Bell M.J.,University of Nottingham |
Garnsworthy P.C.,University of Nottingham |
Stott A.W.,SRUC |
Pryce J.E.,Australian Department of Primary Industries and Fisheries |
Pryce J.E.,Futures Cooperative Research Center
Journal of Agricultural Science | Year: 2015
The aim of the present study was to compare the effect of changing a range of biological traits on farm profit and greenhouse gas (GHG) emissions (expressed as carbon dioxide equivalent, CO2-eq.) in the UK dairy cow population. A Markov chain approach was used to describe the steady-state herd structure of the average milk-recorded UK dairy herd, as well as to estimate the CO2-eq. emissions per cow, and per kilogram of milk solids (MS). Effects of changing each herd production and fitness trait by one unit (e.g. 1 kg milk; 1% mastitis incidence) were assessed, with derived values for change in profit (economic values) being used in a multi-trait selection index. Of the traits studied, an increase in survival and reductions in milk volume, live weight, residual feed intake, somatic cell count, mastitis incidence, lameness incidence and calving interval were traits that would be both profitable and reduce CO2-eq. emissions per cow and per kg MS of a dairy herd. A multi-trait selection index was used to estimate the annual response in production and fitness traits and the economic response, with an estimate of annual profit per cow from selection on multiple traits. Milk volume, milk fat and protein yield, live weight, survival and dry matter intake were estimated to increase each year and body condition score, residual feed intake, somatic cell count, mastitis incidence, lameness incidence and calving interval were estimated to decrease, with selection on these traits estimated to result in an annual increase of 1% per year in GHG emissions per cow, but a reduction of 0.9% per unit product. Improved efficiencies of production associated with a reduction in milk volume (and increasing fat and protein content), live weight and feed intake (gross and metabolic efficiency, respectively), and increase in health, fertility and overall survival will increase farm annual profit of UK dairy systems and reduce their environmental impact. Copyright © 2014 Cambridge University Press.
Ekanayake P.N.,La Trobe University |
Ekanayake P.N.,Futures Cooperative Research Center |
Hand M.L.,La Trobe University |
Hand M.L.,Futures Cooperative Research Center |
And 6 more authors.
Crop Science | Year: 2012
A number of pasture and turf grass species form mutually beneficial symbiotic associations with endophytic fungal species. Within the fescue grasses, diploid meadow fescue (Festuca pratensis Huds.) interacts with Neotyphodium uncinatum while allohexaploid tall fescue (Festuca arundinacea Schreb.) has been reported to associate with Neotyphodium coenophialum and two other morphologically distinct taxa (Festuca arundinacea taxonomic groups 2 and 3 [FaTG-2 and FaTG-3]). The evolutionary history of hexaploid tall fescue is complex, as part of a species group with varying ploidy levels and exhibiting distinct ecogeographical morphotypes. To evaluate both naturally occurring variation and host grass taxon specificity, diversity was determined in collections representing multiple meadow fescue and tall fescue accessions. Initial screening with a minimal set of endophytespecific simple sequence repeat (SSR) genetic markers detected endophyte incidence in 33% of 701 tested accessions. Subsequent analysis identified N. coenophialum genotypes within Continental and rhizomatous hexaploid and octoploid tall fescue [F. arundinacea subsp. atlantigena (St.-Yves) Auquier] accessions. Festuca arundinacea taxonomic group 2 and FaTG-3 endophytes appeared to be restricted to Mediterranean hexaploid and decaploid tall fescue [F. arundinacea cirtensis (St.-Yves) Gamisans] hosts. Endophytes of meadow fescue were confirmed as belonging to N. uncinatum. This study has elucidated host specificity of fescue endophyte taxa and supported models for host-symbiont coevolution. A substantial number of candidate novel endophytes have been identified that are suitable for metabolic characterization and deployment by inoculation in fescue breeding programs. © Crop Science Society of America.