516 research outputs found
Cow serum and colostrum immunoglobulin (IgG1) concentration of five suckler cow breed types and subsequent immune status of their calves
peer-reviewedB. Murphy would like to gratefully
acknowledge receipt of a Walsh Fellowship provided
by Teagasc.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 growth, ultrasound and skeletal measurements, muscularity scores and carcass traits and composition of progeny of five beef suckler cow genotypes
peer-reviewedB. Murphy was in receipt of a Walsh Fellowship provided by Teagasc.Post-weaning growth, ultrasound and skeletal measurements, muscularity scores, and carcass traits and composition of the progeny of spring-calving Limousin (L), Charolais (C), Limousin × Holstein-Friesian (LF), Limousin × (Limousin × Holstein-Friesian) (LLF) and Simmental × (Limousin × Holstein-Friesian) (SLF) cow genotypes was determined over 3 years. Bull and heifer progeny were slaughtered at ~460 and ~610 days of age, respectively. Post-weaning growth did not differ significantly between the genotypes. Progeny from LF and SLF cows had the highest (P<0.001) carcass gain per day of age, whereas progeny from L and C cows had the highest (P < 0.01) carcass conformation score and lowest (P < 0.001) fat score. The proportion of meat in the car¬cass was higher (P < 0.001) and bone lower (P < 0.001), and meat to bone ratio higher (P < 0.001) for the progeny of L cows than all other genotypes, which were similar. Carcass fat proportion was similar for progeny of L and C cows and lower (P < 0.001) than LLF and SLF, with LF being intermediate. The progeny from L cows tended to have the greatest proportion of hind-quarter in the carcass. Genotype effects were mini¬mal when the proportion of high-value cuts was expressed relative to weight of meat in the carcass and hind-quarter. In conclusion, there was no effect of cow genotype on the performance of their progeny from weaning to slaughter. However, crossbred cows with good maternal (milk) traits produced progeny with a higher carcass weight per day of age, whereas the purebred continental cows produced progeny with superior carcass classification traits.Teagasc Walsh Fellowship Programm
Performance and feed intake of five beef suckler cow genotypes and pre-weaning growth of their progeny
peer-reviewedThe effect of beef suckler cow genotype on feed intake, performance, milk yield and on pre-weaning growth of their progeny was determined over four lactations. The five cow genotypes examined were Limousin (L), Charolais (C), Limousin × Holstein-Friesian (LF), Limousin × (Limousin × Holstein-Friesian) (LLF) and Simmental × (Limousin × Holstein-Friesian) (SLF). The herd calved in spring and the progeny spent from April until weaning (October/ November) at pasture with their dams. Live weight (kg) at the start of the indoor winter period was greater (P 0.05) between the genotypes but followed a similar trend to grass silage intake. The decrease in live weight over the indoor winter period was greater (P < 0.01) for L and C cows than for LLF and SLF, whereas LF were intermediate. The increase in live weight during the grazing season was greater (P < 0.01) for C cows than all except L, which were intermediate. Calving difficulty score was greater (P < 0.01) for C cows than LLF, L and SLF, whereas LF were intermediate. Birth weight of calves from LF cows was lower (P < 0.001) than C with L being intermediate, but greater than LLF, with SLF being intermediate. Milk yield (kg/day) was higher (P < 0.001) for LF (9.7) and SLF (8.7) cows than the other genotypes (5.5 to 7.0), which did not differ significantly. Pre-weaning live-weight gain was greater (P < 0.001) for progeny of LF cows than all other genotypes except SLF, which in turn were greater than L and C, with LLF being intermediate. In conclusion, calf pre-weaning growth was higher for cow genotypes with higher milk yield, which was also associated with higher cow DM intake.B. Murphy was in receipt of a Walsh Fellowship provided by Teagasc
Changes in yield and composition of barley, wheat and triticale grains harvested during advancing stages of ripening
peer-reviewedThis study involved an evaluation of the changes in grain yield, nutritive value, ensilability
and harvesting losses of intensively managed winter cereals harvested during
the advancing stages of ripening. Five cereal crops (barley cv. Regina and wheat cv.
Madrigal in 2001; barley cv. Regina, wheat cv. Falstaff and triticale cv. Fidelio in 2002)
were assessed. Twenty plots per crop were arranged in a randomised complete block
design, with five times of harvest (four for barley in 2002) and four replicate blocks
per harvest. Dry matter (DM) yields changed relatively little between harvest dates,
but fresh yields declined (P < 0.001) over time due to the moisture loss associated with
ripening. Time-course changes in indices of nutritive value, such as concentrations of
crude protein, starch and ash, and organic matter digestibility, were relatively small
and did not follow a consistent pattern. Ensilability indices, such as DM and watersoluble
carbohydrate concentrations and buffering capacity, indicated that satisfactory
fermentations were likely if such crops were ensiled; buffering capacity, generally
declining with advancing maturity. Harvesting losses were not clearly related to growth
stage at harvest. It is concluded that winter cereal grain (barley, wheat and triticale)
DM yields and quality were relatively constant as ripening progressed from DM concentrations
of around 550 to >800 g/kg.One of the authors (P.S.) was in receipt
of a Teagasc Walsh Fellowship
Evaluation of Lolium perenne L. cv. AberDart and AberDove for silage production
peer-reviewedThe objective of this study was to assess the value, for silage production, of intermediateheading
Lolium perenne L. cultivars, AberDart and AberDove (diploid), bred for increased water-soluble carbohydrate (WSC) concentrations, relative to four control cultivars (Fennema, AberElan and Spelga (diploid), and Greengold (tetraploid)). Cultivars were evaluated for forage dry matter (DM) yield, ground cover and indirect laboratory measures of nutritional value and ensilability over 3 harvest years within intensive silage-production systems. AberDove was the most desirable diploid for silage production producing on average 316 kg/ha higher (2%) DM yield per annum, having a 10 g/kg higher (1%) dry matter digestibility (DMD) and, based primarily on a 6 g/L higher (19%) concentration of WSC expressed in the aqueous extract (WSCAE), offered the greatest potential to produce well preserved silage. Ensiling AberDart compared to the diploid controls offered a slightly greater probability of producing well preserved silage based on a modest increase of 2 g/L (6%) in WSCAE concentration. The dilemma for silage production is that AberDart, on average produced 558 kg/ha less (4%) DM yield per annum but had a greater (1%) DMD of 6 g/kg than the diploid controls. The tetraploid control had, on average, 13 and 8 g/kg higher (2% and 1%, respectively) DMD than AberDart and AberDove, but at a cost of lower ensilability with lower (6% and 21%, respectively) WSCAE values of 2 and 6 g/L. In its favour, the
tetraploid control outyielded AberDart by, on average, 917 kg/ha DM per annum (7%) and produced comparable yields to AberDove. Final ground cover ratings were high (≥ 95%) for all cultivars. Evaluation of nutritional value and ensilability offers further grounds to differentiate and select cultivars for animal production potential.A Teagasc Walsh Fellowship, awarded to P. Conaghan and H. Howard, and the European Commission under the Fifth Framework Programme (QLK5-CT-2001-0498) supported this research
New approaches to renewable energy education
The rapid expansion of the renewable energy industry is producing a huge demand for welltrained professional people to design, install and maintain new systems. There is also a substantial need for policy analysts, researchers and teachers with experience in renewables. Many professional people are now seeking to move their career paths into the renewable energy field and they require advanced, on-the-job training. It is no longer sufficient to add a few topics or units on renewables to a conventional science or engineering course. Renewable energy education is emerging as a new discipline in its own right, with its own interdisciplinary curriculum that meets the criteria for sustainable development. Educating the community is also vital for creating a greater awareness of, and confidence in, renewable energy systems, and for training people to use them properly.
This paper describes some new approaches to renewable energy education that seek to meet the needs of industry and society for high-quality, environmentally friendly and socially responsible energy supply systems
Characterisation of feedstuffs for ruminants.
End of Project ReportA wide variety of feed ingredients are used in the manufacture of
compound feeds in Ireland. Unprocessed feedstuffs vary from batch
to batch due to differences caused by variety, soils, weather, etc. By
-product feeds may also vary due to the processes from which they
were produced. Accurate information on the nutritive value of feeds
is essential for accurate ration formulation. A series of experiments
was carried out to determine various nutritional characteristics of
concentrate ingredients either locally produced or imported into
Ireland. From these experiments it was concluded that :
* The digestibility values of concentrate ingredients derived in
maintenance-fed sheep are applicable to maintenance-fed
cattle.
* Feed is not utilised as efficiently when the level of feeding is
increased from maintenance to 2 x maintenance.
* The improved feed conversion efficiency in steers offered a
restricted allowance of concentrates cannot be attributed to
a difference in digestibility but can be attributed in part to a
lower rate of fat deposition compared to steers offered ad
libitum concentrates.
* The residue after oil extraction from Camelina sativa could
replace some imported protein-rich feedstuffs in ruminant
rations but to fully achieve this potential, the residual oil
content must be decreased.
* For measurement of ruminal degradability of concentrate
ingredients a wide range of forage to concentrate ratios and
feeding levels can be used.
* It is important to consider the actual outflow rate of
nutrients from the rumen when measuring the feed value of
individual concentrate ingredients as this can have an impact
on the effective degradability and the relative nutritive values
assigned to such ingredients.
* Large variations in ruminal degradation occur within and among feeds. The ruminal degradability of different samples
of any one feed should be measured to determine their
true nutritive value for feeding ruminants.
* Within most concentrate ingredients examined, the variation
in small intestinal digestibility (SID) due to source indicates a
range in the quantity of amino acids supplied to the animal
for productive purposes. The more rapid and cost effective
in vitro technique can be used to screen the SID of
concentrate ingredients.
* Target volatile fatty acid (VFA) concentrations and
proportions may be produced by varying the proportions
of the individual ingredients in a concentrate ration.
* An in vitro procedure allowed VFA production to be
measured across a large range of feeds under standardised
conditions.
* On average, 75% of gas produced during ruminal
fermentation consists of carbon dioxide. The variation in
methane production among individual concentrate
ingredients provides an opportunity to formulate rations to
minimize environmental pollution with methane.European Union Structural Funds (EAGGF
Self broadening of hydrogen lines: Initial results
For the first time broadening by both resonance and dispersive-inductive interactions with H-atoms are included in the formation of Balmer lines in cool stars, without the use of a multipole expansion. Comparison of synthetic profiles with observed profiles for the Sun and two late F dwarfs shows that this improvement in broadening theory accounts for some of the problems found in previous work. It is anticipated that planned future developments in the theory of self broadening will lead to further improve ments in the modelling of cool star atmospheres
Self-broadening in Balmer line wing formation in stellar atmospheres
Details of a theory of self-broadening of hydrogen lines are presented. The main features of the new theory are that the dispersive-inductive components of the interaction (van der Waals forces) have been included, and the resonance components have been computed by perturbation theory without the use of the multipole expansion. The theory is applied to lower Balmer lines and the theoretical and observational impact of the new broadening theory is examined. It is shown that this theory leads to considerable differences in the predicted line profiles in cool stars when compared with previous theories which include only resonance interactions. In particular, the effect is found to be very important in metal poor stars. The theory provides a natural explanation for the behaviour of effective temperatures derived from Balmer lines by others using a theory which includes only resonance broadening. When applied to Balmer lines in the solar spectrum the theory predicts an improved agreement between observed and computed profiles for models which also match limb darkening curves and rules out a model which does not. However significant discrepancies still remain which could be due to inadequacies in our theory or the atmospheric model or both
Comments on alternative calculations of the broadening of spectral lines of neutral sodium by H-atom collisions
With the exception of the sodium D-lines recent calculations of line
broadening cross-sections for several multiplets of sodium by Leininger et al
(2000) are in substantial disagreement with cross-sections interpolated from
the tables of Anstee and O'Mara (1995) and Barklem and O'Mara (1997). The
discrepancy is as large as a factor of three for the 3p-4d multiplet. The two
theories are tested by using the results of each to synthesize lines in the
solar spectrum. It is found that generally the data from the theory of Anstee,
Barklem and O'Mara produce the best match to the observed solar spectrum. It is
found, using a simple model for reflection of the optical electron by the
potential barrier between the two atoms, that the reflection coefficient is too
large for avoided crossings with the upper states of subordinate lines to
contribute to line broadening, supporting the neglect of avoided ionic
crossings by Anstee, Barklem and O'Mara for these lines. The large
discrepancies between the two sets of calculations is a result of an
approximate treatment of avoided ionic crossings for these lines by Leininger
et al (2000).Comment: 18 pages, 5 ps figures included, to appear in J Phys B: At. Mol. Opt.
Phy
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