Pinares-Patino C.S.,Agresearch Ltd.
Animal : an international journal of animal bioscience | Year: 2013
The objective of this study was to determine the genetic parameters of methane (CH4) emissions and their genetic correlations with key production traits. The trial measured the CH4 emissions, at 5-min intervals, from 1225 sheep placed in respiration chambers for 2 days, with repeat measurements 2 weeks later for another 2 days. They were fed in the chambers, based on live weight, a pelleted lucerne ration at 2.0 times estimated maintenance requirements. Methane outputs were calculated for g CH4/day and g CH4/kg dry matter intake (DMI) for each of the 4 days. Single trait models were used to obtain estimates of heritability and repeatability. Heritability of g CH4/day was 0.29 ± 0.05, and for g CH4/kg DMI 0.13 ± 0.03. Repeatability between measurements 14 days apart were 0.55 ± 0.02 and 0.26 ± 0.02, for the two traits. The genetic and phenotypic correlations of CH4 outputs with various production traits (weaning weight, live weight at 8 months of age, dag score, muscle depth and fleece weight at 12 months of age) measured in the first year of life, were estimated using bivariate models. With the exception of fleece weight, correlations were weak and not significantly different from zero for the g CH4/kg DMI trait. For fleece weight the phenotypic and genetic correlation estimates were -0.08 ± 0.03 and -0.32 ± 0.11 suggesting a low economically favourable relationship. These results indicate that there is genetic variation between animals for CH4 emission traits even after adjustment for feed intake and that these traits are repeatable. Current work includes the establishment of selection lines from these animals to investigate the physiological, microbial and anatomical changes, coupled with investigations into shorter and alternative CH4 emission measurement and breeding value estimation techniques; including genomic selection.
McDowell R.W.,Agresearch Ltd.
Current Opinion in Biotechnology | Year: 2012
Phosphorus loss from land, due to agricultural intensification, can impair water quality. The quantity lost is a function of runoff and availability, which is affected by inputs and the ability of the soil to retain P. Losses are exacerbated if surface runoff or drainage occurs soon after P inputs (e.g. fertiliser and/or manure and dung). Strategies to mitigate P losses depend on the farming system. The first step is to maintain a farm P balance (inputs-outputs) close to zero and the agronomic optimum. The next step is to use mitigation strategies in areas that lose the most P, but occupy little of the farm or catchment's area. Focusing on these areas, termed critical source areas, is more cost-effective than farm or catchment-wide strategies. However, the worry is that mitigation strategies may not keep pace with losses due to increasing intensification. Therefore, a proactive approach is needed that identifies areas resilient to P inputs and unlikely to lose P if land use is intensified. © 2012 Elsevier Ltd.
Farouk M.M.,Agresearch Ltd.
Meat Science | Year: 2013
The worldwide volume and value of trade in halal and kosher meat and co-products are huge. Muslim countries alone consumed meat estimated to be worth USD 57.2. billion in 2008. The halal and kosher principles that govern the production of red meat have many similarities, as well as some fundamental differences. Perhaps the most significant difference is that at the time of slaughter, the animal needs only to be alive to meet the minimum halal requirement, but must be both alive and conscious for kosher. It is for this reason that reversible pre-slaughter stunning is acceptable only for halal meat, although a compromise form of post-slaughter stunning is now considered kosher in some countries. Extensive research on animal physiology and welfare has characterised and optimised the methods for stunning livestock, and enabled advancement in associated technologies. This forms the basis for harmonising the religious and secular requirements for the protection of animal welfare at slaughter. These technologies and the associated processing practices for the industrial production of halal and kosher meat are reviewed in this paper. © 2013 Elsevier Ltd.
McDowell R.W.,Agresearch Ltd.
Science of the Total Environment | Year: 2014
Managing phosphorus in catchments is central to improving surface water quality, but knowing how much can be mitigated from agricultural land, and at what cost relative to a natural baseline (or reference condition), is difficult to assess. The difference between median concentrations now and under reference was defined as the anthropogenic loss, while the manageable loss was defined as the median P concentration possible without costing more than 10% of farm profitability (measured as earnings before interest and tax, EBIT). Nineteen strategies to mitigate P loss were ranked according to cost (low, medium, high, very high). Using the average dairy and drystock farms in 14 grassland catchments as test cases, the potential to mitigate P loss from land to water was then modelled for different strategies, beginning with strategies within the lowest cost category from best to least effective, before applying a strategy from a more expensive category. The anthropogenic contribution to stream median FRP and TP concentrations was estimated as 44 and 69%, respectively. However, applying up to three strategies per farm theoretically enabled mitigation of FRP and TP losses sufficient to maintain aesthetic and trout fishery values to be met and at a cost <. 1% EBIT for drystock farms and <. 6% EBIT for dairy farms. This shows that defining and acting upon the manageable loss in grassland catchments (with few point sources) has potential to achieve a water quality outcome within an ecological target at little cost. © 2013 Elsevier B.V.
Otter D.E.,Agresearch Ltd.
British Journal of Nutrition | Year: 2012
Amino acids (AA) are essential nutritional components of a balanced diet and occur in foods in either the free AA form or as the building blocks of proteins. The analysis of AAs in foods is composed of a number of unit operations; the release of the AAs from the food matrix, the separation of the individual AAs and their quantification using calibration standards. Each of these steps has their own idiosyncrasies, e.g. different hydrolysis conditions are required for the optimal release of different AAs and there are a diverse number and type of food matrices, such that most laboratories adapt methods to best suit their applications. There is currently no official standardised method for AA analysis, although the Association of Analytical Communities (AOAC) has validated methods for a number of individual AA components. The established analytical techniques of HPLC (ion exchange or reversed phase) and GC-MS have recently been supplemented by a number of new methods. These include capillary electrophoresis MS and Ultra HPLC-MS, and LC with other detectors. This review will address the intricacies and concerns of the protein hydrolysis step, discuss what specifications or prerequisites need to be placed on the existing and new methods and laboratories using these methods, comment on whether one method can successfully satisfy the exacting requirements of the various unit operations, and finally pose the question. Is there any merit in "developing" a validated (e.g. AOAC) official method of analysis for AAs in food?" © 2012 The Author.