Live weight parameters in Dorper, Damara and Australian Merino lambs subjected to restricted feeding

Seasonal weight loss (SWL) is a serious constraint to ruminant production in tropical and Mediterranean climates. SWL is controlled using supplementation, costly and difficult to implement in extensive production systems; or alternatively, using breeds with a natural adaptation to tropical climates, namely hair and fat tailed sheep. Albeit a 15-year presence in Australia, little is known on how Dorper and Damara sheep compared to the most widely used sheep breed in Australia, the Australian Merino. In this trial, the responses of the Damara, Dorper and Merino breeds to nutritional stress were compared during a 42-day trial. Seventy-two ram lambs, 24 from each breed, were randomly allocated to a growth (gaining 100 g/day) or a restricted diet (losing 100 g/day). Animals were weighed twice weekly. Individual rations were calculated from bodyweight, with animals being confined to consume their ration daily. The breeds were compared for bodyweight changes as a percentage of their initial weight for three periods (Days 0–10, 10–21 and 21–42). The significant differences between breeds in the percentage growth rates were that the Damara breed lost more weight than the other breeds on the restricted diet from Days 10 to 21 and gained less weight on the growth diet during Days 21–42. For all other periods the weights of Damara, Dorper and Merino breeds were not significantly different. By Day 24 all breeds had stopped losing weight on the restricted diet. We conclude that under confined feeding and considering growth parameters, the three breeds performed similarly

Making Decisions to Identify Forage Shrub Species for Versatile Grazing Systems

Grazing systems in many parts of the world face large challenges, including a declining natural resource base (e.g. soil fertility), marked fluctuations in feed production across seasons and years, climate change (including the contribution of greenhouse gases from livestock), and market demands for sustainable and ethical production systems. The ‘Enrich’ project was established in Australia (Revell et al. 2008; Bennell et al. 2010) within this broad context of emerging challenges to explore the potential of using Australian native perennial shrub species as part of the feedbase for sheep and cattle in southern Australia. The underlying rationale was to: add perennial shrub species into the existing annual-based pasture feedbase so that the forage system could tolerate extended dry periods but provide green edible plant material during periods where a ‘feed gap’ would otherwise exist; be productive on marginal soils where other productive options are limited (Masters et al. 2010); and have a positive effect on gut function and health (Vercoe et al. 2007); i.e. a versatile grazing system. This paper outlines the research approach that was taken, and reports on a ‘decision tree’ to prioritise species from an initial large list, based on a wide range of plant characteristics and how they can be used in a grazing system

Does the fat tailed Damara ovine breed have a distinct lipid metabolism leading to a high concentration of branched chain fatty acids in tissues?

Articles in International JournalsFat tailed sheep breeds are known for their adaptation to nutritional stress, among other harsh production conditions. Damara sheep, native to Southern Africa, have recently been exported to other areas of the world, particularly Australia, aiming to produce lamb in semi-arid regions. Damaras have a unique hanging fat tail, a fat depot able to be mobilized under nutritional stress. In this article we perform an in-depth characterization of the fatty acid profiles of the fat tail in underfed and control Damara rams. Profiles were very similar between experimental groups, with the exception of palmitic acid (16:0) that was lower (P = 0.014) in underfed animals. However, the most striking result was the very high proportions of non-terminal branched chain fatty acids found in the fat tail adipose tissue, as well as the gastrocnemius muscle of Damara rams. The muscle of Dorper and Merino rams used in the same experiment did not present non-terminal branched chain fatty acids, suggesting that Damara rams have a unique lipid metabolism. Herein, we interpret this trait relating it to a higher ability of Damara sheep to digest fibrous fodder and to putative differences in the propionate metabolism by comparison to other sheep breeds

Agribusiness Sheep Updates - 2004 part 3

Posters Can Merino Ewes be Teased to Synchronise Oestrus for a Summer/Autumn Mating? Ken Hart, Keith Croker, Department of Agriculture Western Australia, Rob Davidson, School of Animal Biology, University of Western Australia. Mario D\u27Antuono, Department of Agriculture Western Australia Damara Sheep: Now Looking Domestic Evan Burt and Tanya Kilminster, Department of Agriculture Western Australia Production and Water Use of Lucerne and French Serradella Under Three Sowing Rates Diana Fedorenko1,4, Darryl McClements1,4 , Robert Beard3,4 1Department of Agriculture, 3 Farmer, Meckering, 4CRC for Plant-based Management of Dryland Salinity. E-SHEEP - Individual Animal Management is here Sandy Turton & Martin Atwell, Department of Agriculture, Western Australia. Using Radio Frequency Identification Technology on Farm Martin Atwell & Sandy Turton, Department of Agriculture, Western Australia The Impact of Introducing Lucerne into a Wheat / Sheep Farming System on Wool and Meat Production Robert Beard1,3 and Diana Fedorenko2,3. 1Farmer, Meckering; 2Department of Agriculture, Western Australia, 3CRC for Plant-based Management of Dryland Salinit

The ovine hepatic mitochondrial proteome: understanding seasonal weight loss tolerance in two distinct breeds

Research ArticleSeasonal weight loss (SWL) is a primary constraint for farmers in the Mediterranean and tropics. One cost-effective solution to SWL is utilizing breeds like the Damara sheep that have adapted to deal with nutritional stress. Previous studies concluded that one of the adaptation mechanisms of SWL is a specialized fatty acid metabolism. Accordingly, hepatic-mitochondrial proteomes were compared across two different breeds (24 sheep total, Merino, n = 12 and Damara, n = 12) and two different diets (restricted vs unrestricted diet, 6 per breed, per diet, 24 total). Mitochondrial-proteins were isolated and relatively quantified using Blue native PAGE / 2D-electrophoresis and then analyzed via mass spectrometry. The tool ReviGO summarized the proteomes’ gene-ontology terms. A total of 50 proteins were identified with 7 changing significantly in abundance (ANOVA p-value<0.05). Specific abundance patterns of corticosteroid and inflammatory response-associated proteins such as annexin and glutamate dehydrogenase suggests that the Damara has an unusual inflammation response when subjected to SWL in addition to its unique metabolism. All significant proteins warrant further study; Annexin in particular shows promise as a potentially useful biomarkerinfo:eu-repo/semantics/publishedVersio

Sheep Updates 2008 - part 2

This session covers eleven papers from different authors: The Sheep Room 1. Analgesia for Surgical Husbandry Procedures in Sheep and Other Livestock, Dr Meredith L. Sheil, Animal Ethics Pty Ltd, Associate Sydney University Faculty of Veterinary Science The Wool Enterprise 2. Unmulsed sheep - implications for chemical use, Di Evans & Brown Besier, Department of Agriculture and Food WA 3. Are Damara and Dorper sheep better adapted than Merinos to nutritional stress? - Growth rates, Tim Scanlon1, Andre Martinho de Almeida2, Johan Greeff1, Tanya Kilminster1, John Milton3, Chris Oldham1, Department of Agriculture and Food WA1, Instituto de Investigacao Cientifica Tropical, Lisbon, Portugal2, University of Western Australia3 4. Are Damara and Dorper sheep better adapted than Merinos to nutritional stress? - Carcass attributes, Tanya Kilminster1, Andre Martinho de Almeida2, Johan Greeff1, John Milton3, Chris Oldham1, Tim Scanlon1, Department of Agriculture and Food WA1, Instituto de Investigacao Cientifica Tropical, Lisbon, Portugal2, University of Western Australia3 The Beef Room 5. Benefits of matching animal requirements with pasture feed supply and animal supply market requirements, B.L. McIntyre, Department of Agriculture and Food Western Australia, 6. Optimal grazing for beef, Alison Wheatley, Beef farmer Winnejup, John Lucey, Department of Agriculture and Food, Western Australia 7. Grain Introduction in commercial cattle feedlots, Fiona Jones1,2, Nick Costa2, 1 Department of Agriculture and Food WA and 2 Murdoch University. Mixed Systems 8. Confinement feeding stock in mixed enterprises, John Milton, The University of Western Australia & Independent Lab Services The Sheep Enterprise 9. Making More than Sheep, Ed Riggall, Australian Wool Innovation and Meat & Livestock Australia 10. Sheep Cost of Production - the enemy is at the gate!, JRL (Bob) Hall, JRL Hall & Co 11. Australian lamb - high yielding good to eat, Robin Jacob1, Dave Pethick2, Dave Hopkins3 and Graham Gardner2, 1Department of Agrcultre and Food WA, 2Murdoch University, 3NSW Department of Primary Industrie

Sheep Updates 2003 - Posters

This session covers eleven papers from different authors:1 Sheep production on annual stubbles/pastures vs lucerne Maxine Brown Gaye Krebs Muresk Institute, Curtin University Diana Fedorenko Kathryn Egerton-Warburton Centre for Cropping Systems, Department of Agriculture Western Australia 2. The value chain of the Lake Grace livestock industry Evan Burt Nazrul Islam Department of Agriculture Western Australia 3. Native pastures, Dorper sheep and the 2002 drought Roy Butler Department of Agriculture Western Australia 4. Commercial sheep breeders can improve their sheep breeding program using wether trials L.G. Butler, S.R. Brown, M.F. D’Antuono, J.C. Greeff Department of Agriculture 5. Western Australia Linked ewe trials to benchmark wool traits and reproductive performance of Western Australian sheep flocks Ken Hart Department of Agriculture Western Australia 6. Damara sheep - what is their potential? A case study from the North-eastern wheatbelt Tanya Kilminster Evan Burt Department of Agriculture Western Australia 7, Australian Sheep Industry CRC - nutrition sub-program Rachel Kirby Sheep CRC Research Fellow 8. Dust penetration is not genetically and phenotypically the same trait as dust content M.E. Ladyman J.C. Greeff Department of Agriculture Western Australia A.C. Schlink CSIRO Livestock Industries, Private Bag 5, Wembley WA I.H. Williams P.E. Vercoe University of Western Australia, Crawley WA 9.Developing sustainable fodder crop systems with new annual pasture legumes Anyou Lui Department of Agriculture Western Australia 10. Seasonal pricing and seasonality of supply of prime lambs in the western wheatbelt Karen Smith Martin Bent Muresk Institute, Curtin University 11. The role of alternative and exotic sheep breeds in the Western Australian sheep industry Matthew Young Department of Agriculture Western Australi

Seasonal weight loss effect in the hepatic fatty acid composition in Australian Merino, Damara and Dorper sheep

Seasonal weight loss (SWL) is one of the major limitations in small ruminant production in drought-prone regions. The study of breeds with higher tolerance to the effects of SWL is particularly important to define breed selection strategies. In this work we evaluated the effect of SWL in the hepatic fatty acids profile in three ovine breeds with different levels of tolerance: the Merino (susceptible to SWL), the Dorper (intermediate tolerant to SWL), and Damara (tolerant to SWL). Animals from each breed were divided into two experimental groups: a growth group and a restricted fed group. The more representative fatty acids in the three breeds were stearic acid, oleic acid and palmitic acid. Univariate analysis revealed interaction between breed and feed-restriction in eighteen of the total fatty acids identified. Multivariate analysis showed separation between growth and restricted animals in each of the three breeds. Variations observed in the three breeds are in general related with fatty acid mobilization from the adipose tissue. Dorper and Damara breed showed exclusive variations, related with muscular tissue maintenance and hepatic adaptations respectively. Generally, Damara and Dorper breeds performed better under nutritional restriction, in accordance with results previously obtained following other approaches.info:eu-repo/semantics/publishedVersio

Assessing carcass and meat characteristics of Damara, Dorper and Australian Merino lambs under restricted feeding

Articles in International JournalsSeasonal weight loss (SWL) is the most pressing constraint in ruminant production systems in tropical climates. SWL is controlled using supplementation, which is costly and difficult to implement in extensive systems, or using breeds adapted to tropical hot dry climates, like the Damara and Dorper. Albeit 15 years in Australia, little is known on how these sheep compare to Australian Merino. Here, the responses of the Damara, Dorper and Merino breeds to nutritional stress were compared. Seventy-two 6-month-old ram lambs, 24 from each breed, were allocated to growth (gaining 100 g/day) or restricted diets (losing 100 g/day, 85 % of maintenance needs). Animals were weighed and carcass and meat characteristics determined. Results point out to the existence of important differences between the three genotypes, in particular between the Merino and the Southern African breeds. Additionally, Merino ram lambs seem to have been more influenced by SWL than the other two, with consequences on meat characteristics

Agribusiness Sheep Updates - 2004 part 3

Posters Can Merino Ewes be Teased to Synchronise Oestrus for a Summer/Autumn Mating? Ken Hart, Keith Croker, Department of Agriculture Western Australia, Rob Davidson, School of Animal Biology, University of Western Australia. Mario D\u27Antuono, Department of Agriculture Western Australia Damara Sheep: Now Looking Domestic Evan Burt and Tanya Kilminster, Department of Agriculture Western Australia Production and Water Use of Lucerne and French Serradella Under Three Sowing Rates Diana Fedorenko1,4, Darryl McClements1,4 , Robert Beard3,4 1Department of Agriculture, 3 Farmer, Meckering, 4CRC for Plant-based Management of Dryland Salinity. E-SHEEP - Individual Animal Management is here Sandy Turton & Martin Atwell, Department of Agriculture, Western Australia. Using Radio Frequency Identification Technology on Farm Martin Atwell & Sandy Turton, Department of Agriculture, Western Australia The Impact of Introducing Lucerne into a Wheat / Sheep Farming System on Wool and Meat Production Robert Beard1,3 and Diana Fedorenko2,3. 1Farmer, Meckering; 2Department of Agriculture, Western Australia, 3CRC for Plant-based Management of Dryland Salinit