CSIRO Publishing Books Journals About Us Shopping Cart You are here: Journals > Animal Production Science   
Animal Production Science
  Food, Fibre and Pharmaceuticals from Animals
 
Search
 
 
  Advanced Search
   

Journal Home
About the Journal
Editorial Board
Contacts
Content
Online Early
Current Issue
Just Accepted
All Issues
Special Issues
Research Fronts
Reviews
Sample Issue
For Authors
General Information
Notes for Authors
Submit Article
Open Access
For Referees
General Information
Review Article
Annual Referee Index
For Subscribers
Subscription Prices
Customer Service
Print Publication Dates

 Early Alert
Subscribe to our Email Alert or RSS feeds for the latest journal papers.

 Connect with us
facebook   youtube

Training

Publication Workshops


 

Open Access Article << Previous     |     Next >>   Contents Vol 49(6)

Effects of growth path, sire type, calving time and sex on growth and carcass characteristics of beef cattle in the agricultural area of Western Australia

B. L. McIntyre A B G, G. D. Tudor A C D, D. Read A C E, W. Smart A C , T. J. Della Bosca A C, E. J. Speijers A B, B. Orchard A F

A Cooperative Research Centre for Cattle and Beef Quality, University of New England, Armidale, NSW 2351, Australia.
B Department of Agriculture and Food, Western Australia, Baron Hay Court, South Perth, WA 6151, Australia.
C Department of Agriculture and Food, Western Australia, PO Box 1231, Bunbury, WA 6230, Australia.
D 6153 Bolsena Circuit, Hope Island, Qld 4212, Australia.
E Rabobank, 2/5 Wollaston Street, Bunbury, WA 6230, Australia.
F New South Wales Department of Primary Industries Agricultural Institute, Private Bag, Wagga Wagga, NSW 2650, Australia.
G Corresponding author. Email: bmcintyre@agric.wa.gov.au
 
 Full Text
 PDF (293 KB)
 Export Citation
 Print
  


Abstract

Growth, carcass characteristics and meat quality of the steer and heifer progeny of autumn (AC: March–April) and winter (WC: June–July) calving cows following weaning in January in each of 3 years (2003–05) were measured. The cows were mated to sires with a high estimated breeding value for either retail beef yield (RBY), intramuscular fat (IMF) or both RBY and IMF. After weaning, the progeny entered one of three growth paths until slaughter at an average steer liveweight of 500 kg: (i) fast – fast growth from weaning on a high concentrate feedlot diet; (ii) slow – slow growth from weaning (~0.6 kg/day) to 400 kg liveweight followed by growth at over 1 kg/day on high quality pasture; or (iii) comp. – 10% weaning weight loss, immediately after weaning followed by compensatory or rapid growth of over 1 kg/day on high quality pasture. Steers on the fast growth path had higher (P < 0.001) P8 fat thickness than those on the slow or comp. growth paths whereas heifers on the fast growth path only had higher (P < 0.001) P8 fat thickness than those on the slow growth path. Animals on the fast growth treatment had higher (P < 0.001) levels of IMF% than the slow animals which were higher (P < 0.001) than the comp. growth treatment. AUS-MEAT and US marbling scores were not different among growth paths. Animals finished on the fast growth path had a lower (P < 0.001) RBY% than those on either the slow or comp. growth paths. The RBY-sired progeny had higher (P < 0.001) finishing liveweight and hot standard carcass weight than either RBY and IMF or IMF-sired animals. IMF-sired progeny had higher (P < 0.01) rib fat thickness than either RBY or RBY- and IMF-sired animals. There was also a similar trend for P8 fat thickness but the effects were not significant. The RBY-sired animals had lower AUS-MEAT marbling scores (P < 0.01), US marbling scores (P < 0.001) and levels of IMF% (P < 0.01) than either of the other two sire treatments. RBY-sired animals also had higher (P < 0.001) estimated RBY% than those from the IMF sires while those by RBY and IMF sires were intermediate and not significantly different from either. Calving time had little influence on most carcass characteristics. However, WC animals tended to be fatter and have higher marbling scores than AC animals. The IMF% was higher (P < 0.01) in WC animals from RBY and IMF sires than in the corresponding AC animals. Heifers had lighter slaughter liveweight, carcass weight, were fatter and had higher marbling scores than steers. Heifers also had lower (P < 0.001) RBY% than the steers. Ossification scores for heifers were higher (P < 0.001) than for steers by ~30 units in AC calves and by 20 units in WC calves. The results of this experiment confirm the effectiveness of using sires with high estimated breeding value for the required characteristics in producing the desired improvements in the progeny. The absence of any interactions of sire type with growth path indicates that differences between sire types will be similar regardless of environmental conditions. Animals raised on a faster growth path after weaning produce carcasses with more fat and more IMF% than those grown on slower growth paths.

   
    


 
Top  Email this page
 
Legal & Privacy | Contact Us | Help

CSIRO

© CSIRO 1996-2012