• Adding value to cull cow beef

      O'Donovan, Michael; Minchin, William; Buckley, Frank; Kenny, David; Shalloo, Laurence (Teagasc, 01/08/2009)
      This project addressed the prospects of increasing the value of cull cow beef and examined the potential of a number of different management and dietary strategies. In Ireland, the national cow herd contributes 350,000 animals to total beef production annually, which represents 22% of all cattle slaughtered (DAF, 2007). A dominant feature of beef production in Ireland is the disposal of cows from the dairy and beef industries, the time of year at which culling occurs influences the number of cows available for slaughter. Suitability of a cow for slaughter is generally not a consideration for dairy or beef farmers.
    • 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.
    • The effect of floor type in farrowing crates on piglet welfare

      Lewis, Eva; Boyle, Laura; O’Doherty, J.V.; Brophy, P.; Lynch, P Brendan (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
      The effect on piglet welfare of different combinations of flooring in the sow and piglet areas of farrowing crates was examined. One hundred and three multiparous sows were housed, from one week pre-farrowing through farrowing and lactation to weaning, in farrowing crates with one of five flooring combinations: SS – slatted steel in both the sow and piglet areas of the crate; SP – slatted steel sow flooring and plasticcoated expanded metal for the piglets; AP – slatted steel (with a checker-plate panel)sow flooring and plastic-coated expanded metal for the piglets; CP – expanded cast iron sow flooring and plastic-coated expanded metal for the piglets; PP – plastic-coated woven wire sow flooring and plastic-coated expanded metal for the piglets. The number of litters assigned to SS, SP, AP, CP and PP were 27, 23, 17, 18 and 18, respectively. All piglet areas had a water-heated pad. Piglets were examined for lesions, scored from zero to three according to severity, at six locations on each foot and at seven locations on each limb during the suckling period. Addition of scores at each location yielded a foot and limb lesion score. In addition, the proportion of piglets in a litter affected by at least one injury was calculated for each of the following: the carpal joints, coronets, accessory digits, footpads. Piglet behaviour was recorded for 2 h, between 1330 and 1630, at 24 h after birth. Litters were weighed at birth and at weaning, and all deaths were recorded during the suckling period. SS litters had higher foot and limb lesion scores (P < 0.001). In addition, a greater proportion of piglets in SS litters were affected by at least one injury to the carpal joint, coronet, accessory digit and footpad (P < 0.001). SP piglets were active on the heatpad in more observations than AP piglets (P < 0.05). PP piglets were inactive in other areas of the pen in more observations than SS piglets (P < 0.05). There was no effect of treatment on piglet weight gain or mortality. It is concluded that the use of slatted steel in piglet areas of farrowing crates cannot be recommended because of injuries to piglets’ feet and limbs. The combination of slatted steel in the sow area and plastic-coated expanded metal in the piglet area encourages use of the heatpad. However, use of plastic-coated woven wire in the sow area encourages piglets to use this area which puts them in danger of being overlaid by the sow.
    • Comparison of growth curves of three strains of female dairy cattle

      Berry, Donagh P.; 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.
    • A survey of fertilizer use from 2001-2003 for grassland and arable crops

      Coulter, B.S.; Murphy, W.E.; Culleton, Noel; Quinlan, G.; Connolly, Liam (Teagasc, 2005-07-01)
      Farm management data for the years 2001-2003 from the Teagasc National Farm Survey (NFS) were used as the basis for this fertilizer use survey. The farms which took part in the survey were randomly selected to represent the major farm systems and sizes using information from the CSO Census of Agriculture 2000. Farms were classified into 6 main farm systems namely: dairying, dairying with other enterprises, cattle rearing, cattle with other systems, mainly sheep and tillage systems. These systems refer to the dominant enterprise in each group.
    • Grazing and ensiling of energy-rich grasses with elevated sugar contents for the sustainable production of ruminant livestock (Acronym: SweetGrass)

      O'Kiely, Padraig; Conaghan, Patrick; Howard, Hilda; Moloney, Aidan P; Black, Alistair D (Teagasc, 2005-09-01)
      Permanent grassland dominates the Irish landscape and for many decades perennial ryegrasses have been the main constituent in seed mixtures for grassland.
    • Effects of transporting bulls at different space allowances on physiological, haematological and immunological responses to a 12-h journey by road

      Earley, Bernadette; O'Riordan, Edward G. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The effects of space allowance during transportation on physiological, haematological and immunological responses in nine-month old bulls (250 kg) were assessed before and after a 12-h road journey. Following transport, animals transported at a spatial allowance of 1.27 m2 had higher (P ≤0.001) non-esterified fatty acid concentrations than control. The stimulated production of interferon-, in response to concanavalin-A and keyhole limpet haemocyanin, and plasma cortisol were not different at the 0.85 m2 and 1.27 m2 stocking densities. Glucose and albumin concentrations were higher (P ≤0.001) post-transport in all transported animals than control. The percentage lymphocytes was reduced (P ≤0.001) and neutrophil percentage and the number of neutrophils were increased (P ≤0.001) in all transported treatments. There were no changes (P 0.05) in monocyte numbers, monocyte percentage or platelet numbers following transportation. The haematocrit values were higher (P ≤0.001) in the transported treatments while RBC numbers were higher (P ≤0.001) in the animals transported at a spatial allowance of 1.27 m2 than control. Protein, globulin, urea and lactate concentrations, and white blood cell numbers were not changed at any time during the study. The concentration of -hydroxybutyrate was lower (P ≤0.001) in all animals following transport. Plasma haptoglobin concentrations were unchanged following transportation while plasma fibrinogen concentrations were reduced in all transported treatments. There were no differences among treatments in rectal temperature or live weights pre- and post-transport. The results indicate that within the conditions of the study, there was no welfare advantage in transporting bulls at 1.27 m2 versus the standard spatial allowance of 0.85 m2 on a 12-h road journey.
    • Comparison of a Calan gate and a conventional feed barrier system for dairy cows: feed intake and cow behaviour

      Ferris, C.P.; Keady, Tim; Gordon, F.J.; Kilpatrick, D.J. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      There is little published information on comparisons of individual and group feeding systems for dairy cows. Twenty-four dairy cows were used in a three-period incompletely balanced, change-over design study, to examine food intake and feeding behaviour of dairy cows offered their food via group-access electronic Calan gates, or via a conventional feed-barrier system. The food offered was in the form of a complete diet, and comprised grass silage and concentrates (60:40 dry matter (DM) basis). With the conventional feed-barrier system a maximum of eight animals were able to feed at any one time, while the Calan-gate system allowed a maximum of three animals to feed at any one time. Method of offering the ration had no effect on daily DM intake. During the 8-h period after animals were given access to fresh food, the mean number of animals feeding at any one time was 5.4 and 3.0 for the conventional and Calan-gate systems, respectively, while total intake over this period was 11.0 and 9.2 kg DM per cow, respectively. When access to feed was restricted by the use of Calan gates, animals responded by increasing their intake rate. It is concluded that total DM intake was unaffected by the use of a group Calan-gate feeding system as animals modified their feeding behaviour to maintain food intake.
    • Effects of pre-transport fasting on the physiological responses of young cattle to 8-hour road transport

      Earley, Bernadette; Fisher, A.D.; O'Riordan, Edward G. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The effects of fasting animals for 8 h prior to an 8-h road journey and their ability to cope with the stress of transport were investigated. The treatments were: 1) fasted and then transported (n=20); 2) non-fasted and transported (n=18); 3) non-fasted at grass (n=18); 4) fasted then fasted (n=18), and 5) non-fasted then fasted (n=18). There was no significant difference in rectal body temperature, pre- or post-transport, or live weight among treatments on days 0 (pre-transport), 1, 4 or 10 (post-transport). The ambient relative humidity and temperature of the outside environment ranged from 82.8 to 99.8% and 9.9 to 14.5 oC, respectively. Holstein × Friesian bulls (230 kg) undergoing an 8-h transportation at stocking densities of 0.82 m2/animal showed physiological and haematological responses that were within normal referenced ranges. Animals that were fasted for 8 h and transported lost 9.4% of live weight while non-fasted transported animals lost 7.2%. The control non-fasted animals remaining at grass gained 2% of live weight. Animals that were fasted continuously but not transported and the initially non-fasted control animals that were subsequently fasted for 9 h lost 6.1% and 6.2% of live weight, respectively. There was no significant change in concentrations of globulin, glucose, urea, haemoglobin or fibrinogen, or in haematocrit percentage before or after transport. Transport reduced lymphocyte percentage (P < 0.001) and increased neutrophil percentage (P < 0.001) in the fasted and non-fasted animals. Following transport, protein concentration was greater (P ≤0.001) in the fasted and transported animals than in the non-fasted animals at grass and haptoglobin concentrations were higher (P ≤0.001) in the fasted plus transported animals than the controls at grass. In conclusion, from the physiological and haematological measurements, an 8-h journey time, even without access to feed for 8 h prior to transport did not appear to impact negatively on animal welfare.
    • The microbiological and chemical composition of baled and precision-chop silages on a sample of farms in County Meath

      McEniry, Joseph; O'Kiely, Padraig; Clipson, N.W.J; Forristal, P.D.; Doyle, E.M.; Teagasc Walsh Fellowship Programme; (Teagasc, Oak Park, Carlow, Ireland, 2006)
      Baled and precision-chop silages were examined on a sample of farms in the Irish midlands to determine microbiological and chemical composition at feedout. Silage making practices and chemical composition were similar to those in national surveys. Wilting was an integral part of baled silage production and was reflected in a more restricted fermentation (higher pH and water-soluble carbohydrates, with lower fermentation acids and buffering capacity) compared to precision-chop silage. Yeast numbers were higher in baled silage, suggesting a more aerobic environment within the bale. Although the fermentation appeared similar in the outer and inner horizons of baled silage, yeast, lactic acid bacteria and Enterobacteria numbers were higher in the outer horizon suggesting less exacting anaerobiosis adjacent to the surface of the bale.
    • Changes in yield and composition of barley, wheat and triticale grains harvested during advancing stages of ripening

      Stacey, P.; O'Kiely, Padraig; Hackett, Richard; Rice, B.; O'Mara, Frank P.; Teagasc Walsh Fellowship Programme (Teagasc, Oak Park, Carlow, Ireland, 2006)
      This study involved an evaluation of the changes in grain yield, nutritive value, ensilability and harvesting losses of intensively managed winter cereals harvested during the advancing stages of ripening. Five cereal crops (barley cv. Regina and wheat cv. Madrigal in 2001; barley cv. Regina, wheat cv. Falstaff and triticale cv. Fidelio in 2002) were assessed. Twenty plots per crop were arranged in a randomised complete block design, with five times of harvest (four for barley in 2002) and four replicate blocks per harvest. Dry matter (DM) yields changed relatively little between harvest dates, but fresh yields declined (P < 0.001) over time due to the moisture loss associated with ripening. Time-course changes in indices of nutritive value, such as concentrations of crude protein, starch and ash, and organic matter digestibility, were relatively small and did not follow a consistent pattern. Ensilability indices, such as DM and watersoluble carbohydrate concentrations and buffering capacity, indicated that satisfactory fermentations were likely if such crops were ensiled; buffering capacity, generally declining with advancing maturity. Harvesting losses were not clearly related to growth stage at harvest. It is concluded that winter cereal grain (barley, wheat and triticale) DM yields and quality were relatively constant as ripening progressed from DM concentrations of around 550 to >800 g/kg.
    • A Study of Time and Labour Use on Irish Suckler Beef Farms

      Fallon, R.J.; Leahy, H.; O’Riordan, Edward G.; Ruane, D. (Teagasc, 2006-01-01)
      Labour is one of the four factors of production and an increasingly costly and scarce input on farms. The attractiveness of non-farming employment, the nature of farm work and the price received for farm outputs are resulting in falling levels of hired and family labour.
    • Manipulation of grass supply to meet feed demand

      French, Padraig; Hennessy, Deirdre; O’Donovan, Michael; Laidlaw, S. (Teagasc, 2006-01-01)
      Grazed grass is generally the cheapest form of feed available for beef and milk production in Ireland. Grass growth is variable during the year with a peak in May/June and a secondary peak in August. There is little net growth from December to February. Grass growth is also variable across the country with higher grass growth in the south and south-west (14 to 15 t DM/ha/year) compared with approximately 11 t DM/ha/year in the north-east (Brereton, 1995). There is poor synchrony between grass supply and feed demand on beef and dairy farms. The feed demand curve for a calf to two year old beef system shows feed demand decreasing as grass supply increases, and grass supply decreasing as feed demand increases. Similarly, the feed demand curve of a spring calving dairy herd shows poor synchrony with grass supply, with a surplus of grass from about mid-April to mid-August, and a deficit for the rest of the year. Traditionally surplus grass produced during May and June is conserved as silage or hay and fed back to cattle and dairy cows during the deficit times of the year.
    • Soil Properties and their Influence on Grassland Production under Low Input and Organic Farming Conditions

      Leonard, C.; Mullen, G.J.; Culleton, Noel; Breen, J. (Teagasc, 2006-01-01)
      This project set out to identify soil properties that most influence grassland production under low mineral nitrogen input conditions. Sixteen farms were selected in Counties Limerick and Clare and the soil sampled. Soil physical and chemical characteristics and soil biological aspects involved in the carbon and nitrogen cycles were studied in the laboratory. Nutrient additions to farms as well as the nature of grazing by livestock (numbers, types of grazing animals, grazing practices), grassland management, and production from the farms were recorded.
    • 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 P.; 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.
    • An evaluation of earth banked tanks for slurry storage

      Scully, Heather; Gleeson, Timothy; Purcell, Patrick J.; O’Riordan, Edward G.; Long, Mike; Crosse, Seamus (Teagasc, 2006-09-01)
      This study examines the feasibility of using earth-banked tanks (EBT’s) as an alternative and economical means of winter storage for animal and other farmyard wastes. The study contains a detailed literature review on the subject, the results of a series of laboratory-scale experiments, field studies and a predictive model of the transport process through the soil liner of an earth-banked tank.
    • Conservation characteristics of grass and dry sugar beet pulp co-ensiled after different degrees of mixing

      Cummins, B.; O'Kiely, Padraig; Keane, Michael G.; Kenny, David A. (Teagasc, Oak Park, Carlow, Ireland, 2007)
      The objective of this experiment was to quantify the effects of the degree of mixing of dry molassed sugar beet pulp (BP) with grass on silage conservation characteristics. Herbage from a timothy (Phleum pratense) sward was precision chopped and treated with a formic acid based additive (3 l/t grass). Units of 50 kg grass, without or with 2.5kg BP were randomly allocated among four replicates on each of seven treatments. The treatments were (1) no BP (NONE), (2) BP evenly mixed through the grass (EVEN), (3) BP evenly mixed through the lower 25 kg grass (LOWH), (4) BP evenly mixed through the lower 12.5 kg grass (LOWQ), (5) 0.625 kg BP mixed through the top 25 kg grass and 1.875 kg SBP mixed through the lower 25 kg grass (25/75), (6) BP placed in 0.5 kg layers beneath each 10 kg grass (LAYR), and (7) BP placed in a single layer under all of the grass (BOTM). Laboratory silos were filled and sealed, and stored at 15 °C for 163 days. Effluent was collected and weighed from each silo throughout the ensilage period. At opening, silage composition and aerobic stability measurements were made. Total outflow of effluent was reduced (P<0.001) by the addition of BP; LAYR had a greater effect (P<0.001) than any of the other treatments. Effluent dry matter (DM) concentration was highest (P<0.05) for BOTM and lowest (P<0.01) for NONE. All treatments underwent similar lactic-acid dominant fermentations. Incorporation of BP with grass increased silage DM concentration (P<0.001), in vitro DM digestibility (P<0.05) and water soluble carbohydrate (P<0.001) concentration and reduced acid detergent fibre (P<0.001) concentration. Aerobic stability was similar across treatments and aerobic deterioration at 192 h was higher (P<0.05) for LOWQ, 25/75, LAYR and BOTM than for NONE. In conclusion, the incorporation of BP increased silage DM digestibility but had relatively little effect on fermentation or aerobic stability. Placing BP in layers gave the largest and most sustained restriction in effluent output.
    • Effects of breed type, silage harvest date and pattern of offering concentrates on intake, performance and carcass traits of finishing steers

      Cummins, B.; Keane, Michael G.; O'Kiely, Padraig; Kenny, David A. (Teagasc, Oak Park, Carlow, Ireland, 2007)
      The objective of this experiment was to investigate the effects and interactions of breed type, silage harvest date and pattern of offering concentrates on intake, performance and carcass traits of finishing steers. Seventy-two steers (36 Friesian and 36 beef cross) were blocked on weight within breed type and assigned to a pre-experimental slaughter group or to one of 4 dietary treatments in a 2 (breed type) 2 (early- or late- cut silage) 2 (flat rate or varied pattern of offering concentrates) factorial arrangement of treatments. The flat-rate feeding pattern was silage ad libitum plus 5 kg concentrates per head daily to slaughter. The varied feeding pattern was silage only for 79 days followed by concentrates ad libitum to slaughter. All animals were slaughtered together after 164 days when the groups on the two feeding patterns had consumed the same total quantity of concentrates. Friesians had a higher (P < 0.001) silage dry matter (DM) intake and a higher (P < 0.01) total DM intake than the beef crosses. Live-weight gain was similar for both breed types but the beef-cross animals had a higher (P < 0.001) kill-out proportion, higher (P < 0.01) carcass gain, and better (P < 0.001) carcass conformation than the Friesians. The beef-cross type also had a higher (P < 0.001) proportion of muscle and a lower (P < 0.001) proportion of bone in the carcass. Silage harvest date had no effect on silage or total DM intakes but the early-cut silage did result in higher (P < 0.01) carcass gain. Animals on the varied feeding pattern consumed less (P < 0.01) silage DM and less (P < 0.001) total DM than those on the flat rate feeding pattern. Live-weight gain and carcass gain were similar for the two feeding patterns. It is concluded that Friesians had a higher intake, but had lower carcass gain than the beef-cross type. Animals on the early-cut silage had higher carcass gain than those on the late-cut silage. The varied feeding pattern resulted in lower DM intake but efficiency of feed energy utilisation was similar for both feeding patterns. Interactions were generally not statistically significant.
    • Effects of extended grazing during mid, late or throughout pregnancy, and winter shearing of housed ewes, on ewe and lamb performance

      Keady, Tim; Hanrahan, James P; Flanagan, S. (Teagasc, Oak Park, Carlow, Ireland, 2007)
      A flock of March-lambing ewes was used to evaluate the effects of (i) extended (deferred, winter) grazing of pasture during mid, late or throughout pregnancy, and (ii) winter shearing of ewes housed during mid and late pregnancy, on lamb birth weight and subsequent growth to weaning. Ewes (n = 265) were allocated at random to five treatments for the period from 7 December (~ day 47 of pregnancy) to lambing. The treatments were: housed shorn (HS), housed unshorn (HU), grazing throughout (EG), grazing to 20 January followed by housing (EGH), housed to 20 January followed by grazing (HEG). From 1 March to lambing the HEG and EG ewes were dispersed on the paddocks intended for grazing post lambing. All ewes were offered a concentrate supplement during the final 6 weeks of pregnancy. Housed ewes were offered grass silage while ewes on extended grazing were allocated 1.3 kg herbage dry matter per head per day from swards that had been closed for approximately 10 weeks. Ewes plus lambs (except triplet-rearing ewes which were grazed separately) from all treatments were grazed together post lambing, grouped according to lambing date. For treatments HS, HU, EGH, HEG and EG gestation lengths were 147.0, 145.6, 146.3, 146.6 and 146.9 (s.e. 0.34, P < 0.001) days, lamb birth weights were 4.9, 4.3, 4.4, 4.6 and 5.0 (s.e. 0.10, P < 0.001) kg, and lamb weaning weights were 34.6, 32.1, 33.3, 33.8 and 34.9 (s.e. 0.66, P < 0.001) kg, respectively. Extended grazing in mid and late pregnancy resulted in 35% and 65%, respectively, of the increase in lamb birth weight associated with extended grazing throughout. Treatment effects on lamb birth weight were associated with those on weaning weight (P < 0.01, R2 = 0.93). It is concluded that extended grazing or shearing of housed ewes increased lamb birth weight and subsequent weaning weight. The increased lamb birth weight from deferred grazing in mid pregnancy was probably due to improved protein utilisation from the grazed herbage. Meanwhile, the increased
    • Manipulating the ensilage of wilted, unchopped grass through the use of additive treatments

      McEniry, Joseph; O'Kiely, Padraig; Clipson, N.W.J.; Forristal, P.D.; Doyle, E.M.; Teagasc Walsh Fellowship Programme (Teagasc, Oak Park, Carlow, Ireland, 2007)
      Baled silage composition frequently differs from that of comparable conventional precision-chop silage. The lower final concentration of fermentation products in baled silage makes it more conducive to the activities of undesirable microorganisms. Silage additives can be used to encourage beneficial microbial activity and/or inhibit detrimental microbial activity. The experiment was organised in a 2 (chop treatments) × 6 (additive treatments) × 2 (stages of ensilage) factorial arrangement of treatments (n = 3 silos/treatment) to suggest additive treatments for use in baled silage production that would help create conditions more inhibitory to the activities of undesirable microorganisms and realise an outcome comparable to precision-chop silage. Chopping the herbage prior to ensiling, in the absence of an additive treatment, improved the silage fermentation. In the unchopped herbage, where the fermentation was poorer, the lactic acid bacterial inoculant resulted in an immediate increase (P < 0.001) in lactic acid concentration and a faster decline (P < 0.001) in pH with a subsequent reduction in butyric acid (P < 0.001) and ammonia-N (P < 0.01) concentrations. When sucrose was added in addition to the lactic acid bacterial inoculant, the combined treatment had a more pronounced effect on pH, butyric acid and ammonia-N values at the end of ensilage. The formic acid based additive and the antimicrobial mixture restricted the activities of undesirable microorganisms resulting in reduced concentrations of butyric acid (P < 0.001) and ammonia-N (P < 0.01). These additives offer a potential to create conditions in baled silage more inhibitory to the activities of undesirable microorganisms.