The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor

The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere.     

Escape protein supplementation of yearling steers grazing smooth brome pastures

Two grazing trials utilizing individually supplemented yearling steers were conducted to study the effect of supplemental escape protein on steer performance during the active growth periods, spring and fall, of smooth brome (Bromus inermis). Graded levels (0, .11, .23 and .34 kg.head-1.d-1) of an equal-protein-basis mixture of bloodmeal and corn gluten meal were offered daily, replacing corn starch, which was used as the negative control. All steers received 582 g supplemental dry matter per day. Supplementation with escape protein improved daily performance in both spring (P less than .01) and fall (P less than .02). Analysis of pooled data from both trials indicated a linear (P less than .01) and quadratic (P less than .05) increase in steer performance with increasing level of escape protein in the diet. Analysis of grass samples collected throughout and composited over each trial demonstrated that grass protein was highly degraded in the rumen. Using a modified dacron bag technique, 12-h degradability was found to be 80 to 90% of the potentially digestible protein fraction. Rates of protein degradability were 14 and 11.7%/h. Assuming 5%/h rate of passage, escape protein was calculated to be 9.2 and 13.1% of total protein. As a result of the significant growth response observed above that of the energy-supplemented controls and the high ruminal protein degradabilities of the grass observed in the laboratory, it was concluded that growing ruminants grazing actively growing smooth brome pastures were deficient in metabolizable protein.     

Hydrolysis time as a factor affecting the nutritive value of feather meal and feather meal-blood meal combinations for growing calves

The objectives of this research were to determine 1) the effects of hydrolysis time on feather meal (FTH) protein digestion and ruminal escape and 2) whether adding blood meal (BM) to FTH evoked a complementary response in animal performance. A lamb digestion trial was conducted to estimate true protein digestibility of soybean meal (SBM), BM, and FTH hydrolyzed for 10, 12, 15, or 18 min. Ruminal escape was estimated in situ. Two 94-d growth trials were conducted using 60 growing calves (226 kg) per trial to evaluate urea, FTH, BM, and 87.5:12.5, 75:25, and 50:50 combinations (CP percentage basis) of FTH:BM. There were small numerical differences in estimated escape of protein from the rumen and DM and protein digestibilities due to hydrolysis time. True protein digestibility of the 10- and 18-min samples was 5% higher (P less than .05) than for the 12- or 15-min FTH samples. In the growth trial, the slope-ratio technique showed that the most efficiently used protein supplement was 100% BM (protein efficiency = 2.45 +/- .19). No differences (P = .30) in protein efficiency were observed among supplements containing various combinations of FTH:BM. There was a quadratic (P less than .01) response to the level of BM, indicating a complementary effect. The largest complementary effect occurred at the 12.5% level of the BM addition. There were no nutritionally important effects of hydrolysis time between 10 and 18 min. Furthermore, supplements can be formulated more economically using small amounts of BM with FTH without compromising biological efficiency.     

Residues from long-acting antimicrobial preparations in injection sites in cattle

Objective To investigate tissue residues of two longacting oxytetracycline (OTC) preparations in cattle.
Design A randomised drug residue trial.  

Animals

Two hundred and forty beef cattle in 24 groups of ten.
Procedure Two blind-coded 200 mg/mL OTC preparations were used in five treatment regimens of various combinations of injection sites (from one to five) and administrations (one or two). Five cattle from each group were slaughtered at 21, 30 and 60 days after injection and the injection site, urine, kidney and diaphragm muscle analysed for residues.
Results The OTC concentration exceeded the maximum residue limit in kidney in animals slaughtered 21 days after treatment, which is the prescribed withholding period. Concentration at the injection site was much greater than the maximum residue limit 30 days post-treatment, but not 45 days post-treatment. The residue was smaller when OTC had been injected in multiple sites. There was no difference between the two OTC preparations.
Conclusion A review of the maximum injection volume, site of injection and the withholding period is needed for long-acting OTC formulations.     

Energy value of corn wet milling by-product feeds for finishing ruminants

Five trials were conducted to evaluate the energy value of corn wet milling by-products in finishing diets. In trials 1 (45 finishing lambs, 34 kg) and 2 (70 digestion wethers, 32 kg), Rambouillet X Suffolk lambs fed corn gained faster (P less than .10), more efficiently (P less than .10) and had higher (P less than .01) digestibilities of neutral and acid detergent fiber (NDF, ADF) and starch than lambs fed dry corn gluten feed (DCGF). Lambs fed wet corn gluten feed (WCGF) consumed less feed (trial 1, P less than .05; trial 2, P less than .01), were more efficient (P less than .01) NDF and ADF digestibilities than lambs fed DCGF. Starch, NDF and ADF digestion were higher (P less than .01) for lambs fed WCGF vs wet corn bran (WCB). Lambs fed WCGF gained faster (P less than .10) and consumed more (trial 1, P = .12; trial 2, P less than .10) feed than lambs fed WCB. Dried corn bran increased (trial 1, P less than .05; trial 2, P less than .01) intake and increased (P less than .01) dry matter digestion (DMD) compared with WCB. In trial 3, rates of in vitro dry matter and NDF disappearance were similar among by-product feeds. In trial 4 (50 individually fed Shorthorn-Hereford-Angus steers, 316 kg), steers fed WCGF tended to consume more (P = .14) feed than steers fed DCGF. Corn gluten feed (CGF) replacing 0 to 46% corn decreased gain (linear, P less than .05) and DMD (linear, P less than .10), while starch digestion was highest for 23% CGF (quadratic, P less than .01). A level X CGF type interaction (P = .15) occurred for efficiency due to the lower gain of steers fed 46% DCGF. The efficiency of CGF utilization was 97% that of corn when WCGF replaced 23 or 46% corn or DCGF replaced 23% corn. Dry CGF replacing 46% corn had 87% the value of corn. In trial 5 (186 Hereford-Angus cattle, 310 kg), DCGF replacing 25 and 50% corn had 97 to 100% the efficiency of corn, while intake and gain were not affected. Dry CGF replacing 25 and 50% corn silage increased (linear, P less than .05) intake 11.3% and gain 13.8%. In ruminants, CGF is highly digestible and feed efficiency is similar to corn when WCGF is fed up to 50% of the grain component or when DCGF is fed up to 25% of the grain component.     

Protein supplementation of ammoniated roughages. III. Corncobs supplemented with a blood meal-corn gluten meal mixture--steer studies

Two factorial experiments were conducted to investigate site and extent of organic matter (OM) digestion, nitrogenous fractions flowing at the abomasum and rates-of-passage in steers fed 0, 2 or 4 g NH3/100 g dry matter of treated corncobs supplemented with either a corn or a blood meal-corn gluten meal (BM-CGM) supplement. Rumen and total tract OM digestion coefficients were quadratically increased (P less than .05) and dietary N was quadratically increased (P less than .07) due to the main effect of ammonia. The main effect of protein supplement increased (P less than .05) postruminal OM digestibility, nonammonia N and dietary-N flow. Quadratic protein X ammonia interactions were noted for fluid flow, total-N flow, total amino acid flow and ammonia-N flow. Linear protein X ammonia interactions were noted for bacterial-N flow, which appeared to indicate that N utilization of the ammoniated corn-cob was improved by the inclusion of BM-CGM in the diet. Diet dry matter intake, fluid volume, rate of fluid passage, particulate mass and rate of particulate passage in rumen-fistulated steers were unaffected by either main effect. However, rumen fluid pH of steers fed BM-CGM was lower than that from steers fed the corn supplement.