• Comparison of growth curves of three strains of female dairy cattle

      Berry, Donagh; Horan, Brendan; Dillon, Pat (Cambridge University Press, 2005-04)
      The objective of the present study was to compare growth curves for live weight (LW) and body size of three strains of female dairy cattle reared under common environments in Ireland. One strain (HP) was selected from a predominantly North-American/European Holstein-Friesian genetic pool selected for high milk production. The second strain (HD) represented a predominantly North-American/European Holstein-Friesian genetic pool selected for high milk production but with greater selection emphasis on functional non-production traits. The third strain (NZ) consisted of New Zealand Holstein-Friesian females of high genetic merit for profitability in New Zealand. The data consisted of 99 animals (33 animals in each strain) with records on LW, length, girth and height from birth to a minimum of 594 days of age. The von Bertalanffy growth function was fitted to each animal's records separately and least-squares analyses were used to investigate the effect of strain on birth LW/body size, parameters of the growth function and average daily gains. Average mature live weight of the HD animals (591 kg) was significantly larger than that of the HP (566 kg) or NZ (543 kg) strain; the HD strain matured more slowly. The HD (134 cm) and HP (135 cm) strains were significantly taller than the NZ (128 cm) strain. Although the data set was relatively small there are indications that dairy females of North-American genetic origin were heavier at birth, grew faster, and were heavier and taller at maturity than dairy females of New Zealand origin.
    • Development of an efficient milk production profile of the Irish dairy Industry

      Shalloo, Laurence; Dillon, Pat; Wallace, Michael; Dairy Levy Research Trust; European Union (Teagasc, 2008-07)
      Fluctuation around milk price will be the biggest factor that the dairy industry will experience over the next number of years. This fluctuation is being driven by fluctuation on the world dairy markets. In the past, when intervention was a much bigger feature of the CAP regime, the fluctuation in world markets had little effect on the EU price. This was because the Intervention system bought product from the market when prices were depressed and placed products on the world market when the price rose. This in effect meant that the CAP regime was having a regulatory effect on the world market as well as the EU markets. An example of the type of fluctuation observed on the world market can be gleamed from the Fonterra milk price in 2006-2007 ($4.50/kg (MS) milk solid) versus 2007-2008 ($7.90/kg MS). This corresponds to a 76% increase in price in 1 year. For the Dairy Industry in Ireland to prosper under these conditions all sectors will be required to be as efficient as possible from the farm, processing and marketing sectors. This report deals with; (1) Milk payment (2) Optimum milk production systems and (3) Seasonality of milk supply. (1) Milk payment systems in Ireland currently do not adequately reward high solids quality milk. Virtually all milk payment systems include a positive constant which reward the production of volume rather than the production of protein and fat kilograms. The A+B-C system of milk payment would adequately reward the production of protein and fat while at the same time correcting for the volume related processing costs. (2) Optimum systems of milk production will be built around the maximization of grass utilization in the future. Grazed grass is the cheapest feed that can be fed to dairy cows. Stocking rates nationally are 1.74cows/Ha around the milking platform and therefore when dairy farms are expanding they should do so by increasing stocking rate. The inclusion of supplementary feeds will reduce profitability for the vast majority of dairy farmers and could only possibly lead to increases in profitability when coupled increases in stocking rate. (3) Grass based systems while substantially reducing costs at farm level result in a seasonal milk supply profile. This results in a reduced capacity utilization of the milk processing facilities as well as restricted product port folio. However the production of Winter milk will lead to significant cost increases at farm level and should only be encouraged if the specific product produced would be sufficient to cover the additional costs associated with over winter production. Within spring calving systems milk payment systems should be used to encourage an efficient milk supply profile with a mean compact calving date of mid February.
    • Effect of autumn/spring nitrogen application date and level on dry matter production and nitrogen efficiency in perennial ryegrass swards

      O'Donovan, Michael; Delaby, Luc; Stakelum, G.; Dillon, Pat; National Development Plan 2000–2006 (Teagasc, 2004)
      The influence of autumn/spring N-application date and level on grass dry matter (DM) production in spring and on N uptake, recovery and efficiency were examined over 3 years (1998, 1999 and 2000, identified as Year 1, 2 and 3, respectively). Seven N-application dates were investigated in years 2 and 3 while four application dates were investigated in Year 1. The application dates were 21 October (T1), 11 November (T2), 2 December (T3), 23 December (T4), 12 January (T5), 3 February (T6) and 23 February (T7). Three N-application rates (kg N/ha) were used: 30 (N30), 60 (N60) and 90 (N90) plus a zero-N control (N0). Herbage DM yields were determined on: 18 March (H1) and 8 April (H2). Two herbage masses (HM) (40 mm above ground level) at initial Napplication date were investigated: a high HM (HHM) of 500 kg DM/ha and a low HM (LHM) of 100 kg DM/ha. The HM at initial N-application date in Year 1 was HHM, in Year 2 LHM and in Year 3 both HHM and LHM. There was a significant effect of Year (P<0.001), HM (P<0.001), N-application date (P<0.001) and N level (P<0.001) on DM production at both H1 and H2. At H1 there was a significant interaction between N-application date and level for DM production. N-application date had a significant (P<0.001) effect on N recovery at both H1 and H2. The highest N recovery rate at the two harvest dates was at T5, while the lowest was at T1 and T2. At H1 and H2 there was a significant effect (P<0.001) of application date on response to applied N. The responses were 7.5, 8.0, 8.3, 12.0, 15.7, 7.3 and 5.6 (kg DM/kg N) (s.e. 1.88) for T1 to T7,respectively, at H1, while the corresponding values at H2 were 10.3, 8.7, 6.1, 15.2, 17.6,11.4 and 15.1 (s.e. 1.88). At H2 the response to applied N was 15.6, 11.5 and 9.1 (kg DM/kg N) for N30, N60 and N90, respectively (P<0.05). Regression analysis indicated that highest DM production was achieved with T5 for both H1 and H2 harvest dates, while the lowest responses were associated with T1, T2 and T3 application dates.
    • The effect of Holstein-Friesian genotype and feeding system on selected performance parameters of dairy cows on grass-based systems of milk production in Ireland

      Dillon, Pat; O’Connor, Paula M.; McCarthy, S.; Shalloo, Laurence; Linnane, M.; Berry, Donagh; Buckley, James F.; Mee, John F; Horan, Brendan (Teagasc, 2006-01-01)
      The overall objective of this project was to assess, the effect of strain of Holstein-Friesian dairy cow, pasture-based feed system (FS) and their interaction on animal performance in terms of milk productivity and lactation profile, body weight (BW), body condition score (BCS), feed intake and energy balance (EB), reproductive performance and overall economic profitability.
    • Evaluation of the n-alkane technique for estimating herbage dry matter intake of dairy cows offered herbage harvested at two different stages of growth in summer and autumn

      Wright, Marliene; Lewis, Eva; Garry, B.; Galvin, Norann; Dunshea, Frank; Hannah, M.C.; Auldist, Martin J.; Wales, W.J.; Dillon, Pat; Kennedy, Emer; et al. (Elsevier, 2018-11-10)
      The n-alkane technique for estimating herbage dry matter intake (DMI) of dairy cows was investigated in this experiment. Eight Holstein-Friesian dairy cows were offered perennial ryegrass ad libitum that had been harvested at two different herbage masses and during two different seasons, in order to assess the effect of herbage mass and season on the accuracy of the n-alkane technique. Two pre-harvested herbage mass treatments (low, target 1500 kg DM/ha versus high, target 4000 kg DM/ha, measured above 4 cm), were investigated in a crossover factorial arrangement within each of two seasons (summer versus autumn), in Ireland. Each season consisted of two periods, each 12 days in length. Cows were housed in individual metabolism stalls to allow for accurate determination of measured DMI. Herbage DMI was estimated, with the n-alkane technique, by dosing cows twice daily with a C32 n-alkane. Pre-harvest herbage mass and season did not affect the n-alkane estimated DMI, although lack of season and herbage mass effects may have been masked by variation that occurred between swards within the same herbage mass and season. However, there were a number of differences between summer and autumn in the fecal recovery rates of a number of n-alkanes suggesting that the effect of season requires further investigation prior to the application of recovery rates from literature values when investigating diet selection and botanical composition. Overall, the n-alkane technique provided good estimates of DMI; the discrepancy had a standard deviation due to sward of 1.2 and 1.0 kg DM/cow per day, and hence potential bias of up to twice this, and a measurement error standard deviation of 1.3 and 1.0 kg DM/cow per day, for the C33/C32 and C31/C32 n-alkane pair methods respectively. Two n-alkane pairs were tested, and C33/C32 n-alkane provided the most precise estimates of DMI, compared with the C31/C32 n-alkane pair. This research provides some strong evidence for future use of the n-alkane technique including that the accuracy of the technique has not been influenced by contemporary changes to herbage management, is not affected by seasonal changes, and overall is an accurate and precise technique for estimating DMI.
    • Pasture Feeding Changes the Bovine Rumen and Milk Metabolome

      O’Callaghan, Tom; Vázquez-Fresno, Rosa; Serra-Cayuela, Arnau; Dong, Edison; Mandal, Rupasri; Hennessy, Deirdre; McAuliffe, Stephen; Dillon, Pat; Wishart, David; Stanton, Catherine; et al. (MDPI AG, 2018-04-06)
      The purpose of this study was to examine the effects of two pasture feeding systems—perennial ryegrass (GRS) and perennial ryegrass and white clover (CLV)—and an indoor total mixed ration (TMR) system on the (a) rumen microbiome; (b) rumen fluid and milk metabolome; and (c) to assess the potential to distinguish milk from different feeding systems by their respective metabolomes. Rumen fluid was collected from nine rumen cannulated cows under the different feeding systems in early, mid and late lactation, and raw milk samples were collected from ten non-cannulated cows in mid-lactation from each of the feeding systems. The microbiota present in rumen liquid and solid portions were analysed using 16S rRNA gene sequencing, while 1H-NMR untargeted metabolomic analysis was performed on rumen fluid and raw milk samples. The rumen microbiota composition was not found to be significantly altered by any feeding system in this study, likely as a result of a shortened adaptation period (two weeks’ exposure time). In contrast, feeding system had a significant effect on both the rumen and milk metabolome. Increased concentrations of volatile fatty acids including acetic acid, an important source of energy for the cow, were detected in the rumen of TMR and CLV-fed cows. Pasture feeding resulted in significantly higher concentrations of isoacids in the rumen. The ruminal fluids of both CLV and GRS-fed cows were found to have increased concentrations of p-cresol, a product of microbiome metabolism. CLV feeding resulted in increased rumen concentrations of formate, a substrate compound for methanogenesis. The TMR feeding resulted in significantly higher rumen choline content, which contributes to animal health and milk production, and succinate, a product of carbohydrate metabolism. Milk and rumen-fluids were shown to have varying levels of dimethyl sulfone in each feeding system, which was found to be an important compound for distinguishing between the diets. CLV feeding resulted in increased concentrations of milk urea. Milk from pasture-based feeding systems was shown to have significantly higher concentrations of hippuric acid, a potential biomarker of pasture-derived milk. This study has demonstrated that 1H-NMR metabolomics coupled with multivariate analysis is capable of distinguishing both rumen-fluid and milk derived from cows on different feeding systems, specifically between indoor TMR and pasture-based diets used in this study.
    • Teagasc submission made in response to the Consultation Paper on Interim Review of Ireland’s Nitrates Derogation 2019

      Spink, John; Buckley, Cathal; Burgess, Edward; Daly, Karen M.; Dillon, Pat; Fenton, Owen; Horan, Brendan; Humphreys, James; Hyde, Tim; McCarthy, Brian; et al. (Teagasc, 2019-06-04)
      This submission was made in response to the consultation process run jointly by the Department of Housing, Planning, Community and Local Government (DHPCLG) and the Department of Agriculture, Food and the Marine (DAFM) inviting views and comments on proposals for the Interim Review of Ireland’s Nitrates Derogation Programme in 2019. It has been prepared by Teagasc’s Water Quality Working Group in consultation with the Gaseous Emissions Working Group. These working groups have members drawn from both the Knowledge Transfer and Research Directorates of Teagasc. It was prepared following consultation with colleagues across Teagasc using their collective knowledge and expertise in agri-environmental science and practice and the implementation of the Good Agricultural Practice (GAP) and Nitrates Derogation Regulations.