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 320- August 2014
Feeding strategies for early-weaned calves
Tiago Alves Correa Carvalho da Silva, Research Officer/PhD Candidate – The University of Queensland
A new research project experiment has commenced at the Katherine Research Station (KRS) to
explore the interaction between liveweight at weaning and dry season growth and the effect of these on
growth in the subsequent wet season. The experiment, which is funded by the Australian Centre for
International Agricultural Research, will be conducted in the new 30 pen complex constructed at KRS
(Photo 1 and 2).
Extensive cattle production systems across northern Australia face conditions of variable pasture
quality and quantity throughout the year. Growth of young cattle over the wet season can be 120 to 150
kg while low weight gains or weight loss occurs in the dry season when pasture quality and availability
are low. Protein supplements may be used to avoid liveweight loss and promote the growth of weaners
during the dry season to achieve liveweight targets for mating of heifers or turn-off of steers.
Weaners that undergo low or negative
growth in the dry season are able to grow
faster in the wet season than counterparts
that exhibit growth during the dry season.
This physiological phenomenon is known as
compensatory growth (Figure 1).
Compensatory growth over the wet season
reduces the difference in liveweight at the
end of the wet season of weaners that had
different growth rates during the dry season.
The degree of compensation may be
influenced by the liveweight of the weaner
under restriction, the duration and severity of
the restriction in the dry season and the
duration of the compensatory period.
Figure 1. An example of full compensation of liveweight
of weaners that underwent a period of liveweight loss.
Contents:
Feeding strategies for early-weaned calves......................... 1
Degradable mulch trials ....................................................... 3
New varieties of lucerne & peanuts being trialled at KRS .... 6
Pasture rejuvenation regimes under scruitiny ...................... 7
KRS hosts visitors from Brazil and Japan ............................ 8
DPIF Annual Bull Clearance .............................................. 10
Round the Region .............................................................. 13
Pastoral Market Update ................................................ 14-15
Katherine region events calendar ...................................... 16
Katherine Rural Review
Brahman heifers were selected at weaning
from two commercial cattle stations in the
Katherine district. Two groups of heifers
were selected from each station; early (120
kg liveweight) and normal (180 kg liveweight)
weaned heifers. All of the heifers will be fed
Sabi grass hay (approximately 3-4% crude
protein) ad libitum with increasing amounts
of copra meal fed to achieve different growth
rates (-0.1 to 0.8 kg/day) over five to six
months during the dry season. At the start of
the wet season the heifers will be transferred
to Victoria River Research Station where
they will graze as a single mob for four
years.
Page |1
The experiment will determine dry and wet season liveweight gain and skeletal growth and longer-term
effects on reproductive performance and frame size.
This experiment will provide information on the likely wet season response and the subsequent
reproductive performance of heifers after dry season supplementation for different classes of weaners.
Producers will then be able to use this information to make decisions on dry season supplementation of
weaner heifers to achieve their specific production targets.
For further information regarding this experiment please contact Tiago Silva
(Tiago.Alvescorrea@uq.net.au) or Kieren McCosker (Kieren.McCosker@nt.gov.au) at the Katherine
Research Station.
The author would like to acknowledge his scholarship funding body: CAPES Foundation, Ministry of
Education of Brazil, Brasília - DF 70040-020, Brazil.
Photo 1. Heifers consuming copra meal in the new pen complex.
Photo 2.
Page |2
The new pen complex at KRS with experiment heifers fed Sabi grass hay
and copra meal.
Katherine Rural Review
Degradable mulch trials
S. Smith and H. Wallace, Plant Industries, Darwin
Plastic mulch is commonly used in the Northern Territory (NT) in conjunction with drip tape irrigation for
growing sweet melons and vegetables. The irrigation tape can be buried slightly or can be laid on the
soil surface and then covered with the plastic mulch. Plastic mulch helps to control weeds, improve
water use efficiency by lowering evaporation and increase crop yields.
It is estimated that the NT has 987 hectares under melon production. Based on 1.5 metre rows, this
equates to 6.6 km of plastic mulch per hectare. The total length of plastic mulch used in the NT every
year is therefore 6514 km. Based on a common commercial roll being 2.3 km long, approximately 2832
rolls of plastic mulch are used per year. As each roll weighs 66 kg, the total weight of plastic mulch
waste for disposal every year is 187 tonnes. This does not take into account the plastic mulch used on
other vegetables, such as Asian melons, cucumber, okra and snake beans. Therefore, the total amount
of plastic mulch to be disposed of every year in the NT is close to 200 tonnes.
Over the past few years, degradable mulch technology has been developing to tackle the problem of
plastic waste disposal. The technology belongs to the manufacturer, and is often protected
commercially. Some mulches are made from cellulose or starch and break down through normal
biological processes. Other mulches are made from normal polyethylene that contains a chemicaldegrading agent that shortens the length of the polyethylene chain, making it more exposed to
microbial degradation.
Even though the technology to degrade plastic mulch is a positive outcome, there are management
risks with its use. Questions remain about the breakdown of these mulches to greenhouse gases, the
toxicity of breakdown products, the possibility of small pieces of mulch creating a mess and the efficacy
of the products compared with conventional mulches. Cost comparisons show that some degradable
mulch is approximately 15 to 30% more expensive than conventional mulch.
Trials in the NT
The Department of Primary Industry and Fisheries, in collaboration with the NT Farmers Association,
AgNova, Econverte and Novomont conducted simple trials at Berrimah Farm in 2012 and 2013 to
determine the efficacy of biodegradable mulches for use in the NT. A number of vegetables, including
sweet corn, tomatoes, eggplants, pumpkins, and watermelons were grown using plastic mulch. The
trials were conducted during both the wet and dry seasons. The results were as follows:
Degricover - 2012-13 wet season
Econverte Degricover ‘three month’ and ‘six month’ (black) was useful in the wet season of 2012-13
and remained intact from when it was laid on 6 December 2012, with only small amounts of splitting
until watermelons were harvested in February 2013. It did eventually split during and after harvesting
the watermelons; it continued to break down until 22 April 2013, when the remaining mulch was pulled
up so that the ground could be reworked for a dry season crop.
There was no observable difference between the three month and six month Degricover. According to
the manufacturer, the three month rolls were designed to break down after three months, and the six
month rolls, after six months. Our experience showed that appreciable, but not total, breakdown
occurred after five months in both. It should be noted that the wet season had below average rainfall,
which may have affected the trial results. The crops were watered twice daily to ensure there was
always moisture under the mulch.
Katherine Rural Review
Page |3
Figure 1. Ecoconverte Degricover
‘three month’ on 17 December
2012, 11 days after laying
Figure 2. Ecoconverte Degricover ‘three month’ on 14
February 2013, 70 days after laying (close up)
Agnove efilm – 2012-2013 wet season
Agnova efilm was not robust in the wet season of 2012-13 and started to break apart after 18 days. It
was not useful as an alternative to conventional mulch. The buried portion of the mulch did, however,
last longer and could still be found 10 months after laying. The supplier said that the batch used did
have problems that were subsequently rectified. We have not yet tested any new product.
Figure 3. Agnova e-film on
17 December 2012, 11 days
after laying
Figure 4. Agnova e-film on
7 January 2013, 32 days after
laying
Degricover – dry season
Econverte Degricover ‘three month’ black/black and white/black was useful to mulch watermelons,
sweet corn, eggplants, tomatoes and pumpkins in the dry season of 2013. It was robust through the
duration of all these crops and was intact from 8 May to 19 September (134 days, or just over four
months). This was enough time for all the crops to go through their cycle until harvest. There was some
splitting and breakdown, more in the black mulch than in the white mulch. On 26 November, the
condition of the mulch was reassessed. It was found to be very fragile and split, but was still intact.
Page |4
Katherine Rural Review
Figure 5. Econverte ‘three month’
white/black on 17 May 2013, 11
days after laying, with tomato
seedlings
Figure 6. Econverte ‘three month’ white/black
on 19 September 2013, 134 days after laying;
watermelons had been harvested
Novomont – 2013 late dry season
Novomont Mater-Bi CE04P and EF04P were laid with Econverte ‘three month’ black/black in a new
trial, which started on 2 August 2013 on rough ground. The sticks and stones in the rough ground
damaged the Novomont products; one row was further damaged by wind and magpie geese. The
Econverte product was more resilient in this tougher environment. Pumpkins, watermelons and sweet
corn were planted in this trial. By 74 days after laying (mid-October), all plastic types had split open and
were very thin and brittle. The trial area was sprayed with glyphosate in early November and, after all
the vegetation had died, the area was cultivated with tines (Triple K) on 20 November and most of the
mulch was worked into the soil very easily. Some of the mulch got attached to the tines and was handcleared at the paddock edge. Very little residue was left after cultivation.
Figure 7. Novomont Mater Bi CE04P, on
19 September 2013, 38 days after laying
Figure 8. Novomont Mater Bi EF04P, on
19 September 2013, 38 days after laying
Conclusions
No commercial degradable mulch can be confidently recommended at this stage. None of the mulches
we have tested so far have been able to meet all the desired requirements. These inlcude being strong
enough to withstand varied conditions at laying, remaining intact over the course of the growing
season, and breaking down rapidly when cultivated at the end. Manufacturer activity in this area is
highly competitive and several companies are developing degradable mulches based on a number of
technologies. It is expected that with further research and development, adequate degradable mulches
will be developed to suit NT conditions.
Katherine Rural Review
Page |5
New varieties of lucerne and peanuts being trialled at KRS
Grant Cutler, Senior Technical Officer, Katherine Research Station
The Plant Industry Team has been busy in recent months establishing a peanut variety trial at
Katherine Research Station. Peanuts have previously been grown successfully in the NT. The trial at
KRS, sown on 2 May, is aiming to evaluate Ultra-Early (110 day) and Full-Season (150 day) new and
improved experimental lines against existing cultivars, to stay up-to-date with advances in peanut
breeding. So far the lines have performed well and are currently in the flowering and pegging stage of
production. Anticipated harvest for the Ultra-Early lines is approximately mid-August with the harvesting
of the Full-Season lines expected in mid-September (just in time for the NT Field Days).
A lucerne variety trial was alo planted - a follow-on from the previous wet season trials conducted at
KRS. Past broad acre trials as well as the previous trial at KRS showed that lucerne persisted poorly
during the Top End wet season. The crop also competed poorly with weed pressure during this time.
Sown on 13 June, the current trial has been planted under replicated experimental conditions to
evaluate a number of experimental lines that have shown promise in tropical climates as well as a
number of unique characteristics such as salt tolerance. All lines being evaluated range from being
winter active to summer active which will give a good indication of the type of lucerne suitable to the
Top End.
Photo 1. Experimental Full-Season peanut lines being evaluated at KRS
Page |6
Katherine Rural Review
Delamere trial explores pasture rejuvenation regimes
Jodie Ward, Pastoral Production Officer, Katherine Research Station
On the highly fertile black soil plains of Number 2 paddock at Delamere Station is the Delamere Spell
Burn Demonstration Site. The trial is investigating whether regular wet season spelling, or a
combination of regular early wet season burning followed by wet season spelling would be better at
rejuvenating desirable grasses. The main pasture species of interest in the trial site is the palatable,
perennial and productive, Curly bluegrass (Dichanthium fecundum).
The site is comprised of two fenced exclosures, starting 1 km from a bore and heading away from it for
1.6 km. Each exclosure contains six treatment plots of approximately 14 hectares. Originally the
spelling and burning treatments were to be applied every two and every three years, but prior to the
application of treatments, the demonstration was modified to be more consistent with the
recommendations of the Kidman Springs Shruburn Experiment. The treatments are now as follows:
1. Wet season spelling only (no burning) –
None (control), every three years, and every four
years
2. Early wet season burning followed by a wet
season spell – None (control), every three years
and every four years
Following burning, cattle are excluded from the
trial for the wet season and are allowed to graze
the trial area during the subsequent dry season.
In years where there is no burning or spelling,
the exclosures are open to grazing at all times.
DPIF staff have been conducting pasture
surveys at the trial site annually since 2011.
Progress update:
Every 3 years
Every 4 years
In November 2010, all of the burn and spell plots
were burnt to establish a level playing field
between the three year and four year treatment
application plots. In November 2013, the first
early wet season burn treatments were applied
to the ‘every three years’ plots and all in this half
of the trial were spelled over the 2013/14 wet
season. At the same time the plots in the ‘every
four years’ half were open to grazing. The plots
in the ‘every four years’ section will have their
first treatment burns and spelling implemented
this coming wet season.
Results to date:
Figure 1. The Delamere Burn Spell Demonstration The 2014 pasture survey was completed
Site. Virtual boundaries are graded lines that are recently with the full results yet to be analysed.
also used as firebreaks.
We hope to be able to identify trends in pasture
composition as a result of the initial burn in 2010 and also from the spelling, and burning and spelling of
the every three year treatments that were applied late last year. Our pasture survey observations have
confirmed that the yields of Curly bluegrass increase as distance from water increases due to historical
land condition differences. We will continue to monitor the recovery of this species and others as we
implement the scheduled treatments over the coming years.
More findings will be published in upcoming editions of the Katherine Rural Review.
Katherine Rural Review
Page |7
KRS hosts visitors from Brazil and Japan
Interest in new cropping
options for the Northern
Territory led a delegation
from Brazil and Japan to visit
the Katherine region on 26
June. The visitors,
associated with Japanese
company Mitsui, were
especially interested in the
potential for soybean
production in the region.
During their visit to the
Katherine Research Station
they inspected the peanut
and lucerne variety trials
currently underway in the
bird-exclusion zone,
discussed regional soil
types, and viewed guinea
Photo 1. (L-R) DPIF technical officer Grant Cutler and Plant Industry grass (Panicum maximum cv
Director Bob Williams discussing crop variety trials at KRS with visiting
Alto) growing under
soybean agronomists, marketers and their Australian partners.
irrigation.
Second round of Farm Finance Concessional Loans Scheme
Producers in the Northern Territory are now able to access the second round of the Australian
Government’s Farm Finance: Concessional Loans Scheme.
Eligible producers in the agricultural, pastoral, livestock, horticultural, aquacultural or
apicultural (beekeeping) industries can submit their applications between 1 July 2014 and 30
April 2015 for the 2014–15 program.
Loans are for less than 50 percent of eligible commercial debt and this year the minimum loan
amount has been reduced from $250 000 to $100 000 to enable smaller enterprises to access
the scheme. The maximum loan amount remains at $1 million.
The Farm Finance Scheme in the Northern Territory will continue to be delivered by QRAA in
Brisbane. QRAA is a specialist administrator of government financial assistance programs to
the rural sector. All application forms are available from the NT Department of Primary Industry
and Fisheries.
Advice and support regarding scheme guidelines is provided through the department’s Farm
Finance Promotions Officer, David Collinson, at david.collinson@nt.gov.au or phone 8936
4089.
Further information, including scheme guidelines and application forms, is available from the
DPIF website http://www.nt.gov.au/d/Primary_Industry or email industry.programs@nt.gov.au
Page |8
Katherine Rural Review
Katherine Rural Review
Page |9
DPIF Annual Bull Clearance
Our excess Selected Brahman and Composite bulls are sold each year. Normally
this is done by a tender process. This year we have decided to give a different
method a try…
Bulls will be available for viewing at the
NT Field Days at the Katherine Research
Station, 18-19 September 2014.The animals will
then be auctioned on
Friday 26 September using AuctionsPlus online
auction website.
More details are to follow, however feel free to contact us for more information.
If you would like to be put on the mailing list for the Bull Clearance as well as
other Selected Brahman and Composite tenders please contact the Douglas
Daly Research Farm (Spud Thomas, Spud.Thomas@nt.gov.au, 08 8978 2442)
or the Katherine Research Station (Whitney Dollemore,
Whitney.Dollemore@nt.gov.au or 08 8973 9749).
P a g e | 10
Katherine Rural Review
Katherine Rural Review
P a g e | 11
P a g e | 12
Katherine Rural Review
Round the Region
Left: Good kill of woody tree
and shrubs from a burn
October 2013 on the late 6
yearly burn treatment at
Kidman Springs Fire
Experiment red soil site.
Right: Pasture sampler
extraordinaires, Helen McMillan,
Dionne Walsh and Robyn Cowley
preparing to tackle another chilly
morning out on the quad bikes at
Kidman Springs
Left: Ali Sarkhosh,Technical
Officer, preparing to start
spraying mites in melons.
Katherine Rural Review
P a g e | 13
Katherine Rural Review
P a g e | 14
Katherine Rural Review
P a g e | 15
Katherine region events calendar
Event
Location
Date
Beetaloo Rotational Grazing Pilot
Field Day
Beetaloo Station
10
September
Jane.Douglas@nt.gov.au
NT Field Days
Katherine
Research Station
18–19
September
Neil.MacDonald@nt.gov.au
North Australia Food Futures
Conference
Darwin
4-5
November
Warren.Hunt@nt.gov.au
Please email us with updates of events happening in your area: jodie.ward@nt.gov.au
POSTAGE
If undelivered
please return to:
PAID
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.
P a g e | 16
Katherine Rural Review