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Dietary choice and grazing behaviour of sheep on spatially arranged pasture systems. 2. Wether lamb growth and carcass weight at slaughter
- Source :
- Animal Production Science. 57:710
- Publication Year :
- 2017
- Publisher :
- CSIRO Publishing, 2017.
-
Abstract
- Dry matter production and nutritive characteristics of the pasture feedbase during autumn are key drivers of profitability in Australia’s prime lamb systems. An experiment was conducted to test the hypothesis that offering lambs dietary choice through spatially separated combinations of perennial ryegrass (Lolium perenne L.), plantain (Plantago lanceolata L.) and/or lucerne (Medicago sativa L.) improves the post-weaning liveweight gain, condition score (CS), pre- and post-slaughter carcass characteristics and reduces the internal parasite burdens of wether lambs finished to a slaughter weight over autumn, relative to lambs offered no dietary choice. The experiment tested seven treatments, replicated four times in a randomised complete block design with plot sizes of 1 ± 0.1 ha. The treatments were: 100% perennial ryegrass (PR), 100% plantain (PL), 100% lucerne (LU), 50 : 50 perennial ryegrass/plantain (PR + PL), 50 : 50 perennial ryegrass/lucerne (PR + LU), 50 : 50 plantain/lucerne (PL + LU) and 33 : 33 : 33 perennial ryegrass/plantain/lucerne (PR + PL + LU). Plots were grazed by weaned lambs between March and June 2011. The lambs had been born between 3 August and 7 September 2010 and were derived from either Coopworth composite dams joined to Coopworth maternal sires or from Merino dams (Toland or Centreplus bloodlines) joined to Border Leicester sires. Backgrounding the lambs on a pasture system that contained lucerne during the lactation to weaning period increased (P < 0.05) liveweight at slaughter by 8% and hot carcass weight by 10%, relative to lambs backgrounded on perennial ryegrass. Finishing lambs on the LU treatment between weaning and slaughter increased (P < 0.05) liveweight at slaughter by 11%, CS at slaughter by 0.3 units, hot carcass weight by 16%, carcass CFAT (measured over the loin) by 2.5 mm, carcass eye muscle depth by 1.1 mm and carcass GRFAT (total tissue depth at 11/12th rib, 11 cm from mid line) by 3.8 mm, relative to lambs finished on the PR treatment. Finishing lambs on LU + PR, LU + PL or LU + PR + PL did not (P > 0.05) improve any of the measured parameters, relative to finishing lambs on the LU treatment. The PL and PR treatments did not differ (P > 0.05) in liveweight at slaughter, CS at slaughter or carcass characteristics, but the PL treatment had lower (P < 0.05) liveweight gain than the PR treatment during the first 2 weeks of the experiment (39 g/day vs 330 g/day), which was later partially compensated for. Our hypothesis has not been supported given that the use of spatially arranged mixes resulted in no improvement in liveweight gain, CS, carcass characteristics or internal parasite burdens relative to the comparable single species sward.
- Subjects :
- 0106 biological sciences
geography
geography.geographical_feature_category
Animal breeding
Perennial plant
04 agricultural and veterinary sciences
Biology
biology.organism_classification
01 natural sciences
Pasture
Lolium perenne
Animal science
Agronomy
Grazing
040103 agronomy & agriculture
0401 agriculture, forestry, and fisheries
Backgrounding
Weaning
Animal Science and Zoology
Dry matter
010606 plant biology & botany
Food Science
Subjects
Details
- ISSN :
- 18360939
- Volume :
- 57
- Database :
- OpenAIRE
- Journal :
- Animal Production Science
- Accession number :
- edsair.doi...........0a9ae61bea7b307cf661baf64f4ba61e
- Full Text :
- https://doi.org/10.1071/an15540