Recent Submissions

  • Protocols and strategies to study the migration of veterinary drug residues into milk and dairy products in licensed trials – Corrigendum

    Power, C.; Sayers, Riona; O'Brien, Bernadette; Furey, A.; Danaher, Martin; Jordan, Kieran (Teagasc (Agriculture and Food Development Authority), Ireland, 2014)
  • A note on the fermentation characteristics of red clover silage in response to advancing stage of maturity in the primary growth Corrigendum

    King, Colman; McEniry, Joseph; O'Kiely, Padraig (Teagasc (Agriculture and Food Development Authority), Ireland, 2014)
  • A note on the effectiveness of selenium supplementation of Irish-grown Allium crops.

    Reilly, Kim; Valverde, Juan; Finn, Leo; Gaffney, Michael; Rai, Dilip K.; Brunton, Nigel (Teagasc (Agriculture and Food Development Authority), Ireland, 2014)
    Onions and other Allium crops contain high levels of dietary phenolics and, unlike many other crops, accumulate the beneficial mineral selenium. Selenium-enhanced Allium crops are of interest both from a public good perspective and as a market positioning strategy for growers. Field trials were carried out to i) identify onion and scallion varieties that contain high levels of health-promoting phenolic and flavonoid compounds as potential targets for selenium supplementation and ii) investigate selenium supplementation in the widely-grown commercial onion variety ‘Hyskin’ at different application rates of nitrogen fertilizer. Levels of selenium in onion bulbs were significantly increased from 0.5–5.9 μg/g dry weight (DW) to 40.6–70.0 μg/g DW.
  • Modelling the exposure to Cronobacter sakazakii by consumption of a cocoa-milk-based beverage processed by pulsed electric fields

    Pina-Perez, M. C.; Guillier, Laurent; Rodrigo, D.; Martinez, A. (Teagasc (Agriculture and Food Development Authority), Ireland, 2014)
    Infants’ exposure (Nf ) to Cronobacter sakazakii via the consumption of infant-rich-inpolyphenols cocoa-milk-based beverages (CCX-M) treated with high-intensity pulsed electric fields (PEF) was evaluated. Monte Carlo simulation enabled the prediction of the variability in C. sakazakii load in beverages at the time of consumption to be estimated. Different scenarios (initial contamination levels; PEF treatment conditions; and time-temperature combinations of CCX-M beverages storage after treatment) were simulated. Cocoa addition and PEF treatment resulted in the most influential input factors to control bacterial final load. Cronobacter spp. exposure risk was reduced by a maximum of 100 times at 95% of iterations due to addition of cocoa at 5 g/100 mL, corresponding to scenario 3 (PEF: 15 kV/cm–3,000 μs; storage 120 h at 8 °C). Moreover, the probability of illness for a healthy population was reduced from 2.15 × 10-8, in the baseline scenario, to 4.78 × 10-10 due to cocoa addition and application of 15 kV/cm–3,000 μs PEF treatment.
  • Influence of extrusion conditions on the colour of millet-legume extrudates using digital imagery

    Chakraborty, S. K.; Singh, D. S.; Kumbhar, B. K. (Teagasc (Agriculture and Food Development Authority), Ireland, 2014)
    Colour acts as one of the triggers for acceptance of snack foods. Digital imaging in conjunction with Adobe Photoshop can help identification of variations in the colour of extruded products. Response surface methodology-based central composite rotatable designed experiments were conducted to understand the colour components and overall acceptability (OAA) of extruded snacks made from millet–legume blends, 12–28% legume, at different moisture content (MC) of 12–24% wet basis (w.b.), extruded at varying die head temperatures (DHT) from 160–200 °C, barrel temperatures from 100–140 °C and screw speeds of 100–140 rpm. A simple digital camera was used for capturing the images of the extrudates. An L*a*b* colour model (where L* is the black/ white element, a* is green/red and b* is blue/yellow) was used for colour characterisation and OAA was determined by a hedonic scale. It was inferred from the analysis of the resulting statistically valid second order models for the responses that all the colour components were significantly affected by the amount of legume in the extruder feed and by the DHT. It was also observed that DHT, synergistically with other processing parameters, had a significant effect on all the responses. The OAA was highest for the extrudates with higher L* values. Optimum processing conditions were derived while the responses adhered to constraints. The responses of the extrudates prepared under optimum conditions exhibited no significant variation from model predicted values.
  • Variogram investigation of covariance shape within longitudinal data with possible use of a krigeage technique as an interpolation tool: Sheep growth data as an example

    Chalh, A.; El Gazzah, M. (Teagasc (Agriculture and Food Development Authority), Ireland, 2014)
    Most quantitative traits considered in livestock evolve over time and several continuous functions have been proposed to model this change. For individual records (longitudinal data), it is evident that measures taken at close dates are generally more related than these further apart in time. Since milk production involves several parities, the covariance structure within this trait has been analysed by time series methodology. However, the covariance structure within traits that are not repeated during life, such as those linked to growth, has not yet been formally modelled by considering time lags as is done in time series analysis. We propose an adaptation of the variogram concept to shape this structure; which gives the possibility of kriging missing data at any particular time. A new parameter, the halftime variogram, has been proposed to characterise the growing potential of a given population. The weight records of a Barbarine male lamb population were used to illustrate the methodology. The variogram covering the whole growth process in this population could be modelled by a logistic equation. To estimate the missing data from birth to 105 days of age, a simple linear interpolation was sufficient since kriging on a linear model basis gives a relatively more accurate estimation than kriging on a logistic model basis. Nevertheless, when both known records around the missing data are distant, a krigeage on the basis of the logistic model provides a more accurate estimation.
  • Is emamectin benzoate effective against the different stages of Spodoptera exigua (Hübner) (Lepidoptera, Noctuidae)?

    Bengochea, I.; Sanchez-Ramos, I.; Saelices, R.; Amor, F.; del Estal, P.; Vinuela, E.; Adan, A.; Lopez, A.; Budia, F.; Medina, P. (Teagasc (Agriculture and Food Development Authority), Ireland, 2014)
    The beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera, Noctuidae), is a major polyphagous pest in greenhouses and open fields worldwide and also a main problem in sweet pepper greenhouses. The effectiveness of the pesticide emamectin benzoate was tested in the laboratory on different stages of S. exigua using different concentrations and uptake routes. After dipping young (<24-h-old) and old (>48-h-old) S. exigua eggs in emamectin benzoate at 0.5, 1 and 1.5 mg/L a.i. the chemical did not exhibit any ovicidal activity. There was, however, progressive neonate mortality at all concentrations, culminating at 72 hours after hatching, when 100% of the larvae from the treated young eggs died. Second and fourth instar S. exigua larvae did not exhibit significant mortality when exposed to the inert surfaces which were treated. In contrast, ingesting a diet contaminated with 0.5 mg/L a.i. of emamectin benzoate caused 100% mortality in L2 and L4 larvae 24 and 72 hours after ingestion, respectively. The LC50 value of the compound against L4 larvae that fed on sprayed sweet pepper leaves for 24 hours was 0.81 mg/L a.i.. When adults were fed on a solution of 0.5 mg/L a.i., there was a reduction in the female and male lifespan of 29.3% and 55.3%, respectively. Fecundity was reduced by more than 99%. These data suggest that emamectin benzoate is not only a useful insecticide when ingested by beet armyworm larvae but it also has ovolarvicidal and adult activity.
  • The effect of water-soluble carbohydrate concentration and type on in vitro rumen methane output of perennial ryegrass determined using a 24-hour batch-culture gas production technique

    Purcell, Peter J; Boland, T.M.; O'Kiely, Padraig (Teagasc (Agriculture and Food Development Authority), Ireland, 2014)
    The objective of this study was to examine the effects of water-soluble carbohydrate (WSC) concentration and type on the in vitro rumen methane (CH4) output of perennial ryegrass (PR) using a 24-hour batch-culture gas production technique. Dried and milled PR was incubated either alone (PR-O) or with added sucrose (PR-S), inulin (PR-I), or sucrose plus inulin (PR-S+I; sucrose:inulin ratio of 1:4) in sealed glass bottles [0.5 g total substrate dry matter (DM) per bottle] at 39 °C for 24 hours with buffered rumen fluid. The WSC types were added (except for PR-O) so that the WSC concentration in each fermentation bottle at the start of the incubation was either 180 (i.e., PR-O), 225, 270, 315, or 360 g/kg of total substrate DM incubated. There were linear decreases in CH4 output per gram of DM disappeared (CH4/ivDMD) and per mmol of total volatile fatty acid output (CH4/tVFA) with increasing WSC concentration in the incubated substrate. The WSC type had no effect on in vitro rumen CH4 output. It is concluded that since CH4/ivDMD and CH4/tVFA were reduced by increasing the concentration of WSC incubated with PR, it would be worthwhile to undertake in vivo experiments to examine these effects on in vivo CH4 emissions per unit of animal product.
  • Effect of concentrate feeding level in winter and turnout date to pasture in spring on biological and economical performance of weanling cattle in suckler beef production systems

    McGee, Mark; Drennan, Michael J; Crosson, Paul (Teagasc (Agriculture and Food Development Authority), Ireland, 2014)
    Three experiments were carried out to determine the effects of supplementary concentrate feeding level (Low, LC; High, HC) to grass silage and/or turnout date to pasture in spring (Early, ET; Late, LT) for a second grazing season on performance to slaughter of spring-born, weaned beef calves (n = 188). Experiment 1 comprised of two concentrate levels (0.5 and 1.5 kg/day). Experiment 2 comprised of two turnout dates (19 March, 9 April). Experiment 3 comprised of two concentrate levels (0.5 kg and 2.0 kg/day) and two turnout dates (22 March, 12 April). In Experiment 1, live-weight gain during the indoor winter period was 25 kg higher (P < 0.001) for HC, whereas during the subsequent grazing season it was 17 kg higher (P < 0.05) for LC resulting in similar (P > 0.05) total live-weight gain for both treatments. In Experiment 2, live weight at turnout to pasture was 11 kg lower (P < 0.001) for ET than LT, whereas 8 days after late turnout, it was 15 kg lower (P < 0.01) for LT than ET. This difference in live weight was still evident 28 days later (P < 0.01) but not (P > 0.05), subsequently. In Experiments 1 and 2, live-weight gain during the finishing period and carcass weight, conformation and fat scores did not differ (P > 0.05) between the treatments. In Experiment 3, at turnout to pasture, HC were 35 kg heavier (P < 0.001) than LC, and ET were 12 kg lighter (P < 0.05) than LT, whereas 8 days after late turnout, ET were 13 kg heavier (P < 0.05) than LT. There was a concentrate level × turnout date interaction (P < 0.05) for live weight at the end of the grazing season, whereby the LC, LT treatment were lighter than the other treatments, which did not differ. Live weight at slaughter and carcass weight did not differ (P > 0.05) between the concentrate levels, whereas they were higher (P < 0.05) for ET than LT. Economic and stochastic analysis of Experiment 3 indicated that, in the context of whole-farm systems, (i) feeding HC was dependent on date of sale such that only where progeny were sold at the start of the second grazing season, net farm margin (NFM) was increased, (ii) ET only increased NFM where progeny were retained through to finish and, (iii) taking progeny through to finish was more profitable than selling earlier in the animals’ lifetime. In conclusion, subsequent compensatory growth at pasture diminishes the growth and economic advantage from concentrate supplementation or early turnout to pasture, of young late-maturing cattle.