RSS 1.0IJAFR, Volume 53, number 2, 2014
Recent Submissions
-
A note on the chemical composition and in vitro digestibility of contrasting stover components of maize grown in climatically marginal conditions and harvested at differing maturities.This study evaluated the nutritive value of three contrasting components of maize stover (leaf, upper stem, lower stem) at three harvest dates. The leaf component had a greater in vitro dry matter digestibility (DMD) and a lower NDF concentration, compared to the stem components. Delaying harvest reduced the in vitro DMD of the stem components to a greater extent than leaf, reflecting lower increases in the NDF and lignin concentrations in leaf tissue. The stem components of maize stover had a lower nutritive value than the leaf component, and had a larger decrease in digestibility with delayed harvest.
-
A note on the comparison of three near infrared reflectance spectroscopy calibration strategies for assessing herbage quality of ryegrassPerennial ryegrass (n = 1,836), Italian ryegrass (n = 137) and hybrid ryegrass (n = 103) herbage was taken from harvested plots from the Irish national variety evaluation scheme and analysed for in vitro dry matter digestibility, water soluble carbohydrate concentration, crude protein concentration and buffering capacity. Spectral data were obtained using near infrared reflectance spectroscopy and three calibration strategies (global, species-specific or local) were utilised to relate the reference values to the spectral data. The local strategy generally provided the poorest estimation of herbage composition, with global and species-specific calibration strategies producing similarly accurate estimates of each quality trait. The higher accuracy and easier maintenance of the global strategy make it the recommended calibration method for analysing quality of ryegrass.
-
Effect of housing on rubber slat mats during pregnancy on the behaviour and welfare of sows in farrowing cratesThe aim of this study was to evaluate the effect of flooring type during gestation, lameness and limb lesion scores on welfare and behaviour of sows in farrowing crates. Sixty sows group-housed during gestation in pens with solid concrete floored feeding stalls and a concrete, fully slatted group area either uncovered (CON; n = 30) or covered with 10 mm thick rubber slat mats (RUB; n = 30) were transferred to the farrowing crate at 110d of gestation (-5d). Lameness was scored on -5d and at weaning (28 d postfarrowing). Limb lesions were scored on -5d, 24 h later (-4d), 3 to 5 days post farrowing and at weaning (i.e., day 28 post farrowing). Sows were video recorded for 24 h on -5d, after the last piglet was born (FARROW) and prior to weaning. Videos were sampled every 10 min and an index of the proportion of time spent in different postures (standing [S], ventral [VL] and lateral lying [LL] and total lying) and number of postural changes was calculated. Median scores were calculated for limb lesions and classified as ≤ median or > median. Postural data were tested for normality and analysed using mixed model equations methodology. Flooring during gestation did not affect any of the variables recorded in this study. However, RUB sows tended to make more postural changes than CON sows (P = 0.10). Sows with swelling scores > median spent more time LL (68.9 vs. 63.1 ± 2.19%; P < 0.05) and less time VL (19.9 vs. 25.8 ± 2.27%; P < 0.05) than sows with swelling scores ≤ median. Time spent S and VL decreased and LL increased at FARROW compared to -5d and prior to weaning (P < 0.01). We found no effect of flooring type during gestation on welfare and behaviour in the farrowing crate. Factors such as limb lesions and adaptation to confinement (i.e., time spent inside the farrowing crate) appeared to have a greater influence on sow welfare and behaviour in farrowing crates than the flooring on which they were housed during gestation.
-
Nitrogen dynamics in a mature Miscanthus x giganteus crop fertilized with nitrogen over a five year periodThe objective of this study was to investigate N dynamics and response to N fertilization in a mature crop of Miscanthus x giganteus. A crop of Miscanthus x giganteus sown in 1994 was fertilized with five N rates (0, 38, 63, 90 and 125 kg N/ha/year) over a five year period (2008–2012) in Carlow, Ireland. Foliar chlorophyll concentrations were directly related to N fertilization level throughout the study and rose after N applications until July before falling with the onset of N remobilisation. Shoot numbers were unaffected by N fertilization until the final years of the study when they increased with N level. Crop height was unaffected by fertilization in the early years of the study but in the final years of the study, it increased with N level until July after which the effect diminished. There was a small but significant stimulation of harvested biomass yields in autumn (average 15 t/ha) with increasing N fertilization, but there was no effect on harvested yields in spring (average 10.5 t/ha). The N concentration in the rhizome network gradually built up during the course of the study and was proportional to N application. Aboveground biomass N content was also proportional to N application. Nitrogen remobilisation between the October and February harvests was small; abscissed leaves accounted for most of the N loss over this period. The deleterious environmental consequences of N fertilizer may outweigh any potential economic benefits if increases in biomass production are small or non-existent.
-
The employment effects of Food Harvest 2020 in IrelandThis paper examines the job creation potential of the four main sectoral growth targets in the Food Harvest 2020 (FH2020) development plan for Irish agriculture, namely the growth targets for milk, beef, sheep and pigs. As well as the direct employment that would be created from an increase in activity in the agriculture sector, there would be a knock-on benefit for the rest of the economy arising out of the linkages between agriculture and other economic sectors, as well as the spending of those additionally employed on goods and services produced in the economy. Commonly this is described as the multiplier impact. Two scenarios are simulated using different assumptions to assess how employment will respond to increased output. The first scenario shows the effects of the four shocks calculated using average or direct employment coefficients. The second scenario calculates the effects using marginal employment coefficients estimated using an econometric model of the output-employment relationship. Our results are sensitive to the choice of coefficients used to simulate the employment potential of the FH2020 targets. Based on our preferred scenario using marginal employment coefficients, we estimate that achieving the FH2020 targets will create at least an additional 16,500 jobs in the Irish economy.
-
Bioeconomic modelling of male Holstein-Friesian dairy calf-to-beef production systems on Irish farmsWith the abolition of milk quota in 2015 and increase in the use of Holstein-Friesian sires in recent years there is predicted to be an increase in the number of male Holstein-Friesian animals available for beef production. In broad terms, farmers have two options for finishing these animals; as bulls or steers. In either case, Irish beef cattle systems are based on maximising lifetime live-weight gain from grass-based diets. Managing the relationship between the supply and demand for grazed grass is complicated in these pasture-based systems due to the seasonal variability in grass growth. The Grange Dairy Beef Systems Model (GDBSM) was used to simulate the relationship between grazed grass supply and demand and then determine the profitability of Holstein-Friesian male animals finished as bulls at 16 (B16), 19 (B19) and 22 (B22) months of age and steers at 24 (S24) months of age. Combinations of these cattle finishing options were also evaluated. The most profitable system was S24. All systems were very sensitive to variations in beef and concentrate prices and less sensitive to calf price changes with fertiliser price changes having very little effect. Bull systems were more sensitive than the steer system to variation in beef, calf and concentrate prices. There was no advantage of combination systems in terms of utilisation of grass grown or net margin.
-
Potential antioxidant activity of pomegranate peel and seed extracts and synergism with added phenolic antioxidants in a liposome system: a preliminary studyThis study describes the use of liposomes as biological membrane models to evaluate the potential of natural antioxidants as inhibitors of lipid peroxidation. Antioxidative effects of by-products from the pomegranate juice industry, i.e., pomegranate peel (PPE) and seeds extracts (PSE) and combined antioxidative effects of PPE or PSE with a-tocopherol (TOH), quercetin (QC) and ascorbic acid (AA) on peroxidation of L-aphosphatidylcholine liposomes as initiated by lipophilic or hydrophilic azo-initiators were investigated. Extracts from PPE and PSE had an antioxidative effect as evidenced by a lag phase for formation of phosphatidylcholine-derived conjugated dienes. A combination of TOH or QC with PPE or PSE respectively, showed synergism in prolonging of the lag phase. Thus, the results of the present study show the possibility of utilising waste PPE or PSE
-
Farm-gate phosphorus balances and soil phosphorus concentrations on intensive dairy farms in the south-west of IrelandPhosphorus (P) loss to water is a significant threat to water quality in Ireland. Agriculture is an important source of this P. There is concern about balancing agronomic requirements and environmental protection in regulations prescribing P management on farms. This study examined farm-gate (P) balances and soil test P (STP) concentrations on 21 dairy farms in the south west of Ireland over four years, from 2003 to 2006 inclusive. Stocking density on the farms averaged 2.4 (s.d. = 0.4) livestock units (LU) per ha. Annual mean import of P onto farms was 21.6 (1.9) kg P/ha. Fertilizer P accounted for 47% (0.041), concentrates 35% (0.060) and organic manures 18% (0.034) of imported P. The mean annual P balance per farm was 9.4 (1.2) kg/ha, ranging from –3 to 47 kg/ha and mean P use efficiency was 0.71 (0.05) ranging from 0.24 to 1.37. The mean STP per farm following extraction using Morgan’s solution was 8.15 (2.9) mg/L of soil and ranged from 4.4 (2.2) to 14.7 (6.4) mg/L. There was a positive relationship (R2 = 0.34; P < 0.01) between STP and P balance; farms with a deficit of P tended to have agronomically sub-optimal STP and vice versa. The high between- and withinfarm variation in STP indicates that farmers were either unaware or were not making efficient use of STP results, and consequently there was agronomically sub-optimal soil P status in some fields and potentially environmentally damaging excesses on others (often within one farm). There was considerable potential to improve P management practices on these farms with clear agronomic and environmental benefits.
