• Farm management factors associated with bulk tank total bacterial count in Irish dairy herds during 2006/07

      Kelly, PT; O'Sullivan, K; Berry, Donagh P.; More, Simon J; Meaney, William J; O'Callaghan, Edmond J; O'Brien, Bernadette (Biomed Central, 01/01/2009)
      Research has shown that total bacterial count (TBC), which is the bacterial growth per ml of milk over a fixed period of time, can be decreased by good hygiene and farm management practices. The objective of the current study was to quantify the associations between herd management factors and bulk tank TBC in Irish spring calving, grass-based dairy herds. The relationship between bulk tank TBC and farm management and infrastructure was examined using data from 400 randomly selected Irish dairy farms where the basal diet was grazed grass. Herd management factors associated with bulk tank TBC were identified using linear models with herd annual total bacterial score (i.e., arithmetic mean of the natural logarithm of bulk tank TBC) included as the dependent variable. All herd management factors were individually analysed in a separate regression model, that included an adjustment for geographical location of the farm. A multiple stepwise regression model was subsequently developed. Median bulk tank TBC for the sample herds was 18,483 cells/ml ranging from 10,441 to 130,458 cells/ml. Results from the multivariate analysis indicated that the following management practices were associated with low TBC; use of heated water in the milking parlour; participation in a milk recording scheme; and tail clipping of cows at a frequency greater than once per year. Increased level of hygiene of the parlour and cubicles were also associated with lower TBC. Herd management factors associated with bulk tank TBC in Irish grazing herds were generally in agreement with most previous studies from confinement systems of milk production.
    • Farm management factors associated with bulk tank somatic cell count in Irish dairy herds

      Kelly, PT; O'Sullivan, K; Berry, Donagh P.; More, Simon J; Meaney, William J; O'Callaghan, Edmond J; O'Brien, Bernadette (Biomed Central, 01/04/2009)
      The relationship between bulk tank somatic cell count (SCC) and farm management and infrastructure was examined using data from 398 randomly selected, yet representative, Irish dairy farms where the basal diet is grazed grass. Median bulk tank SCC for the farms was 282,887 cells/ml ranging from 82,209 to 773,028 cells/ml. Two questionnaires were administered through face-to-face contact with each farmer. Herd-level factors associated with bulk tank SCC were determined using linear models with annual somatic cell score (i.e., arithmetic mean of the natural logarithm of bulk tank SCC) included as the dependent variable. All herd level factors were analysed individually in separate regression models, which included an adjustment for geographical location of the farm; a multiple regression model was subsequently developed. Management practices associated with low SCC included the use of dry cow therapy, participation in a milk recording scheme and the use of teat disinfection post-milking. There was an association between low SCC and an increased level of hygiene and frequency of cleaning of the holding yard, passageways and cubicles. Herd management factors associated with bulk tank SCC in Irish grazing herds are generally in agreement with most previous studies from confinement systems of milk production.
    • Adding value to milk by increasing its protein and CLA contents

      Murphy, J.J.; Stanton, Catherine; O'Donovan, Michael; Kavanagh, S.; Maher, J.; Patton, Joe; Mohammed, Riaz (Teagasc, 01/08/2008)
      The mid-summer milk protein study was undertaken on 34 commercial dairy farms in 2005 to evaluate the influence of dietary and management variables on milk protein content in mid-season. Data on grass composition, genetic merit of the herds and milk protein content were collected and analysed by multiple regression. Both calving date and genetic merit for milk protein content were significantly associated with milk protein content and were used as adjustment factors when evaluating the association between measures of grass quality and milk protein content. Milk protein content was associated with grass OMD (P = 0.04) and NDF content (P = 0.02) but not with CP content (P = 0.80). It is concluded that herds calving earlier, with a greater genetic merit for milk protein content and consuming better quality pasture would have greater milk protein contents in mid-season.
    • 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.
    • N leaching to groundwater from dairy production involving grazing over the winter on a clay-loam soil

      Necpalova, Magdalena; Fenton, Owen; Casey, I.; Humphreys, James; Department of Agriculture, Food and the Marine, Ireland; RSF07-511 (Elsevier B. V., 15/08/2012)
      This study investigated concentrations of various N species in shallow groundwater (< 2.2 m below ground level) and N losses from dairy production involving grazing over the winter period on a clay loam soil with a high natural attenuation capacity in southern Ireland (52˚51’N, 08˚21’W) over a two year period. A dense network of shallow groundwater piezometers was installed to determine groundwater flow direction and N spatial and temporal variation. Estimated vertical travel times through the unsaturated zone (<0.5 yr, time lag) allowed the correlation of management with groundwater N within a short space of time. There was a two way interaction of the system and sampling date (P < 0.05) on concentrations of DON, oxidised N and NO3--N. In contrast, concentrations of NH4+-N and NO2--N were unaffected by the dairy system. Grazing over the winter had no effect on N losses to groundwater. Mean concentrations of DON, NH4+-N, NO2--N and NO3--N were 2.16, 0.35, 0.01 and 0.37 mg L-1 respectively. Soil attenuation processes such as denitrification and DNRA resulted in increased NH4+-N levels. For this reason, DON and NH4+-N represented the highest proportion of N losses from the site. Some of the spatial and temporal variation of N concentrations was explained by correlations with selected chemical and hydro-topographical parameters (NO3--N/Cl- ratio, distance of the sampling point from the closest receptor, watertable depth, depth of sampling piezometer, DOC concentration). A high explanatory power of NO3--N/Cl- ratio and the distance of the sampling point from the closest receptor indicated the influence of point sources and groundwater-surface water interactions.
    • Groundwater: A pathway for terrestrial C and N losses and indirect greenhouse gas emissions

      Jahangir, Mohammad M. R.; Johnson, P.; Khalil, M.I.; Hennessy, D.; Humphreys, James; Fenton, Owen; Richards, Karl G.; Department of Agriculture, Food and the Marine, Ireland; Department of Civil, Structural and Environmental Engineering, Trinity College Dublin; RSF 06383 (Elsevier, 16/07/2012)
      Estimating losses of dissolved carbon (C) and nitrogen (N) via groundwater in an agricultural system provides insights into reducing uncertainties in the terrestrial C and N balances. In addition, quantification of dissolved nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) in groundwaters beneath agricultural systems is important for global greenhouse gas (GHG) budgets. Dissolved C (DC: dissolved organic carbon (DOC) + CO2-C + CH4-C) and dissolved nitrogen (DN: NO3−-N + NH4+ + NO2−-N + N2O-N + N2) in groundwater were measured in two low permeability (<0.02 m d−1) and two high permeability (>0.05 m d−1) aquifers in Ireland. Groundwater in multilevel piezometers was sampled monthly over two years. Mean groundwater discharge to surface water was higher in 2009 (587–836 mm) than in 2010 (326–385 mm). Dissolved C and N delivery to surface water via groundwater caused substantial losses of terrestrial C and N. The extent of delivery was site specific and depended on N input, recharge and aquifer permeability. Mean dissolved N losses ranged from 8–12% of N input in low permeability to 27–38% in high permeability aquifers. The dominant fraction of DN was NO3−-N (84–90% of DN) in high permeability aquifers and N2 (46–77% of DN) in low permeability aquifers. Indirect N2O emissions via groundwater denitrification accounted for 0.03–0.12% of N input, which was equivalent to 3–11% of total N2O emissions. Dissolved C loss to surface waters via groundwater was not significant compared to total carbon (TC) content of the topsoil (0.06–0.18% of TC). Site characteristics contributed greatly to the distribution of N between NO3−-N and dissolved N gases, N2O and N2. Indirect GHG emissions from groundwater were an important part of farm nutrient budgets, which clearly has implications for national GHG inventories.
    • A review of nitrous oxide mitigation by farm nitrogen management in temperate grassland-based agriculture

      Li, Dejun; Watson, Catherine J.; Yan, Ming Jia; Lalor, Stanley T. J.; Rafique, Rashid; Hyde, Bernard; Lanigan, Gary; Richards, Karl G.; Holden, Nicholas M.; Humphreys, James; Department of Agriculture, Food and the Marine; RSF 07 516; RSF 07 511 (Elsevier, 20/07/2013)
      Nitrous oxide (N2O) emission from grassland-based agriculture is an important source of atmospheric N2O. It is hence crucial to explore various solutions including farm nitrogen (N) management to mitigate N2O emissions without sacrificing farm profitability and food supply. This paper reviews major N management practices to lower N2O emission from grassland-based agriculture. Restricted grazing by reducing grazing time is an effective way to decrease N2O emissions from excreta patches. Balancing the protein-to-energy ratios in the diets of ruminants can also decrease N2O emissions from excreta patches. Among the managements of synthetic fertilizer N application, only adjusting fertilizer N rate and slow-released fertilizers are proven to be effective in lowering N2O emissions. Use of bedding materials may increase N2O emissions from animal houses. Manure storage as slurry, manipulating slurry pH to values lower than 6 and storage as solid manure under anaerobic conditions help to reduce N2O emissions during manure storage stage. For manure land application, N2O emissions can be mitigated by reducing manure N inputs to levels that satisfy grass needs. Use of nitrification inhibitors can substantially lower N2O emissions associated with applications of fertilizers and manures and from urine patches. N2O emissions from legume based grasslands are generally lower than fertilizer-based systems. In conclusion, effective measures should be taken at each step during N flow or combined options should be used in order to mitigate N2O emission at the farm level.
    • 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.
    • A note on the effects of test-end vacuum on milking characteristics

      O'Callaghan, Edmund J.; Gleeson, David E; European Union (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.
    • Effect of liner design, pulsator setting, and vacuum level on bovine teat tissue changes and milking characteristics as measured by ultrasonography

      Gleeson, David E; O'Callaghan, Edmond J; Rath, Myles V (Biomed Central, 2004-05-01)
      Friesian-type dairy cows were milked with different machine settings to determine the effect of these settings on teat tissue reaction and on milking characteristics. Three teat-cup liner designs were used with varying upper barrel dimensions (wide-bore WB = 31.6 mm; narrow-bore NB = 21.0 mm; narrow-bore NB1 = 25.0 mm). These liners were tested with alternate and simultaneous pulsation patterns, pulsator ratios (60:40 and 67:33) and three system vacuum levels (40, 44 and 50 kPa). Teat tissue was measured using ultrasonography, before milking and directly after milking. The measurements recorded were teat canal length (TCL), teat diameter (TD), cistern diameter (CD) and teat wall thickness (TWT). Teat tissue changes were similar with a system vacuum level of either 50 kPa (mid-level) or 40 kPa (low-level). Widening the liner upper barrel bore dimension from 21.0 mm (P < 0.01) or 25.0 mm (P < 0.001) to 31.6 mm increased the magnitude of changes in TD and TWT after machine milking. Milk yield per cow was significantly (P < 0.05) higher and cluster-on time was reduced (P < 0.01) with the WB cluster as compared to the NB1 cluster. Minimum changes in teat tissue parameters were achieved with system vacuum level of 40 kPa and 50 kPa using NB and WB clusters, respectively. Similar changes in teat tissue and milk yield per cow were observed with alternate and simultaneous pulsation patterns. Widening pulsator ratio from 60:40 to 67:33 did not have negative effects on changes in teat tissue and had a positive effect on milk yield and milking time. Milk liner design had a bigger effect on teat tissue changes and milking characteristics than pulsation settings.
    • Effect of suckler cow genotype on cow serum immunoglobulin (Ig) levels, colostrum yield, composition and Ig concentration and subsequent immune status of their progeny

      McGee, Mark; Drennan, Michael J; Caffrey, Patrick J. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
      Survival of the neonatal calf is largely dependent on humoral immunity. The objective of three experiments reported here was to compare cow serum immunoglobulin (Ig) concentration, colostrum yield, composition and Ig concentration and calf serum Ig concentrations at ~8- and 48-h post partum of spring-calving Charolais (C) and Beef × Holstein-Friesian (BF) cows and their progeny. Cows were individually offered a restricted allowance of grass silage pre partum in Experiments 1 and 2 and silage ad libitum in Experiment 3. In Experiment 1 calves were assisted to suckle after parturition. In Experiments 2 and 3, colostrum yield and Ig concentration were measured following administration of oxytocin and hand milking of half or the complete udder, respectively. It was intended to feed each calf 50 ml (Experiment 2) or 40 ml (Experiment 3) of colostrum per 1 kg birth weight via stomach tube. Following an 8-h period, during which suckling was prevented, a further colostrum sample was obtained. The decrease in cow serum IgG1 concentration pre partum was greater (P < 0.05) in BF cows than C cows. In comparison to BF cows, C cows had a lower colostrum yield (P < 0.001) and the colostrum had lower concentrations of dry matter (P < 0.01), crude protein (P < 0.05), fat (P < 0.05), IgG1 (P = 0.06), IgG2 (P < 0.01), IgM (P < 0.01) and Ig total (P < 0.05). The mass of IgG1, IgG2, IgM, IgA and Ig total in the colostrum produced was significantly lower for C cows than BF cows. Calves from C cows had significantly lower serum Ig subclass concentration at 48-h post partum than calves from BF cows. In conclusion, due to a lower Ig mass produced by their dams, calves from C cows had a lower humoral immune status than those from BF cows
    • Effect of suckler cow genotype on energy requirements and performance in winter and subsequently at pasture

      McGee, Mark; Drennan, Michael J; Caffrey, Patrick J. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
      Three experiments using a total of 62 Charolais (C) and 110 Beef × Holstein-Friesian (BF) spring-calving cows were carried out to determine the relative energy requirements of the genotypes. Cows were individually offered a restricted allowance of grass silage daily during the last 85 and 107 days pre partum in Experiments 1 and 2, respectively, and ad libitum grass silage during the last 93 days pre partum in Experiment 3. In all 3 experiments grass silage was offered ad libitum during the first 34 days of lactation. In Experiments 1 and 2, cows and calves were grazed together during the subsequent grazing seasons. When fed to appetite, silage dry matter intake was similar for both cow genotypes but was higher for the BF cows when expressed relative to live weight. For Experiments 1 and 2 combined, initial live weights and live weight changes to post-partum, over the indoor period and at pasture were 720 (s.e. 14.1), 613 (s.e. 8.4), –74 (s.e. 4.0), –63 (s.e. 2.7), –106 (s.e. 6.0), –89 (s.e. 4.0) and 120 (s.e. 7.0), 88 (s.e. 5.3) kg for C and BF cows, respectively. In Experiment 3 the corresponding initial live weights and live weight changes to post partum were 759 (s.e. 12.3), 659 (s.e. 9.1) and –63 (s.e. 4.9) and –52 (s.e. 3.5) kg. There was no effect of genotype on body condition score or adipose cell diameter or their changes. Plasma creatinine concentrations were higher (P < 0.001) in C cows than BF cows. It is concluded that the energy requirements of a 660 kg C cow are approximately equivalent to a 600 kg BF cow during late pregnancy.
    • Effect of suckler cow genotype on milk yield and pre-weaning calf performance

      McGee, Mark; Drennan, Michael J; Caffrey, Patrick J.; Teagasc Walsh Fellowship Programme (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
      Milk yield and pre-weaning calf performance of spring-calving Charolais (C) and Beef × Holstein-Friesian (BF) cows was compared over 3 experiments. Cows were individually offered a restricted allowance of grass silage pre partum in Experiments 1 and 2 and ad libitum silage in Experiment 3. In all three experiments cows received silage to appetite for the first 34 (s.d. 16.2) days of lactation. In Experiments 1 and 2, cows and calves were grazed together during the subsequent grazing seasons. The daily milk yield of C cows was significantly lower from parturition until turnout to pasture (1.8 to 2.5 kg/day lower) and subsequently at pasture (4.5 and 3.1 kg/day lower in Experiments 1 and 2, respectively) than that of BF cows. Calves from C cows consumed more (P <0.01) concentrate creep feed during the indoor period than calves from BF cows. Compared to calves from BF cows, pre-weaning daily live-weight gain was lower for calves from C cows in Experiments 1 (P < 0.05) and 2 (P = 0.06). The pre-weaning growth response per 1 kg increase in milk yield was greater for calves from C cows than those from BF cows. In conclusion, compared to BF cows the milk yield of C cows was lower resulting in increased calf concentrate intake indoors and lower pre-weaning calf daily live-weight gains.
    • Post-weaning performance and carcass characteristics of steer progeny from different suckler cow breed types

      Drennan, Michael J; McGee, Mark; Keane, Michael G. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
      In two experiments a total of 44 steer progeny of spring-calving Charolais (C) and Hereford × Friesian (HF) suckler cows and C sires were slaughtered at approximately 2 years of age. Following weaning they were offered silage and 1 kg of concentrate per head daily during a 5 month winter after which they spent 7 months at pasture. In Experiment 1, animals were given a silage/concentrate diet during a finishing period of either 95 or 152 days. In Experiment 2, steers were offered either a daily diet of silage plus 6 kg of concentrates or concentrates to appetite plus 5 kg of silage(fresh weight)during the final 140-day finishing period. Following slaughter, an 8-rib pistola from each animal was dissected. For the two experiments combined C and HF progeny had carcass weights of 372 and 385 (s.e. 6.1) kg, proportions of carcass as pistola of 467 and 454 (s.e. 2.8) g/kg and pistola meat proportions of 676 and 642 (s.e. 5.1) g/kg, respectively. All fat traits were lower for the C than HF progeny but there was no difference in carcass conformation score. Increasing slaughter weight increased carcass weight (P < 0.001), kidney plus channel fat weight (P < 0.001), and pistola fat proportion(P < 0.001) and decreased the proportions of carcass as pistola (P < 0.05), pistola meat (P < 0.01), and bone (P < 0.05). In conclusion, breed type had no effect on carcass growth but the C progeny had higher meat yield than the HF. Increasing slaughter weight increased fatness and reduced meat yield.
    • Post-weaning performance and carcass characteristics of steer progency from different suckler cow breed types

      Drennan, Michael J; McGee, Mark; Keane, Michael G. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005-04)
      In two experiments a total of 44 steer progeny of spring-calving Charolais (C) and Hereford × Friesian (HF) suckler cows and C sires were slaughtered at approximately 2 years of age. Following weaning they were offered silage and 1 kg of concentrate per head daily during a 5 month winter after which they spent 7 months at pasture. In Experiment 1, animals were given a silage/concentrate diet during a finishing period of either 95 or 152 days. In Experiment 2, steers were offered either a daily diet of silage plus 6 kg of concentrates or concentrates to appetite plus 5 kg of silage (fresh weight) during the final 140-day finishing period. Following slaughter, an 8-rib pistola from each animal was dissected. For the two experiments combined C and HF progeny had carcass weights of 372 and 385 (s.e. 6.1) kg, proportions of carcass as pistola of 467 and 454 (s.e. 2.8) g/kg and pistola meat proportions of 676 and 642 (s.e. 5.1) g/kg, respectively. All fat traits were lower for the C than HF progeny but there was no difference in carcass conformation score. Increasing slaughter weight increased carcass weight (P < 0.001), kidney plus channel fat weight (P < 0.001), and pistola fat proportion (P < 0.001) and decreased the proportions of carcass as pistola (P < 0.05), pistola meat (P < 0.01), and bone (P < 0.05). In conclusion, breed type had no effect on carcass growth but the C progeny had higher meat yield than the HF. Increasing slaughter weight increased fatness and reduced meat yield.
    • 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; European Union; QLK5-CT-2001-0498 (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.
    • The effect of cereal type and feeding frequency on intake, rumen fermentation, digestibility, growth and carcass traits of finishing steers offered a grass silage-based diet

      Drennan, Michael J; McGee, Mark; Moloney, Aidan P (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The effect of concentrate cereal type (rolled barley-based v. rolled wheat-based) and concentrate feeding frequency (one 6 kg feed v. two 3 kg feeds per day) on intake, rumen fermentation, diet digestibility and performance of finishing steers offered grass silage to appetite was evaluated over four experiments using a total of 154 animals. Not all four feeding treatments were used in each of the four experiments. The duration of the growth measurement period was 152, 112, 111 and 113 days for experiments 1 to 4, respectively, after which all animals were slaughtered. Dietary dry matter (DM) intake and in vivo digestibility, final live weight, kill-out proportion, carcass weight, carcass conformation score, carcass fat score and daily liveweight and estimated carcass gain were not affected (P > 0.05) by cereal type or feeding frequency. Cereal type or feeding frequency had no effect (P > 0.05) on feed conversion efficiency (FCE) expressed as either live-weight or carcass gain per unit DM intake. Neither mean rumen fluid pH or concentrations of ammonia or L-lactate were influenced by cereal type or feeding frequency. The mean molar proportion of propionate was higher and that of butyrate lower (P < 0.05) with wheat than with barley. Estimated carcass weight gain and FCE to carcass were similar for wheat based and barley-based concentrate as a supplement to grass silage offered either as one feed or two equal feeds daily.
    • Effect of age and nutrient restriction pre partum on beef suckler cow serum immunoglobulin concentrations, colostrum yield, composition and immunoglobulin concentration and immune status of their progeny

      McGee, Mark; Drennan, Michael J; Caffrey, Patrick J.; Teagasc Walsh Fellowship Programme (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The effect of cow age (multiparous (MP) v. primiparous (PP)) and nutritional restriction pre partum (grass silage ad libitum v. straw only ad libitum for the last 15 (s.d. 3.3) days of gestation) on cow serum immunoglobulin (Ig) concentration, on colostrum yield, composition and Ig concentration and on calf serum Ig concentrations (at ~8 and 48 h post partum) using spring-calving Limousin Holstein-Friesian cows and their progeny was studied over 3 years. The method of colostrum administration (stomach tube vs. assisted suckling within 1 h post partum) on calf immune status was also investigated. When feeding colostrum the target was to give each calf 50 mL per kg birthweight via stomach tube. Colostrum yield and Ig concentration were measured following administration of oxytocin and hand-milking of half (Experiments 1 and 2) or the complete udder (Experiment 3). Following an 8-h period after birth during which suckling was prevented a further colostrum sample was obtained. There was no significant difference in first milking colostrum Ig subclass concentrations between the within-quarter fractions or between the front and rear quarters of the udder in either MP or PP cows. Colostrum Ig subclass concentrations at second milking were 0.46 to 0.65 of that at first milking. Compared to MP cows offered silage, colostrum yield and the mass of colostrum IgG1, IgG2, IgM, IgA and total Ig produced was lower (P < 0.001) for PP cows and the mass of IgG1, IgM and total Ig produced was lower (P < 0.05) for MP cows offered straw. Calves from PP cows and MP cows offered straw had significantly lower serum IgG1 and total Ig concentrations at 48 h post partum than calves from MP cows offered silage but there was no difference (P > 0.05) between colostrum feeding methods. In conclusion, calves from PP cows and MP cows offered straw had a lower humoral immune status than those from MP cows offered grass silage.
    • A Comparison of the Productivity of Suckler Cows of Different Breed Composition

      Drennan, Michael J; Murphy, B. (Teagasc, 2006-01-01)
      The findings obtained in a comparison of 5 suckler dam breed types {Limousin x Friesian (LF), Limousin x (Limousin x Friesian) (LLF), Limousin (L), Charolais (C) and Simmental x (Limousin x Friesian) (SLF)} and their progeny through to slaughter
    • Body and carcass measurements, carcass conformation and tissue distribution of high dairy genetic merit Holstein, standard dairy genetic merit Friesian and Charolais x Holstein-Friesian male cattle

      McGee, Mark; Keane, Michael G.; Neilan, R.; Moloney, Aidan P; Caffrey, P.J. (Teagasc, Oak Park, Carlow, Ireland, 2007)
      The increased proportion of Holstein genes in the dairy herd may have undesirable consequences for beef production in Ireland. A total of 72 spring-born calves, (24 Holstein (HO), 24 Friesian (FR) and 24 Charolais X Holstein-Friesian (CH)) were reared from calfhood to slaughter. Calves were artificially reared indoors and spent their first summer at pasture following which they were assigned to a 3 breeds (HO, FR and CH) 2 production systems (intensive 19-month bull beef and extensive 25-month steer beef) 2 slaughter weights (560 and 650 kg) factorial experiment. Body measurements of all animals were recorded at the same time before the earliest slaughter date. After slaughter, carcasses were graded and measured and the pistola hind-quarter was separated into fat, bone and muscle. HO had significantly higher values for withers height, pelvic height and chest depth than FR, which in turn had higher values than CH. HO had a longer back and a narrower chest than either FR or CH, which were not significantly different. Carcass length and depth, pistola length, and leg length were 139.2, 134.4 and 132.0 (s.e. 0.81), 52.1, 51.3 and 47.7 (s.e. 0.38), 114.4, 109.0 and 107.0 (s.e. 0.65) and 76.7, 71.9 and 71.4 (s.e. 0.44) cm for HO, FR and CH, respectively. Breed differences in pistola tissue distribution between the joints were small and confined to the distal pelvic limb and ribs. There were relatively small breed differences in the distribution of pistola muscle weight between individual muscles. Body measurements were significantly greater for animals on the intensive system (bulls) than the extensive system (steers) in absolute terms, but the opposite was so when they were expressed relative to live weight. The only significant difference in relative carcass measurements between the production systems was for carcass depth, which was lower for the intensive compared with the extensive system. Increasing slaughter weight significantly increased all carcass measurements in absolute terms but reduced them relative to weight. It is concluded that there were large differences between the breed types in body and carcass measurements, and hence in carcass shape and compactness but differences in tissue distribution were small.