season’s greetings to all dpifmers - dpir.nt.gov.au web viewmovement restrictions ... (three...

Katherine Research StationPO Box 1346, Katherine NT 0851

Phone (08) 8973 9739Fax (08) 8973 9777

[email protected] 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 phosphorus per day (300g) and over another eight weeks she will use 5g of phosphorus per day, the remainder of her body reserves. Some phosphorus will be supplied by the pasture however, in regions

Katherine Rural Review P a g e | 1

ContentsWet season phosphorus – Why? When? Who? How much? 1

Beetaloo rotational grazing field day 3

DPIF annual bull sale results 5

Buyer’s market 6

Resources to get you started burning your bushes 9

Share your knowledge, promote your invention 9

Who’s the money maker? Identifiying bull reproductive performance indicators 10

Greener pastures call Grant’s name 12

Movement restrictions (Banana Freckle) 13

Animal Health News 14

Round the Region 21

Pastoral Market Update 22

of acute phosphorus deficiency including most of the NT, extra phosphorus will be required via supplementation.

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 Northern Australia, as a 10% increase in weaning rate, a 15kg/year increase in live weight gain and a 2% reduction in breeder mortalities.

Currently, a wet season phosphorus loose lick mix (50% salt, 40% P and 10% Gran 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-and-events/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.


Without P With P

GM/10,000 AE $866,100 $965,800

GM/AE $86.61 $96.58

GM difference/AE $9.97

Beetaloo Rotational Grazing Field DayJane 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.

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


Scotty Armstrong giving some insight on the development at Beetaloo

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

DPIF Annual Bull Sale ResultsWhitney 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 prices shown in the table below. There has been very positive feedback about the process of the online auction, it was said to be “very easy and convenient”. Other features that people liked were that the process is transparent and is available to a wider 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.

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.


A Selected Brahman bull at 18 months of age (left), the same Selected Brahman bull at four years of age (right)

The native pastures the Selected Brahman Sale bulls have been running on at Douglas Daly Research Station for the past 18 months

Breed Average Price Number of Animals

Composite $944 25

Selected Brahman $1,052 46

All $1,014 71

Buyer’s marketThis 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 “un-studlike” 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 re-breeding 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


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 buyingI 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 genotypeThe 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 clothesI 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.

TailpieceThe 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.


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 geneticsThe 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, Breedlink.


This Selected Brahamn bull is in the top 1% for the breed according to the Jap Ox Index

Resources to get you started burning your bushesRobyn 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 photo-standards, 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 inventionThe 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 ([email protected]) for assistance.


mailto:[email protected]

http://bit.ly/1wRcQRe

http://bit.ly/1C8CeDH

http://bit.ly/1zDK7BP

http://bit.ly/1r4zuWR

http://bit.ly/1x3Qm2w

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

Reproductive TraitSire

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.


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 Barkly producers, so is the most


Figure 1. Importance weighting of factors that were incorporated into the Live Export Index.

Table 2: Group BREEDPLAN EBVs for Lancefield 4999M

September 2014 Brahman GROUP BREEDPLAN

Birth Wt.(kg)

200 Day Wt. (kg)

400 DayWt. (kg)

600 DayWt.(kg)

Mature Cow Wt.(kg)

ScrotalSize(cm)

DaystoCalving(days)

CarcaseWt. (kg)

EyeMuscleArea(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 BREEDPLANBirthWt.(kg)

200DayWt.(kg)

400DayWt.(kg)

600DayWt.(kg)

Mat.CowWt.(kg)

ScrotalSize(cm)

DaystoCalving(days)

CarcaseWt.(kg)

EyeMuscleArea(sq.cm)

EBV +1.0 +15 +12 +23 +15 +2.2 +10.2 +4 +3.4

Acc 95% 94% 96% 96% 94% 90% 85% 91% 88%

Breed Avg. EBVs for 2012 Born Calves

EBV +2.7 +18 +25 +34 +40 +0.4 +0.9 +21 +2.4

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 LineBuying 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 nameOn 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.


LeptospirosisWet 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

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 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


IN THIS ISSUE

Leptospirosis Pestivirus National TSE (Mad

Cow) Program Screw Worm Fly Feral Animal Culling

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.


Important diseases affecting cattle productivity in the NT – PestivirusPestivirus, 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.)


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 lifelongo This should be sufficient for properties with high levels of infectiono A course of two vaccinations four weeks to six months apart is requiredo Immunity does not develop until after the second dose is administeredo The second dose must occur four weeks prior to joining beginso 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 pregnancyo Provides ongoing insurance against an abortion storm

4. Autovaccination program using PI animals:o Identify PI animals through blood or ear notch testingo 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 [email protected].


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).

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.

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.

PaymentProducers are provided with a payment for all eligible cases. The current payment rate for cattle submissions is $300.

EligibilityCattle 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

Clinical SignsClinical signs associate with BSE are as follows:

Behavioural• apprehension

• changes in herd hierarchical status

• excessive nose and flank licking

• excitability

• frenzy

• head rubbing or pressing

• head shyness

• hesitation at doors, gates, barriers

• persistent kicking when milked

• teeth grinding

Neurological• abnormal ear position

• abnormal head carriage

• altered consciousness

• ataxia

• blindness

• circling

• falling

• fetlock knuckling

• hyperaesthesia (sound, touch)

• hypo aesthesia (sound, touch)

• moribund without evidence of infection

or trauma

• paralysis/paresis

• recumbency

• tremor

SamplingThe 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).

More Information For more information on the NTSESP, please refer to Animal Health Australia’s National TSE Surveillance page

(http://www.animalhealthaustralia.com.au/programs/biosecurity/tse-freedom-assurance-program/national-tse-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


http://www.animalhealthaustralia.com.au/programs/biosecurity/tse-freedom-assurance-program/national-tse-surveillance-program/



Screw Worm FlyOld 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 888If 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 blue-green 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


http://www.animalhealthaustralia.com.au/screwwormfly

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 Katherine Region Tennant Creek Region Alice Springs Region Ian Doddrell

(RLBO) Josh Haigh (RLBO) Tom Haines (RLBO) Greg Crawford (RLBO)

Ph: 08 8999 2030 Ph: 08 8973 9767 Ph: 08 8962 4458 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: [email protected]


Round the Region


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.

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: 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)

Katherine region events calendarEvent Location Date2015 NTCA AGM and Conference Katherine 26-27 March [email protected]

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: [email protected]

DisclaimerWhile 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 articlesThe 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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