Irish Journal of Agricultural and Food Research Volume 43, No 1 2004
An economic comparison of dual-purpose and Holstein-Friesian cow breeds in a seasonal grass-based system under different milk production scenarios
Irish Journal of Agricultural and Food Research 43: 1–16, 2004
R.D. Evans1,2†, P. Dillon1, L. Shalloo1, M. Wallace2 and D.J. Garrick3
1Teagasc, Moorepark Research Centre, Fermoy, Co. Cork
2Department of Agribusiness, Extension and Rural Development, Faculty of
Agriculture, University College Dublin, Belfield, Dublin 4
3Department of Animal Sciences, Colorado State University, Fort Collins, Colorado, USA
The objective of this study was to compare the economic efficiency of Dutch Holstein Friesian (HF), Montbeliarde (MB), Normande (NM) and Castlelyons Holstein Friesian (CL) cows on a seasonal spring-calving milk production system. Physical performance data were obtained from a 5-year study carried out previously. The CL Holstein Friesians were considered representative of the Irish dairy cattle population. The economic performance of the breeds was derived for three production scenarios: EU milk quota applied at farm level with the consequence that higher milk fat yield necessitates a reduction in cow numbers (S1); EU milk quota applied at industry level, thus leasing of quota is feasible (S2); and no quota (S3). Results show that the production circumstances (quota or non-quota) and evaluation criteria (replacement heifer and beef pricing) influence the economic outcomes and therefore the ranking of breeds. Risk analysis showed that MB were stochastically dominant in all milk production scenarios while the HF performed poorest under S1 and S2. The higher profitability of MB was due to lower replacement costs, higher beef values and higher milk returns. If current economic circumstances prevail in Ireland and the reproductive performance of the Holstein Friesian does not improve, then upgrading to a dual-purpose breed like the Montbeliarde may be an alternative.
Keywords: Dairy cow breed; economics; sensitivity; pasture-based system
†Corresponding author: revans@moorepark.teagasc.ie
The effect of herbage mass and allowance on herbage intake, diet composition and ingestive behaviour of dairy cows
Irish Journal of Agricultural and Food Research 43: 17–30, 2004
G. Stakelum† and P. Dillon
Teagasc, Moorepark Research Centre, Fermoy, Co. Cork
An experiment was conducted to examine the effects of herbage mass [HM, based on regrowth intervals of 35 (T) and 21 (S) days] and herbage allowance [HA, 20.2 (H) and 12.7 (L) kg organic matter (OM)/cow] on herbage OM intake (OMI), dietary composition and ingestive behaviour of dairy cows. Four groups of three cows each were used in a 4 × 4 greco-latin square design along with four oesophageal-fistulated cows. The treatment periods were 7 days and the squares (SQ) were repeated three times in a balanced way. The experiment was conducted from 11 April to 3 July 1986. The HM (organic matter) above 3 cm was 3064, 3472 and 3515 kg/ha for T and 2395, 1113 and 2396 kg/ha (s.e. 94) for S, for SQ 1 to 3, respectively. Organic matter digestibility (OMD) was 842, 799 and 778 g/kg for T, and 851, 842 and 804 g/kg for S (s.e. 0.9), for SQ 1 to 3, respectively. Sward height (cm) after grazing was 8.5 and 7.6 for T and S, and 9.6 and 6.5 for H and L (s.e. 0.18), respectively. OMI was 15.2, 14.8 and 15.2 kg for TH, 12.3, 11.9 and 10.7 kg for TL, 15.8, 14.8 and 14.5 kg for SH and 11.9, 11.1 and 11.2 kg for SL (s.e. 0.24), for SQ 1 to 3, respectively. The OMD of the diet was closely related to proportion of live leaf in the diet and sward OMD. Average biting rate increased with decreasing HM (R2 0.65). Grazing time was 8.93, 9.11 and 9.06 h for TH, 8.13, 7.96 and 7.91 h for TL, 8.96, 9.59 and 9.29 h for SH and 8.56, 9.36 and 8.52 h for SL (s.e. 0.155), for SQ 1 to 3, respectively. Multiple regression analysis showed that OMI was significantly related to HM (+0.48 kg/t), OMD of the sward (+0.18 kg per 10 g/kg) and pre-experimental milk yield (+0.37 kg/kg) (R2 0.89). The increase in OMI with potential milk yield, as indicated by pre-experimental yield, accounted for 0.80 of the supplementary energy requirements.
Keywords: Cows; diet; herbage
†Corresponding author: gstakelum@moorepark.teagasc.ie
Effect of autumn/spring nitrogen application date and level on dry matter production and nitrogen efficiency in perennial ryegrass swards
Irish Journal of Agricultural and Food Research 43: 31–41, 2004
M. O’Donovan1†, L. Delaby2, G. Stakelum1 and P. Dillon1
1Teagasc, Moorepark Research Centre, Fermoy, Co. Cork
2INRA, UMR Production du Lait 35590 St Gilles, France
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 N-application 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.
Keywords: Nitrogen; response; spring grass
†Corresponding author: maodonovan@moorepark.teagasc.ie
Comparison of flail-harvested, precision-chopped and round-bale silages for growing beef cattle
Irish Journal of Agricultural and Food Research 43: 43–57, 2004
E. Charmley1†and S. Firth2
1Crops and Livestock Research Centre, Agriculture and Agri-Food Canada,
Nappan, Nova Scotia, Canada
2Agrapoint, 92 Webster Street, Kentville, Nova Scotia, Canada
The effects of silage conservation method on silage composition and animal performance were examined in two experiments. In Experiment 1, unwilted, flail-chopped silages made with or without an additive (sodium nitrite and hexamethylene tetramine) were compared with wilted, round-bale silage. The dry matter (DM) concentration of round bale silage (460 g/kg) was higher than that of flail silage (214 g/kg) and this restricted fermentation and N solublisation. When fed to growing cattle, intake (P<0.01), live-weight (LW) gain (P<0.001) and LW gain to feed ratio (P<0.05) were greater for round-bale silage than for flail silage. In Experiment 2, flail-harvested silage was compared with wilted, precision-chopped and round-bale silages conserved either without or with pre-slicing immediately before baling. The DM concentration of flail, precision-chopped and round-bale silages were 163, 334 and 468 g/kg, respectively. Fermentation in flail silage was more extensive than in precision-chopped and particularly round-bale silages, but insoluble-N concentration was unaffected. Round-bale silage was more digestible (P<0.05) than flail or precision-chopped silages. Voluntary intake was higher for steers fed round-bale silages compared to flail silage (P<0.05), while intake of steers fed precision-chopped silage was intermediate (P>0.05). Steers fed round-bale silages had higher LW gain (1.0 kg/day) than those fed flail (0.7 kg/day) or precision-chopped silage (0.8 kg/day; P<0.05). Efficiency of utilization of DM for LW gain was similar for all silages. Pre-slicing at baling had no effect on animal performance. It is concluded that the increased performance by cattle offered silages made by the wilted round-bale system was largely due to higher voluntary intake.
Keywords: Cattle; dry matter intake; live-weight gain; silage systems
†Corresponding author: Charmleye@agr.gc.ca
Rearing calves outdoors with and without calf jackets compared with indoor housing on calf health and live-weight performance
Irish Journal of Agricultural and Food Research 43: 59–67, 2004
B. Earley†, M. Murray, J.A. Farrell and M. Nolan
Teagasc, Grange Research Centre, Dunsany, Co. Meath
The objective of this study was to compare the effects of rearing calves outdoors, with and without all-weather calf jackets, with calves reared indoors on calf immunity and animal performance. In February 1999, male Holstein calves (mean (s.e.) weight 55 (1.90) kg) were randomly assigned to one of three treatments (n=30 per treatment): 1) outdoors with jacket, (J; mean age 19 (s.e. 2.0) days); 2) outdoors without jacket (NJ; mean age 19 (s.e. 1.8) days), and 3) indoors on straw (I; mean age 19 (s.e. 1.0) days). Calves received an individual allowance of 25 kg of milk replacer dry matter during the first 42 days with ad libitum access to a concentrate ration from day 0 to 63. The jackets were removed from the calves on day 42. Live-weight gain from day 0 to day 63 of the study was not significantly different between treatments (J, 0.79; NJ, 0.80; I, 0.80 kg). Sixty percent of the J calves and 53% of the NJ calves required four or more anti-biotic treatments for respiratory disease while corresponding treatments were required for 97% of the I calves. The incidence of diarrhoea was significantly higher in both outdoor treatments compared to the I treatment. There was no significant difference in white blood cell counts or in serum immunoglobulin concentrations between treatments on days 0, 21, 42 and 63 or in in vitro interferon-γ production on day 63. It is concluded that using calf jackets on calves reared outdoors had no beneficial effect on calf performance or immune status. The incidence of respiratory disease was higher and diarrhoea incidence was lower in calves reared indoors compared with calves reared outdoors. There was no significant difference in incidences of diarrhoea and respiratory disease between the two outdoor treatments.
Keywords: Calf health; calf welfare; calves; immune function; Interferon-γ
†Corresponding author: bearley@grange.teagasc.ie
Effect of feed on cholesterol concentration and oxidation products development of longissimus dorsi muscle from Iberian pigs
Irish Journal of Agricultural and Food Research 43: 69–83, 2004
A.I. Rey1†, C.J. López-Bote1 and J.D. Buckley2
1Departamento de Producción Animal, Facultad de Veterinaria,
Universidad Complutense, 28040 Madrid, Spain
2Department of Food and Nutritional Science, University College, Cork
The effect of dietary free-range feeding or supplementation with copper and/or vitamin E in confinement on total cholesterol, neutral and polar lipids and cholesterol oxidation of the longissimus dorsi muscle from Iberian pigs was studied. Free-range fed pigs had higher (P=0.001) contents of γ-tocopherol and lower concentrations of α-tocopherol in the muscle than pigs fed diets supplemented with 100 mg/kg vitamin E. The total cholesterol content of the muscle was not significantly affected by the diets. However, the cholesterol:phospholipid ratio was higher (P<0.05), and consequently the membrane fluidity was lower, in the free-range fed pigs than in the pigs fed in confinement with either copper-supplemented (P<0.05) or vitamin E-supplemented (P<0.01) diets. The proportion of saturated fatty acids in phospholipids was greater (P<0.05) in the free-range fed group, which suggests metabolic regulation to maintain membrane structure. Free-range feeding produced higher levels of free fatty acids (P<0.01), lysophosphatidylcholine (P<0.05) and phosphatidylserine (P<0.01) and lower cholesterol esters (P<0.01) and sphingomyelin (P<0.05) in the muscle than the other groups. The ratios of phosphatidylethanolamine:phosphatidylcholine and sphingomyelin:phosphatidylcholine, which are indicators of membrane fluidity, were not significantly affected in any group. Dietary α-tocopheryl acetate supplementation produced lower β-epoxide (P<0.01), 7β-OH (P<0.05), and total cholesterol oxides (P<0.01) in cooked muscle after refrigerated display than in the other groups. These results indicate that supplementation with dietary α-tocopheryl acetate is more effective in reducing cholesterol oxidation than free-range feeding in cooked muscle from Iberian pigs. In evaluating oxidation, the composition of the muscle and meat treatment have to be considered as well as membrane fluidity.
Keywords: α-tocopherol; cholesterol oxides; copper; Iberian pig; membrane fluidity
†Corresponding author: Ana I. Rey Muñoz, Departamento de Producción Animal, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid, Spain. Tel: 00-34-91-3943785. Fax: 00-34-91-3943889. E-mail: anarey@vet.ucm.es
Surveys of cereal diseases in Northern Ireland, 1976 to 2000
Irish Journal of Agricultural and Food Research 43: 85–101, 2004
P.C. Mercer1, 2† and A. Ruddock1
1Applied Plant Science Division, Department of Agriculture and Rural Development,
Newforge Lane, Belfast BT9 5PX
2Department of Applied Plant Science, The Queen’s University of Belfast,
Agriculture and Food Science Centre, Newforge Lane, Belfast BT9 5PX
A number of disease surveys was carried out on the three main cereals grown in N. Ireland from 1976 to 2000, namely spring and winter barley and winter wheat. Although not all crops were surveyed in each year, the surveys provide a good picture of changes in disease spectra over the years. The most dramatic change in spring barley disease has been the almost complete disappearance of Blumeria graminis (mildew) and its replacement as the dominant disease by Rhynchosporium secalis (leaf blotch). Leaf-spotting ascribed to physiological causes also became more common in the latter years of the surveys. The disease spectrum of winter barley was more consistent from year to year, with Rhynchosporium secalis as the most common pathogen. Barley yellow dwarf virus was relatively severe in 1984, but in no other years. In winter wheat, there was a major change with the almost complete eclipse of Phaeosphaeria nodorum leaf blotch by Mycosphaerella graminicola (septoria tritici blotch). Gaeumannomyces graminis (take-all) was frequently severe. Surveys of cultivar popularity generally showed a rapid change in varieties over a relatively short time. Surveys of fungicide usage tended to show an increase in numbers of sprays applied, in spite of the fact that commercial pressures should have been acting towards a reduction in spraying.
Keywords: Barley; cereal disease survey; cultivar; fungicide; wheat
†Corresponding author: peter.mercer@dardni.gov.uk
A note on the effects of paddock size on the white clover content of swards grazed by sheep
Irish Journal of Agricultural and Food Research 43: 103–107, 2004
P. de Wolf1, R.P.O. Schulte2† and E.A. Lantinga1
1Department of Plant Sciences, Wageningen University, Binnenhaven 12,
6709 PD, Wageningen, The Netherlands
2Teagasc, Johnstown Castle Research Centre, Wexford
The maintenance of a high white clover content in mixed swards under sheep grazing has been a challenge to date. This paper presents the results of an experiment in which the effect of the length of a grazing period on the botanical composition of a mixed sward was studied. Paddocks ranging in size from 0.014 to 0.133 ha were rotationally grazed by a flock of seven dry ewes. Consequently, grazing periods ranged from 1 to about 8 days. On all paddocks, the proportion of perennial ryegrass declined progressively during the grazing season, regardless of paddock size. The proportions of both white clover and creeping bentgrass content increased on all paddocks during the same period. For white clover, the size of the increase was negatively related to paddock size, whereas a positive relationship was found between the paddock size and the magnitude of the increase in creeping bentgrass. This suggests that the proportion of white clover may be increased under sheep grazing by implementation of strip-grazing.
Keywords: Agrostis stolonifera; creeping bentgrass; sheep grazing; Trifolium repens; white clover
†Corresponding author: rschulte@johnstown.teagasc.ie
