Cottle D.J.,SAC |
Cottle D.J.,University of New England of Australia |
Journal of Animal Breeding and Genetics | Year: 2013
The objective of this study was to assess the impact of using different relative economic values (REVs) in selection indices on predicted financial and trait gains from selection of sires of cows and on the choice of leading Holstein bulls available in the UK dairy industry. Breeding objective traits were milk yield, fat yield, protein yield, lifespan, mastitis, non-return rate, calving interval and lameness. Relative importance of a trait, as estimated by a.h2, was only moderately related to the rate of financial loss or total economic merit (ΔTEM) per percentage under- or overestimation of REV (r=0.38 and 0.29, respectively) as a result of the variance-covariance structure of traits. The effects on TEM of under- or overestimating trait REVs were non-symmetrical. TEM was most sensitive to incorrect REVs for protein, fat, milk and lifespan and least sensitive to incorrect calving interval, lameness, non-return and mastitis REVs. A guide to deciding which dairy traits require the most rigorous analysis in the calculation of their REVs is given. Varying the REVs within a fairly wide range resulted in different bulls being selected by index and their differing predicted transmitting abilities would result in the herds moving in different directions in the long term (20years). It is suggested that customized indices, where the farmer creates rankings of bulls tailored to their specific farm circumstances, can be worthwhile. © 2012 Blackwell Verlag GmbH.
Bley T.,SAC |
Kyriazakis I.,Cherry Valley Farms Ltd |
Howie J.A.,University of Thessaly |
Tolkamp B.J.,University of Thessaly
British Poultry Science | Year: 2010
1. This study is the first to quantitatively compare the structure of feeding behaviour of broilers, ducks and turkeys as recorded by electronic feeders. It tests the hypothesis that this structure is so similar that the same models would be suitable to group the feeding behaviour of these species into meals. Visits to electronic feeders were recorded from 3470 broilers, 3314 turkeys and 480 ducks. The frequency distributions of the length of short intervals between visits to feeders varied between species as a result of differences in the number of visits within a feeding bout, the frequency of re-visits to the same feeder and probably in the likelihood of birds drinking within meals. The lengths of longer day-time intervals between visits to feeders were all log-normally distributed. Disaggregation of these intervals by feeding strategy (meal frequency) showed that the probability of birds starting to feed increased with time since feeding last in all species, which is consistent with the satiety concept. Two methods, one based on fitting a truncated log-normal, function, the other on observed changes in the probability of birds starting to feed with time since last feeding, gave very similar meal criteria estimates. These ranged from 1050 to 1200 s in broilers, 1650 to 1725s in ducks and 1250 to 1320 s in turkeys. There were large between-species differences in the average number of daily meals, intake per meal, and feeding rate. Despite this variation, the overall structure of feeding behaviour of broilers, ducks and turkeys was so similar that the same models were suitable for application in all three species. This would allow for standardised analyses of feeding behaviour of different avian species kept in different husbandry systems. © 2010 British Poultry Science Ltd.
Howie J.A.,SAC |
Avendano S.,Aviagen |
Tolkamp B.J.,SAC |
Kyriazakis I.,Northumbria University
Poultry Science | Year: 2011
Current selection goals in broiler breeding focus on the improvement of live performance traits, such as feed intake, BW, and feed conversion ratio (FCR). The use of electronic feeders allows measurement of feed intake of individuals housed in groups as well as the identification of different feeding behaviors. Feed intake can thus be split into underlying feeding behavior traits, allowing the estimation of genetic correlations and assessment of the genetic consequences of selecting for performance traits on feeding behavior traits. To investigate the genetic relationships between performance traits and feeding behavior, data of visits to feeders by birds from 4 lines of broilers that differed in selection focus on growth and FCR were analyzed. Visits were recorded electronically and grouped into meals using an existing model for estimating meal criteria. Mean individual feeding behavior traits were then calculated across the entire test period (2 to 5 wk of age). Records were available for between 14,000 and 18,000 birds/line. Analyzed feeding behavior traits were meals per day, meal size, visits per meal, meal duration, nonfeeding time in meal, time feeding per day, proportion of meal spent feeding, feeding rate, and ADFI. Analyzed performance traits were 35-d BW, total feed intake over the entire test period, and FCR. All feeding behavior traits showed moderate to high heritabilities (0.24 to 0.57) but low genetic correlations with performance traits (-0.20 to 0.18), except for ADFI, which was moderately correlated with total intake on test (0.57) and highly correlated with FCR (0.91). The low genetic correlations indicate that the difference in selection intensity among lines for these performance traits has had limited effect on feeding behavior. Different feeding strategies that would result in favorable breeding values for FCR were identified, adding opportunities for further improvements in feed efficiency within and across environments. © 2011 Poultry Science Association Inc.
Newton A.C.,Scottish Crop Research Institute |
Gravouil C.,Scottish Crop Research Institute |
Annals of Applied Biology | Year: 2010
The phyllosphere is a rich and varied microbial community comprising organisms with diverse functional types. Its composition is strongly influenced by both genotypic and environmental factors, many of which can be manipulated by breeding, agronomy and crop protection strategies in an agricultural context. These factors also affect the complex interactions between the microbes, which in turn affect their interaction with their host plant. Whether or not an organism becomes pathogenic and the subsequent expression of disease are also influenced by all these factors. Understanding the population dynamic balance between the organisms of the phyllosphere as an ecological system should lead to new approaches in agronomy, crop protection and breeding that enhance sustainability, where the previously presumed requirement to eliminate putative pathogens is replaced by management that favours dominance of beneficial organisms and contains putative pathogens in asymptomatic or stable states. © 2010 Association of Applied Biologists.
Mehta U.S.,Nirma University |
Devashrayee N.M.,Nirma University |
Proceedings - IEEE Annual Symposium on VLSI, ISVLSI 2010 | Year: 2010
The data compression of any partially specified test data depends upon how the unspecified bits are filled with 1s and 0s. In this paper, the five different approaches for don't care bit filling based on nature of runs are proposed. These methods are used here to predict the maximum compression based on entropy relevant to different run length based data compression code. These methods are also analyzed for test power and area overhead corresponding to run length based codes. The results are shown with various ISCAS circuits. © 2010 IEEE.
Pappa V.A.,SAC |
Rees R.M.,SAC |
Walker R.L.,SAC |
Baddeley J.A.,SAC |
Agriculture, Ecosystems and Environment | Year: 2011
The effects of cereal legume intercropping on nitrogen dynamics and losses from an arable rotation are reported. The main hypotheses were that: (a) intercrops can reduce nitrous oxide (N2O) emissions relative to those from cereal monocrops; (b) the choice of legume cultivars can change N losses from a system and also influence soil available-N. Two field experiments were established in the east of Scotland. The treatments in 2006 consisted of either component monocrops (barley, oat, pea or clover) or cereal-legume intercrops. Spring oats were planted in 2007 and perennial ryegrass in 2008 on both sites. Nitrate leaching was reduced under legume intercrops when compared with the barley monocrop (cumulative values of 0.67 and 3.80kg NO3 --Nha-1, respectively) in 2006. Nitrous oxide losses were significantly different between the treatments and especially the two barley/pea cultivar (cumulative values of 6.02 and 2.14kg N2O-Nha-1 for intercrops cv. Nitouche and cv. Zero 4, respectively) in 2006. The leguminous intercrops increased the soil available-N during the first growing season and in the subsequent crop. Thus intercrops may reduce N losses and this work highlights the need to choose suitable cultivars, taking into account the effects upon the growth of the main crop and the wider environment effects. © 2011 Elsevier B.V.
Rooke J.A.,SAC |
Flockhart J.F.,SAC |
Journal of Agricultural Science | Year: 2010
A possible outcome of policies designed to reduce obesity in the human population and to mitigate greenhouse gas (GHG) emissions may be a decrease in human consumption of livestock products. However, livestock products currently make substantial contributions to intakes of specific micro-nutrients. Therefore, the present review examines the potential for increasing micro-nutrient concentrations of milk, muscle meats and eggs by nutritional and genetic means. Of the trace elements, copper (Cu), iron (Fe) and zinc (Zn) concentrations were largely resistant to manipulation by dietary means, but iodine (I) and selenium (Se) could be readily manipulated. Similarly, while α-tocopherol concentrations were readily manipulated, responses to dietary supplementation with retinol, folate and cobalamin were lower and riboflavin was resistant to dietary manipulation. There were differences between products in the ease with which composition could be manipulated: egg concentrations were most responsive followed by milk and muscle meats. However, livestock products with increased micro-nutrients concentrations can supply a substantial proportion of the daily reference nutrient intake. Copyright © 2010 Cambridge University Press.
Rees R.M.,SAC |
Soil Use and Management | Year: 2010
Between 1990 and 2008, Soil Use and Management has published around 42 articles which have dealt with nitrous oxide (N2O) emissions from soils. The importance of this subject to readers of the journal has increased rapidly in recent years. A substantial number of these papers have appeared in two supplements. These were 'Soils and the Greenhouse Effect', vol. 13 (4) and 'Soils as Carbon Sinks', vol. 20. The number of annual citations of articles on N2O in the journal has risen from zero in the early 1990s to 160 per year in 2008. In this article, we have highlighted some of the more important papers on N2O that have been published by Soil Use and Management, and explain how they have helped advance our understanding of the role that soil management plays in influencing N2O emissions. © 2010 The Authors. Journal compilation © 2010 British Society of Soil Science.
Computers and Electronics in Agriculture | Year: 2011
A virtual fence can be defined as a structure serving as an enclosure, a barrier, or a boundary without a physical barrier. The concept of virtual fencing occurs increasingly in discussions wherever free-ranging livestock is managed. It is especially interesting because of its potential to initially enhance ecological management, improve management by turning manual labour into cognitive labour as well as improve the life-style of livestock managers. All of these have the potential to reduce costs. Moreover, it opens up the possibility of managing areas that are not manageable at the moment. Therefore, a patent and literature search was conducted to investigate what virtual fencing involves, what opportunities there are for implementing it and what issues still need to be tackled. It was found that there are many different approaches in the development of virtual fencing, which can be split into three categories: first, to contain animals in a defined area or keep them out of a defined area using devices that are animal-borne; second, to contain animals without mounting a device onto the animal; and third, keeping animals apart with a moving fence line or using a virtual fence as a remote gathering device. The first two categories deal with static control of livestock, whereas the third category could be described as a control within moving boundaries. However, despite many patents having been found, only very few products are available on the market. Two important development areas are the energy use of the device and provision of a system that animals can easily understand, in order to assure welfare standards. The paper critically analyses the wide range of developments to date and points out the advantages and challenges virtual fencing offers. It also provides an indication of how far we are from a marketable product. © 2010 Elsevier B.V.
McVittie A.,SAC |
Moran D.,SAC |
Regional Studies | Year: 2010
MCVITTIE A., MORAN D. and ELSTON D. Public preferences for rural policy reform: evidence from Scottish surveys, Regional Studies. Agricultural reform across the European Union has focused debate on how agriculture delivers wider rural objectives. The authors undertook economic valuation and multicriteria studies to explore public preferences for rural policy. The results suggest simultaneous preferences for both environmental and social benefits, notably locally grown food, water quality, wildlife habitats, and maintaining rural communities. The public assigned greatest weight to locally grown food, which is closely linked to them as a direct use and is also routinely transacted for. The multicriteria study yielded a different preference ordering potentially arising from the differing elicitation methods indicating a possible drawback of the approach employed. © 2010 Regional Studies Association.