2,099 research outputs found
Urea applied to puccinellia-based pastures increases pasture and sheep production
No full textM.L. Hebart, N.J. Edwards, A.D. Craig, EA. Abraham, JD. McFarlane and JE. Hocking Edwardshttp://www.wageningenacademic.com/igcpaper
Post-weaning weight is highly genetically correlated to adult ewe weights
No full textS. F. Walkom, F. D. Brien, M.L. Hebart, N. M. Fogarty, S. Hatcher and W. S. Pitchfor
Genetic trends achieved under industry control for different selection strategies in Australian Merinos
No full textThe Australian Selection Demonstration Flock (SDF) project was established under industry directive to publicise alternative selection strategies for Australian Merino sheep. Three selection lines under industry control have used different degrees of objective and subjective techniques to reduce mean fibre diameter whilst maintaining or improving clean fleece weight and body weight. Genetic trends reveal relative advantages and limitations for each selection line, although communication amongst the wool industry factions has been the primary benefit of the SDF project. Producer involvement has ensured industry relevance and improved understanding of alternative breeding practices within the wool industry.K.E. Kemper, Hebart, M.L., Brien, F.D., Jaensch, K.S., Smith, D.H. and Grimson, R.J
Realtà, realismo, straniamento : Auerbach e il romanzo cavalleresco fino a Cervantes
No full textAuerbach’s research, besides exploring the three main fields the author explicitly names (i.e. the succession of different and differently grounded forms of realism in literary fiction, the alternate splitting and melting of styles, the link between literary work and a Christian vision of the world), in various chapters of Mimesis, and particularly in chs. 2, 6, 12, 14 and 20, is also focused, albeit only implicitly, on the developments of a further distinctive feature in Western literature, which is the emergence of subjectivity in the representation of reality. Focusing mainly on the chapter on courtly romance (ch. 6) and on the Quijote (ch. 14), this essay will examine Auerbach’s interpreting work on texts that adopt, in different ways, a ‘subjective point of view’; this kind of interpretation is, in part, unexpectedly similar to the approach of other critics and theorists of literature contemporary to Auerbach, like Bachtin, Américo Castro and Viktor Šklovskij
Shedding light on the black hole: The roll-out of broadband access networks by private operators
No full textSeveral market studies have indicated that the roll-out of broadband has significant economic and social relevance. The investments in broadband infrastructures needed to realise these economic and social benefits are, however, high-risk. This is firstly caused by the fact that the roll-out of access networks is extremely costly and requires high initial investments. Moreover, the multidisciplinary environment and involvement of many actors with diverging objectives and interests cause high complexity. Moreover, the market for broadband is changing fast and continuously. Although broadband has been on the academic research agenda for quite some time, this has as yet not resulted in a structured insight into the decision-making process around the upgrading of broadband networks, seen from the perspective of private operators and taking into account the vast complexity of the surroundings in which this decision-making process takes place in. The objective of this research was to provide a unifying theory combining technical, economic, market-related and regulatory factors with regard to an evolutionary, flexible approach of network upgrading from a decision-maker perspective. The result of this research is a robust, explanatory, parsimonious model for the impact and outcomes of broadband roll-out. This model provides a certain degree of stability in this multidisciplinary, unpredictable and highly dynamic research field.Technology, Policy and Managemen
Genetic relationships among yearling fertility, body composition and weight traits in tropically adapted composite cattle
No full textPublished: 6 April 2023Context. Reproduction is an economically important trait in both males and females; however, the relationships between fertility and body composition traits are little researched, but essential to breeding programs, as they will help inform selection decisions and allow the greatest opportunity for genetic gain. Aims. Estimate genetic and phenotypic correlations between male and female yearling fertility traits and investigate their relationship with yearling body composition traits, which have an effect on the attainment of puberty. Methods. Genotype and phenotype data were obtained from a tropical composite commercial cattle population and imputed to 27 638 single nucleotide polymorphisms. A series of univariate and bivariate linear mixed models using a genomic relationship matrix were run to estimate genetic parameters, genetic and phenotypic correlations for a series of male and female fertility and body composition traits. These parameters were then compared to help understand the genetic relationships. Key results. Scrotal circumference was favourably genetically correlated with weight (0.34), fat traits (0.06–0.24), muscle (0.24) and heifer days to calving (−0.32). Heifer days to calving was favourably correlated with muscle (−0.18) but not fat traits (0.11 to 0.21). The genetic correlations between heifer days to calving and sperm morphology traits were generally unfavourable (−0.32 to 0.25). Sperm morphology traits were favourably genetically correlated with fat traits (−0.84 to 0.31) and muscle (−0.61 to 0.31) but not weight (−0.15 to 0.09). Conclusions and implications. Yearling sperm morphology traits were unfavourably correlated with heifer days to calving, indicating that they are not good candidates for indirect selection on improving female fertility in the herd. A different trend was found for yearling scrotal circumference and heifer days to calving, identifying it as a good candidate for indirect selection of heifer fertility as it is easy to measure and heritable. The genetic correlations estimated between composition traits with male and female fertility traits allow breeding programs to make an informed selection decision to optimise genetic gain across all traits.M.L. Facy, M.L. Hebart, H. Oakey, R.A. McEwin and W.S. Pitchfor
Selection demonstration flocks - What have we learnt?
No full textproject are presented. Long-term responses to selection are also discussed. Established along with an unselected control flock (CON) in 1996, the original three selection flocks emphasise use of either measured performance (MPR), professional classer assessment (PCA) or an elite wool or ‘soft rolling skin’ approach (EWF). A Meat Merino flock was added in 1999 (FM+). All SDFs are outperforming the CON. Commencing with the 2001-drop, considerable divergence between the selection flocks was observed for mean fibre diameter and fleece weight; since that time divergence in mean fibre diameter has not increased, whereas the MPR, EWF and PCA flocks have tended to converge again for fleece weight. Most of the initial advantage in 16-month live weight in the FM+ flock over the CON has been retained in later years, whilst achieving small increases in fleece weight and maintaining a lower mean fibre diameter.F.D. Brien, K.S. Jaensch, R.J. Grimson, K.E. Kemper, D.H. Smith, M.L. Hebart and A.M.M. Ramsa
Meat quality in merino ram hoggets
No full textGenetic, environmental and management effects on meat pH and colour and their relationship with other production traits were estimated from pooled data based on carcase measurements from 5870 Merino hogget rams from New South Wales, South Australia and Western Australia. Principal component analyses failed to generate a trait which would be superior to the direct use of meat pH and colour as criteria in selection against dark cutting meat. No genetic or environmental links were found between dark cutting and production traits that could provide a causative effect or potential for indirect selection. In addition to parameter estimates, the contribution of various sources of variation for meat pH and colour have been quantified and the implications of the findings are discussed.S. F. Walkom, F.D. Brien, M.L. Hebart, J.C. Greeff, D.L. Hopkins and W.S. Pitchfor
Partitioning genetic variance in composite sheep
No full textAustralian sheep producers have been moving towards an increased use of composite crossbred ewes to achieve higher performance and greater genetic gain, taking advantage of the high value lamb market. Sheep research has traditionally been carried out on purebred flocks or their first and second crosses with replication and uniformity of breed types within the data. Within composite lines, the breed combinations are often complex, with multiple breeds in variable proportions with few sheep per breed combination. To enable estimation of between and within breed genetic effects, the analysis performed in our study included both additive and dominance genetic effects at the breed level. Breed additive effects contributed to 1.3% of the variation in weight. The variance associated with breed dominance effects were significant for both weight and height (10 and 5%). Results from this analysis on the small sub set are promising, and suggest the model will account for breed effects when a larger composite sheep data set is analysed.S.F. Walkom, A.P. Verbyla, F.D. Brien, M.L. Hebart and W.S. Pitchfordhttp://www.aaabg.org/aaabg19/?conference19=19th+AAABG+Conference+201
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