Territory Stories

Technical annual report 2000-01

Details:

Title

Technical annual report 2000-01

Collection

Dept. of Regional Development, Primary Industry, Fisheries and Resources technical annual report; Department of Regional Development, Primary Industry, Fisheries and Resources technical and annual report; Reports; PublicationNT; Technical bulletin (Northern Territory. Dept. of Primary Industry and Fisheries) ; no. 295

Date

2001-10

Description

Made available via the Publications (Legal Deposit) Act 2004 (NT).

Notes

Date:2001-10

Language

English

Subject

Agriculture -- Northern Territory -- Periodicals; Fisheries -- Northern Territory -- Periodicals

Publisher name

Dept. of Primary Industry and Fisheries

Place of publication

Darwin

Series

Technical bulletin (Northern Territory. Dept. of Primary Industry and Fisheries) ; no. 295

ISSN

0158-2763

Copyright owner

Check within Publication or with content Publisher.

Parent handle

https://hdl.handle.net/10070/223369

Citation address

https://hdl.handle.net/10070/687151

Page content

Department of Primary Industry and Fisheries 68 Tree and shrub impact, and feeding observations Tree and shrub cover (Table 1) was largely driven by seasonal conditions. In 1998, good autumn rain and subsequent herbage availability enabled the camels to graze more ground storey species. In 1999, the decrease in canopy cover was a result of cattle browsing on preferred topfeed species during the dry conditions. In 2000, extraordinary herbage availability enabled the camels to predominantly graze forbs. Only minor browsing impact on the trees and shrubs in the cograzed paddock was recorded. From August 2000 to May 2001, canopy cover increased everywhere in response to excellent seasonal conditions. Table 1. Percentage changes in canopy cover inside the cograzed paddock and comparative transects in the control paddock and paddock with cattle only Year Control (%) Cograzed (%) Cattle only (%) 1997 1998 1999 2000 2001 +22.4 +4.7 -9.5 +33 +9.1 -15.5 no change -8.8 +30 +11.8 +19.4 This project did not demonstrate impacts on vegetation that would be attributable to cograzing, however it did not run long enough to ascertain long term differences. Despite camels being generally perceived as browsing animals, they can preferentially graze forbs when they are available. They also graze fresh grass growth after the first rains following a dry period, until forbs become available. Therefore some dietary overlaps occur between cattle and camels for preferred tree, shrub and herbage species and for grass at certain times. Cattle and camel production 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 (Table 2). Table 2. Average weight gains (kg) and average daily gains (kg/day) of steers and camels Period Species Average daily gain (kg/day) Annual weight gains (kg) Mar 1998 - May 2000 Steers 0.41 0.45 150 - 165 Mar 1999 May 2000 Aug 2000 May 2001* Young bull camels Steers Young bull camels 0.16 0.58 0.63 0.26 64 145 - 160 109 *This was a period of exceptionally high rainfall. 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. These differences were not statistically significant during the first two periods, but were significantly different 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. Cograzing with camels was not shown 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. Although steer growth information cannot be directly compared between years because of different seasonal conditions, if cograzing reduced steer growth rates, the maximum possible difference was 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 showed signs of rut, and 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 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. Their average weight gain, and average daily