Recent Submissions

  • Yield losses caused by late blight (Phytophthora infestans (Mont.) de Bary) in potato crops in Ireland

    Dowley, L.J.; Grant, Jim; Griffin, D. (Teagasc, Oak Park, Carlow, Ireland, 2008)
    Field experiments, using foliage blight susceptible cultivars, were conducted at Oak Park, Carlow from 1983 to 2007 to determine the loss in potato production caused by crop infection with Phytophthora infestans. In each of the 25 years an untreated control was compared with protectant and with systemic fungicide programmes to determine the effect of late blight on the defoliation percentage at the end of the season, the area under the disease progress curve, marketable tuber yield, total tuber yield and yield of blighted tubers. The earliest date of first recorded late blight was 22 June and the latest was 15 September, but in 15 of the 25 years, blight was first recorded between 17 July and 13 August. Disease reached epidemic proportions in all but 4 of the years. Yields varied considerably among years. The mean loss in total yield from not using a fungicide was 10.1 t/ha. Differences in yield were significant across the 25 seasons. No overall increase in aggressiveness of the pathogen could be detected over the 25-year period.
  • The spatial variation in degree days derived from locational attributes for the 1961 to 1990 period

    Fealy, R.; Fealy, Reamonn (Teagasc, Oak Park, Carlow, Ireland, 2008)
    The relationship between degree days and locational attributes for a selection of sites in Ireland were examined in order to objectively extrapolate values for unmeasured locations. While a number of previous researchers have employed similar methodologies in order to map the geographical variation for selected degree-day thresholds, the authors seek to expand on this existing research through the inclusion of a denser network of stations and for a longer time period (1961 to 1990). Degree days were calculated on a daily basis for three selected threshold temperatures, 0 oC, 5 oC, 10 oC, in order to provide a more accurate assessment of the accumulated monthly energy available at each station. The geographical distribution of degree days was then mapped employing a stepwise linear regression which related locational parameters for each station to the calculated monthly accumulations. While none of the selected thresholds are specific to any plant or insect species they are indicative of the likely spatial variation in degree days due to location and elevation. It is intended that the derived spatial distributions will be useful in providing a basis for assessing likely changes in the thermal regime arising as a consequence of climate change over the course of the present century with the associated potential impact on spatial location of arable cropping in Ireland.
  • Post-weaning growth, ultrasound and skeletal measurements, muscularity scores and carcass traits and composition of progeny of five beef suckler cow genotypes

    Murphy, B.M.; Drennan, Michael J; O'Mara, Frank P.; McGee, Mark (Teagasc, Oak Park, Carlow, Ireland, 2008)
    Post-weaning growth, ultrasound and skeletal measurements, muscularity scores, and carcass traits and composition of the progeny of spring-calving Limousin (L), Charolais (C), Limousin × Holstein-Friesian (LF), Limousin × (Limousin × Holstein-Friesian) (LLF) and Simmental × (Limousin × Holstein-Friesian) (SLF) cow genotypes was determined over 3 years. Bull and heifer progeny were slaughtered at ~460 and ~610 days of age, respectively. Post-weaning growth did not differ significantly between the genotypes. Progeny from LF and SLF cows had the highest (P<0.001) carcass gain per day of age, whereas progeny from L and C cows had the highest (P < 0.01) carcass conformation score and lowest (P < 0.001) fat score. The proportion of meat in the car¬cass was higher (P < 0.001) and bone lower (P < 0.001), and meat to bone ratio higher (P < 0.001) for the progeny of L cows than all other genotypes, which were similar. Carcass fat proportion was similar for progeny of L and C cows and lower (P < 0.001) than LLF and SLF, with LF being intermediate. The progeny from L cows tended to have the greatest proportion of hind-quarter in the carcass. Genotype effects were mini¬mal when the proportion of high-value cuts was expressed relative to weight of meat in the carcass and hind-quarter. In conclusion, there was no effect of cow genotype on the performance of their progeny from weaning to slaughter. However, crossbred cows with good maternal (milk) traits produced progeny with a higher carcass weight per day of age, whereas the purebred continental cows produced progeny with superior carcass classification traits.
  • Performance and feed intake of five beef suckler cow genotypes and pre-weaning growth of their progeny

    Murphy, B.M.; Drennan, Michael J; O'Mara, Frank P.; McGee, Mark (Teagasc, Oak Park, Carlow, Ireland, 2008)
    The effect of beef suckler cow genotype on feed intake, performance, milk yield and on pre-weaning growth of their progeny was determined over four lactations. The five cow genotypes examined were Limousin (L), Charolais (C), Limousin × Holstein-Friesian (LF), Limousin × (Limousin × Holstein-Friesian) (LLF) and Simmental × (Limousin × Holstein-Friesian) (SLF). The herd calved in spring and the progeny spent from April until weaning (October/ November) at pasture with their dams. Live weight (kg) at the start of the indoor winter period was greater (P < 0.001) for C (702) than L (616) cows who in turn were heavier than LF (552) and LLF (574), with SLF (582) being intermediate. Silage dry matter (DM) intake (kg /day) was greater (P < 0.01) for C and SLF cows than L and LLF, whereas LF were inter-mediate. Dry matter intake (kg/day) of zero-grazed grass did not differ (P > 0.05) between the genotypes but followed a similar trend to grass silage intake. The decrease in live weight over the indoor winter period was greater (P < 0.01) for L and C cows than for LLF and SLF, whereas LF were intermediate. The increase in live weight during the grazing season was greater (P < 0.01) for C cows than all except L, which were intermediate. Calving difficulty score was greater (P < 0.01) for C cows than LLF, L and SLF, whereas LF were intermediate. Birth weight of calves from LF cows was lower (P < 0.001) than C with L being intermediate, but greater than LLF, with SLF being intermediate. Milk yield (kg/day) was higher (P < 0.001) for LF (9.7) and SLF (8.7) cows than the other genotypes (5.5 to 7.0), which did not differ significantly. Pre-weaning live-weight gain was greater (P < 0.001) for progeny of LF cows than all other genotypes except SLF, which in turn were greater than L and C, with LLF being intermediate. In conclusion, calf pre-weaning growth was higher for cow genotypes with higher milk yield, which was also associated with higher cow DM intake.
  • A note on the effect of supplementation with microbial phytase and organic acids on feed intake and growth performance of growing pigs

    Guy, J.H.; Edge, H.L.; Blanchard, P.J.; Ilsey, S.E.; Coonan, C.; Feuerstein, D. (Teagasc, Oak Park, Carlow, Ireland, 2008)
    This experiment was designed to investigate the effects of supplementation with phytase, either alone or in combination with organic acids, on feed intake and growth of pigs from 8 to 89 kg live weight. Some 240 pigs were used in four experimental treatments comprising: (1) control, (2) control plus phytase, (3) control plus phytase plus liquid organic acids (formic, propionic), and (4) control plus phytase plus powdered organic acids (formic, fumaric, propionic). Feed intake and growth rate in the weaner stage were increased (P < 0.05) by phytase supplementation, with some additional benefits from organic acid inclusion. Interval to slaughter was reduced (P < 0.05) by phytase supplementation.
  • Effects of feeding management and breed type on muscle chemical composition and relationships between carcass and muscle compositional traits in steers

    Keane, Michael G.; Moloney, Aidan P (Teagasc, Oak Park, Carlow, Ireland, 2008)
    There is little published information on the chemical composition of muscle from beef steers produced in Irish production systems. The objective of this study was to determine the effects of feeding management and breed type on m. longissimus chemical composition of steers, and to examine relationships between selected carcass traits and measures of carcass and muscle composition. A total of 117 steers (65 Friesians and 52 Charolais  Friesians) were assigned on weight within breed type to a pre-experimental slaughter group and to one of 12 finishing groups (6 feeding treatments by 2 finishing periods). The 6 feeding treatments were: (1) silage only offered ad libitum (SO), (2) and (3) SO plus a low concentrate level, (4) and (5) SO plus a high concentrate level, (6) concentrates ad libitum. In Treatments 2 and 4, the silage and concentrates were offered separately whereas in Treatments 3 and 5 they were offered as a total mixed ration (TMR). The two finishing periods were 105 and 175 days. Mean low, high and ad libitum concentrate levels were proportionately 0.415, 0.732 and 0.927, respectively, of daily dry matter intake. Carcass weight, fat depth, fat proportion in the rib joint and m. longissimus lipid concentration all increased (P < 0.01) asymptotically with increasing concentrate level. Carcass fat class (P < 0.07), perinephric plus retroperitoneal fat weight (P < 0.001), fat depth (P < 0.06), fat proportion in the rib joint (P < 0.001) and m. longissimus lipid concentration (P < 0.001) were higher for Friesians than for Charolais crosses. Carcass weight increased (P < 0.001) with increased duration of the finishing period, as did carcass fat class (P < 0.06), fat proportion in the rib joint (P < 0.001) and m. longissimus lipid concentration (P < 0.001). Method of feeding had no effect on any of the traits measured.
  • The effect of cultivator/ridger type on the physical properties of ridge, power requirement and potato yield

    Bernik, R.; Vucajnk, F. (Teagasc, Oak Park, Carlow, Ireland, 2008)
    In 2002, 2003 and 2004, field trials were carried out in Slovenia in the form of random blocks with five replications. Three potato cultivators/ridgers were used on medium textured soil. The aim was to establish which potato cultivator/ridger was the most suitable for inter-row space cultivation, ridge shaping and achievement of the highest possible potato yield, work-rate and productivity. A drawn cultivator/ridger with spring tines on a parallelogram framework and wing ridge heads attached (STC), was com¬pared with a drawn cultivator/ridger with rigid tines on a parallelogram framework and cogwheel ridge discs attached (RTC) and with a rotary, PTO-driven cultivator/ridger (RC). The latter created the largest cross-sectional area of the ridge and proved to be the most efficient at crushing soil aggregates in the inter-row space and at ridge shap¬ing. It also allowed the lowest cone resistance at the ridge centre and in the central part of the ridge side. A higher number of tubers per plant resulted from ridges made by the PTO-driven cultivator/ridger giving a higher total yield of tubers than with the other two cultivators/ridgers. In comparison with the drawn cultivators/ridgers, the PTO-driven cultivator/ridger shaped ridges with better physical properties on medium textured soil; however both drawn cultivators/ridgers had greater work-rates, and also needed less energy to cultivate a unit of area.
  • The effect of boar breed type on reproduction, production performance and carcass and meat quality in pigs

    McCann, M.E.E.; Beatie, V.E.; Watt, D.; Moss, B.W. (Teagasc, Oak Park, Carlow, Ireland, 2008)
    A total of 720 sows were inseminated with semen from eight commercially available boar breed types (Landrace, Large White, Duroc, Landrace Large White, Landrace  Duroc, Landrace Large White Duroc, Large White Duroc and Landrace Large White Pietrain). There were no effects of purebred versus crossbred boar breed type on reproductive performance or on production performance of progeny. The only carcass evaluation parameter affected was V measurement (backfat thickness at the edge of the eye muscle) which was 2 mm thicker (P < 0.05) for the progeny of crossbred boars. Meat from pigs of purebred boars breed had a higher proportion of intramuscular fat than that from crossbred boars breed (26.5 v 21.1 g/kg, respectively, P < 0.05). There were inconsistent effects of individual boar breed type on performance, carcass quality and meat qua lity. Producers should consider the variation between the progeny of individual boars to achieve improved production performance. There was also a lack of relationship between backfat at the P2 position and eye muscle area or depth (r  −0.03 and −0.01, respectively) which suggests that carcass characteristics other than P2 backfat need to be included in the selection of breeding animals. Similarly, the weak correlations between carcass and meat quality traits (r < 0.3) indicate that if meat quality is to be improved, it must be specifically included in the selection criteria.
  • Effect of beef sire expected progeny difference for carcass conformation on live animal muscularity scores and ultrasonic muscle and fat depths, and on carcass classification and composition of their progeny

    Drennan, Michael J; McGee, Mark (Teagasc, Oak Park, Carlow, Ireland, 2008)
    The objective was to examine the effect of sire expected progeny difference (EPD) for carcass conformation score on the live animal and carcass traits of their progeny. In each of 4 years a Charolais sire of high and one of average EPD for carcass conformation score were mated to spring-calving suckler cows and the bull and heifer progeny were taken to slaughter at 455 (s.d. 25.2) and 607 (s.d. 29.5) days of age in 4 and 3 years, respectively. The difference in EPD between the sire EPD groups for carcass conformation and fat scores (scale 1 to 15), and carcass weight were, 0.45 units, −0.53 units and 9.7 kg, respectively. Muscularity scores were recorded at weaning (7 to 9 months of age) and pre-slaughter, and ultrasound measurements were recorded pre-slaughter. Carcass weight, and conformation and fat scores were recorded at slaughter and an 8-rib pistola from the right side of each carcass was dissected into lean, fat and bone. There was no significant effect of sire EPD group on live weight or carcass weight, but kill-out proportion, ultrasound muscle depth and the Irish Cattle Breeding Federation muscularity scores were greater (P < 0.001) for progeny of the high than the average EPD group. Bull progeny of high EPD sires had better (P < 0.001) Signet muscularity scores and carcass conformation scores than bull progeny from average EPD sires, whereas there was no effect of sire EPD group on heifer progeny. Compared to progeny of the average EPD sire group, those from the high EPD group had a lower weight of kidney and channel fat (P 0.06) and carcass fat score (P < 0.05), lower proportions of fat (P < 0.001) and bone (P < 0.01) in the pistola, and higher weight of pistola, both absolutely (P < 0.01) and relative to carcass weight (P < 0.05), higher proportions of lean and high-value cuts in the pistola and higher carcass value (P < 0.001). Linear regression analysis showed that a 1 unit increase in sire EPD for carcass conformation score increased (P < 0.01) carcass lean proportion by 19.4 g/kg. In conclusion, although sire EPD for carcass conformation score was reflected in the conformation score of intensively-reared bull progeny and not in extensively-reared heifer progeny, carcass lean proportion and carcass value were higher for both genders.
  • Determination of benzo[alpha]pyrene in Turkish döner kebab samples cooked with charcoal or gas fire

    Terzi, G.; Celik, T.H.; Nisbet, C. (Teagasc, Oak Park, Carlow, Ireland, 2008)
    In order to investigate the levels of the potent carcinogen benzo[a]pyrene (B(a)P), 40 samples of döner kebab were analysed. The samples tested included 20 cooked using a charcoal fire and 20 cooked using a gas fire. A liquid chromatographic method was developed using a fluorescence detector. The mean levels of B(a)P were found to be 24.2 (s.e. 0.84) g/kg for charcoal fire cooked meat samples and 5.7 (s.e. 3.48 g/kg) for gas fire cooked meat samples. Sixteen samples were found to be over the maximum level recommended by FAO/WHO (10 g/kg) and all of the samples exceeded the maximum tolerance level of the Turkish Food Codex (1 g/kg).
  • Alternatives to formic acid as a grass silage additive under two contrasting ensilability conditions

    Lorenzo, B. Fernandez; O'Kiely, Padraig (Teagasc, Oak Park, Carlow, Ireland, 2008)
    The effects of formic acid and four alternative additives on silage fermentation, in-silo DM losses and aerobic stability were compared in an experiment using both difficultto- ensile (DIFF) and easier-to-ensile (EASI) herbages. Both were ensiled in laboratory silos with either no additive or following the application of formic acid (FA; 850 g/kg) at 3 mL/kg herbage, Add-SaFeR® (ATF1) and GrasAAT® (ATF2), both based on ammonium tetraformate, at 4 mL/kg herbage, an antimicrobial mixture (MIX; potassium formate, sodium disulfite and sodium benzoate) at 3 g/kg herbage, or Ecosyl (LAB; Lactobacillus plantarum) at 3 mL/kg herbage. There were four replicates per treatment and the silos were stored for 132 days. DIFF silage made without additive was poorly fermented. All additives increased the extent and improved the direction of DIFF silage fermentation, and reduced in-silo losses. However, MIX did not reduce butyric acid concentration and increased the extent of aerobic deterioration. LAB had a smaller effect on fermentation and in-silo losses than FA. With EASI silages, all additives restricted the extent of fermentation and improved fermentation quality, with the latter effect being smaller than for DIFF silages. LAB promoted a particularly homolactic fermentation but subsequently increased aerobic deterioration. In both DIFF and EASI silages additive treatment improved in vitro digestibility. It is concluded that only ATF1, ATF2 and MIX were as effective as FA at improving silage preservation and reducing in-silo losses with both DIFF and EASI herbages. However, ATF1 and ATF2 were superior in reducing the apparent extent of proteolysis and MIX was slightly less effective at reducing the activity of saccharolytic Clostridia.
  • A note on the evaluation of a beta-casein variant in bovine breeds by allele-specific PCR and relevance to β-casomorphin

    Keating, A.F.; Smith, T.J.; Ross, R Paul; Cairns, M.T. (Teagasc, Oak Park, Carlow, Ireland, 2008)
    Two genetic variants of the bovine β-casein gene (A1 and B) encode a histidine residue at codon 67, resulting in potential liberation of a bioactive peptide, β-casomorphin, upon digestion. An allele-specific PCR (AS-PCR) was evaluated to distinguish between the β-casomorphin-releasing variants (A1 and B) and the non-releasing variants. AS-PCR successfully distinguished β-casein variants in 41 of 42 animals as confirmed by sequence analysis. Overall, while the incidence of the homozygous A1 and B animals (i.e., homozygous for the histidine residue; 21.4%) was lower than that for animals without the histidine residue (30.9% respectively), 69% of animals carried at least one allele for the histidine residue at codon 67.
  • Non-carcass parts and carcass composition of high dairy genetic merit Holstein, standard dairy genetic merit Friesian and Charolais × Holstein-Friesian steers

    McGee, Mark; Keane, Michael G.; Neilan, R.; Moloney, Aidan P; Caffrey, Patrick J. (Teagasc, Oak Park, Carlow, Ireland, 2008)
    The increased use of Holstein genetic material in the dairy herd has consequences for beef production. A total of 24 spring-born calves comprising 8 Holsteins (HO), 8 Friesians (FR) and 8 Charolais × Holstein-Friesians (CH) were reared from calfhood to slaughter. At the end of the second grazing season they were assigned to a 3 (breeds; HO, FR and CH) × 2 (slaughter weights; 620 and 730 kg) factorial experiment and fin¬ished indoors. After slaughter carcasses were classified for conformation and fatness, all organs and non-carcass parts were weighed, and the right side of each carcass was dissected into fat, bone and muscle. Non-carcass parts, carcass weight, kill-out propor¬tion, carcass conformation score and m. longissimus area were 405, 398 and 368 (s.e. 8.31) g/kg empty body weight, 355, 344 and 383 (s.e. 9.4) kg, 509, 520 and 545 (s.e. 8.99) g/kg, 1.0, 2.0 and 3.1 (s.e. 0.16), 7616, 7096 and 9286 (s.e. 223.4) mm2 for HO, FR and CH, respectively. Corresponding proportions of carcass muscle and fat were 631, 614 and 656 (s.e. 8.4), and 165, 200 and 165 (s.e. 10.5) g/kg. Increasing slaughter weight increased the proportion of total non-carcass parts, carcass weight, carcass fat score and fat proportion, and reduced carcass muscle and bone proportions. It is concluded that differences in kill-out proportion between the two dairy breeds was primarily due to the lower proportion of gastrointestinal tract (GIT) in FR, and the higher kill-out proportion of CH was mainly due to lower proportions of GIT, internal organs and internal fat. In terms of beef production, HO and FR were broadly comparable for most traits except carcass conformation score and carcass fat proportion, which were lower for HO. CH was superior to the dairy breeds in all important production traits.
  • 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.
  • 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.
  • Farm-gate nitrogen balances on intensive dairy farms in the south west of Ireland

    Treacy, M.; Humphreys, James; McNamara, K.; Browne, R.; Watson, C.J. (Teagasc, Oak Park, Carlow, Ireland, 2008)
    Nitrogen management and farm-gate N balances were evaluated on 21 intensive dairy farms in the south west of Ireland for each of four years (2003 to 2006). The mean annual stocking density was equivalent to 202 kg/ha (s.d. 29.6) of N excreted by livestock on the farm. The mean annual farm-gate N surplus (imports – exports) declined between 2003 and 2006 (277 to 232 kg/ha, s.e. 6.8; P < 0.001) due to a decline in annual N imports (fertilizer, feed and imported manures; 335 to 288 kg/ha, s.e. 6.9; P < 0.001). Overall annual fertilizer N use on the farms decreased during the study period (266 to 223 kg/ha, s.e. 6.5; P < 0.001) mainly due to lower inputs for the first application in spring and for the production of first-cut silage. These decreases were partly offset by applying more slurry in spring for early grazing and for first-cut silage. The introduction of white clover resulted in lower N imports on four farms. Export of N from farms was unaffected by reductions in N imports. The mean efficiency of N use tended to increase over time (0.18 in 2003 to 0.20 in 2006). The large variation in quantities of fertilizer N applied on farms with similar stocking densities suggests potential for further improvements in the efficiency of N use. In terms of fertilizer N use, complying with S.I. No. 378 of 2006 did not require major changes in the N management practiceson 19 of the farms.
  • Evaluation of Lolium perenne L. cv. AberDart and AberDove for silage production

    Conaghan, P.; O'Kiely, Padraig; Howard, H.; O'Mara, Frank P.; Halling, M.A. (Teagasc, Oak Park, Carlow, Ireland, 2008)
    The objective of this study was to assess the value, for silage production, of intermediateheading Lolium perenne L. cultivars, AberDart and AberDove (diploid), bred for increased water-soluble carbohydrate (WSC) concentrations, relative to four control cultivars (Fennema, AberElan and Spelga (diploid), and Greengold (tetraploid)). Cultivars were evaluated for forage dry matter (DM) yield, ground cover and indirect laboratory measures of nutritional value and ensilability over 3 harvest years within intensive silage-production systems. AberDove was the most desirable diploid for silage production producing on average 316 kg/ha higher (2%) DM yield per annum, having a 10 g/kg higher (1%) dry matter digestibility (DMD) and, based primarily on a 6 g/L higher (19%) concentration of WSC expressed in the aqueous extract (WSCAE), offered the greatest potential to produce well preserved silage. Ensiling AberDart compared to the diploid controls offered a slightly greater probability of producing well preserved silage based on a modest increase of 2 g/L (6%) in WSCAE concentration. The dilemma for silage production is that AberDart, on average produced 558 kg/ha less (4%) DM yield per annum but had a greater (1%) DMD of 6 g/kg than the diploid controls. The tetraploid control had, on average, 13 and 8 g/kg higher (2% and 1%, respectively) DMD than AberDart and AberDove, but at a cost of lower ensilability with lower (6% and 21%, respectively) WSCAE values of 2 and 6 g/L. In its favour, the tetraploid control outyielded AberDart by, on average, 917 kg/ha DM per annum (7%) and produced comparable yields to AberDove. Final ground cover ratings were high (≥ 95%) for all cultivars. Evaluation of nutritional value and ensilability offers further grounds to differentiate and select cultivars for animal production potential.
  • A note on the design and testing of single teatcups for automatic milking systems

    O'Callaghan, Edmund J; Berry, Donagh P. (Teagasc, Oak Park, Carlow, Ireland, 2008)
    In automatic milking units single independent teatcups or shell/liner combinations are required. The milking characteristics of three designs of single-teatcup milking units were compared with a conventional milking unit in a pipeline milking system. The combined weight of each single-teatcup shell and liner used in the single-teatcup units was 0.18 kg, 0.38 kg or 0.56 kg. The conventional milking cluster had a claw volume of 150 mL and a weight of 3.16 kg. The single sets of teatcups were applied manually and removed automatically when milk flow from the four teatcups reached 0.2 kg/min. The experiment involved a latin square design with four groups of Friesian cows (10 cows/group), four 2-day periods and four treatments. At a flow rate of 4 L/min during simulated milking the mean vacuum level at the teat-end (artificial teat) during the “bphase” of pulsation was 43.8 kPa with the conventional milking unit and 33 kPa for the three single-teatcup units. The corresponding mean and minimum teat-end vacuum in the “d-phase” were 38.46 kPa and 29.54 kPa, respectively, for the conventional system and 24.95 kPa and 17.59 kPa, respectively, for the single-teatcup configuration. The light teatcup (weight 0.18 kg) gave longer time to milk letdown, longer milking time and both lower peak and average milk flow than the conventional cluster.