Recent Submissions

  • A laboratory study of the effects of water dissolved gypsum application on hydraulic conductivity of saline-sodic soil under intermittent ponding conditions

    Sahin, U.; Anapali, O. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    Reclamation of saline-sodic soils has great importance in agricultural management. The objective of this study was to evaluate the effectiveness of the methods used to apply water and gypsum on hydraulic conductivity of a saline-sodic soil with an electrical conductivity of 28 dS/m and exchangeable sodium percentage of 46%. The experiment was conducted under laboratory conditions using disturbed and non-cropped soil columns. A total of 45 cm of water was applied to each column with 3, 6, or 9 separate water applications. Finely ground gypsum (< 0.5 mm maximum particle diameter) was either incorporated into the surface 2 to 3 cm of soil or was dissolved into the leaching water at a rate corresponding to 3.82 t/ha. Six or nine separate water applications of gypsum dissolved into leaching water significantly increased hydraulic conductivity (P < 0.01). Soil hydraulic conductivity increased (P < 0.01) with depth at separate applications of gypsum.
  • The phosphorus requirements for silage production on high fertility soils

    Power, V.; Tunney, Hubert; Jeffrey, D.W. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    The minimum phosphorus requirement for a mid-season ryegrass was investigated under cutting conditions over a 10-year period at each of three Teagasc sites (Clonroche, Johnstown Castle and Oak Park) in southeast Ireland. Treatments consisted of 0, 20, 30, 40, and 50 kg ha–1 year–1 P applied in autumn. Generally, there were three grass cuts each year and soil samples were taken after the third cut prior to the application of P. Nitrogen and potassium fertiliser was applied to ensure maximum grass yield. There was an emerging treatment effect over time as evidenced by the significance of the treatment × year interaction. The effect of site varied with year reflecting the variability in weather and number of cuts taken at the individual sites. A treatment effect on annual first-cut-silage yield was observed. The largest treatment difference for dry matter (DM) yield of first-cut silage was between the control and the P treated plots (0.32 t/ha). The results show that the draw down of soil-P reserves was adequate to maintain yield for a number of years without additional fertiliser P application. Initial soil tests indicated moderate to high soil test P levels (STP) as measured by the Morgan’s test. Application of P at equivalent to removal rates did not maintain STP. The results suggest that application of a regular small maintenance dressing of P, replacing realistic removals, is the most appropriate fertiliser application strategy.
  • Environmental aspects of soil phosphorus testing

    Daly, Karen M.; Casey, A. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    Soil phosphorus testing in Ireland uses Morgan’s reagent from samples taken to 10 cm depth for agronomic recommendations. However, its suitability as an environmental indicator has been questioned in terms of sample depth and extraction solution. Seven grassland sites were sampled to depths of 2, 5 and 10 cm and extracted for Morgan’s P, the standard agronomic test, as well as iron-oxide impregnated paper strip P (FeOP), calcium chloride extractable P (CaCl2-P) and water soluble P (WSP), all proposed as environmental soil tests. Extractable soil P decreased with increasing sample depth, as did variances in each test, such that, 2 cm samples had highest concentrations and variances. The current standard sample depth (10 cm) was linearly related to corresponding data from samples taken to 2 and 5 cm, indicating that surface soil P can be consistently estimated from the current standard depth. When soil tests were compared with dissolved reactive P (DRP) in overland flow collected from two field sites, certain soil tests were better indicators of P loss than others. The relative difference in Morgan’s P values at the standard sample depth (10 cm) was reflected in the relative difference in P loss between the two sites. Average values of DRP collected from two sites ranged from 0.032 to 0.067 mg/l at the low P site and 0.261 to 0.620 at the high P site. Average DRP values from the high P site and maximum DRP values from the low P site were simulated using water-soluble P extraction at water to soil ratios 5 to 250 l/kg. In this study, Morgan’s P to 10 cm gave a good indication of the relative difference in DRP loss between the two sites.
  • The application of low crude protein wheat-soyabean diets to growing and finishing pigs: 2. The effects on nutrient digestibility, nitrogen excretion, faecal volatile fatty acid concentration and ammonia emission from boars

    Leek, A. B. G.; Callan, J.J.; Henry, R. W.; O'Doherty, John V. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    Diets containing 132, 152, 183 and 206 g/kg crude protein (CP) were fed to growing and finishing boars to evaluate the effect on nutrient digestibility, N balance, faecal volatile fatty acids (VFA) and ammonia-N (NH3–N) emission. Dietary CP concentration was adjusted by altering the ratio of wheat:soyabean meal. Lysine, threonine, tryptophan and total sulphur-containing amino acids were included in all diets at concentrations equivalent to that in the highest CP diet. All diets were formulated to provide 9.7 MJ/kg of net energy. Urine and faeces were collected from 16 boars (4 boars per treatment) housed in metabolism crates. Collections were performed at 72, 80 and 87 kg live weight. NH3–N emission was measured over 10 days using a laboratory scale procedure. Reducing the concentration of dietary CP decreased N intake (linear, P < 0.01), the excretion of urinary N, ammoniacal N and total N (linear, P < 0.001; cubic, P < 0.001) and the emission of NH3–N (linear, P < 0.001; cubic, P < 0.01). Total N excretion and NH3–N emission decreased 8.7% and 10.1% per 10 g/kg reduction in dietary CP concentration between 205.6 and 131.9 g/kg, respectively. There was no interaction between dietary CP concentration and collection period. N balance differed between the collection periods and less NH3–N was emitted at 87 kg than at 72 kg. Decreasing dietary CP reduced faecal VFA concentration (linear, P < 0.05) and the molar proportions of acetic and butyric acids (quadratic, P < 0.01).
  • Production and carcass traits of high dairy genetic merit Holstein, standard dairy genetic merit Friesian and Charolais × Holstein-Friesian male cattle

    McGee, Mark; Keane, Michael G.; Neilan, R.; Moloney, Aidan P; Caffrey, Patrick J. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    The increased proportion of Holstein genetic material in the dairy herd has consequences for beef production in Ireland. A total of 72 spring-born male calves (24 Holsteins (HO), 24 Friesian (FR) and 24 Charolais × Holstein-Friesians (CH)) were reared from calfhood to slaughter. Calves were artificially reared indoors and spent their first summer at pasture following which they were assigned, on a breed basis, to a factorial combination of two production systems (intensive 19-month bull beef and extensive 25-month steer beef) and two slaughter weights (560 and 650 kg). After slaughter the pistola hind quarter was separated into fat, bone and muscle. Live-weight gain, carcass gain, kill-out proportion, carcass conformation and carcass fat scores were 830, 811 and 859 (s.e. 14.9) g/day, 540, 533, 585 (s.e. 7.7) g/day, 526, 538 and 561 (s.e. 3.0) g/kg, 1.51, 2.18 and 2.96 (s.e. 0.085), and 3.40, 4.25 and 4.06 (s.e. 0.104) for HO, FR and CH, respectively. Corresponding values for pistola weight as a proportion of carcass weight, pistola muscle proportion and pistola fat proportion were 458, 459 and 461 (s.e. 2.6) g/kg, 657, 645 and 667 (s.e. 3.7) g/kg, and 132, 161 and 145 (s.e. 4.1) g/kg. Compared with the intensive system, animals on the extensive system had a lower (P < 0.001) daily live-weight gain, kill-out proportion and a lower muscle proportion in the pistola. Increasing slaughter weight increased (P < 0.001) carcass weight and carcass fat score and reduced the proportion of muscle in the pistola. Allometric regression coefficients for pistola weight on side weight, and total bone, muscle and fat weights on pistola weight were 0.898, 0.755, 0.900 and 1.910 respectively. It is concluded that HO grew at least as fast as FR but had a lower killout proportion. Carcass conformation and fat scores were greater for FR than for HO and muscle proportion in the pistola was lower and total fat proportion was higher. Compared with FR, CH had heavier carcasses, a higher kill-out proportion and less fat and more muscle in the pistola.
  • Cow serum and colostrum immunoglobulin (IgG1) concentration of five suckler cow breed types and subsequent immune status of their calves

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

    Cullen, S.P.; Monahan, Frank J; Callan, J.J.; O'Doherty, John V. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    The objective of this study was to investigate the effects of inclusion of rosemary (Rosmarinus officinalis) and garlic (Allium sativum) in pig diets on apparent nutrient digestibility, pig performance, carcass characteristics and on sensory characteristics of the pork. Seventy individually-fed grower-finisher pigs (42 kg live weight) were offered one of the following diets ad-libitum: (1) control diet (based on wheat, pollard and soyabean meal), (2) control diet supplemented with rosemary at 1 g/kg (low rosemary; LR), (3) control diet supplemented with rosemary at 10 g/kg (high rosemary; HR), (4) control diet supplemented with garlic at 1 g/kg (low garlic; LG) and (5) control diet supplemented with garlic at 10 g/kg (high garlic; HG). Pigs offered diets with garlic had a lower feed intake (P < 0.01) and lower digestible energy intake (P < 0.05) compared to the pigs offered the control or rosemary diets during the grower-finisher period. Pigs offered the LG and HG diets had a better (P < 0.05) food conversion ratio (FCR) than the pigs offered the control or rosemary diets. Digestibility of dry matter and organic matter were lower (P < 0.05) for the HG diet than the LG diet. Gross energy digestibility and digestible energy concentration were lower for the HR than the LR diet. Sensory panellists found a significant difference (P < 0.001) in the sensory properties of cooked muscle from the control and HG treatments. In conclusion, the addition of garlic to the diets of grower-finisher pigs reduced feed intake and improved FCR while the addition of rosemary had no beneficial effects on growth performance or carcass characteristics.
  • The effect of floor type in farrowing crates on piglet welfare

    Lewis, Eva; Boyle, Laura; O'Doherty, John V.; Brophy, P.; Lynch, P Brendan; Teagasc Walsh Fellowship Programme (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.
  • The Flow of Water Through Gravels

    Mulqueen, J. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    The linear flow law of Darcy, relating the flux to the hydraulic gradient by a constant of proportionality, the hydraulic conductivity (K), is almost universally employed to analyse and predict the flow of fluids through soils and aquifers. Laminar flow is a prerequisite for its application and while not a problem in soils, it may be problematic in high velocity flows through gravel aquifers and drains. In the present study, the velocity of water flow through 30 screened gravel aggregates, comprising pit and broken stone gravels and ranging in particle diameter from 38.1 to 1.6 mm was measured. Some of the aggregates were reconstituted, derived by combining in various proportions fractions from laboratory screenings. The experimental arrangement comprised a 1.53-m long, 60-mm bore PVC smooth-walled pipe with retainer screens at both ends. This pipe was carefully packed with the particular gravel aggregate in 0.5 kg aliquots, placed horizontally on adjustable supports and connected to a 3-m3 reservoir held at a constant level. Hydraulic gradients applied were generally in the range 0.05–0.56. Each test was repeated at least twice. The flow of water through the gravels did not obey Darcy’s Law. The relationship between velocity, v (m/s), and the hydraulic gradient (i) was of the form, v = aib , with a and b (–) constants for a particular gravel. Darcy’s Law can be applied by considering a gradient-dependent hydraulic conductivity, v = K(i), from which K(i) = aib–1. Under unit gradient K(i) = a. In the coarser gravel aggregates, the value of b approached 0.5, similar to that for turbulent flow in roughwalled pipes. In fine-particle gravels, b tended toward unity indicating that Darcy’s Law could be applied without too much error. Results of tests in this series were in good agreement with those from another laboratory. Log-log curves and equations relating K(i) of individual aggregates to i are provided. K(i) values ranged over two orders of magnitude from 120,000 m/day for coarse gravel to about 700 m/day for a 4.76 to 1.6 mm gravel. There were very large declines in K(i) with increase in i in coarse gravels and small declines in the finer gravels. Results are discussed in relation to drainage and filter gravels and gravel aquifers.
  • Effect of creep feeding, dietary fumaric acid and level of dairy product in the diet on post-weaning pig performance

    Lawlor, Peadar G; Lynch, P Brendan; Caffrey, Patrick J. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    Fumaric acid (FA), level of dairy product in the diet and creep feeding were evaluated in three experiments using individually fed pigs (weaned at ca. 21 days and weighing about 6 kg). They were assigned at random to treatments. In Experiment 1, the treatments were: (1) no pre-weaning creep and no FA post-weaning, (2) no pre-weaning creep and 20 g/kg FA post-weaning, (3) pre-weaning creep and no FA post-weaning, and (4) pre-weaning creep and 20 g/kg FA post-weaning. In Experiment 2, the treatments were: (1) 50 g/kg dried whey, (2) 50 g/kg whey with 20 g/kg FA, (3) 50 g/kg whey with 30 g/kg FA, (4) 200 g/kg whey, (5) 200 g/kg whey with 20 g/kg FA, (6) 200 g/kg whey with 30 g/kg FA. In Experiment 3, the treatments were: (1) high dairy product (whey plus skim milk powder) diet, (2) high dairy product diet with 20 g/kg FA, (3) low dairy product diet, (4) low dairy product diet with 20 g/kg FA. The number of pigs per treatment in Experiments 1, 2 and 3 was 16, 10 and 10, respectively. All diets contained barley, wheat, herring meal and full-fat soybean meal. In Experiment 1, FA inclusion increased intake (518 ν. 466, s.e.d. 21.5 g/day, P < 0.05), daily gain (339 ν. 280, s.e.d. 18.1 g/day, P < 0.01) and improved feed conversion rate (1.55 ν. 1.70, s.e.d. 0.06, P < 0.05) in the first 3 weeks post-weaning. In Experiment 2, there was no effect of treatment. In Experiment 3, increasing the level of dairy product in the diet increased feed intake (P = 0.06) and daily gain (P < 0.05) and improved feed conversion rate (P < 0.01). The conclusions are that FA improved post-weaning performance and that increasing the level of dairy products in postweaning diets also improved performance.
  • Evaluation of Recovered Vegtable Oil as a Biodiesel Feedstock

    Frohlich, A.; Rice, B. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    About 7,000 t of recovered vegetable oil (RVO) are collected in Ireland each year. The use of this material in animal feed has been banned under recent EU legislation because of food safety and animal health concerns. In order to assess its potential as a biodiesel (fatty acid methyl ester) feedstock, twenty-two 350-kg batches, with a wide range of acid values, were esterified. Ester properties were largely within specification, though variable low-temperature properties sometimes caused the material to be unsuitable for winter use. This problem could be overcome by blending with mineral diesel, but the addition of two pour-point depressants had little effect. Total glycerol concentrations in some batches were high; it could be improved by small changes in the process. Ester yields were low, due mainly to dissolution of ester in the glycerol, but also to saponification of the triglycerides. Tests of the biodiesel in vehicles showed no adverse effects on engine or lubricating oil. Specific fuel consumption was slightly higher than with mineral diesel, which would be expected with biodiesel from any feedstock. The results indicate that it is possible to produce biodiesel of acceptable quality from RVO. Where ester low-temperature properties are inadequate, the problem can be overcome by blending with mineral diesel.
  • Grain yield reductions in spring barley due to barley yellow dwarf virus and aphid feeding

    Kennedy, T.F.; Connery, J. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    The occurrence and control of barley yellow dwarf virus (BYDV) in spring barley was investigated, at Oak Park, in the periods 1990 to 1993 and 1996 to 2001. Barley was sown in March and April and treated with either organophosphorous or pyrethroid aphicide at various plant growth stages. The most common aphid encountered was Sitobion avenae and MAV the most common strain of BYDV. In untreated plots of March- and April-sown barley, 0.85% and 5.9%, respectively, of tillers had virus symptoms. Best control of symptoms, from a single aphicide in March- and April-sown crops, was a treatment at growth stage (g.s.) 14. This treatment contributed 77% of the reduction in symptoms recorded for multiple treatments in April-sown plots. The reduction in grain yield due to high, moderate and low BYDV infection in April-sown barley was 1.1 t/ha (20%), 0.65 t/ha (10%) and 0.36 t/ha (7%), respectively. In Marchsown barley, pyrethroid aphicide applied at g.s. 14 significantly improved grain yield by 0.26 t/ha (4%). In the season having the most severe BYDV outbreak, a pyrethroid aphicide at g.s. 14 was best in controlling yield loss. Pyrethroid aphicide gave better control of symptoms and better yields than organophosphorous aphicide. The estimated yield reductions in untreated April-sown barley due to feeding damage by Sitobion avenae was 0.71 t/ha and 0.83 t/ha (10.6% and 11.3%) in the two seasons in which this aphid was plentiful. In the three seasons in which Metopolophium dirhodum was recorded the estimated yield reductions were 0.32 t/ha, 0.48 t/ha and 0.43 t/ha (5.2%, 5.6% and 5.7%).
  • Effects of supplementary concentrate level with grass silage, and separate or total mixed ration feeding, on performance and carcass traits of finishing steers

    Caplis, J.; Keane, Michael G.; Moloney, Aidan P; O'Mara, Frank P.; National Development Plan 2000–2006 (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    Concentrates are a major component of feed costs in winter finishing of beef cattle. The objectives of this study were (1) to determine the response to increasing levels of supplementary concentrates with grass silage, and (2) to determine the effects of feeding silage and concentrates separately or as a total mixed ration (TMR). A total of 117 finishing steers (mean initial live weight 538 (s.d. 35.5) kg) were assigned to a pre-experimental slaughter group of 9 animals and to 6 feeding treatments of 18 animals each. The feeding treatments were (1) silage only offered ad libitum (SO), (2) SO plus a low level of concentrates offered separately (LS), (3) SO plus a low level of concentrates offered as a TMR (LM), (4) SO plus a medium level of concentrates offered separately (MS), (5) SO plus a medium level of concentrates offered as a TMR (MM), and (6) concentrates ad libitum plus a restricted silage allowance (AL). Low and medium concentrate target levels were 3 and 6 kg dry matter (DM) per head daily. When silage (210g/kg DM, 758 g/kg in vitro DM digestibility, pH 3.7) and concentrates were fed separately, the daily concentrate allowance was given in one morning feed. The animals were individually fed for a mean period of 132 days. After slaughter, carcasses were weighed and graded and a rib (6th to 10th) joint was dissected into its component tissues. Silage DM intake decreased (P < 0.001) but total DM intake increased (P < 0.001) with increasing concentrate level. Average live-weight gains for SO, LS, LM, MS, MM and AL was 0.34, 0.86, 0.86, 1.02, 1.00 and 1.12 (s.e. 0.064) kg/day, respectively. Corresponding carcass weight gains were 0.25, 0.58, 0.58, 0.71, 0.68 and 0.82 (s.e. 0.028)kg/day. All measures of fatness increased (P < 0.05), bone proportion of the rib joint decreased (P < 0.001), and muscle proportion was not significantly affected by dietary concentrate level. There were no significant interactions between concentrate level and method of feeding. Compared with offering the feeds separately, feeding as a TMR increased silage DM intake by proportionately 0.06 (P < 0.05) and total DM intake by proportionately 0.04 (P < 0.05). Method of feeding had no significant effect on performance, slaughter or carcass traits. It is concluded that silage intake decreased and total intake increased with increasing concentrate level. Live-weight and carcass-weight gains also increased with increasing concentrate level. Feeding a TMR had no effect on animal performance or carcass traits compared with separate feeding.
  • Comparison of sugar-beet pulp and barley with and without soya bean meal as supplements to silage for growing steers

    Keane, Michael G.; National Development Plan 2000–2006 (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    The optimum live-weight gain for growing steers in winter depends on the cost of feed and subsequent compensatory growth. The objectives of this experiment were: (1) to determine the response in growing steers to increasing levels of molassed sugar-beet pulp (MSBP) as a supplement to grass silage, (2) to compare MSBP and barley, and (3) to ascertain if there was a response to the inclusion of soya bean meal as a protein source with both MSBP and barley. Weanling steers (n = 154) were assigned to the following treatments: (1) silage only, (2) silage plus a low level of MSBP, (3) silage plus a low level of MSBP plus soya bean meal, (4) silage plus a high level of MSBP, (5) silage plus a high level of MSBP plus soya bean meal, (6) silage plus a high level of barley, and (7) silage plus a high level of barley plus soya bean meal. Low MSBP, high MSBP and barley levels were 1.5 kg, 3.0 kg and 3.0 kg per head daily, respectively. Where soya bean meal was included it replaced 0.2 kg/day (low) or 0.4 kg/day (high) of MSBP or barley. The duration of the treatments was 125 days (winter) after which the animals grazed together for 148 days. Silage intake decreased linearly (P < 0.001) with increasing MSBP level. Addition of soya bean meal had no effect on silage intake with low MSBP or barley but increased (P < 0.05) intake with high MSBP. Live-weight gain increased both linearly (P < 0.001) and quadratically (P < 0.01) with increasing MSBP. There was a significant live-weight response to the addition of soya bean meal which was greater at the high than at the low MSBP level and was greater for MSBP than barley. Across all treatments, growth rate at pasture was inversely related to growth rate in winter. Final live weights for the treatments as listed were 376, 395, 411, 400, 430, 427 and 428 (s.e. 14.2) kg. It is concluded that there was a curvilinear live-weight gain response to increasing MSBP level. There was no end-of-grazingseason live-weight response to the inclusion of soya bean meal with barley but there was with MSBP, particularly at the high level. MSBP with soya bean meal was equivalent to a similar quantity of barley.
  • Predicting the soil moisture conditions of Irish grasslands

    Schulte, Rogier P.; Diamond, J.; Finkele, K.; Holden, Nicholas M.; Brereton, A. J. (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    Soil moisture conditions are an important interface between agriculture and the environment, as they impact on the length of the grazing season, grass growth rate and nutrient uptake, and the loss of nutrients to the wider environment. Moisture conditions are conveniently quantified by the soil moisture deficit (SMD) but diverging methods for deriving SMD have been applied in Ireland to date. A simple hybrid model for computing SMD is presented, which accounts for differences in drainage regimes between soil types, and is calibrated for contrasting soil types in Ireland. This hybrid model accurately predicted the temporal patterns of SMD on well-drained and poorlydrained soils. Three soil drainage classes were defined, which satisfactorily describe the differences in drainage between soils.
  • Cow factors affecting the risk of clinical mastitis

    Berry, Donagh; Meaney, William J (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    The objective of the present study was to identify cow risk factors associated with development of clinical mastitis (CM) in subsequent stages of lactation. A total of 3,309 lactations from spring-calving Holstein-Friesian cows were included in the analysis; parity number ranged from one to three, inclusive. A generalised estimating equations approach with a logit link function was used to account for the binary nature of the data and the unequal number of repeated records per cow. The dependent variable was the probability of developing CM in the subsequent stage of lactation. Independent variables included in the model were chosen using stepwise selection; herd, year of birth, month of calving, parity, period of lactation and previous CM history significantly affected the probability of CM. Two-way interactions between parity and period of lactation and between parity and incidence of CM in the previous lactation were also included in the model. A greater probability of developing CM is expected in cows that experienced CM in the previous lactation and/or previously within the same lactation. The probability of CM occurring in cows that experienced at least one case of CM in the previous lactation was 0.92 to 3.75 times that of a cow that experienced no CM in the previous lactation. It is possible to predict the probability of an animal developing CM in the subsequent stage of lactation when information is available on the parity and month of calving of the animal and its previous history of CM.
  • Empirical algebraic modelling of lactation curves using Irish data

    Quinn, N.; Killen, L.; Buckley, Frank (Teagasc (Agriculture and Food Development Authority), Ireland, 2005)
    The purpose of this study was to find a well-fitting, robust, single-equation model to describe the shape of lactation curves for Irish dairy cows. The suitability of a number of algebraic models that depict lactation curves was examined, using Irish test day data. The analysis was carried out on a total of 14,956 lactation records from commercial and experimental herds and included both autumn and spring calving animals. ‘Goodness of fit’ and adherence of the various models to the assumptions of regression analysis were examined. Multicollinearity posed a severe problem in the application of the best-fit model but omitting one of the variables from the estimation procedure reduced this effect. The modified model, referred to as the Ali-B model, is a single equation model that can be easily updated and incorporated into computer code. This is in contrast with the Standard Lactation Curve (SLAC) method, a method of interpolation, which is currently used by the Irish industry. The effects of seasonal factors on milk production were estimated and added to the Ali-B model to create a production profile for cows calving in specific months. The Ali-B model provided an acceptable level of accuracy in representing the shape of the lactation curve for Irish dairy cows, and can be easily modified for different environmental scenarios.
  • 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 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

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