• The eating quality of beef from young dairy bulls derived from two breed types at three ages from two different production systems

      Nian, Yingqun; Kerry, J. P.; Prendiville, Robert; Allen, Paul; Teagasc Walsh Fellowship Programme (Teagasc (Agriculture and Food Development Authority), Ireland, 08/07/2017)
      Expansion of the Irish dairy herd has led to more dairy breed male calves being available for beef production. This study investigated the physico-chemical and sensory characteristics of beef from Holstein-Friesian (HF) and Jersey × HF (JEX) young bulls fed pasture grass only or pasture grass plus 2 kg concentrate during their first grazing season and slaughtered at 15, 19 or 22 mo of age. Longissimus thoracis (LT) muscles were collected from 67 carcasses. Postmortem pH, ultimate pH (pHu), meat colour, chemical composition, collagen content and solubility were evaluated. After ageing for 21 d, Warner-Bratzler shear force and cooking loss were determined, and assessments by a trained sensory panel were conducted. Meat from older animals was darker. The pHu, moisture and ash contents decreased, while residual roast beef flavour length increased with age. However, increasing age to slaughter did not negatively influence tenderness. JEX beef had lower cooking loss, was darker and redder, in addition to having higher sensory scores for initial tenderness and fattiness than HF beef. Warner-Bratzler variables were positively correlated with cooking loss and chewiness and were negatively correlated with intramuscular fat (IMF) content, soluble collagen and initial tenderness. In summary, most young dairy bull beef samples were acceptably tender after 21 d of ageing and half of them had acceptable IMF content. Slaughter age affected beef colour, pHu, chemical composition and flavour length. The eating quality of meat from the JEX breed type was considered to be superior to that of the HF breed type. Diet during the first season had no effect on meat quality traits.
    • 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.
    • Determination of Listeria monocytogenes numbers at less than 10 cfu/g

      Hunt, K.; Vacelet, M.; Jordan, Kieran; Department of Agriculture, Food and the Marine, Ireland; Dairy Processing Technology Centre; 11/F/008; TC 2014 0016. (Teagasc (Agriculture and Food Development Authority), Ireland, 09/06/2017)
      Listeria monocytogenes is a foodborne pathogen that causes a relatively rare foodborne disease called listeriosis, with a high mortality rate of 20%-30% and an undefined dose response. Current European Union regulations permit up to 100 colony-forming units (cfu)/g in food at the end of its shelf life, where the food has been shown not to support the growth of this pathogenic bacterium. Therefore, enumeration of L. monocytogenes at low numbers in food is important. The objective of this study was to reduce the detection limit of L. monocytogenes in food by a factor of 10. The International Organisation for Standardisation (ISO) 11290-2 method for enumeration of L. monocytogenes in food recommends spreading 0.1 mL of a 1:10 dilution of the food on the surface of an agar plate (detection limit 100 cfu/g), or 1.0 mL spread in equal parts on the surface of three agar plates (detection limit: 10 cfu/g). The pour-plate method (using 1 or 10 mL of an appropriate dilution) was compared to the spread-plate method using the ISO-approved chromogenic medium Agar Listeria according to Ottaviani and Agosti (ALOA). Using the pour-plate method, the colony morphology and halo formation were similar to the spread-plate method from pure cultures and inoculated foods. Using the pour-plate method in a 140 mm Petri dish, 10 mL of a 1:10 dilution of food allowed determination of numbers as low as 1 cfu/g. Applying this method, L. monocytogenes in naturally contaminated food samples were enumerated at numbers as low as 1-9 cfu/g.
    • Sinapinic and protocatechuic acids found in rapeseed: isolation, characterisation and potential benefits for human health as functional food ingredients

      Quinn, Leah; Gray, Stephen G.; Meaney, Steven; Finn, Stephen; Kenny, Owen; Hayes, Maria (Teagasc (Agriculture and Food Development Authority), Ireland, 13/12/2017)
      Rapeseed is one of the world’s major oilseeds, and rapeseed oil is produced by pressing of the seeds. This process results in the production of a low-economic-value by-product, rapeseed meal, which is commonly used as animal feed. Rapeseed meal is rich in bioactive phenolic compounds, including sinapinic acid (SA) and protocatechuic acid (PCA). Isolation of these bioactive compounds from a by-product of rapeseed oil production is largely in agreement with the current concept of the circular economy and total utilisation of crop harvest using a biorefinery approach. In this review, current information concerning traditional and novel methods to isolate phenolic compounds – including SA and PCA – from rapeseed meal, along with in vitro and in vivo studies concerning the bioactivity of SA and PCA and their associated health effects, is collated. These health effects include anti-inflammatory, anti-cancer, anti-diabetes activities, along with histone deacetylase inhibition and protective cardiovascular, neurological and hepatic effects. The traditional extraction methods include use of solvents and/or enzymes. However, a need for simpler, more efficient methodologies has led to the development of novel extraction processes, including microwave-assisted, ultrasound-assisted, pulsed electric field and high-voltage electrical discharge extraction processes.
    • The effect of antimicrobials on verocytotoxin bacteriophage transduction under bovine rumen fluid and broth conditions

      Nyambe, Sepa; Burgess, Catherine; Whyte, P.; Bolton, Declan; Department of Agriculture, Food and the Marine, Ireland; 11/F/051 (Teagasc (Agriculture and Food Development Authority), Ireland, 15/11/2017)
      The verocytotoxin genes in verocytotoxigenic Escherichia coli (VTEC) are carried by bacteriophages, incorporated into the bacterial genome (prophage). Antibiotics may promote phage replication and release to infect other cells (transduction), thus leading to the emergence of new VTEC strains. This study investigated transduction of a verocytotoxin2-encoding bacteriophage (3538(vtx2::cat)) under laboratory conditions, including the effect of antibiotic treatments. Luria-Bertani Miller broth and rumen fluid (raw and sterilised by irradiation) were inoculated with the donor (C600φ3538(Δvtx2::cat)) and recipient (E. coli C600::kanamycinR) strains (4 log10 cfu/mL) and incubated at 38°C. Antibiotic treatments (minimal inhibitory and sub-inhibitory concentrations of ampicillin, cefquinome, oxytetracycline and sodium sulfamethazine) were applied after 3 h. Samples were tested for donor, recipient, cell-free phage and transductants at times t = 0, 3, 4, 6, 27 (24 h post-antibiotic treatment) and 51 h. Free phage was detected in the untreated broth and rumen samples, as were the transductants confirmed by polymerase chain reaction. The antibiotic treatments did not significantly (P > 0.01) increase the concentrations of free phage or transductants detected. It was therefore concluded that, under laboratory conditions, the antibiotics tested did not induce bacteriophage lysis, release and infection of new bacterial cells beyond that constitutively found in the phage population.
    • 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.
    • Assessment of water-limited winter wheat yield potential at spatially contrasting sites in Ireland using a simple growth and development model

      Lynch, J. P.; Fealy, Reamonn; Doyle, D.; Black, L.; Spink, John; Department of Agriculture, Food and the Marine, Ireland (Teagasc (Agriculture and Food Development Authority), Ireland, 19/09/2017)
      Although Irish winter wheat yields are among the highest globally, increases in the profitability of this crop are required to maintain its economic viability. However, in order to determine if efforts to further increase Irish wheat yields are likely to be successful, an accurate estimation of the yield potential is required for different regions within Ireland. A winter wheat yield potential model (WWYPM) was developed, which estimates the maximum water-limited yield achievable, within the confines of current genetic resources and technologies, using parameters for winter wheat growth and development observed recently in Ireland and a minor amount of daily meteorological input (maximum and minimum daily temperature, total daily rainfall and total daily incident radiation). The WWYPM is composed of three processes: (i) an estimation of potential green area index, (ii) an estimation of light interception and biomass accumulation and (iii) an estimation of biomass partitioning to grain yield. Model validation indicated that WWYPM estimations of water-limited yield potential (YPw) were significantly related to maximum yields recorded in variety evaluation trials as well as regional average and maximum farm yields, reflecting the model’s sensitivity to alterations in the climatic environment with spatial and seasonal variations. Simulations of YPw for long-term average weather data at 12 sites located at spatially contrasting regions of Ireland indicated that the typical YPw varied between 15.6 and 17.9 t/ha, with a mean of 16.7 t/ha at 15% moisture content. These results indicate that the majority of sites in Ireland have the potential to grow high-yielding crops of winter wheat when the effects of very high rainfall and other stresses such as disease incidence and nutrient deficits are not considered.
    • Visual drainage assessment: A standardised visual soil assessment method for use in land drainage design in Ireland

      Tuohy, P.; Humphreys, James; Holden, N.M.; O'Loughlin, James; Reidy, B.; Fenton, Owen T. (Teagasc (Agriculture and Food Development Authority), Ireland, 20/08/2016)
      The implementation of site-specific land drainage system designs is usually disregarded by landowners in favour of locally established ‘standard practice’ land drainage designs. This is due to a number of factors such as a limited understanding of soil–water interactions, lack of facilities for the measurement of soil’s physical or hydrological parameters and perceived time wastage and high costs. Hence there is a need for a site-specific drainage system design methodology that does not rely on inaccessible, time-consuming and/or expensive measurements of soil physical or hydrological properties. This requires a standardised process for deciphering the drainage characteristics of a given soil in the field. As an initial step, a new visual soil assessment method, referred to as visual drainage assessment (VDA), is presented whereby an approximation of the permeability of specific soil horizons is made using seven indicators (water seepage, pan layers, texture, porosity, consistence, stone content and root development) to provide a basis for the design of a site-specific drainage system. Across six poorly drained sites (1.3 ha to 2.6 ha in size) in south-west Ireland a VDA-based design was compared with (i) an ideal design (utilising soil physical measurements to elucidate soil hydraulic parameters) and (ii) a standard design (0.8 m deep drains at a 15 m spacing) by model estimate of water table control and rainfall recharge/drain discharge capacity. The VDA method, unlike standard design equivalents, provided a good approximation of an ideal (from measured hydrological properties) design and prescribed an equivalent land drainage system in the field. Mean modelled rainfall recharge/drain discharge capacity for the VDA (13.3 mm/day) and ideal (12.0 mm/day) designs were significantly higher (P < 0.001, s.e. 1.42 mm/day) than for the standard designs (0.5 mm/day), when assuming a design minimum water table depth of 0.45 m.
    • A note on the effects of test-end vacuum on milking characteristics

      O'Callaghan, Edmund J.; Gleeson, David E (Teagasc (Agriculture and Food Development Authority), Ireland, 2004)
      The magnitude of vacuum applied to the teat end can have a major effect on milking characteristics. While milking vacuum is usually measured in the milk pipeline, the teat-end vacuum during milk flow depends on the configuration of the milking unit. The objective was to establish the effect of teat-end vacuum, recorded during flow simulation, on actual milking time, milk yield, and both mean and peak milk-flow rates. Four configurations of milking units were set up to give vacuum levels of 35, 38, 40 and 42 kPa at the apex of an artificial teat during simulated milking. The experiment involved a latin square design with four groups of Friesian cows (14/group), four 2-day periods and four treatments (vacuum level). Altering the vacuum level had no significant effect on milk yield. There were no differences in milking characteristics between vacuum levels of 38 and 40 kPa. A vacuum level of 42 kPa gave a shorter milking time (P < 0.001), higher average milk-flow rate (P < 0.01) and higher peak milk-flow rate (P < 0.001) than the three lower vacuum levels. Milking time was significantly longer (P < 0.001) and peak milk-flow rate lower (P < 0.001) with a vacuum of 35 kPa compared to other vacuum levels.
    • A note on the effects of paddock size on the white clover content of swards grazed by sheep

      de Wolf, P.; Schulte, Rogier P.; Lantinga, E. A. (Teagasc (Agriculture and Food Development Authority), Ireland, 2004)
      The maintenance of a high white clover content in mixed swards under sheep grazing has been a challenge to date. This paper presents the results of an experiment in which the effect of the length of a grazing period on the botanical composition of a mixed sward was studied. Paddocks ranging in size from 0.014 to 0.133 ha were rotationally grazed by a flock of seven dry ewes. Consequently, grazing periods ranged from 1 to about 8 days. On all paddocks, the proportion of perennial ryegrass declined progressively during the grazing season, regardless of paddock size. The proportions of both white clover and creeping bentgrass content increased on all paddocks during the same period. For white clover, the size of the increase was negatively related to paddock size, whereas a positive relationship was found between the paddock size and the magnitude of the increase in creeping bentgrass. This suggests that the proportion of white clover may be increased under sheep grazing by implementation of strip-grazing.
    • Surveys of cereal diseases in Northern Ireland, 1976 to 2000

      Mercer, P. C.; Ruddock, A. (Teagasc (Agriculture and Food Development Authority), Ireland, 2004)
      A number of disease surveys was carried out on the three main cereals grown in N. Ireland from 1976 to 2000, namely spring and winter barley and winter wheat. Although not all crops were surveyed in each year, the surveys provide a good picture of changes in disease spectra over the years. The most dramatic change in spring barley disease has been the almost complete disappearance of Blumeria graminis (mildew) and its replacement as the dominant disease by Rhynchosporium secalis (leaf blotch). Leaf-spotting ascribed to physiological causes also became more common in the latter years of the surveys. The disease spectrum of winter barley was more consistent from year to year, with Rhynchosporium secalis as the most common pathogen. Barley yellow dwarf virus was relatively severe in 1984, but in no other years. In winter wheat, there was a major change with the almost complete eclipse of Phaeosphaeria nodorum leaf blotch by Mycosphaerella graminicola (septoria tritici blotch). Gaeumannomyces graminis (take-all) was frequently severe. Surveys of cultivar popularity generally showed a rapid change in varieties over a relatively short time. Surveys of fungicide usage tended to show an increase in numbers of sprays applied, in spite of the fact that commercial pressures should have been acting towards a reduction in spraying.
    • Rearing calves outdoors with and without calf jackets compared with indoor housing on calf health and live-weight performance

      Earley, Bernadette; Murray, Margaret; Farrell, J.A.; Nolan, Marie-Jean (Teagasc (Agriculture and Food Development Authority), Ireland, 2004)
      The objective of this study was to compare the effects of rearing calves outdoors, with and without all-weather calf jackets, with calves reared indoors on calf immunity and animal performance. In February 1999, male Holstein calves (mean (s.e.) weight 55 (1.90) kg) were randomly assigned to one of three treatments (n=30 per treatment): 1) outdoors with jacket, (J; mean age 19 (s.e. 2.0) days); 2) outdoors without jacket (NJ; mean age 19 (s.e. 1.8) days), and 3) indoors on straw (I; mean age 19 (s.e. 1.0) days). Calves received an individual allowance of 25 kg of milk replacer dry matter during the first 42 days with ad libitum access to a concentrate ration from day 0 to 63. The jackets were removed from the calves on day 42. Live-weight gain from day 0 to day 63 of the study was not significantly different between treatments (J, 0.79; NJ, 0.80; I, 0.80 kg). Sixty percent of the J calves and 53% of the NJ calves required four or more antibiotic treatments for respiratory disease while corresponding treatments were required for 97% of the I calves. The incidence of diarrhoea was significantly higher in both outdoor treatments compared to the I treatment. There was no significant difference in white blood cell counts or in serum immunoglobulin concentrations between treatments on days 0, 21, 42 and 63 or in in vitro interferon-γ production on day 63. It is concluded that using calf jackets on calves reared outdoors had no beneficial effect on calf performance or immune status. The incidence of respiratory disease was higher and diarrhoea incidence was lower in calves reared indoors compared with calves reared outdoors. There was no significant difference in incidences of diarrhoea and respiratory disease between the two outdoor treatments.
    • Effect of suckler cow genotype and nutrition level during the winter on voluntary intake and performance and on the growth and slaughter characteristics of their progeny

      Drennan, Michael J; McGee, Mark (Teagasc (Agriculture and Food Development Authority), Ireland, 2004)
      A 4-year study comparing Hereford × Friesian (HF) and Limousin × Friesian (LF) spring-calving cows and two grass silages on the performance of suckler cows and their progeny was undertaken using 163 cows. Cows were offered, to appetite, grass silage of either low (L) or moderate (M) digestibility in late pregnancy and early lactation. Cows and their calves spent from April until weaning in October at pasture. Bulls were slaughtered at 16 months of age and heifers at 20 months of age. There was no significant effect of cow genotype on dry matter (DM) intake, annual live-weight change or reproductive performance but annual body condition score gain was higher (P < 0.05) for HF than for LF cows. Cows offered the M silage had higher (P < 0.001) DM intake, lower winter live-weight loss (P < 0.001) and lower (P < 0.01) live-weight gain at pasture than cows offered the L silage. Calf birth, weaning and slaughter weights were not significantly different (P > 0.05) between genotypes. The male progeny of LF cows had a higher kill-out proportion (P < 0.001) and carcass weight (P < 0.05) and lower (P < 0.05) carcass fat score than HF cows. Compared to the M silage, the male progeny from cows offered the L silage had a greater daily gain from birth to slaughter (P < 0.05), slaughter weight (P < 0.05) and carcass weight (P < 0.05). The corresponding differences for female progeny were in the same direction but were not statistically significant.
    • Effect of autumn/spring nitrogen application date and level on dry matter production and nitrogen efficiency in perennial ryegrass swards

      O'Donovan, Michael; Delaby, L; Stakelum, G; Dillon, Pat (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.
    • Cow serum and colostrum immunoglobulin (IgG1) concentration of five suckler cow breed types and subsequent immune status of their calves

      Murphy, B.M.; Drennan, Michael J; O'Mara, Frank P.; Earley, Bernadette (Teagasc (Agriculture and Food Development Authority), Ireland, 2004)
      The objective of this study was to determine the effect of cow breed type on (a) cow serum and colostrum immunoglobulin (IgG1) concentrations and (b) subsequent calf serum IgG1 concentration and zinc sulphate turbidity (ZST) units. Five cow breed types were examined: LF (Limousin × Friesian), LLF (Limousin × (Limousin × Friesian)), L (Limousin), C (Charolais) and SLF (Simmental × (Limousin × Friesian)). Three blood samples were taken by jugular venipuncture from the cows at approximately 90, 60 and 30 days pre partum, at parturition and at 15 days or more post partum and from the calves at 48 (40 to 56) h post partum. Prior to suckling a 20 ml sample of colostrum was obtained. Milk yield was estimated using the weigh-suckleweigh technique. The decrease in serum IgG1 concentration in cows between 90 days pre partum and parturition was greater (P < 0.01) for LF cows than all other breed types, except SLF. There was no difference between LLF, L, C and SLF cows. There was no effect of cow breed type on colostrum IgG1 concentration. Milk yield was higher (P < 0.001) for LF cows than all other breed types, while that of SLF was higher than the three remaining breed types, which were similar. Calf serum IgG1 concentration and ZST units were higher (P < 0.01) for the progeny of LF cows than all others except SLF. There was no difference between the progeny of LLF, L, C and SLF cows. Calf serum IgG1 was affected by cow breed type and showed a positive relationship with cow serum IgG1 decreases in late pregnancy.
    • 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.
    • Effects over time of fertiliser P and soil series on P balance, soil-test P and herbage production

      Herilhy, Mary M.; McCarthy, J.; Breen, James; Moles, Richard (Teagasc (Agriculture and Food Development Authority), Ireland, 2004)
      Quantification of the balance between P input and offtake (P balance), and the consequent effect on soil-test P, is essential for management of sustainable soil and fertiliser nutrient supply. Results of measurements on 31 cut swards showed that change in P balance over 4 years was significantly affected by both P treatment and soil series. The more negative P balances were in high-P soils, and in soils of non-limestone parent material compared with limestone parent material. Initial mean Morgan P of 4.3 and 12.6 mg/l, in low and high index groups (0 to 6.0 and ≥6.1 mg/l) decreased to 1.7 and 4.4 mg/l after 4 years with no P treatment, in response to annual changes of ca. 25 to 35 kg/ha in P balance. Decreases were progressively smaller with increased P input, and smaller in non-limestone than limestone soils. The ratio of negative P balance to change in Morgan P varied from 20:1 to 70:1 depending on soil P index and parent material. Five sites gave a response to P in the final year following annual P inputs of 20 and 40 kg/ha, although Morgan P was ≤3.0 mg/l at 12 sites in the preceding autumn and 3.1 to 6.0 at nine sites. The results showed that both P balance and soil series should be taken into account in efficient fertiliser management, and that data from cut swards can be extrapolated to grazed swards when adjusted for P offtake. However, the results did not support the assumption that inputs balance offtakes in direct proportion.
    • Comparison of concentrates or concentrates plus forages in a total mixed ration or discrete ingredient format: effects on beef production parameters and on beef composition, colour, texture and fatty acid profile

      Cooke, D.W.I; Monaghan, Frank J; Brophy, P.; Boland, Maurice (Teagasc (Agriculture and Food Development Authority), Ireland, 2004)
      Diets consisting primarily of concentrates or of concentrates plus silage in a total mixed ration (TMR) or discrete ingredient format were compared for effects on beef production traits and on beef quality. Sixty continental cross heifers (377 kg, s.d. 31) were allocated to one of the following feeding regimens for 96 days pre-slaughter: (i) a control ration of grass silage, maize silage, a cereal-based concentrate and straw at proportionately, 0.23, 0.15, 0.59 and 0.03 of dietary dry matter, respectively; (ii) a total mixed ration (TMR) with the same dietary ingredients as the control ration; (iii) a high concentrate ration (HC) of a cereal-based diet and straw at proportionately 0.95 and 0.05 of dietary dry matter, respectively. Subcutaneous fat samples were taken from all animals at slaughter and the strip-loin was excised from 10 animals per group for colour, texture and fatty acid determination. The HC and TMR groups had higher (P < 0.05) daily live-weight gain, slaughter weight and carcass weight than the control group. Muscle protein was highest (P < 0.01) in the TMR group while muscle marbling was highest (P < 0.01) in the HC group. Subcutaneous fat from the HC group was less (P < 0.001) yellow than fat from the other groups. Fatty acid analysis of intramuscular fat showed that the HC group had higher C18:1 and lower C18:3 proportions than the control group (P < 0.05). The n-6:n-3 fatty acid ratio of intramuscular fat from the HC group was higher (P < 0.05) than that of the other groups. The results suggest that, at similar feed intakes, TMR feeding offers advantages for beef production over feeding ingredients separately, and yields muscle with a higher protein concentration, while high concentrate feeding yields whiter subcutaneous fat and intramuscular fat with a less nutritionally favourable n-6:n-3 fatty acid ratio.
    • Note on a portable simulator for analysis of milking machine porformance

      O'Callaghan, Edmund, J. (Teagasc (Agriculture and Food Development Authority), Ireland, 2004)
      A portable flow simulator was developed for recording vacuum variations in commercial milking machine clusters. The cluster in the milking unit under evaluation was mounted on the frame of the simulator and the flow of water through each liner was regulated by separate flow meters. By placing an artificial teat into the liners the flow characteristics during actual milking were simulated. Measurement vacuum sensors were mounted in the claw, in one artificial teat, in the pulsation chamber and in the milk pipeline. Analog and digital outputs were recorded. The system was validated by comparing the outputs with those obtained with a laboratory flow simulator and with recordings taken during cow milking. The recordings with the portable simulator and the laboratory simulator were identical; the profiles of the analogue signals obtained with the portable simulator and from cow milking were similar. The portable flow simulator will allow recording of vacuum variations in commercial milking machines during simulated or actual milking.
    • Analysis of DRB1 exon 2 genotyping by STR size analysis in Suffolk and Texel sheep breeds

      Sayers, Gearoid; Mitchel, S; Ryan, Marion T; Stear, M.J.; Hanrahan, James P; Sweeney, Torres (Teagasc (Agriculture and Food Development Authority), Ireland, 2004)
      Alleles of the DRB1 exon 2 locus of the major histocompatibility complex have recently been associated with genetic resistance to gastrointestinal nematodes in sheep. While sequence-based typing is the standard method for allele discrimination, a rapid, high throughput method for DRB1 exon 2 genotyping is required if such information is to be incorporated into national breeding programmes. Previous studies have highlighted a simple tandem repeat (STR) located within intron 2 of the DRB1 gene, which could potentially be used to accurately assess the allele present within the adjacent exon 2. The aims of this study were firstly to compare two methods of STR analysis, Genescan™ and autoradiography, and secondly to investigate if STR analysis of DRB1 intron 2 could be used to accurately assess the profile of DRB1 exon 2. Six DRB1 exon 2 alleles were identified by sequence-based typing in Suffolk (n = 31) and eight in Texel (n = 60) sheep. The results indicated that Genescan™ was a more accurate method of STR analysis than autoradiography. The expected 1:1 correspondence between STR size, analysed by Genescan™ and DRB1 exon 2 allele, determined by sequence-based typing, was not observed. However, the correspondence was found to be degenerate, whereby some alleles were associated with two STR sizes. Thus, irrespective of the STR size identified, STR analysis by Genescan™ identified the correct allele in all cases within both populations of animals studied. However, the Genescan™ method of allele identification cannot be used for Suffolk × Texel crossbred progeny or in other breeds where the relationship between STR size and DRB1 exon 2 allele is not known.