• Gains in dry matter yield and herbage quality from breeding perennial ryegrass

      Wilkins, P.W.; Lovatt, J.A. (Teagasc (Agriculture and Food Development Authority), Ireland, 2011)
      During the last 100 years, in Western Europe and elsewhere, considerable effort has been devoted to improving perennial ryegrass (Lolium perenne L.) for agriculture. The first persistent cultivars to be widely used were more digestible than other common pasture species but were no higher yielding than the better wild populations of perennial ryegrass. Two main approaches (here called mainstream breeding and population improvement) have been used to further improve the species for the UK, but no recent experiments to assess progress have been published. In 2006, two plot trials were established at IBERS to compare the performance of some newer cultivars and candidate varieties with the first persistent cultivars to be widely used in the UK. One trial involved comparing 10 intermediate-heading (6 diploid and 4 tetraploid) cultivars and candidate varieties with the intermediate-heading cv. Talbot, and the other involved comparing 11 late-heading (4 diploid and 7 tetraploid) cultivars and candidate varieties with the late-heading cv. S23. During 2007 to 2009, one silage cut and 6 other cuts were harvested each year, annual dry matter (DM) yields were determined and DM samples analysed for in vitro DM digestibility (DMD), water soluble carbohydrate (WSC) and crude protein (CP) concentrations in the DM. Percentage ground covered by perennial ryegrass in November 2009 was estimated visually. Twenty of the 21 cultivars were significantly (12 to 38%) higher yielding, 15 were significantly (10 to 27 g/kg) higher in mean DMD, 15 were significantly (25 to 58 g/kg) higher in mean WSC and 7 (all diploids) were significantly higher in ground cover in autumn of the third harvest year than their respective control cultivars. There were no significant differences among the varieties in mean CP over all harvests. The newest intermediate-heading cultivar (the diploid Abermagic) produced 29% more DM, was 10 g/kg higher in DMD and 51 g/kg higher in WSC, and had significantly better ground cover at the end of the third harvest year than Talbot. The newest late-heading cultivar (the tetra-ploid Aberbite) produced 28% more DM than S23 and was 22 g/kg higher in DMD and 58g/kg higher in WSC, although it was similar to S23 for ground cover at the end of the third harvest year. Both of these new varieties were developed entirely or partly by population improvement at IBERS over 26 years (1980 to 2005). These results suggest that the rates of gain in DM yield under nitrogen-limiting conditions and in herbage WSC concentration from perennial ryegrass breeding can be improved by utilizing new technologies and better breeding strategies.
    • Genetic relationships among linear type traits, milk yield, body weight, fertility and somatic cell count in primiparous dairy cows

      Berry, Donagh P.; Buckley, Frank; Dillon, Pat; Evans, Ross D; Veerkamp, R. F. (Teagasc (Agriculture and Food Development Authority), Ireland, 2004)
      Phenotypic and genetic (co)variances among type traits, milk yield, body weight, fertility and somatic cell count were estimated. The data analysed included 3,058 primiparous spring-calving Holstein-Friesian cows from 80 farms throughout the south of Ireland. Heritability estimates for the type traits varied from 0.11 to 0.43. Genetic correlations among some type traits were very strong and may indicate the possibility of reducing the number of traits assessed on each animal; the genetic correlation between angularity and body condition score was –0.84. Genetic correlations between all type traits (except body condition score, udder depth and teat length) and milk yield were positive and ranged from 0.08 to 0.69. The possibility of selecting for body weight may be achievable within a national progeny-testing programme using type traits within a selection index. Moderate to strong genetic correlations existed between some type traits and the various fertility measures and somatic cell count indicating the opportunity of indirect selection for improved fertility and health of animals using type traits within a selection index; however, the standard errors of some of the genetic correlations were large and should thus be treated with caution. Genetically taller, wider, deeper, more angular cows with tighter, stronger, shallower udders were predisposed to have inferior pregnancy rates to first service and require more services.
    • Genetic relationships among linear type traits, milk yield, body weight, fertility and somatic cell count in primiparous dairy cows

      Berry, Donagh P.; Buckley, Frank; Dillon, Pat; Evans, Ross D; Veerkamp, Roel F (Teagasc (Agriculture and Food Development Authority), Ireland, 2004)
      Phenotypic and genetic (co)variances among type traits, milk yield, body weight, fertility and somatic cell count were estimated. The data analysed included 3,058 primiparous spring-calving Holstein-Friesian cows from 80 farms throughout the south of Ireland. Heritability estimates for the type traits varied from 0.11 to 0.43. Genetic correlations among some type traits were very strong and may indicate the possibility of reducing the number of traits assessed on each animal; the genetic correlation between angularity and body condition score was –0.84. Genetic correlations between all type traits (except body condition score, udder depth and teat length) and milk yield were positive and ranged from 0.08 to 0.69. The possibility of selecting for body weight may be achievable within a national progeny-testing programme using type traits within a selection index. Moderate to strong genetic correlations existed between some type traits and the various fertility measures and somatic cell count indicating the opportunity of indirect selection for improved fertility and health of animals using type traits within a selection index; however, the standard errors of some of the genetic correlations were large and should thus be treated with caution. Genetically taller, wider, deeper, more angular cows with tighter, stronger, shallower udders were predisposed to have inferior pregnancy rates to first service and require more services.
    • Genetics of reproductive performance in seasonal calving dairy cattle production systems

      Berry, Donagh P.; Kearney, J. F.; Twomey, K.; Evans, R. D. (Teagasc (Agriculture and Food Development Authority), Ireland, 2013)
      Profitable seasonal calving dairy production systems require a cow that will establish pregnancy early in the breeding season implying a quick return to service post-calving and good pregnancy rates. Genetic selection provides an opportunity to achieve this goal so therefore the objective of this study was to estimate the necessary genetic parameters for fertility traits, pertinent to seasonal calving herds, in order to facilitate genetic selection for fertility. The data, following editing, consisted of parity 1 to 3 records on up to 397,373 Holstein-Friesian dairy cows in Ireland. Variance components for the defined interval fertility traits (age at first calving, calving to first service interval, calving interval), binary fertility traits (submission rate in the first 21 days of the breeding season, pregnant to first service, pregnant in the first 42 days of the breeding season, calved in the first 42 days of the calving season) and the count fertility trait (number of services) were estimated using univariate animal models and covariances among traits were estimated using bivariate sire models. Heritability estimates of the nine fertility traits (including age at first calving and survival) varied from 0.01 to 0.07 within parity one to three. The coefficient of genetic variation for the fertility traits varied from 3.3% to 15.3%. Calving to first service interval, within parity, was moderately positively genetically correlated (0.54 to 0.75) with calving interval and was, in general, moderately negatively correlated with both submission rate (-0.68 to -0.29) and pregnant in the first 42 days of the breeding season (-0.36 to -0.14). Calving interval was moderately positively correlated (0.24 to 0.68) with number of services. Irrespective of parity, the genetic correlations between calving interval with calving in the first 42 days of the calving season, and submission rate with pregnant in the first 42 days of the breeding season were all negative. The genetic correlations among calving in the first 42 days of the calving season, submission rate and pregnant in the first 42 days of the breeding season were all positive. All fertility traits were generally antagonistically genetically correlated with lactation milk yield, but most were moderate to strongly favourably correlated with survival to the next lactation. This study provides the necessary genetic parameters to undertake national genetic evaluations for fertility to help achieve the fertility targets in seasonal calving herds.
    • Grain yield reductions in spring barley due to barley yellow dwarf virus and aphid feeding

      Kennedy, T.F.; Connery, J. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
      The occurrence and control of barley yellow dwarf virus (BYDV) in spring barley was investigated, at Oak Park, in the periods 1990 to 1993 and 1996 to 2001. Barley was sown in March and April and treated with either organophosphorous or pyrethroid aphicide at various plant growth stages. The most common aphid encountered was Sitobion avenae and MAV the most common strain of BYDV. In untreated plots of March- and April-sown barley, 0.85% and 5.9%, respectively, of tillers had virus symptoms. Best control of symptoms, from a single aphicide in March- and April-sown crops, was a treatment at growth stage (g.s.) 14. This treatment contributed 77% of the reduction in symptoms recorded for multiple treatments in April-sown plots. The reduction in grain yield due to high, moderate and low BYDV infection in April-sown barley was 1.1 t/ha (20%), 0.65 t/ha (10%) and 0.36 t/ha (7%), respectively. In Marchsown barley, pyrethroid aphicide applied at g.s. 14 significantly improved grain yield by 0.26 t/ha (4%). In the season having the most severe BYDV outbreak, a pyrethroid aphicide at g.s. 14 was best in controlling yield loss. Pyrethroid aphicide gave better control of symptoms and better yields than organophosphorous aphicide. The estimated yield reductions in untreated April-sown barley due to feeding damage by Sitobion avenae was 0.71 t/ha and 0.83 t/ha (10.6% and 11.3%) in the two seasons in which this aphid was plentiful. In the three seasons in which Metopolophium dirhodum was recorded the estimated yield reductions were 0.32 t/ha, 0.48 t/ha and 0.43 t/ha (5.2%, 5.6% and 5.7%).
    • The health status of Irish honeybee colonies in 2006

      Coffey, M. F.; Barth, Susanne; Hayes, K.; Breen, James; European Agricultural Guidance and Guarantee Fund; Department of Agriculture, Food and the Marine, Ireland (Teagasc (Agriculture and Food Development Authority), Ireland, 2013)
      This study assessed the health status of Irish honeybee colonies and provides a snapshot of the incidence of a number of important colony parasites/pathogens including: the mite Varroa destructor; three associated viruses (deformed wing virus (DWV), acute bee paralysis virus (ABPV) and Kashmir virus (KBV)); the tracheal mite Acarapis woodi; the microsporidian Nosema spp., and the insect Braula coeca. During June/July 2006, 135 samples of adult bees were collected from productive colonies throughout Ireland and standard techniques were used to determine the presence and absence of the parasites and pathogens. Varroa destructor was positively identified in 72.6% of the samples and was widely distributed. Although the samples were analysed for three viruses, DWV, ABPV and KBV, only DWV was detected (frequency = 12.5%). Acarapis woodi and Nosema spp. occurred in approximately 11% and 22% of the samples, respectively, while B. coeca, a wingless dipteran that was once common in Irish honeybee colonies, was very rare (3.7%). Samples where all the pathogens/parasites were jointly absent were statistically under-represented in Leinster and DWV was statistically over-represented in Munster. In Ulster, there was over-representation of the categories where all parasites/pathogens were jointly absent and for A. woodi, and underrepresentation of V. destructor.
    • How much grassland biomass is available in Ireland in excess of livestock requirements?

      McEniry, Joseph; Crosson, Paul; Finneran, Eoghan; McGee, Mark; Keady, Tim; O'Kiely, Padraig; Department of Agriculture, Food and the Marine; RSF 07 557 (Teagasc (Agriculture and Food Development Authority), Ireland, 2013)
      Grassland is a dominant biomass resource in Ireland and underpins most animal production systems. However, other commercial uses for grassland biomass exist, including, for example, the production of biogas through anaerobic digestion for the generation of heat, electricity and transport fuel. The objective of this study was to estimate the annual grassland resource available in Ireland in excess of livestock requirements under six contrasting scenarios. Under current grassland management and production practices there is an estimated average annual grassland resource of ca. 1.7 million tonnes of dry matter (DM) available in excess of livestock requirements. Only a small proportion of this resource (0.39 million tonnes of DM per annum) would be available if the targets set out in ‘Food Harvest 2020’ were achieved. However, increasing nitrogen (N) fertiliser input (to the limit permitted by the E.U. Nitrates Directive) combined with increasing the grazed grass utilisation rate of cattle (from 0.60 to 0.80 kg DM ingested by livestock per kg DM grown) has the potential to significantly increase this average resource to 12.2 million t DM/annum, even when allowing for achievement of ‘Food Harvest 2020’ targets. Under these scenarios, alternative uses for grassland biomass such as anaerobic digestion and green biorefining would not compete with traditional dairy, beef and lamb production systems, but could provide an alternative enterprise and income to farmers.
    • Identification of existing and emerging chemical residue contamination concerns in milk

      Danaher, Martin; Jordan, Kieran; Department of Agriculture, Food and the Marine, Ireland (Teagasc (Agriculture and Food Development Authority), Ireland, 2013)
      In order to maintain the quality of Irish milk and meet increasingly demanding specifications, it is necessary to focus on chemical residues in milk, in addition to other quality issues. The objective of the work was to assess the current status of chemical contaminant analysis and to identify technological and knowledge needs. This was achieved through a review of literature with respect to chemical contaminants. Quaternary ammonium compounds (QACs) have been identified as an area of concern for the dairy industry because of the recent reports of QAC residues in dairy products internationally. Analytical support to analyse QAC residues in milk and dairy products on an ongoing basis is required. Furthermore, the source of QAC residues along the milk production chain needs to be identified. Similarly, analytical support and research is needed in the area of phthalates, to support the development of intervention strategies to reduce contamination, if present. Cephalosporin antibiotics have been a concern for the dairy industry because of the lack of suitable chemical tests to measure these substances.
    • Imaginal and ovicidal effect of some insecticides against Bruchus pisorum L. (Coleoptera: Chrisomelidae)

      Nikolova, I. M. (Teagasc (Agriculture and Food Development Authority), Ireland, 2016-01-13)
      Trials were conducted in 2011 and 2012 at the Institute of Forage Crops, Pleven, Bulgaria, in order to study the imaginal and possible ovicidal effect of some insecticides against Bruchus pisorum under field conditions. Treatments with insecticides were started after the appearance of the first pea weevils eggs on pods located on the bottom two nodes. It was found that treatment with acetamiprid; thiacloprid; thiacloprid+deltamethrin; 50 g cypermethrin+480 g chlorpyrifosethyl, 50 g cypermethrin+500 g chlorpyrifosethyl and zeta-cypermethrin resulted in the cessation of additional oviposition on the lower nodes by Bruchus pisorum, due to the toxic effect of the insecticides on the pea weevil. It was found that spraying with acetamiprid and zeta-cypermethrin was the most effective. These insecticides significantly reduced the proportion of infected pods in comparison with the proportion of pods with eggs before the treatment by 30.2 and 27.4% and by 15.8 and 24.0% in 2011 and 2012, respectively. The use of acetamiprid and zeta-cypermethrin was also associated with the lowest percentage of infected seeds (21.7 and 23.6%, respectively), with the lowest percentage of infected seed in infected pods (40.5 and 42.5%, respectively) and the highest weight of 1000 infected seeds (161.94 and 182.04 g, respectively). It was concluded that the management of pea weevils in the crop with acetamiprid and zetacypermethrin can lead to satisfactory results when spray timing is chosen when the first eggs are visible.
    • Impact of slurry application method on phosphorus loss in runoff from grassland soils during periods of high soil moisture content

      McConnell, D.A.; Doody, D.G.; Elliott, C.T.; Matthews, D.I.; Ferris, C.P. (Teagasc (Agriculture and Food Development Authority), Ireland, 2016-08-27)
      Previous studies have reported that the trailing shoe application technique reduces phosphorus (P) in the runoff postslurry application when compared to the traditional splash-plate application technique. However, the effectiveness of the trailing-shoe technique as a means of reducing P losses has not been evaluated when slurry is applied during periods of high soil moisture levels and lower herbage covers. To address this issue, three treatments were examined in a 3 × 4 factorial design split-plot experiment, with treatments comprising three slurry treatments: control (no slurry), splashplate and trailing-shoe, and four slurry application dates: 7 December, 18 January, 1 March and 10 April. Dairy cow slurry was applied at a rate of 20 m3/ha, while simulated runoff was generated 2, 9 and 16 days later and analysed for a range of P fractions. Dissolved reactive P concentrations in runoff at day two was 41% lower when slurry was applied using the trailing-shoe technique, compared to the splash-plate technique (P < 0.05). In addition, P concentrations in runoff were higher (P < 0.05) from slurry applied in December and March compared to slurry applied in January or April, coinciding with periods of higher soil moisture contents. While the latter highlights that ‘calendar’-based non-spreading periods might not always achieve the desired consequences, the study demonstrated that further field-scale investigations into the trailing shoe as a mitigation measure to reduced P loss from agricultural soils is warranted.
    • Improvement of dry-cured Iberian ham sensory characteristics through the use of a concentrate high in oleic acid for pig feeding

      Jurado, A.; Garcia, C.; Timon, M.L.; Carrapiso, A.I. (Teagasc, Oak Park, Carlow, Ireland, 2008)
      The aim of this study was to investigate the sensory characteristics of dry-cured hams from confined Iberian pigs fed on a high oleic (HO) concentrate (HO-Pienso hams), and to study how different the characteristics of these hams are from those of Iberian hams from the best grade (Montanera hams, from extensively reared pigs). Nearly half of the fatty acids studied were similar in HO-Pienso and Montanera hams. No differences were found for 18:1, but some major fatty acids of subcutaneous fat of Iberian hams were different between the HO-Pienso and the Montanera hams (C16:0, C18:0, C18:2). The descriptive test revealed that 15 of the 23 sensory characteristics were not significantly different between both groups of hams. No sensory differences appeared for fat appearance or lean texture characteristics, but lean appearance, oiliness, saltiness and the most intensively perceived characteristics of odour and flavour were significantly different. These differences in the sensory traits between Montanera and Pienso hams were not as marked as found in previous studies. Therefore, the use of a concentrate high in oleic acid enables simulation, at least in part, of the sensory characteristics, especially texture.
    • 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.
    • Influence of short-term pre-aging in vacuum on physicochemical characteristics and consumer acceptability of modified atmosphere packed beef steaks

      Lopacka, Joanna; Zontala, Katarzyna; Pietras, Jacek; Poltarak, Andrzej; Wierzbicka, Agnieszka (Teagasc (Agriculture and Food Development Authority), Ireland, 2015-12-30)
      The objective of this study was to investigate the physiochemical changes and consumer acceptability of meat packed in high oxygen modified atmosphere during 12 days of storage with and without pre-aging in vacuum for 7 days. Steak samples from forequarter muscles Infraspinatus and Supraspinatus were stored at 2°C and tested for colour, Warner–Bratzler shear force (WBSF), storage/cooking loss, and consumer acceptability. Overall consumer acceptability at the beginning of modified atmosphere display was higher for aged Infraspinatus samples, however at the end of display samples from both treatments were equally rated by consumers. No impact of aging was observed in terms of storage loss, while cooking loss was slightly affected by aging, resulting in higher losses in aged samples at the end of modified atmosphere storage. Inclusion of an aging process prior to modified atmosphere display improved the tenderness of Infraspinatus muscle at the 8th day of display and led to a considerable increase in redness of both muscles.
    • Influence of testing procedure on evaluation of white clover (Trifolium repens L.)

      Gilliland, T.J.; McGilloway, D.; Conaghan, P. (Teagasc, Oak Park, Carlow, Ireland, 2009)
      This study examined data sets derived from the white clover cultivar evaluation programmes of AFBI (N. Ireland), and DAFF (Republic of Ireland) to determine whether elite performing genotypes are identifiable, independent of test procedure and leaf size factors. Genetic variation in yield and persistency, independent of the leaf size continuum effect, was observed. Identification of elite cultivars by breeders or testers therefore required readjustment of assessment standards to account for the mostly curvilinear relationships between performance and leaf size. The different testing procedures, involving cutting or grazing at different heights, frequencies and nitrogen rates changed the relative performances between the cultivars, making it difficult to predict performance potential beyond specific test conditions. The underlying causes for these changes in rankings was considered, including sensitivity to season and location, the antagonistic affects of defoliation pressure and companion grass competition, the independence of different seasonal profiles and the probable role of other morphological characteristics. In is concluded that testing authorities must calculate the management by leaf size relationships to adjust pass/fail standards if elite performing cultivars are to be correctly indentified.
    • Insect assemblages and their preference for Lupinus albus and L. luteus

      Nikolova, I.; Georgieva, N. (Teagasc (Agriculture and Food Development Authority), Ireland, 2018-05-23)
      While lupin has undergone extensive research to ascertain its suitability for growth as forage or grain legume crop, the present trend is for research to be centered on its applicability in the seed protein and oil industry. Study of the literature showed that no intensive study of the lupin insect fauna had been carried out in Bulgaria. The purpose of this study was to identify the insect assemblages associated with Lupinus albus and L. luteus, as well as the insect preference for them. Thrips sampling was made by the tapping-method, aphids were directly counted on the plants and the composition and population density of other species were recorded by sweepings. Insect fauna was studied for the first time in Bulgaria. The fauna was represented on L. albus by 64 species, belonging to eight orders, 28 families and 57 genera, including 23 beetles, 25 hemipteras, five thrips, three butterflies, three bees, one leaf aphid, two grasshoppers, one leafminer and one green lacewing. L. luteus had similar species composition but was less preferred by insects. The use of lupin cultivars with shorter and intense reproductive periods, with a lower content of crude protein and phosphorus, would give an environmentally friendly protection against insect pests, which would be suitable for an organic production system.
    • Intake, growth and feed conversion efficiency of finishing beef cattle offered diets based on triticale, maize or grass silages, or ad libitum concentrates

      O'Kiely, Padraig (Teagasc (Agriculture and Food Development Authority), Ireland, 2011)
      The intake, growth and feed conversion efficiency of finishing cattle offered whole-crop triticale silage, harvested at different stubble heights, or maize silage, supplemented with different amounts and forms of crude protein, were compared with those of cattle offered grass silage or concentrate ad libitum. Ninety-eight continental crossbred steers (mean (s.d.) initial live weight 509 (38.6) kg) were allocated among 7 treatments in a randomized complete-block design: triticale silage from a crop harvested to a 14 (TS-L) or 35 (TS-H) cm high stubble, maize silage supplemented with a low (MS-LS) or high (MS-HS) protein concentrate, or with approximately half of the supplementary crude protein replaced by urea (MS-SU), grass silage (GS) or concentrate offered ad libitum (ALC). Each silage was offered ad libitum for 134 days, supplemented with 3 kg concentrate per head daily. Carcass gain did not differ (P>0.05) between animals on treatments TS-L and TS-H, but the carcass gain associated with TS-L was lower (P<0.05) than with GS or MS-HS, and with TS-H compared with MS-HS. Carcass gain was lower (P<0.05) for steers on GS compared to MS-HS, there were no differences (P>0.05) among the values for MS-LS, MS-HS and MS-SU; the carcass gain associated with ALC was the highest (P<0.001). The feed efficiency for carcass gain for the animals on TS-L, TS-H, GS, MS-LS, MS-HS, MS-SU and ALC was 44.1, 48.2, 60.8, 59.3, 68.3, 59.8 and 90.1 (s.e. 4.26) kg/t total DM intake, respectively (P<0.001). It is concluded that the ranking on nutritive value was TS<GS<MS<ALC. Elevating the cutting height of triticale conferred little benefit. Half the soybean meal in the barley-based supplement to maize silage could be replaced by barley plus urea without a negative effect on animal performance.
    • The interactive effects of fertiliser nitrogen with dung and urine on nitrous oxide emissions in grassland

      Hyde, B.P.; Forrestal, Patrick J.; Jahangir, M.M.R.; Ryan, M.; Fanning, A.F.; Carton, Owen T.; Lanigan, Gary; Richards, Karl G.; Environmental Protection Agency; Department of Agriculture, Food and the Marine, Ireland; RSF 13S430; 11S138 (Teagasc (Agriculture and Food Development Authority), Ireland, 08/09/2016)
      Nitrous oxide (N2O) is an important and potent greenhouse gas (GHG). Although application of nitrogen (N) fertiliser is a feature of many grazing systems, limited data is available on N2O emissions in grassland as a result of the interaction between urine, dung and fertiliser N. A small plot study was conducted to identify the individual and interactive effects of calcium ammonium nitrate (CAN) fertiliser, dung and urine. Application of CAN with dung and urine significantly increased the mass of N2O-N emission. Importantly, the sum of N2O-N emitted from dung and CAN applied individually approximated the emission from dung and CAN fertiliser applied together, that is, an additive effect. However, in the case of urine and CAN applied together, the emission was more than double the sum of the emission from urine and CAN fertiliser applied individually, that is, a multiplicative effect. Nitrous oxide emissions from dung, urine and fertiliser N are typically derived individually and these individual emission estimates are aggregated to produce estimates of N2O emission. The presented findings have important implications for how individual emission factors are aggregated; they suggest that the multiplicative effect of the addition of CAN fertiliser to urine patches needs to be taken into account to refine the estimation of N2O emissions from grazing grasslands.
    • The interactive effects of various nitrogen fertiliser formulations applied to urine patches on nitrous oxide emissions in grassland

      Krol, Dominika J.; Minet, E.; Forrestal, Patrick J.; Lanigan, Gary; Mathieu, O.; Richards, Karl J.; Department of Agriculture, Food and the Marine, Ireland; RSF10/RD/SC/716; 11S138 (Teagasc (Agriculture and Food Development Authority), Ireland, 19/09/2017)
      Pasture-based livestock agriculture is a major source of greenhouse gas (GHG) nitrous oxide (N2O). Although a body of research is available on the effect of urine patch N or fertiliser N on N2O emissions, limited data is available on the effect of fertiliser N applied to patches of urinary N, which can cover up to a fifth of the yearly grazed area. This study investigated whether the sum of N2O emissions from urine and a range of N fertilisers, calcium ammonium nitrate (CAN) or urea ± urease inhibitor ± nitrification inhibitor, applied alone (disaggregated and re-aggregated) approximated the N2O emission of urine and fertiliser N applied together (aggregated). Application of fertiliser to urine patches did not significantly increase either the cumulative yearly N2O emissions or the N2O emission factor in comparison to urine and fertiliser applied separately with the emissions re-aggregated. However, there was a consistent trend for approximately 20% underestimation of N2O loss generated from fertiliser and urine applied separately when compared to figures generated when urine and fertiliser were applied together. N2O emission factors from fertilisers were 0.02%, 0.06%, 0.17% and 0.25% from urea ± dicyandiamide (DCD), urea + N-(n-butyl) thiophosphoric triamide (NBPT) + DCD, urea + NBPT and urea, respectively, while the emission factor for urine alone was 0.33%. Calcium ammonium nitrate and urea did not interact differently with urine even when the urea included DCD. N2O losses could be reduced by switching from CAN to urea-based fertilisers.
    • An investigation of seed treatments for the control of crow damage to newly-sown wheat

      Kennedy, T.F.; Connery, J. (Teagasc, Oak Park, Carlow, Ireland, 2008)
      Seed treatments for the control of crow damage to seed and seedling in winter and spring wheat were evaluated in field trials from 2004 to 2007. Treatments included six fungicides, three insecticides, a product marketed as a bird repellent and three potential repellents. Various rates of selected compounds were investigated. Winter wheat was sown in December and spring wheat in late-January to mid-February. Sowing depth was 2 to 4 cm while some selected treatments were also sown at a depth of 5 to 8 cm. Crow damage was assessed by plant density and grain yield. Severe damage by crows was recorded. The plant population from untreated spring wheat seed in 2004, 2005 and 2006 was reduced by 59%, 69% and 89%, respectively. The corresponding reductions caused by crows to winter wheat sown in 2004, 2005 and 2006 were 96%, 88% and 96%. Best control of crow damage was provided by the fungicide Thiram. Increasing the rate of Thiram applied to seed reduced crow damage and increased plant density in the range 42 to 70% and 36 to 57%, respectively, for spring and winter wheat when compared with untreated seed. Anchor, which contains the fungicides Thiram and Carboxin, also gave reasonably good control. The commonly used fungicide product Panoctine gave poor control of crow damage. Other treatments investigated were ineffective in controlling dam¬age. Increasing the sowing depth to more than 4.6 cm significantly reduced damage to both treated and untreated seed when compared with similar treatments sown less deep.
    • Iodine concentrations in milk

      O'Brien, Bernadette; Gleeson, David E; Jordan, Kieran; Irish Dairy Levy Research Trust (Teagasc (Agriculture and Food Development Authority), Ireland, 2013)
      Iodine tends to be supplemented at farm level in the expectation of increasing cow health and fertility. There is concern that such practices may result in high milk iodine, which could affect ingredients for infant formula and, thus, dairy export markets. The objective of this study was to quantify the effect of iodine fortified feed and teat disinfection practices of dairy cows on milk iodine concentration. Thirty lactating cows were fed 7 kg, 3 kg (10 mg iodine/kg) and 0 kg of concentrate feed during 3 periods of 35 days each. During the first 14 days of each period, cows were on dietary iodine treatments only; during days 15–21, one of three teat disinfection treatments (n = 10) was applied (in addition to the dietary iodine treatments): non-iodine (chlorhexidine) post-milking spray; 0.5% iodine spray post-milking; 0.5% iodine spray pre- and post-milking. Cow milk yield was 21.3 kg/day. Individual cow milk samples were analysed for iodine concentration on 2 days at the end of each treatment period. Dietary supplementation of iodine at both 30 mg and 70 mg/day, when compared to the diet with no supplement, increased milk iodine concentrations significantly (P < 0.001) from 449 to 1034 and 915 μg/kg, respectively. Teat disinfection both pre- and post-milking increased milk iodine concentration at each of the dietary supplementation levels of 0, 30 and 70 mg/day compared with a non-iodine teat disinfectant (P < 0.001). In conclusion, both dietary iodine supplementation and teat disinfection iodine increased milk iodine concentrations in an additive manner, exceeding common target values of 250 μg/kg. As both iodine treatments can occur simultaneously on farm, supplementation strategies should be monitored.