Article
Reproductive Biology
Amellia Redfearn, Estelle Janodet, Jody McNally, Heather Brewer, Emma Doyle, Rebecca Doyle, Sabine Schmoelzl
Summary: Dystocia is a major cause of lamb mortality, leading to newborn hypoxia, CNS damage, increased risk of starvation, exposure, mismothering and death. This study found that dystocic ewes exhibited lower expression of maternal behaviors and higher expression of avoidance behaviors, as well as performing fewer behaviors overall compared to eutocic ewes. Dystocia significantly affects the quality and quantity of ewe maternal behavior, increasing the risk of lamb avoidance, maternal disinterest, and lamb death.
Article
Agriculture, Dairy & Animal Science
Marnie J. Hodge, Sara de las Heras-Saldana, Sally J. Rindfleish, Cyril P. Stephen, Sameer D. Pant
Summary: This study aimed to identify genomic regions and associated genes that may significantly influence semen traits in Merino sheep. A total of 35 quantitative trait loci (QTLs) were identified to be significantly associated with semen traits, and 290 candidate genes were found within these QTLs. The validation of these candidate genes could provide valuable insights into improving sheep reproductive efficiency.
Article
Veterinary Sciences
Edward Narayan, Gregory Sawyer, Dylan Fox, Ryan Smith, Alan Tilbrook
Summary: This study investigates the effects of early shearing on Australian Merino ewes and their lambs. The results show that early shorn ewes grazed more and maintained better body condition compared to once shorn ewes, with lower levels of wool cortisol. DNA methylation analysis reveals that both shearing frequency and pregnancy status have an impact on the genomic modifications in the sheep. This research provides valuable insights into how Merino ewes respond to shearing and can guide further studies on sheep breeding and welfare.
FRONTIERS IN VETERINARY SCIENCE
(2022)
Article
Agriculture, Dairy & Animal Science
Zully Ramos, Dorian J. Garrick, Hugh T. Blair, Ignacio De Barbieri, Gabriel Ciappesoni, Fabio Montossi, Paul R. Kenyon
Summary: This study estimated the genetic parameters for a range of production traits and ewe reproductive performance in an Uruguayan Merino flock. The genetic relationships between fiber diameter and reproduction traits were generally negligible, while moderate unfavorable genetic correlations were found between adult clean fleece weight and ewe reproduction traits. Selecting finer fleeces had little to no effect on ewe reproduction traits, while heavier fleeces were associated with reduced reproduction performance. On the other hand, genetically heavier yearling ewes displayed greater reproductive performance.
JOURNAL OF ANIMAL SCIENCE
(2023)
Article
Agriculture, Dairy & Animal Science
S. M. Robertson, S. H. Edwards, G. S. Doran, M. A. Friend
Summary: Caffeine treatment did not significantly improve perinatal lamb survival according to the results of this study.
ANIMAL REPRODUCTION SCIENCE
(2021)
Article
Chemistry, Analytical
Hamideh Keshavarzi, Caroline Lee, Mark Johnson, David Abbott, Wei Ni, Dana L. M. Campbell
Summary: This study introduced an RTK-GNSS localisation device for sheep and confirmed its accuracy through testing. By analyzing the optimal location update rate and threshold distance, it was found that specific sampling strategies can accurately detect social networks in sheep groups.
Article
Agriculture, Dairy & Animal Science
Amy M. Bell, Sonja Dominik, Duncan Elks, Graham Acton, Jen Smith
Summary: The study investigated dentition changes in Australian Merino sheep and found that progeny that were heavier, fatter, and with higher muscle measurements matured earlier. Female progeny were more likely to be pregnant if classed as hoggets earlier in life.
ANIMAL PRODUCTION SCIENCE
(2021)
Article
Microbiology
Ana Usie, Celia Leao, Daniel Gaspar, Helena Monteiro, Lino Tabuas, Elisa Bettencourt, Pedro Caetano, Ludovina Padre, Nuno Carolino, Antonio Marcos Ramos, Claudino de Matos, Sandra Branco
Summary: In the Portuguese Alentejo region, the Merino sheep breed is commonly reared for meat, dairy, and wool production. Footrot, caused by Dichelobacter nodosus and Fusobacterium necrophorum, leads to lameness and economic losses. Meta-genome sequencing revealed distinct bacterial communities associated with different footrot lesion scores, with a shift from gram-positive to gram-negative dominance as severity increases. Species such as Treponema spp., Staphylococcus spp., Streptococcus spp., and Campylobacter spp. were found proliferating alongside lesion severity, indicating their association with footrot incidence and severity.
VETERINARY MICROBIOLOGY
(2023)
Article
Biology
Hamideh Keshavarzi, Caroline Lee, Tim R. Dyall, Mark Johnson, Dana L. M. Campbell
Summary: This study examines the influence of shared stressful experiences on relationship bonding in animals, focusing on Merino ewes. The results show that sheep prefer to be closest to familiar individuals, but they also develop a preference for individuals with whom they shared a stressful experience. These findings contribute to our understanding of how unfamiliar animals bond and perceive conspecifics in stress-inducing situations.
Article
Agriculture, Dairy & Animal Science
Dayna Hutchison, Bronwyn E. Clarke, Serina Hancock, Andrew N. Thompson, Elise Bowen, Caroline Jacobson
Summary: The reproductive performance of maiden ewes is poorer than that of multiparous ewes, and the extent and causes of this difference are not well understood in Australian sheep farming. This study compared the reproductive performance of maiden ewes and multiparous ewes on the same farms and found significant differences in lamb marking rate and reproductive success. Strategies to improve reproductive rate and lamb survival can address the suboptimal reproductive performance of maiden ewes.
Article
Agriculture, Dairy & Animal Science
Simone Ceccobelli, Vincenzo Landi, Gabriele Senczuk, Salvatore Mastrangelo, Maria Teresa Sardina, Slim Ben-Jemaa, Christian Persichilli, Taki Karsli, Valentin-Adrian Balteanu, Maria Agustina Raschia, Mario Andres Poli, Gabriel Ciappesoni, Farai Catherine Muchadeyi, Edgar Farai Dzomba, Nokuthula Winfred Kunene, Gesine Luehken, Tatiana Evgenievna Deniskova, Arsen Vladimirovich Dotsev, Natalia Anatolievna Zinovieva, Attila Zsolnai, Istvan Anton, Szilvia Kusza, Nuno Carolino, Fatima Santos-Silva, Aldona Kawecka, Marcin Swiatek, Roman Niznikowski, Marija Spehar, Gabriel Anaya, Antonio Granero, Tiago Perloiro, Pedro Cardoso, Silverio Grande, Beatriz Lopez de los Santos, Coralie Danchin-Burge, Marina Pasquini, Amparo Martinez Martinez, Juan Vicente Delgado Bermejo, Emiliano Lasagna, Elena Ciani, Francesca Maria Sarti, Fabio Pilla
Summary: Through genetic analysis of 19 populations and publicly available genotypes, this study reveals the genetic relationships and admixture patterns of Merino and Merino-derived breeds, with Australian, Rambouillet, and German strains playing a crucial role. The study identifies 106 candidate genes potentially under selection, including those related to immune response, morphological traits, growth and reproductive traits, adaptive thermogenesis, and hypoxia responses. This research provides valuable insights into the genetic makeup and adaptive diversity of Merino and Merino-derived breeds, emphasizing their importance in tackling climate changes.
GENETICS SELECTION EVOLUTION
(2023)
Article
Agriculture, Dairy & Animal Science
Antonio Granero, Gabriel Anaya, Maria J. Alcalde
Summary: This study examines the morphometric differences in different historical genetic lines of the Spanish Merino sheep breed. The results show significant differences in measurements and indexes between the genetic lines, suggesting how different lines have developed due to management models and adaptation to specific ecosystems. The study complements previous genomic research and highlights the importance of preserving the genetic variability of the original Spanish Merino breed.
Article
Agriculture, Dairy & Animal Science
Antonio Granero, Gabriel Anaya, Sebastian Demyda-Peyras, Maria J. Alcalde, Francisco Arrebola, Antonio Molina
Summary: This study used a genomic approach to investigate the genetic basis of historical Spanish Merino sheep, and found significant genetic differences between them and modern Merino breeds. They also exhibited high variability and richness in terms of genetics, suggesting that they should be protected as a valuable genetic population for improving sheep breeds.
Article
Agriculture, Dairy & Animal Science
G. Rose, B. Paganoni, C. Macleay, C. Jones, D. J. Brown, G. Kearney, M. B. Ferguson, B. E. Clarke, A. N. Thompson
Summary: Feed intake, methane and feed efficiency are genetically correlated with growth, carcase weights and mature size. Selecting animals that grow faster may reduce meat quality. Fat and muscle have significant correlations with feed efficiency and greenhouse gas traits.
Article
Agriculture, Dairy & Animal Science
N. J. Murdock, A. C. Weaver, J. M. Kelly, D. O. Kleemann, W. H. E. J. van Wettere, A. M. Swinbourne
Summary: The use of caffeine supplementation in late-gestation ewes stimulates neonatal lambs by increasing sucking behavior (4-h serum IgG) and raising body temperatures in the first 24 hours post-birth.
ANIMAL REPRODUCTION SCIENCE
(2021)
Article
Agriculture, Multidisciplinary
Amy L. Lockwood, Serina N. Hancock, Jason P. Trompf, Lyndon J. Kubeil, Mark B. Ferguson, Gavin A. Kearney, Andrew N. Thompson
NEW ZEALAND JOURNAL OF AGRICULTURAL RESEARCH
(2020)
Article
Agriculture, Multidisciplinary
Beth Paganoni, Claire Macleay, Andrew van Burgel, Andrew Thompson
COMPUTERS AND ELECTRONICS IN AGRICULTURE
(2020)
Article
Agriculture, Multidisciplinary
Amy Lockwood, Jason Trompf, Serina Hancock, Lyndon Kubeil, Andrew Thompson, John Young
AGRICULTURAL SYSTEMS
(2020)
Article
Agriculture, Dairy & Animal Science
Andrew N. Thompson, Elise Bowen, John Keiller, Don Pegler, Gavin Kearney, Cesar A. Rosales-Nieto
Summary: Ewe lambs can reach puberty at 7-10 months old and are more fertile if heavier at breeding. The study found that heavier ewes at breeding have higher weaning rates, with a slight decrease after reaching 45 kg. Age at breeding has a linear effect on weaning rates, increasing by 0.4% per day. Increasing liveweight and age at breeding can improve offspring survival rates.
Review
Veterinary Sciences
Mieghan Bruce, John M. Young, David G. Masters, Gordon Refshauge, Andrew N. Thompson, Paul R. Kenyon, Ralph Behrendt, Amy Lockwood, David W. Miller, Caroline Jacobson
Summary: Dystocia contributes to significant lamb and ewe mortality in sheep production in Australia and New Zealand. The financial impacts of dystocia on the Australian sheep industry are substantial, and reducing dystocia through improved genetics and management can lead to improved animal welfare and farm profit.
PREVENTIVE VETERINARY MEDICINE
(2021)
Article
Agriculture, Dairy & Animal Science
Thomas Clune, Amy Lockwood, Serina Hancock, Andrew N. Thompson, Sue Beetson, Angus J. D. Campbell, Elsa Glanville, Daniel Brookes, Colin Trengove, Ryan O'Handley, Gavin Kearney, Caroline Jacobson
Summary: This study provides detailed investigation on abortion and lamb mortality in maiden ewes in Australia. The results show variability in abortion rates and lamb mortality rates among maiden ewe flocks, which significantly contribute to overall lamb losses. Addressing abortion issues may improve reproductive performance in maiden ewe flocks.
Article
Agriculture, Dairy & Animal Science
Dayna Hutchison, Bronwyn E. Clarke, Serina Hancock, Andrew N. Thompson, Elise Bowen, Caroline Jacobson
Summary: The reproductive performance of maiden ewes is poorer than that of multiparous ewes, and the extent and causes of this difference are not well understood in Australian sheep farming. This study compared the reproductive performance of maiden ewes and multiparous ewes on the same farms and found significant differences in lamb marking rate and reproductive success. Strategies to improve reproductive rate and lamb survival can address the suboptimal reproductive performance of maiden ewes.
Article
Agriculture, Dairy & Animal Science
Kirsty Cunningham, Andrew Van Burgel, Khama R. Kelman, Claire M. Macleay, Beth L. Paganoni, Andrew N. Thompson
Summary: Early prediction of lambing dates for ewes can improve their management during pregnancy and lambing. Proximity sensors can be used to measure interactions between ewes and rams during mating, successfully predicting conception and lambing dates. This study demonstrates that proximity sensors are an effective means of predicting lambing dates, which can help improve ewe management and lamb survival.
Article
Agriculture, Dairy & Animal Science
Andrew N. Thompson, Travis Allington, Sarah Blumer, Jo Cameron, Gavin Kearney, Lyndon Kubeil, Amy Lockwood, Jason Trompf, Emma Winslow, Paul Kenyon
Summary: The proportion of triplets among ewes is increasing on sheep farms in Australia due to the use of more fecund genetics and better management practices. A study of sheep producers showed that the mortality rate of triplet-bearing ewes was 6.4%, and the survival rate of triplet-born lambs was 59%. There was variability in the management practices adopted, but no significant differences were found in the mortality rate or lamb survival between different practices. The highest priorities for future research identified by producers were ewe condition score, mob size, feed-on-offer at lambing, and mineral supplementation.
Article
Veterinary Sciences
Tom Clune, Shane Besier, Sam Hair, Serina Hancock, Amy Lockwood, Andrew Thompson, Martina Jelocnik, Caroline Jacobson
Summary: This study investigated the causes of perinatal lamb deaths for lambs born to primiparous ewes in Western Australia. The main causes of death were identified as starvation-mismosthering-exposure, dystocia, and stillbirth. Additionally, a pathogenic strain of Chlamydia pecorum (ST23) was detected in aborted and stillborn lambs on multiple farms.
VETERINARY RESEARCH
(2021)
Article
Veterinary Sciences
S. Hancock, L. Inglis, M. Laurence, D. Miller, A. Thompson
Summary: This study showed that facial action units, activity of the lamb, and time spent with the dam can be used to assess pain in Merino lambs following mulesing, but cannot detect any changes associated with pain relief.
AUSTRALIAN VETERINARY JOURNAL
(2021)
Article
Agriculture, Dairy & Animal Science
S. K. Muir, N. Linden, A. Kennedy, M. Knight, B. Paganoni, G. Kearney, A. N. Thompson, R. Behrendt
SMALL RUMINANT RESEARCH
(2020)
Article
Agriculture, Dairy & Animal Science
S. K. Muir, A. J. Kennedy, G. Kearney, P. Hutton, A. N. Thompson, P. Vercoe, J. Hill
ANIMAL PRODUCTION SCIENCE
(2020)
Review
Agriculture, Dairy & Animal Science
Michael A. Friend, Marie S. Bhanugopan, Shawn R. McGrath, Janelle Hocking Edwards, Serina Hancock, Kate Loudon, David Miller, Peter McGilchrist, Gordon Refshauge, Susan M. Robertson, Andrew N. Thompson, David G. Masters
ANIMAL PRODUCTION SCIENCE
(2020)
Article
Agriculture, Dairy & Animal Science
A. Lockwood, J. Trompf, L. Kubeil, A. Thompson, G. Refshauge, G. Kearney, S. Hancock
ANIMAL PRODUCTION SCIENCE
(2020)