sampling to occur four to six
weeks after initial sampling.
Other methods include
analysis of urine samples, or
collection of blood, liver,
kidney or spleen from foetus.
In the Northern Territory,
there are 1-4 cases of
Leptospirosis reported in
IN THIS ISSUE





Leptospirosis
Pestivirus
National TSE (Mad
Cow) Program
Screw Worm Fly
Feral Animal Culling
humans per year. People
who work in livestock
industries are at risk as
they are likely to be
infected from
contaminated urine,
through splashes into the
eye or sores. Infection may
also occur from contact
with water, mud, soil or
vegetation that has been
contaminated with animal
urine. Handling the foetus
of an aborted calf, or
assisting with calving can
be a further source of
infection for humans.
Human infection of
leptospirosis is a notifiable to
the NT Department of Health.
Symptoms will generally
occur ten days following
exposure to the disease.
Common symptoms include,
fever, headache, chills,
severe muscle pains and
reddened eyes. Illness may
last for a number of weeks;
relapses are common
however it is rare for person
to person transmission to
occur. Vaccination of cattle
reduces the chance of staff
contracting leptospirosis.
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Important diseases affecting cattle productivity in the NT –
Pestivirus
Pestivirus, also known as Bovine Viral Diarrhoea (BVD) or Mucosal Disease, is an acute, highly
contagious, worldwide disease of cattle that results in reproductive loss and intestinal and respiratory
disease . Results from the serosurvey conducted in 2010 indicated that pestivirus was commonly
recorded in all regions of the NT.
The virus is spread via direct contact with infected materials such as saliva, nasal secretions, urine, faeces
and birth fluids of persistently infected (PI) animals. These PI cattle are the main means of spread of the
disease. Temporary high-stocking situations such as mustering, yarding, trucking and supplementary
feeding/watering sites all contribute to the spread of the virus.
Persistently infected animals should always be considered where some young cattle in a mob are doing
very poorly while other cattle are doing very well. These are calves born from cows that were infected prior
to 125 days of gestation. PI animals are generally ill thrifty and most will die before two years of age.
However some will appear normal and may even enter the breeding herd undetected and continue to
infect those cattle around them, throughout their life.
The impact
In adult cattle, pestivirus infection usually causes only mild flu-like symptoms with low mortality rates. Once
recovered, infected animals (other than PI cattle) develop a longlasting immunity to the disease.
The major issue occurs if non-immune heifers and cows are exposed and infected for the first time during
pregnancy. At a herd level this can result in severe consequences. Effects of the disease vary according to
the stage of pregnancy the cow/heifer is in when it becomes infected.

Infection at the time of mating – disrupts cycling and causes early foetal death

Infection at 1-4 months – causes abortion or produces PI calves

Infection at 4-6 months – causes abortions or abnormal calves (brain and eye defects)

Infection at 7-9 months – generally causes no problems
Once a heifer or cow has been exposed to the virus and developed immunity, future pregnancies will not
be affected even if she is re-exposed to the virus later on. On a limited survey carried out on 13 properties
in the NT, it was found that 63% of animals had been infected with pestivirus by the time they were three
years old. In some areas, around Alice Springs and the Stuart Plateau, it was found that more than 90% of
the heifers had been infected with the virus before they were two years of age and thus vaccination against
the virus would be unnecessary in these mobs (Schatz, Melville and Davis 2008).
In herds with high numbers of non-immune animals, the introduction of pestivirus can result in massive
losses through abortion storms, where a high proportion of breeding cows will abort their pregnancies.
Such occurrences will have a flow on effect as the cows will then be able to become pregnant later in the
season causing increased out-of-season calves.
In herds with high levels of persistent infection, it is estimated that annual losses of up to 7% of calves can
occur.
Management strategies
There are four strategies that cattle producers may wish to consider regarding the management of
pestivirus. (A first step to help decide on a strategy is to define the pestivirus status by serological testing
of cows and heifer herds.)
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1. Do nothing and accept current losses or the risk of ‘abortion storms’
2. Vaccinate all heifers prior to joining (immunity lasts 12 months):
o This protects the heifers during their first pregnancy, during which time they should be
exposed to the virus and develop their own natural immunity which is lifelong
o This should be sufficient for properties with high levels of infection
o A course of two vaccinations four weeks to six months apart is required
o Immunity does not develop until after the second dose is administered
o The second dose must occur four weeks prior to joining begins
o The current cost of vaccination is approximately $5 per dose and can be purchased ‘over
the counter’.
3. Vaccinate heifers as above and continue to administer annual vaccination to entire breeding herd:
o May be necessary for properties with low levels of underlying infection where heifers may
not be exposed to the virus naturally and develop their own immunity during their first pregnancy
o Provides ongoing insurance against an abortion storm
4. Autovaccination program using PI animals:
o Identify PI animals through blood or ear notch testing
o Lock heifers with PI animals at a rate of 3-4% in close contact for 24-48 hours
It must be noted that once any control protocol is commenced it must not suddenly be terminated as
this would leave the entire herd in a naive state and open for an abortion storm.
Should readers have any questions or queries regarding any of these diseases or others, please
contact John Eccles, Regional Veterinary Officer on 08 8973 9716 or John.Eccles@nt.gov.au.
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National Transmissible Spongiform Encephalopathies
Surveillance Program (NTSESP) in the Northern Territory
To ensure that Australia is eligible to export
cattle and meat to a number of overseas
markets we must prove that we are free from
Transmissible Spongiform Encephalopathys
(TSEs). To do this it is essential that samples
from cattle and sheep from all areas of Australia
are tested as part of our National TSE
Surveillance Program (NTSESP).
Behavioural
Neurological
• apprehension
• abnormal ear position
• changes in herd
hierarchical status
• abnormal head
carriage
• excessive nose and flank
licking
• altered consciousness
Therefore it is essential for DPIF to test cattle
from regions in the NT and so we need
producers to notify us of eligible cases. There is
a subsidy for participating in the program.
• frenzy
TSEs are fatal diseases that affect brain and
central nervous system tissues. Bovine
Spongiform Encephalopathy (BSE) is the form
associated with cattle and is commonly referred
to as ‘Mad Cow’ disease. Scrapie is the form
found in sheep and goats. Neither exist in
Australia.
• hesitation at doors, gates,
barriers
• excitability
• head rubbing or pressing
• head shyness
• persistent kicking when
milked
• teeth grinding
• ataxia
• blindness
• circling
• falling
• fetlock knuckling
• hyperaesthesia
(sound, touch)
• hypo aesthesia
(sound, touch)
• moribund without
evidence of infection
or trauma
• paralysis/paresis
Payment
• recumbency
Producers are provided with a payment for all
eligible cases. The current payment rate for
cattle submissions is $300.
Eligibility
Cattle are eligible if they are:
-
Older than 30 months and younger than
nine years
Display one or more of the clinical signs
associated with BSE
• tremor
Sampling
The crucial samples are the brain and 2-3cm of
spinal cord. If the brain is damaged during
removal, the animal will not be suitable for
submission. Further samples include bloods and
pieces of the animals’ organs (i.e. lung, heart,
liver, kidney and spleen).
Clinical Signs
More Information
Clinical signs associate with BSE are as follows:
For more information on the NTSESP, please
refer to Animal Health Australia’s National TSE
Surveillance page
(http://www.animalhealthaustralia.com.au/programs/b
iosecurity/tse-freedom-assurance-program/nationaltse-surveillance-program/)
To report an animal with clinical signs consistent
with those associated with BSE please contact
your local Livestock Biosecurity Officer, regional
Veterinarian or private Veterinarian
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Screw Worm Fly
Old world screw worm fly is present throughout South-East Asia and Papua New Guinea and is one of
the most serious emergency animal disease threats to the northern livestock industry.
Screw worm fly (SWF) is a notifiable disease in the NT and suspect cases should be reported.
Call 1800 675 888
If you were to see any maggots on any animals, please:
1. Collect up to ten larvae from DEEP in the wound with forceps. SWF larvae may be difficult
to remove and burrow deeper into the wound when disturbed.
2. Collect larvae of different sizes if possible.
3. Drop larvae into HOT water for one minute. This causes the larvae to extend allowing
better identification.
4. Place maggots in either: 10% formalin; or 70% ethanol; or vinegar
And drop larvae samples off at your regional office to continue with the screw-worm freedom
assurance program.
Screw-worm fly is an insect parasite of warm-blooded animals. The fly has red eyes and a shiny bluegreen body and looks similar to Australian blowflies. Flies lay eggs on the edge of open wounds from
scratches, tick bites, injury, branding, dehorning or castration. Female flies are capable of laying
several egg masses during their lifetime, with each mass consisting of between 100 and 300 eggs.
The larvae (maggots) can grow up to 15 mm in length and 3 mm in diameter and are white or cream in
colour. They are given a screw-like appearance by the dark spines that grow on each body segment.
Once they hatch, the larvae will feed on the underlying flesh, causing extensive tissue damage. Left
untreated, animals can die from infection and loss of tissue fluid.
When mature, the maggots will exit the wound and drop to the ground where they will burrow into the
soil and remain until they have developed and re-emerged as adult flies. Due to the fact that the adults
are able to fly and spread themselves over large distances, the spread of screw worm would be rapid if
not detected early.
Screw worm fly laying its eggs in a wound
Screw worm fly egg masses (white) deposited in a wound
Source: http://www.animalhealthaustralia.com.au/screwwormfly
If you require further information about screw-worm fly visit:
http://www.animalhealthaustralia.com.au/swf
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Animal Biosecurity Branch
Department to assist Pastoralists with Feral
Animal Control
The Department of Primary Industry and Fisheries Stock Inspectors/Biosecurity Officers are required under the
national Emergency Animal Disease Response Agreement to maintain a core group of experienced aerial
platform shooters for emergency animal disease preparedness and response.
Since the successful completion of the Brucellosis and Tuberculosis Eradication Campaign, (BTEC), it has
become increasingly harder for our staff to find cost effective ways of maintaining high levels of competence and
experience in the field.
A plan has been put forward and approved by management to offer the services of this core group to
organisations involved in feral animal control including pastoral properties, aboriginal-controlled areas and other
organisations involved in these activities to assist them and gain the experience we require.
The department would supply the shooter/shooters and firearms required for the job. The other party would be
responsible for the helicopter hire, fuel and ammunition. The job would have to be carried out in accordance with
the department’s high standard of WH&S and animal welfare conditions.
The program will be restricted to the number of hours required to keep our personnel at a high level of
competence, so enquires for these services will be dealt with on a first in, first served basis.
If you think this proposal could assist you or your organisation please contact Ian Doddrell or your Regional
Livestock Biosecurity Officer to discuss your situation.
Darwin Region
Ian Doddrell
(RLBO)
Ph: 08 8999 2030
Katherine Region
Josh Haigh (RLBO)
Tennant Creek Region
Tom Haines (RLBO)
Ph: 08 8973 9767
Ph: 08 8962 4458
Alice Springs Region
Greg Crawford (RLBO)
Ph: 08 8951 8125
Further Animal Health Information
Want information on a particular animal health topic?
Requests for articles on topics of interest are invited. Please send requests to:
Renae McLean
Ph: 08 8973 9765
E: Renae.McLean@nt.gov.au
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Round the Region
Left: Attendees of the Victoria River
District Field Day held at Delamere
Station on 28th October where attendees
heard about the latest findings of the
Delamere Spell+Burn Demonstration
site, as well as information about the
most recent develpments from the
Grader Grass Herbicide Application trial
(DLRM) and the latest research into wild
dog behaviour and control (VRDCA)
Right: Johnny Cooper and Teagan
Alexander working on the Action on
the Ground Project “Management of
nitrogen fertiliser in hay crops to
maximise farmer’s yields” at
Katherine Research Station
Left: Vet student Ayrial Harburn from
James Cook University, Townsville,
assists Cameron Heeb and Tony
Moran to collect National Arbovirus
Monitoring Program samples at
Kidman Springs.
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Katherine region events calendar
Event
Location
Date
2015 NTCA AGM and Conference
Katherine
26-27 March
office.darwin@ntca.org.au
Australian Rangeland Society 18th
Biennial Conference
Alice Springs
12-16 April
arsconference.com.au
Please email us with updates of events happening in your area: Jodie.Ward@nt.gov.au
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PO Box 1346
Katherine NT 0851
Disclaimer
While all care has been taken to ensure that information contained in this publication is true and correct at the time of publication, the Northern Territory
of Australia gives no warranty or assurance, and makes no representation as to the accuracy of any information or advice contained in this publication,
or that it is suitable for your intended use. No serious business or investment decisions should be made in reliance on this information without
obtaining independent and professional advice or both in relation to your particular situation.
Reproduction of Rural Review articles
The Department of Primary Industry and Fisheries (DPIF) welcomes the reproduction of articles appearing in this newsletter, but requests that the
technical information be confirmed with the editor or author, prior to publication. The department also requests that acknowledgement be made for any
original work sourced from the Katherine Rural Review.
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