8,402 research outputs found
The GSFC gound-based lidar for the measurement of stratospheric ozone
Concern has risen over the last decade concerning the release of gases into the atmosphere which when photolyzed in the stratosphere can catalyze the destruction of ozone. Although the expected change is only on the order of 5%, significant changes in the vertical profile are anticipated. Predictions at 40 km run as high as a 60% change in the next 50 to 100 years. Because of the importance of ozone in the thermal budget of the atmosphere, such a change will have a direct impact on the earth's climate. Long term monitoring of stratospheric ozone is required to validate the predictions and Differential Absorption Lidar is particularly well suited to this measurement. GSFC is currently constructing a mobile lidar system based on a high powered XeCl excimer laser. The system is expected to be operating by fall 1986 and a campaign to compare the lidar results with a series of ROCOZ flights is planned
Effect of beef sire expected progeny difference for carcass conformation on live animal muscularity scores and ultrasonic muscle and fat depths, and on carcass classification and composition of their progeny
peer-reviewedThe objective was to examine the effect of sire expected progeny difference (EPD) for carcass conformation score on the live animal and carcass traits of their progeny. In each of 4 years a Charolais sire of high and one of average EPD for carcass conformation score were mated to spring-calving suckler cows and the bull and heifer progeny were taken to slaughter at 455 (s.d. 25.2) and 607 (s.d. 29.5) days of age in 4 and 3 years, respectively. The difference in EPD between the sire EPD groups for carcass conformation and fat scores (scale 1 to 15), and carcass weight were, 0.45 units, −0.53 units and 9.7 kg, respectively. Muscularity scores were recorded at weaning (7 to 9 months of age) and pre-slaughter, and ultrasound measurements were recorded pre-slaughter. Carcass weight, and conformation and fat scores were recorded at slaughter and an 8-rib pistola from the right side of each carcass was dissected into lean, fat and bone. There was no significant effect of sire EPD group on live weight or carcass weight, but kill-out proportion, ultrasound muscle depth and the Irish Cattle Breeding Federation muscularity scores were greater (P < 0.001) for progeny of the high than the average EPD group. Bull progeny of high EPD sires had better (P < 0.001) Signet muscularity scores and carcass conformation scores than bull progeny from average EPD sires, whereas there was no effect of sire EPD group on heifer progeny. Compared to progeny of the average EPD sire group, those from the high EPD group had a lower weight of kidney and channel fat (P 0.06) and carcass fat score (P < 0.05), lower proportions of fat (P < 0.001) and bone (P < 0.01) in the pistola, and higher weight of pistola, both absolutely (P < 0.01) and relative to carcass weight (P < 0.05), higher proportions of lean and high-value cuts in the pistola and higher carcass value (P < 0.001). Linear regression analysis showed that a 1 unit increase in sire EPD for carcass conformation score increased (P < 0.01) carcass lean proportion by 19.4 g/kg. In conclusion, although sire EPD for carcass conformation score was reflected in the conformation score of intensively-reared bull progeny and not in extensively-reared heifer progeny, carcass lean proportion and carcass value were higher for both genders
Rotationally resolved collisional transfer rates in OH
Fluorescence lidar measurements of the hydroxyl radical require detailed information concerning collision induced processes in order to deduce the radical number density from a lidar return. The Goddard SFC OH lidar currently utilizes a broadband detector which precludes the necessity of fully understanding collisional redistribution of rotational energy within the excited state. Numerous advantages result however from the inclusion of a detector with a bandpass only slightly larger that the Doppler width of a rotational line. This however places more stringent requirements on the spectroscopy. Measurements were accordingly made of rotationally resolved quenching rates for collisions with O2, N2, and H2O. Rotational transfer rates were also measured for the same colliders. Quenching rates were measured using a Nd-YAG pumped Rh6G dye laser doubled into the UV. The OH lifetimes were measured as a function of pressure of quenching gas at total pressures of between 50 and 250 microns. Rotational transfer rates were measured by recording the emission spectrum on an intensified diode array and integrating over 10.000 laser shots
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
peer-reviewedThe 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
Effect of suckler cow genotype on cow serum immunoglobulin (Ig) levels, colostrum yield, composition and Ig concentration and subsequent immune status of their progeny
peer-reviewedSurvival 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 cowsTeagasc Walsh Fellowship Programm
Effect of concentrate feeding level in winter and turnout date to pasture in spring on biological and economical performance of weanling cattle in suckler beef production systems
peer-reviewedThree experiments were carried out to determine the effects of supplementary concentrate feeding level (Low, LC; High, HC) to grass silage and/or turnout date to pasture in spring (Early, ET; Late, LT) for a second grazing season on performance to slaughter of spring-born, weaned beef calves (n = 188). Experiment 1 comprised of two concentrate levels (0.5 and 1.5 kg/day). Experiment 2 comprised of two turnout dates (19 March, 9 April). Experiment 3 comprised of two concentrate levels (0.5 kg and 2.0 kg/day) and two turnout dates (22 March, 12 April). In Experiment 1, live-weight gain during the indoor winter period was 25 kg higher (P 0.05) total live-weight gain for both treatments. In Experiment 2, live weight at turnout to pasture was 11 kg lower (P 0.05), subsequently. In Experiments 1 and 2, live-weight gain during the finishing period and carcass weight, conformation and fat scores did not differ (P > 0.05) between the treatments. In Experiment 3, at turnout to pasture, HC were 35 kg heavier (P < 0.001) than LC, and ET were 12 kg lighter (P < 0.05) than LT, whereas 8 days after late turnout, ET were 13 kg heavier (P < 0.05) than LT.
There was a concentrate level × turnout date interaction (P < 0.05) for live weight at the
end of the grazing season, whereby the LC, LT treatment were lighter than the other
treatments, which did not differ. Live weight at slaughter and carcass weight did not differ (P > 0.05) between the concentrate levels, whereas they were higher (P < 0.05) for ET than LT. Economic and stochastic analysis of Experiment 3 indicated that, in the context of whole-farm systems, (i) feeding HC was dependent on date of sale such that only where progeny were sold at the start of the second grazing season, net farm margin (NFM) was increased, (ii) ET only increased NFM where progeny were retained through to finish and, (iii) taking progeny through to finish was more profitable than selling earlier in the animals’ lifetime. In conclusion, subsequent compensatory growth at pasture diminishes the growth and economic advantage from concentrate supplementation or early turnout to pasture, of young late-maturing cattle
Evaluation of thermal insulation materials
Data was obtained on silicone-bonded fiberglass, isocyanurate foam, and two dozen other insulators. Materials were selected to withstand heat sterilization, outer space, and the Martian atmosphere. Significant environmental parameters were vibration, landing shock, and launch venting
Measurement of trace stratospheric constituents with a balloon borne laser radar
The objective of this research was to measure the concentration of the stratospheric hydroxyl radical and related chemical species as a function of altitude, season, and time of day. Although hydroxyl plays a very important role in the chemistry controlling stratospheric ozone, little is known about its behavior because it has been a difficult species to measure. The instrument employed in this program was a laser radar, employing the technique of remote laser induced fluorescence. This instrument offers a number of attractive features including extreme specificity and sensitivity, a straightforward relationship between observed quantity and the desired concentration, and immunity to self-contamination
Post-weaning performance and carcass characteristics of steer progency from different suckler cow breed types
peer-reviewedIn 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
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