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 56 SUBPROGRAM: Improving Breeder Herd Efficiency PROJECT: Breeding Herd Efficiency of Alternative Breeder Genotypes Project Officer: M. Cobiac Location: Victoria River Research Station (VRRS) Objective: To compare the breeding herd efficiency of three genotypes of cows (Brahman, Droughtmaster and F1 Brahman x Charolais. To produce progeny (Brahman, Droughtmaster and 3/4 Brahman x 1/4 Charolais) that are tested for growth and their ability to meet future market specifications. Background: The original 500 Droughtmaster cows on VRRS were reduced in late 1995 to 130 (randomly selected), and new breeders were purchased: 260 high grade commercial Brahmans (split into two equal herds) from a number of properties in Queensland; and 130 first-cross (F1) Brahman x Charolais cows from Newcastle Waters Station. The Droughtmasters are an example of a simple two-breed (British Bos taurus x Bos indicus) composite and provide a link to past breeder research at VRRS. The Brahman (pure Bos indicus) cows represent the current breeding objective of the majority of district herds (currently about 80% Brahman) and are highly adapted to the tropics. Both Droughtmasters and Brahmans are considered to be medium sized mature animals. As the live export trade to South-East Asian countries expanded in the early 1990s (particularly to Indonesia and the Philippines) a problem emerged with overfatness of NT-sourced cattle when turned off from feedlots in their destination country. This was a result of improved post-weaning management in the NT resulting in better weight-for-age at the time of exporting. The introduction of later maturing genes from European Bos taurus cattle was seen as one option to address this issue, and the F1 Brahman x Charolais cattle provide a source of these genes. The 50% of European genes has always been considered as extreme for our environment, however when crossed back to Brahman, the progeny contain a high level of tropical adaptation (75% Bos indicus) as well as some (25% European Bos taurus) later maturing characteristics. There are two sources of these 25% Charolais animals: the progeny of the F1 cows with Brahman bulls, and the progeny of Brahman cows with F1 bulls. Future work is likely to involve evaluating the breeding efficiency of herds containing other proportions (e.g. 17% and 33% Charolais) of late maturing genes. All breeders are run under the Departments Best Bet Management System, the basics of which are outlined in the Best Bet Breeding Herd project report. Some Results: The current phase of breeder research at VRRS finished in May 2001. Herd structures are currently being modified to accommodate the new focus for breeder work, including the criss-cross crossbreeding system for evaluating other proportions of late maturing genes and modifications to the standard Best Bet system. Data from 1995 2001 is presently being collated, checked for errors and prepared for analysis. Some preliminary results are presented here, with full analysis and reporting presently under way.