Now showing items 1-20 of 1789

    • Reaffirmation of known major genes and the identification of novel candidate genes associated with carcass-related metrics based on whole genome sequence within a large multi-breed cattle population

      Purfield, D. C; Evans, R. D; Berry, D. P; European Union; Science Foundation Ireland; 727213; 14/IA/2576; 16/RC/3835 (Biomed Central, 2019-09-18)
      Background The high narrow sense heritability of carcass traits suggests that the underlying additive genetic potential of an individual should be strongly correlated with both animal carcass quality and quantity, and therefore, by extension, carcass value. Therefore, the objective of the present study was to detect genomic regions associated with three carcass traits, namely carcass weight, conformation and fat cover, using imputed whole genome sequence in 28,470 dairy and beef sires from six breeds with a total of 2,199,926 phenotyped progeny. Results Major genes previously associated with carcass performance were identified, as well as several putative novel candidate genes that likely operate both within and across breeds. The role of MSTN in carcass performance was re-affirmed with the segregating Q204X mutation explaining 1.21, 1.11 and 5.95% of the genetic variance in carcass weight, fat and conformation, respectively in the Charolais population. In addition, a genomic region on BTA6 encompassing the NCAPG/LCORL locus, which is a known candidate locus associated with body size, was associated with carcass weight in Angus, Charolais and Limousin. Novel candidate genes identified included ZFAT in Angus, and SLC40A1 and the olfactory gene cluster on BTA15 in Charolais. Although the majority of associations were breed specific, associations that operated across breeds included SORCS1 on BTA26, MCTP2 on BTA21 and ARL15 on BTA20; these are of particular interest due to their potential informativeness in across-breed genomic evaluations. Genomic regions affecting all three carcass traits were identified in each of the breeds, although these were mainly concentrated on BTA2 and BTA6, surrounding MSTN and NCAPG/LCORL, respectively. This suggests that although major genes may be associated with all three carcass traits, the majority of genes containing significant variants (unadjusted p-value < 10− 4) may be trait specific associations of small effect. Conclusions Although plausible novel candidate genes were identified, the proportion of variance explained by these candidates was minimal thus reaffirming that while carcass performance may be affected by major genes in the form of MSTN and NCAPG/LCORL, the majority of variance is attributed to the additive (and possibly multiplicative) effect of many polymorphisms of small effect.
    • Effect of feed allowance at pasture on the lying behaviour of dairy cows

      O'Driscoll, Keelin; Lewis, Eva; Kennedy, Emer (Elsevier, 2019-02-10)
      In temperate climates where cows are primarily managed at pasture shortages of grass could result in nutritional deficits for the cow and may have a variety of behavioural consequences. Lying behaviour is one of the most researched aspects of dairy cow behaviour, and can provide insights into cow welfare and physiological state. This study investigated the effect of daily herbage allowance (DHA) on the lying behaviour of dairy cow during early lactation. Ninety-six cows were randomly assigned to one of eight treatments in a 2 × 4 factorial design; experimental duration (2 week (2 W) or 6 week (6 W)), and nutritional levels (DHA) (60%, 80%, 100% or 120% of intake capacity). Cows were assigned to treatment at 28 ± 8.4 days in milk, and lying behaviour of cows in the 6 W treatments recorded using modified voltage data loggers on 4 occasions; the week prior to the start of the experiment, during week 3 (MID), and week 6 (LATE), and 7 weeks after the study concluded (POST), when the cows were all returned to a feed allowance of 100% intake capacity. Although there was an effect of treatment on daily lying time (P < 0.01), with the 60% cows spending less time lying than the 120% (P < 0.01), cows in all treatments spent at least 9 h lying per day throughout the experiment. Daily lying time increased as the grazing season progressed (P < 0.001). Feed allowance affected both lying bout duration (P < 0.01) and number (P < 0.05), with cows on the highest feed allowance having the highest values for both. There was an effect of feed allowance on the time that cows first lay down after both morning and afternoon milking (P < 0.001), with a similar pattern for both times; the lower the feed allowance, the longer it took. During the POST period, this pattern was no longer evident in the afternoon, but still present in the morning. None of the treatments imposed resulted in daily lying times lower than those reported in other studies at pasture. However, the significant differences in patterns of lying during the day could be reflective of satiety level; the patterns of lying in cows with a low feed allowance compared to those with an allowance aligned with intake capacity are in agreement with previous research. Herd level recording of lying behaviour, relative to time since milking and/or fresh feed allocation, has potential for use as an animal welfare indicator for cows at pasture.
    • Evaluation of alternative strategies to treat anoestrous dairy cows and implications for reproductive performance in pasture-based seasonal calving herds: A pilot study

      Rojas Canadas, E.; Gobikrushanth, M.; Fernandez, P.; Kenneally, J.; Lonergan, P.; Butler, Stephen T.; Department of Agriculture, Food and the Marine; 13S528 (Elsevier, 2019-01-12)
      The objective of the present study was to assess the effects on ovulation and reproductive performance of a single injection of either GnRH or hCG applied 9 days before the start of the seasonal breeding period in anovulatory anoestrus cows compared with a 7-day progesterone-Ovsynch protocol. The study was conducted on four grass-based seasonal calving dairy herds in Ireland. The total number of cows in the herds was 2112, of which 488 were diagnosed as anoestrus based on absence of behavioural oestrus during a 30 day period. Ovarian structures and the uterus were examined by transrectal ultrasound on all 488 presumptive anestrus cows 9 days before mating start date (MSD). The number of corpora lutea (CL), number of large follicles (≥10 mm) and uterine reproductive tract score were recorded. Only cows that had no CL, ultrasound reproductive tract score ≤2 and were ≥30 days in milk (DIM) were enrolled in the study (n = 214). Cows were blocked by parity, DIM and body condition score and randomly assigned to one of four treatments: i.m. injection of gonadotropin releasing hormone analogue [GnRH; (n = 57)], i.m. injection of human chorionic gonadotropin [hCG; (n = 48)], 7-day Progesterone-Ovsynch protocol [P4OV; (n = 60)] and Control (no hormonal intervention, n = 49). A second ultrasound examination was performed 7 days after treatment to determine ovulatory response. There was a treatment effect on ovulation rate (P < 0.0001), whereby Control cows had a lesser ovulation rate compared with GnRH-, hCG- and P4OV-treated cows. Submission rate during the first 21 days of the breeding period [SR21; (P = 0.74)], pregnant to first service [P/AI1; (P = 0.24)], pregnant within 42 days after the onset of breeding [P42; (P = 0.73)], and pregnant within 84 days after the onset of breeding were not affected by treatment. A tendency was observed (P = 0.07) for greater likelihood of pregnancy within 21 days after the onset of breeding (P21) for P4OV and Control cows compared with GnRH- and hCG-treated cows. GnRH- and hCG-treated cows tended (P = 0.10) to have greater P/AI1 when first service events occurred after day 21 of the breeding period compared with Control cows. P4OV cows had shorter MSD to first service interval (P = 0.0001) and shorter MSD to conception interval (P = 0.02) compared with Control, GnRH- and hCG-treated cows. In conclusion, treatment of anestrous cows with GnRH or hCG resulted in an increase in ovulation rate compared with untreated Control cows, but did not improve reproductive performance during the first 21 days of the breeding season. The best reproductive performance results were obtained with the P4OV treatment, but this treatment has the greatest cost, and has the greatest number of interventions. The observation of good P/AI1 in hCG- and GnRH- treated cows when the first insemination occurred later than day 21 after MSD warrants further investigation, and suggests that these interventions should be applied earlier than 9 days before the farm MSD.
    • Inhibition of lactose crystallisation in the presence of galacto-oligosaccharide

      Fu, Shishan; Miao, Song; Ma, Xiaobin; Ding, Tian; Ye, Xingqian; Liu, Donghong (Elsevier, 2018-10-02)
      The stabilization of lactose in the form of amorphous (i.e. non-crystalline form) is the basic requirement to maintain the quality of relevant food and pharmaceutical products. The physiochemical properties of amorphous lactose mixed with galacto-oligosaccharide (GOS) were investigated. Water sorption, glass transition temperature, and crystallisation behaviour of lactose in the present of GOS (1:1 w/w) were measured at various water activity (0.11–0.75 aw, 25 °C) and lactose mutarotation was also evaluated. All of them were compared with the physiochemical properties of trehalose-lactose (1:1 w/w). The addition of GOS to lactose increased the hygroscopicity of the mixture, as well as slightly increased the glass transition temperature compared to lactose alone. The critical water activity (at 0.68 aw) of lactose crystallisation was increased by the addition of GOS as compared to that of trehalose-lactose (1:1 w/w) (at 0.58 aw) or lactose alone (at 0.44 aw). The dramatical inhibition of lactose crystallisation with a lower crystallisation kinetic constant and the alternation of lactose crystal forms in the presence of GOS was observed as compared to the crystallisation behaviour of trehalose-lactose (1:1 w/w) and pure lactose at 0.68 and 0.75 aw, 25 °C. Without affecting its Tg, the significantly delayed crystallisation of lactose in GOS-lactose mixture (1:1 w/w) was more likely due to the change of lactose mutarotation. As comparing to trehalose that is an effective inhibitor, GOS has a stronger ability to prevent lactose from crystallisation in hydrous matrices.
    • Application of broadband acoustic resonance dissolution spectroscopy (BARDS) to the gas release behaviour during rehydration of milk protein isolate agglomerates

      Wu, Shaozong; Fitzpatrick, John; Cronin, Kevin; Ahmed, M. Rizwan; Fitzpatrick, Dara; Miao, Song; China Scholarship Council; Teagasc; 201606350091; MDDT0153 (Elsevier, 2019-02-13)
      The BARDS technique was applied in this study to acoustically assess the rehydration behaviour of milk protein isolate (MPI) agglomerates and to compare with regular MPI powder. The results showed that BARDS has potential to monitor the rehydration behaviour of agglomerates. The greater porosity (>70%) of agglomerated powders introduced more compressible gas into the water. The BARDS profile showed that there was faster initial gas release from the agglomerates, indicating better wetting and dispersion ability of the agglomerates with shorter tM (time of maximum gas volume in solution). At 0.10% powder addition, agglomerated MPI reached tM within 109 s, which was significantly less than the control MPI at 140 s. MPI with lactose binder (MPI-L) had a tM of 80 s at 0.10% powder addition and, larger size MPI-L had a tM of 60 s. At 0.20% and 0.30% powder addition, more time was required to wet and disperse the powders.
    • Systematic review and meta-analysis of the effect of feed enzymes on growth and nutrient digestibility in grow-finisher pigs: Effect of enzyme type and cereal source

      Torres-Pitarch, Alberto; Manzanilla, Edgar G; Gardiner, Gillian E.; O'Doherty, John V.; Lawlor, Peadar G; Teagasc; European Union’s Seventh Framework Programme; Teagasc Walsh Fellowship Programme; PDPG6671; 311794 (Elsevier, 2019-12-28)
      Dietary supplementation of pig diets with exogenous enzymes has been suggested as a strategy to increase nutrient digestibility and improve feed efficiency in grow-finisher pigs. However, inconsistent results are found in the literature. Ingredient composition of the diets is one of the most important sources of variation that may affect enzyme efficacy and consistency of results. A systematic review and a meta-analysis was therefore conducted to determine which exogenous enzymes with which diet type most consistently improve pig growth, nutrient digestibility and feed efficiency. Enzyme type and dietary cereal source were the main explanatory variables included in the models. The mean difference effects of enzyme supplementation on average daily gain (ADG), average daily feed intake (ADFI), gain to feed (G:F), apparent ileal digestibility (AiD) and apparent total tract digestibility (ATTD) of dry matter (DM), crude protein (CP), and gross energy (GE) were calculated for each study and these were used as the effect size estimates in the meta-analysis. A dataset with 139 comparisons from 67 peer-reviewed publications was used in the meta-analysis. In response to enzyme supplementation, G:F was improved in 38 of the 120 comparisons reporting pig growth data, remained un-changed in 78 and deteriorated in 4. Overall, DM and GE AiD, and ATTD were improved by xylanase, xylanase + β-glucanase, mannanase and protease dietary supplementation (P < 0.05). Crude protein AiD was only improved by protease dietary supplementation (P < 0.001). Dietary supplementation with xylanase alone improved ADG of maize- (P < 0.05) and co-product- (P < 0.05) based diets but had no effect on the G:F of grow-finisher pigs. Dietary supplementation with xylanase + β-glucanase had no effect on ADG, ADFI and G:F. Protease supplementation tended to improve the ADG of grow-finisher pigs fed co-product-based diets (P = 0.08) but had no effect on G:F. Dietary supplementation with multi-enzyme complexes improved the ADG (P < 0.05) and G:F (P < 0.01) of maize-, wheat-, barley- and co-product-based diets. In conclusion, dietary supplementation with all enzyme types improved nutrient digestibility depending on ingredient content, while mannanase and multi-enzyme complex supplementation most consistently improved growth and feed efficiency.
    • A consumer study of the effect of castration and slaughter age of lambs on the sensory quality of meat

      Gravador, Rufielyn S.; Pace, Elaine; Mooney, Bernard R.; Jaeger, Sara R.; Gkarane, Vasiliki; Fahey, Alan G.; Brunton, Nigel P.; Claffey, Noel A.; Allen, Paul; Diskin, Michael G.; et al. (Elsevier, 2018-09-20)
      Meat from ram lambs is often considered inferior to meat from castrated lambs, especially in older or heavier animals. This study aimed to determine if differences exist in the sensory quality and acceptability of meat from rams and castrates, slaughtered at mean ages of 196 or 385 days. Rams had higher average daily gain, feed conversion efficiency, total weight gain and lower carcass fatness than castrates. A triangle test (n = 81 consumers) showed a difference (P < 0.05) in the sensory quality of meat from rams vs castrates. A 9-point hedonic test involving 100 consumers showed that, although meat from both rams and castrates was ‘liked’, meat from castrates scored higher (P < 0.05) in Overall Liking, Flavour Liking and Tenderness Liking. Meat from castrates was also rated lower (P < 0.05) in Unpleasant Taste/Off-Flavour Intensity. Flavour Intensity and Unpleasant Taste/Off-Flavour Intensity increased (P < 0.05) with age at slaughter. This consumer study revealed that while meat from castrates was higher in Overall Liking, Flavour Liking and Tenderness Liking and lower in Unpleasant Taste/Off-Flavour Intensity than meat from rams, both meats were ‘liked’ by consumers.
    • Pilot-scale formation of whey protein aggregates determine the stability of heat-treated whey protein solutions—Effect of pH and protein concentration

      Buggy, Aoife K.; McManus, Jennifer J.; Brodkorb, Andre; Hogan, Sean A.; Fenelon, Mark A.; Teagasc Walsh Fellowship Programme; Department of Agriculture, Food and the Marine; 11/F/037 (American Dairy Science Association, 2018-09-20)
      Denaturation and consequent aggregation in whey protein solutions is critical to product functionality during processing. Solutions of whey protein isolate (WPI) prepared at 1, 4, 8, and 12% (wt/wt) and pH 6.2, 6.7, or 7.2 were subjected to heat treatment (85°C × 30 s) using a pilot-scale heat exchanger. The effects of heat treatment on whey protein denaturation and aggregation were determined by chromatography, particle size, turbidity, and rheological analyses. The influence of pH and WPI concentration during heat treatment on the thermal stability of the resulting dispersions was also investigated. Whey protein isolate solutions heated at pH 6.2 were more extensively denatured, had a greater proportion of insoluble aggregates, higher particle size and turbidity, and were significantly less heat-stable than equivalent samples prepared at pH 6.7 and 7.2. The effects of WPI concentration on denaturation/aggregation behavior were more apparent at higher pH where the stabilizing effects of charge repulsion became increasingly influential. Solutions containing 12% (wt/wt) WPI had significantly higher apparent viscosities, at each pH, compared with lower protein concentrations, with solutions prepared at pH 6.2 forming a gel. Smaller average particle size and a higher proportion of soluble aggregates in WPI solutions, pre-heated at pH 6.7 and 7.2, resulted in improved thermal stability on subsequent heating. Higher pH during secondary heating also increased thermal stability. This study offers insight into the interactive effects of pH and whey protein concentration during pilot-scale processing and demonstrates how protein functionality can be controlled through manipulation of these factors.
    • WS16.1 Clinical Outcomes of Real-World Kalydeco (CORK) study – Investigating the impact of CFTR potentiation on the intestinal microbiota, exocrine pancreatic function and intestinal inflammation prospectively over 12 months

      Deane, Jennifer; Ronan, N. J.; O'Callaghan, G. P.; Fouhy, Fiona; Rea, Mary C.; O'Sullivan, Orla; Hill, C. J.; Shanahan, F.; Ross, R Paul; McCarthy, M.; et al. (Elsevier, 2015-06-05)
      Objectives Ivacaftor is effective in the treatment of patients with CF and the G551D gating mutation. We present faecal analysis results of the CORK cohort, a single-centre, adult (n = 20), prospective, longitudinal study of G551D clinical responders (median follow-up 12 months), examining the gut microbiota, exocrine pancreatic function and intestinal inflammation on a 3 monthly basis after commencing treatment.
    • 48 Altered gut microbiota in stable patients with cystic fibrosis (CF) compared to controls and its relationship with intravenous (IV) antibiotic usage and lung function

      Burke, D.G.; Fouhy, Fiona; Rea, Mary C.; Harrison, M.J.; Stanton, Catherine; O’Sullivan, Orla; Murphy, D. M.; O'Callaghan, G. P.; Eustace, J. A.; Shanahan, F.; et al. (Elsevier, 2015-06-05)
      Objective CF is associated with altered digestive function and thus nutrient availability for gut microbes in addition to altered gut microbiota, compared with healthy controls. Equally intensive antibiotic and nutritional therapy may further compound this. We present results from the largest CF gut microbiota study to date.
    • A case study of the carbon footprint of milk from high-performing confinement and grass-based dairy farms

      O’Brien, Donal; Judith Louise, Capper; Garnsworthy, Phil; Grainger, Chris; Shalloo, Laurence; European Union; FP7-244983 (Elsevier, 2014-01-17)
      Life-cycle assessment (LCA) is the preferred methodology to assess carbon footprint per unit of milk. The objective of this case study was to apply an LCA method to compare carbon footprints of high-performance confinement and grass-based dairy farms. Physical performance data from research herds were used to quantify carbon footprints of a high-performance Irish grass-based dairy system and a top-performing United Kingdom (UK) confinement dairy system. For the US confinement dairy system, data from the top 5% of herds of a national database were used. Life-cycle assessment was applied using the same dairy farm greenhouse gas (GHG) model for all dairy systems. The model estimated all on- and off-farm GHG sources associated with dairy production until milk is sold from the farm in kilograms of carbon dioxide equivalents (CO2-eq) and allocated emissions between milk and meat. The carbon footprint of milk was calculated by expressing GHG emissions attributed to milk per tonne of energy-corrected milk (ECM). The comparison showed that when GHG emissions were only attributed to milk, the carbon footprint of milk from the Irish grass-based system (837 kg of CO2-eq/t of ECM) was 5% lower than the UK confinement system (884 kg of CO2-eq/t of ECM) and 7% lower than the US confinement system (898 kg of CO2-eq/t of ECM). However, without grassland carbon sequestration, the grass-based and confinement dairy systems had similar carbon footprints per tonne of ECM. Emission algorithms and allocation of GHG emissions between milk and meat also affected the relative difference and order of dairy system carbon footprints. For instance, depending on the method chosen to allocate emissions between milk and meat, the relative difference between the carbon footprints of grass-based and confinement dairy systems varied by 3 to 22%. This indicates that further harmonization of several aspects of the LCA methodology is required to compare carbon footprints of contrasting dairy systems. In comparison to recent reports that assess the carbon footprint of milk from average Irish, UK, and US dairy systems, this case study indicates that top-performing herds of the respective nations have carbon footprints 27 to 32% lower than average dairy systems. Although differences between studies are partly explained by methodological inconsistency, the comparison suggests that potential exists to reduce the carbon footprint of milk in each of the nations by implementing practices that improve productivity.
    • Sensory and ATP derivative-based indicators for assessing the freshness of Atlantic salmon (Salmo salar) and cod (Gadus morhua)

      Fogarty, Colin; Smyth, Conor; Whyte, Paul; Brunton, Nigel; Bolton, Declan; Department of Agriculture, Food and the Marine; 13F458, (Teagasc, 2019-10-31)
      Irish Journal of Agricultural and Food Research | Volume 58: Issue 1 Sensory and ATP derivative-based indicators for assessing the freshness of Atlantic salmon (Salmo salar) and cod (Gadus morhua) Colin Fogarty , Conor Smyth , Paul Whyte , Nigel Brunton and Declan Boltonemail DOI: | Published online: 31 Oct 2019 PDF       Abstract Article PDF References Recommendations Abstract To estimate the shelf life of fresh fish, the processor must know the period of time between catch/harvest and arrival at the processing plant. This information is not always available, necessitating the provision of methods to estimate the time since catch or harvest. The objectives of this study were therefore to develop and/or validate sensory and ATP derivative-based methods for rapidly assessing the freshness of fish. A quality index method (QIM; raw fish) and a quantitative descriptive analysis (QDA; cooked fish) were developed and validated (against bacterial count [total viable count (TVC)] and time) for salmon (Salmo salar) and cod (Gadus morhua). The production of inosine monophosphate (IMP), inosine and hypoxanthine (Hx) and associated ratios (IMP/Hx, K1-value or H-value) were also investigated for use as freshness markers. There was a linear relationship between QIM and TVC (R2 = 0.93 for salmon and R2 = 0.89 for cod), QIM and time (R2 = 0.96 for salmon and R2 = 0.98 for cod), QDA and TVC (R2 = 0.93 for salmon and R2 = 0.77 for cod) and QDA and time (R2 = 0.94 for salmon and R2 = 0.87 for cod), suggesting that the QIM and QDA schemes developed could be used to monitor/assess freshness. The H-value also increased linearly with TVC (R2 = 0.88 for salmon and R2 = 0.89 for cod) and time (R2 = 0.93 for salmon and R2 = 0.84 for cod). It was therefore concluded that both the QIM/QDA approach and monitoring ATP degradation, specifically expressed as the H-value, could be used as rapid methods to assess the freshness of salmon and cod arriving at the processing plant
    • The agricultural impact of the 2015–2016 floods in Ireland as mapped through Sentinel 1 satellite imagery

      O'HAra, Rob; Teagasc Walsh Fellowship Programme (Teagasc, 2019-10-11)
      Irish Journal of Agricultural and Food Research | Volume 58: Issue 1 The agricultural impact of the 2015–2016 floods in Ireland as mapped through Sentinel 1 satellite imagery R. O’Haraemail , S. Green and T. McCarthy DOI: | Published online: 11 Oct 2019 PDF       Abstract Article PDF References Recommendations Abstract The capability of Sentinel 1 C-band (5 cm wavelength) synthetic aperture radio detection and ranging (RADAR) (abbreviated as SAR) for flood mapping is demonstrated, and this approach is used to map the extent of the extensive floods that occurred throughout the Republic of Ireland in the winter of 2015–2016. Thirty-three Sentinel 1 images were used to map the area and duration of floods over a 6-mo period from November 2015 to April 2016. Flood maps for 11 separate dates charted the development and persistence of floods nationally. The maximum flood extent during this period was estimated to be ~24,356 ha. The depth of rainfall influenced the magnitude of flood in the preceding 5 d and over more extended periods to a lesser degree. Reduced photosynthetic activity on farms affected by flooding was observed in Landsat 8 vegetation index difference images compared to the previous spring. The accuracy of the flood map was assessed against reports of flooding from affected farms, as well as other satellite-derived maps from Copernicus Emergency Management Service and Sentinel 2. Monte Carlo simulated elevation data (20 m resolution, 2.5 m root mean square error [RMSE]) were used to estimate the flood’s depth and volume. Although the modelled flood height showed a strong correlation with the measured river heights, differences of several metres were observed. Future mapping strategies are discussed, which include high–temporal-resolution soil moisture data, as part of an integrated multisensor approach to flood response over a range of spatial scales.
    • Effect of nitrogen fertiliser application timing on grain yield and grain protein concentration of spring barley

      Hackett, R. (Teagasc, 2019-06-01)
      There is relatively little recent information regarding the effect of timing of fertiliser N application to spring barley on grain yield and grain protein concentration (GPC) under Irish conditions. The objectives of this work were to examine the effects of a) timing of the first N application to spring barley (at sowing or at crop emergence), b) altering the proportion of the total N allocation that is applied in the first of two applications and c) delaying a portion of the total N dose until after the tillering phase on grain yield and GPC of spring barley. Twenty experiments were carried out over four seasons (2011–2014) in the south and south-east of Ireland. Results indicated that there was little consistent difference, in terms of grain yield or GPC between applying the first N at sowing compared to where the initial N application was made at crop emergence. Similarly, altering the proportion of N applied in the first application, irrespective of whether the first application was at sowing or at crop emergence, had little effect on either yield or GPC. Delaying the application of a portion (0.2) of the total N until after the tillering stage also had little consistent effect on either yield or GPC. It is concluded that where the majority of N is applied to spring barley before the end of the tillering stage, altering the timing of applications or the proportion of the total applied in each application will have limited effect on grain yield or GPC.
    • Prevalence of QoI resistance and mtDNA diversity in the Irish Zymoseptoria tritici population

      Kildea, S.; Bucar, D.E.; Hutton, F.; Rosa, S. de la; Welch, T.E.; Phelan, S.; Department of Agriculture, Food and the Marine; Erasmus+ programme; Mexican National Council of Science and Technology (CONACYT); 11S113 (Teagasc, 2019-06-15)
      The emergence and spread of Quinone outside Inhibitor (QoI) fungicide resistance in the Irish Zymoseptoria tritici population in the early 2000s had immediate impacts on the efficacy of the entire group of fungicides for the control of septoria tritici blotch. As a result, a dramatic reduction in the quantities applied to winter wheat occurred in the following seasons. Even in the absence of these fungicides, the frequency of the resistance allele, G143A in the pathogens mtDNA has remained exceptionally high (>97%), and as such, it can be anticipated that continued poor efficacy of current QoI fungicides will be observed. Amongst the isolates with G143A, differences in sensitivity to the QoI pyraclostrobin were observed in vitro. The addition of the alternative oxidase (AOX) inhibitor salicylhydroxamic acid increased sensitivity in these isolates, suggesting some continued impairment of respiration by the QoI fungicides, albeit weak. Interestingly, amongst those tested, the strains from a site with a high frequency of inserts in the MFS1 transporter gene known to enhance QoI efflux did not exhibit this increase in sensitivity. A total of 19 mtDNA haplotypes were detected amongst the 2017 strain collection. Phylogenetic analysis confirmed the suggestion of a common ancestry of all the haplotypes, even though three of the haplotypes contained at least one sensitive strain.
    • First evidence of retained sexual capacity and survival in the pyrethroid resistant Sitobion avenae (F.) (Hemiptera: Aphididae) SA3 super-clone following exposure to a pyrethroid at current field-rate

      Walsh, L.E.; Gaffney, M.T.; Malloch, G.L.; Foster, S.P.; Williamson, M.S.; Mangan, R.; Purvis, G.; Department of Agriculture, Food and the Marine; Biotechnology and Biological Sciences Council; Rural ̦ Environment Science ̦ Analytical Services Division of the Scottish Government; et al. (Teagasc, 2019-04-17)
      The grain aphid Sitobion avenae is a prolific pest of cereal crops worldwide, controlled effectively with pyrethroid insecticides. However, the classic knock down resistance (kdr) mutation, L1014F on the S. avenae sodium channel gene, has been identified as the cause of the recently observed heterozygous (kdr-SR) resistance in the SA3 grain aphid super-clone. Results indicate that the kdr-SR SA3 clone can survive pyrethroid exposure above twice the normal field rate, continuing to reproduce thereafter. Additionally, the SA3 clone was found to be capable of producing sexual oviparous morphs, able to lay eggs following pyrethroid exposure. This demonstrates that possession of the L1014F mutation does not preclude the capacity to produce sexual morphs. This makes the adoption of an effective resistance management strategy imperative, within a wider integrated pest management (IPM) approach to control grain aphid.
    • Prediction of 24-hour milk yield and composition in dairy cows from a single part-day yield and sample

      McParland, S.; Coughlan, B.; Enright, B.; O’Keeffe, M.; O’Connor, R.; Feeney, L.; Berry, D.P.; Department of Agriculture, Food and Marine; Science Foundation Ireland; 16/RC/3835 (Teagasc, 2019-08-09)
      Irish Journal of Agricultural and Food Research | Volume 58: Issue 1 Prediction of 24-hour milk yield and composition in dairy cows from a single part-day yield and sample S. McParlandemail , B. Coughlan , B. Enright , M. O’Keeffe , R. O’Connor , L. Feeney and D.P. Berry DOI: | Published online: 09 Aug 2019 PDF       Abstract Article PDF References Recommendations Abstract The objective was to evaluate the accuracy of predicting 24-hour milk yield and composition from a single morning (AM) or evening (PM) milk weight and composition. A calibration dataset of 37,481 test-day records with both AM and PM yields and composition was used to generate the prediction equations; equations were validated using 4,644 test-day records. Prediction models were developed within stage of lactation and parity while accounting for the inter-milking time interval. The mean correlation between the predicted 24-hour yields and composition of milk, fat and protein and the respective actual values was 0.97 when based on just an AM milk yield and composition with a mean correlation of 0.95 when based on just a PM milk yield and composition. The regression of predicted 24-hour yield and composition on the respective actual values varied from 0.97 to 1.01 with the exception of 24-hour fat percentage predicted from a PM sample (1.06). A single AM sample is useful to predict 24-hour milk yield and composition when the milking interval is known.
    • The impact of cattle drinking points on aquatic macroinvertebrates in streams in south-east Ireland

      Madden, D.; Harrison, S.; Finn, J. A.; Ó hUallacháin, D. (Teagasc, 2019-03-25)
      Measures that prevent cattle access to watercourses are commonly implemented through agri-environment schemes, in an effort to address the objectives of the Water Framework Directive. Despite the widespread implementation, few studies have assessed the impact of cattle access to streams on aquatic macroinvertebrates. This study assessed the local-scale impact of cattle drinking points on water quality parameters (i.e. macroinvertebrate and water chemistry metrics) on 39 intensively-managed grassland farms in the south-east of Ireland. The results indicate that sites that were more than or equal to good quality upstream of cattle drinking points, were more susceptible to cattle access impacts than sites where upstream water quality was less than good. The European Court of Auditors (2011) recommended that there should be a higher rate of EU contribution for measures with higher environmental potential, in this instance, for cattle exclusion measures targeted to sites where background quality is more than or equal to good. Appropriate efforts should thus be made to incentivise farmers in good to high status sites to adopt cattle exclusion measures.
    • Low-density genotype panel for both parentage verification and discovery in a multi-breed sheep population

      Berry, D.P.; McHugh, N.; Wall, E.; McDermott, K.; O’Brien, A.C.; Department of Agriculture, Food and the Marine (Teagasc, 2019-03-01)
      The generally low usage of artificial insemination and single-sire mating in sheep, compounded by mob lambing (and lambing outdoors), implies that parentage assignment in sheep is challenging. The objective here was to develop a low-density panel of single nucleotide polymorphisms (SNPs) for accurate parentage verification and discovery in sheep. Of particular interest was where SNP selection was limited to only a subset of chromosomes, thereby eliminating the ability to accurately impute genome-wide denser marker panels. Data used consisted of 10,933 candidate SNPs on 9,390 purebred sheep. These data consisted of 1,876 validated genotyped sire–offspring pairs and 2,784 validated genotyped dam–offspring pairs. The SNP panels developed consisted of 87 SNPs to 500 SNPs. Parentage verification and discovery were undertaken using 1) exclusion, based on the sharing of at least one allele between candidate parent–offspring pairs, and 2) a likelihood-based approach. Based on exclusion, allowing for one discordant offspring–parent genotype, a minimum of 350 SNPs was required when the goal was to unambiguously identify the true sire or dam from all possible candidates. Results suggest that, if selecting SNPs across the entire genome, a minimum of 250 carefully selected SNPs are required to ensure that the most likely selected parent (based on the likelihood approach) was, in fact, the true parent. If restricting the SNPs to just a subset of chromosomes, the recommendation is to use at least a 300-SNP panel from at least six chromosomes, with approximately an equal number of SNPs per chromosome.
    • Carcass characteristics of cattle differing in Jersey proportion

      Berry, Donagh P.; Judge, Michelle; Evans, R. D.; Buckley, Frank; Cromie, A. R.; Science Foundation Ireland; Department of Agriculture, Food and Marine; Meat Technology Ireland; Enterprise Ireland; 16/RC/3835; et al. (Elsevier, 2018-09-27)
      Comparison of alternative dairy (cross-)breeding programs requires full appraisals of all revenues and costs, including beef merit. Few studies exist on carcass characteristics of crossbred dairy progeny originating from dairy herds as well as their dams. The objective of the present study was to quantify, using a national database, the carcass characteristics of young animals and cows differing in their fraction of Jersey. The data set consisted of 117,593 young animals and 42,799 cows. The associations between a combination of sire and dam breed proportion (just animal breed proportion when the dependent variable was on cows) with age at slaughter (just for young animals), carcass weight, conformation, fat score, price per kilogram, and total carcass value were estimated using mixed models that accounted for covariances among herdmates of the same sex slaughtered in close proximity in time; we also accounted for age at slaughter in young animals (which was substituted with carcass weight and carcass fat score when the dependent variable was age at slaughter), animal sex, parity of the cow or dam (where relevant), and temporal effects represented by a year-by-month 2-way interaction. For young animals, the heaviest of the dairy carcasses were from the mating of a Holstein-Friesian dam and a Holstein-Friesian sire (323.34 kg), whereas the lightest carcasses were from the mating of a purebred Jersey dam to a purebred Jersey sire which were 46.31 kg lighter (standard error of the difference = 1.21 kg). The young animal carcass weight of an F1 Holstein-Friesian × Jersey cross was 20.4 to 27.0 kg less than that of a purebred Holstein-Friesian animal. The carcass conformation of a Holstein-Friesian young animal was 26% superior to that of a purebred Jersey, translating to a difference of 0.78 conformation units on a scale of 1 to 15. Purebred Holstein-Friesians produced carcasses with less fat than their purebred Jersey counterparts. The difference in carcass price per kilogram among the alternative sire-dam breed combinations investigated was minimal, although large differences existed among the different breed types for overall carcass value; the carcass value of a Holstein-Friesian animal was 20% greater than that of a Jersey animal. Purebred Jersey animals required, on average, 21 d longer to reach a given carcass weight and fat score relative to a purebred Holstein-Friesian. The difference in age at slaughter between a purebred Holstein-Friesian animal and the mating between a Holstein-Friesian sire with a Jersey dam, and vice versa, was between 7.0 and 8.9 d. A 75.8-kg difference in carcass weight existed between the carcass of a purebred Jersey cow and that of a Holstein-Friesian cow; a 50% Holstein–Friesian-50% Jersey cow had a carcass 42.0 kg lighter than that of a purebred Holstein-Friesian cow. Carcass conformation was superior in purebred Holstein-Friesian compared with purebred Jersey cows. Results from this study represent useful input parameters to populate simulation models of alternative breeding programs on dairy farms, and to help beef farmers evaluate the cost-benefit of rearing, for slaughter, animals differing in Jersey fraction.