 |
Rural Industries Research & Development Corporation |
|| Home || Search || Contact || Publications Eshop || Privacy Statement ||
Rural Industries Research & Development Corporation
Summary of full report
by Andrew Phillips, Dr Jürgen Heucke, Dr Birgit Dörges, and Greg O.Reilly
June 2001
RIRDC Publication No 01/092
RIRDC Project No DNT-20A
Executive Summary
Background
This project began in July 1997 and fieldwork was completed in May 2001. The project began with the idea that beef producers might achieve unchanged beef production with camel production as a bonus through cograzing the two species. The project was developed against a background of relatively low beef prices and several poor seasons in Central Australia. The overall goal was to investigate the livestock productivity and impact on vegetation of cograzing as opposed to cattle grazing. Differences between grazing cattle only and cograzing cattle and camels were investigated in two paddocks on Waite River station, 250 km by road northeast of Alice Springs. An adjoining paddock that was very conservatively stocked with cattle was used for pasture comparisons. This project focused on biological aspects of cograzing, however it is recognised that continued development of camel markets is essential for successful commercial cograzing to become widely adopted.
The project had four components:
1) Tree and shrub impact monitoring
2) Pasture utilisation monitoring
3) Animal production measurements
4) Camel feeding and behavioural observations
The project used cattle and camels belonging to the cooperating station. In 1996, a camel breeding herd of one bull and 14 cows were introduced to the 8.4 km2 .Muller paddock.. Camel browsing on trees and shrubs was recorded in 1996 and 1997 prior to this project commencing.
Both Muller paddock and the comparative
20.9 km2 .DPI paddock. were spelled from cattle grazing over the 1997/98
summer until steers were introduced into both paddocks in March 1998. Steer
groups in both paddocks were replaced with the same number of younger steers
each year. Camel groups were also changed at the same times as steer groups.
The breeding herd of camels was replaced with nine young bulls in March
1999, reducing the camel stocking rate to approximately one per square
kilometer. These camels were removed from Muller paddock in April 2000.
From August 2000 until May 2001 the stocking regimes were reversed. The
DPI paddock was cograzed with steers and 20 young bull camels and Muller
paddock ran steers only. The grazing regimes were as follows:
| Muller paddock | DPI paddock | |
| 1. Mar 98 . Feb 99 | Steers cograzed with breeding camels | Steers only |
| 2. Mar 99 . Apr 00 | Steers cograzed with young bull camels | Steers only |
| 3. Aug 00 . May 01 | Steers only | Steers cograzed with young bull camels |
Seasonal conditions fluctuated markedly during the project:
Summary of findings
Pasture plants, utilisation and ground cover
Pasture yields fluctuated greatly in response to effective rainfall. Pasture yields were high in late 1997, decreased through 1998 to very low in 1999, and returned to or bettered the 1997 yields in 2000. Seasonal conditions were also the main determinant of pasture composition. Despite large fluctuations in the amount of grass and herbage available, there was no consistent significant difference recorded for any pasture attribute (species mix, quantity, or ground cover) that could be attributed to cograzing camels with cattle. At the stocking rates set for both species, camels did not deprive the cattle of grass or herbage. This was the case in both excellent and poor seasonal conditions.
Tree and shrub impact
Browsing on trees and shrubs cover was also driven by seasonal conditions.
• In 1997 camel browsing resulted in a 15% decrease in tree and shrub canopy cover in Muller paddock whilst outside the paddock, canopy cover increased by over 20%.
• In 1998 good autumn rain and subsequent herbage availability enabled the camels to graze more ground storey species. Canopy cover was stable in the Muller paddock and increased slightly outside the paddock.
• In 1999 canopy cover decreased similarly by almost 10% inside and outside Muller paddock.
Outside Muller paddock the decrease in canopy cover was a result of cattle browsing on preferred topfeed species during the dry conditions.
• In 2000 canopy cover increased by approximately 30% in both paddocks due to unusually high rainfall. Extraordinary herbage availability enabled the camels to predominantly graze ground vegetation. Only minor browsing impact on the trees and shrubs in Muller paddock was recorded.
• From August 2000 to May 2001 canopy cover increased everywhere in response to excellent seasonal conditions. The increase was almost 20% in Muller paddock and over 10% in the DPI paddock despite the presence of camels.
Cattle and camel production
The two paddocks in which the project livestock were grazed have somewhat different land types.
Variable land types within small distances are quite typical of many of the more productive areas for running cattle in Central Australia. Steer stocking rates in both paddocks were established according to the area of different land types, resulting in Muller paddock always being more heavily stocked with cattle. Muller paddock ran 4.2 steers/km2 compared to 3.6 steers/km2 in the DPI paddock. This resulted in 16%, 20% and 13% more kg/km2 of steer liveweight maintained in Muller paddock in each period.
Steer growth patterns reflected seasonal conditions and were therefore completely different during the first two periods, yet annual weight gain and overall growth rates were very similar. These steer groups had average daily weight gains of between 0.41 and 0.45 kg per day over approximately one year. Annual weight gains were therefore in the range of 150 to 165 kg. Steer growth rates in the eight months from August 2000 to May 2001 were higher. Average daily gains of 0.58 to 0.63 kg resulted in weight gains of 145 to 160 kg over this period.
Average steer weight gains were consistently slightly higher in Muller paddock. Average daily gains of steers were 38 g/day higher between March 1998 and March 1999, 30 g/day higher between March 1999 and April 2000 and 54 g/day higher between August 2000 and May 2001. Although these differences were quite similar, they were not statistically significantly higher during the first two periods, but were significantly higher during the final period. This finding is believed to have been due to the combination of excellent seasonal conditions and different land types, rather than any impact from reversing the grazing regimes. There are minimal areas of sloping country and no externally draining watercourses in Muller paddock whereas the DPI paddock has a relatively high proportion of sloping country that runs into an externally draining watercourse. More water is retained and available for pasture growth in Muller paddock.
Cograzing with camels did not appear to limit steer performance during the two years in Muller paddock, presumably because they were not in competition for feed resources and did not have any other detrimental interactions. Steer growth information cannot be directly compared between years because of different seasonal conditions. However, if steer growth rates were reduced by cograzing, the maximum possible difference was very minor and in the order of 10 grams per day.
In 1998, when the camel breeding herd was in Muller paddock, all camel weights (except calves) fell in autumn when the bull was in rut. Cow and weaner weights recovered three months later. In April 2000 several of the nine young bulls removed from Muller paddock at that time showed signs of rut, and, although there were complicating factors, their weights had fallen by an average of 58 kg since January. Rut is thought to have been stimulated by the presence of one camel cow that was injured and therefore not removed from the paddock with the rest of the breeder herd. In May 2001 none of the young bull camels were showing signs of rut. They gained an average of 109 kg during the eight months, at an average of 260 g/day. It seems necessary to avoid rutting behaviour to optimise camel production. Importantly however, camel rutting behaviour did not affect cattle weight gains.
Cograzing camels with cattle substantially increased the weight of livestock grazed per square kilometre. In the three periods that camels were cograzed with steers, they accounted for 52%, 28% and 26% of the total livestock weight maintained per square kilometer in the cograzed paddocks.
Equivalent increases in the cattle stocking rate per square kilometre would be expected to cause their production to suffer under most seasonal conditions. Running young bull camels at stocking rates of approximately one camel per square kilometre with steers resulted in camel weight gains accounting for 10% (after being affected by rutting behaviour) of the total livestock weight produced per square kilometre in 1999/2000 and 16% in 2000/01.
Application in industry Cograzing is equally, if not more, applicable to the large areas of marginal land for cattle in Central Australia (such as spinifex and mulga country) than to the more productive land types that dominate the paddocks used in this project. The proportional contribution that camels could make to total livestock production would be expected to be higher on land types more marginal for cattle grazing and where there are long distances between water points.
If markets for camels continue to expand and it becomes economically viable to domesticate significant numbers of camels they can be successfully cograzed with cattle. Cograzing may increase variable and capital costs somewhat when compared to grazing cattle only. Extra fence maintenance and upgrades to yard and loading facilities are among the extra costs that might be incurred.
Under careful management, a successful outcome of unchanged cattle production, plus additional camel production can be achieved without negative impact on pasture resources. This project did not demonstrate serious differences in pasture species attributable to cograzing, however it did not run long enough to be able to ascertain long term differences. Despite camels being generally perceived as browsing animals they preferentially graze many broad-leaved pasture plants commonly referred to as herbage or forbs when they are available. They also graze fresh grass growth after the first rains following a dry period, until herbage becomes available. There are therefore some dietary overlaps between cattle and camels for preferred tree, shrub and herbage species and for grass at certain times.
Plant species preferred by cattle and camels may become indicators of pasture condition if the practice of cograzing expands.
|
