Effects of treating wheat straw with pH-regulated solutions of alkaline hydrogen peroxide on nutrient digestion by sheep

An experiment using a 4 X 4 Latin square design was to determine effects of treating wheat straw with pH-regulated (pH = 11.5) solutions of hydrogen peroxide on site and extent of nutrient digestion in multiple-fistulated sheep. Regulating reaction pH at 11.5 prevented solubilization of some cell wall hemicelluloses, resulting in improved retention of DM. Diets fed to sheep contained 33 or 70% wheat straw either untreated or treated with alkaline hydrogen peroxide. Sheep fed diets of treated wheat straw digested more DM, NDF, ADF, and cellulose anterior to the duodenum and in the total tract than when fed diets of untreated wheat straw. Apparent CP digestion before the duodenum was highest when sheep were fed the treated 33% wheat straw diet and untreated 70% wheat straw diet. Treatments did not affect apparent nutrient digestibilities in the large intestine. Ruminal pH was lower when sheep were fed the alkaline hydrogen peroxide-treated or diets containing 33% wheat straw. Ruminal ammonia concentrations were highest when sheep were fed the untreated 70% wheat straw diet. Molar proportions of ruminal acetic and propionic acids were unaffected by diet. Alkaline hydrogen peroxide treatment substantially increased susceptibility of structural carbohydrates of wheat straw to microbial degradation in the gastrointestinal tract of sheep.     

28—SOME FACTORS INFLUENCING PUCKERING AND COCKLING IN FULLY FASHIONED GARMENTS

A simple technique for the planning of rib cuffs and welts for fully fashioned garments that is based on the classical knitting geometry of plain and 1 × 1 rib fabrics is described. The effects of cover factor and some common loop ratios at the join of 1 × 1 rib and plain fabrics on puckering at the knitted join and the effects of cover factor and some yam characteristics on cockling in plain-knitted fabrics are given.     

Amino acid and energy interrelationships in growing beef steers: II. Effects of energy intake and metabolizable lysine supply on growth

We conducted three experiments to determine the optimal metabolizable Lys:net energy ratio for growth of beef calves. The single basal diet fed contained corn (56.1%), soybean hulls (18%), cottonseed hulls (15%), animal fat (4.25%), and corn gluten meal (5.6%). In Exp. 1, 54 steers were individually fed the basal diet at 1.5, 2.25, and 3.0 times NEm requirement; rations were top-dressed with 3.4 g of rumen-stable (RS) Met and either 0, 2, 4, 6, 8, or 12 g of RS-Lys daily. An additional 18 steers were fed the same three levels of energy and supplemented with 125 g of blood meal per steer. In Exp. 2, 68 crossbred steers were subjected to the same experimental protocol, with the exception that only the two highest levels of energy were used. Of these steers, 48 were fed individually and received the RS-Lys treatments; the remaining 20 steers received 125 g of blood meal per steer. No interaction (P > .10) was detected between level of supplemental Lys and energy intake in Exp. 1 or 2. Supplementation with RS-Lys improved (P < .01) ADG in Exp. 1, but it had no effect (P > .10) on growth in Exp. 2. The Lys requirement estimates were 44.3 and 51.3 g/d, corresponding to maximal growth rates of 1.21 and 1.64 kg/d for the 2.25 and 3.0 times maintenance treatments, respectively. Comparing the growth rates of steers fed supplemental Lys with those of steers fed blood meal in Exp. 1 and 2 revealed an ADG advantage (P < .03) with blood meal supplementation. To confirm the blood meal response, Exp. 3 used 75 crossbred steers fed the basal diet at 3.0 times NEm requirement plus either 3.4 g RS-Met, 3.4 g RS-Met and 12 g RS-Lys, or 125 g of blood meal per steer. Blood meal supplementation improved (P < .01) growth of steers over those fed supplemental Met or Met plus Lys. Although a distinct relationship between amino acid requirements and energy supply may exist, Lys and Met were not first-limiting in these experiments, or selective supplementation with undegradable protein may have provided some factor that enhanced performance beyond that detected with Lys and Met alone.     

Evaluation of ruminally protected methionine and lysine or blood meal and fish meal as protein sources for lactating Holsteins.

Forty lactating Holstein cows averaging 55 days in milk were used in a randomized block designed experiment to evaluate the effectiveness of ruminally protected Met and Lys compared with that of ruminally undegradable protein for supporting lactation. Cows were fed total mixed diets for 15 wk. Diets were formulated to be isonitrogenous with the same base ingredients resulting in base crude protein percentage of 15.5. Supplemental crude protein supplied by urea, soybean meal, or a 50:50 (wt/wt) mixture of fish and blood meal increased total dietary nitrogen to 18.0% of diet DM. Two additional diets consisted of the basal diets soybean meal and urea, which were supplemented with ruminally protected DL-Met and Lys-HCL at 10 and 25 g/d, respectively (soybean meal + amino acids (AA), urea + AA). Mean measures of dry matter intake, milk yield, milk protein percentage, and milk fat percentage were not affected by protein supplement. Milk protein yield, milk fat yield, casein yield, and casein percentage also were not affected by source of supplemental protein. Results indicate that at the level of crude protein intake relative to milk production in this experiment, the source of protein did not affect lactational performance.     

The response of materials to dynamic loading

The response of materials to hypervelocity impact spans a wide region of material behavior, ranging from high impact pressures and temperatures, where thermodynamic effects prevail, to low pressures where mechanical properties are important. This paper discusses thermomechanical and physical processes important to hypervelocity impact events, presents a perspective of theoretical foundations and provides an overview of current equation-of-state and constitutive modeling capabilities.     

Ecology and energetics of slacks in the Alexandria coastal dunefield

This paper summarises information on the structure and function of dune slacks as discrete ecosystems within the Alexandria coastal dunefield. A typical slack, with a total area of 1900 m² and floor area of 8833 m², harbours four dominant species of pioneer plants in a succession spanning 5 years, corresponding to the interval between a section of slack floor being uncovered by a retreating dune and smothered by an advancing dune. Vegetation biomass totals 221.1 g m⁻² and detritus mass 40.1 g m⁻², with 31% and 3% above ground, respectively. Annual plant production is estimated at 190 g m⁻² using a combination of theoretical calculations and vegetative growth estimates. Animal biomass has been quantified for interstitial meiofauna at 1.0 g m⁻² and all arthropod and vertebrate macrofauna at 0.2 g m⁻². Based on estimated decomposition coefficients of 0.5 year⁻¹ and theoretical consumption estimates for the fauna, 14% of plant production is grazed directly (93% by plant parasitic nematodes, 7% by macrofauna) and 86% enters the detritus pool. Of the latter, 2% is consumed by macrofauna detritivores, 63% is decomposed by the interstitial fauna and 35% accumulates to add to the detritus pool. Vegetation succession and production in the slack thus results in a net build-up of organic matter in the sand. This is finally decomposed when the slack is smothered by an advancing dune ridge, thus maintaining a long term equilibrium level of soil organics. These slacks require minimal management as long as free dune movement and limited human access are maintained.     

Human activity and potential impacts on dune breeding birds in the Alexandria coastal Dunefield

Human use of coasts has increased considerably with increasing demand for recreational experiences, increased availability of off-road vehicles (ORVs) and population increase. Besides impacts on dune morphology and flora, humans and ORVs also affect the fauna. The Alexandria Dunefield in Algoa Bay comprises a 50 km sandy beach backed by a 2.1 km wide strip of dunefield. The dunefield is largely conserved, but access to the beach is allowed under permit, and the beach is heavily utilised by fishermen and recreational ORV drivers. The area is also important for dune breeding birds. Beach and dune use by fishermen and other users was quantified by recording their position relative to the high water mark and along a 20 km stretch of beach, and through analysis of access permits and angling competition data. An increase in vehicle use in the area was observed. An indication of human perception of the area was obtained by questionnaires. Eighty percent of human activity was concentrated in 50% of the study site where the highest concentration of dune breeding birds nest. Sixty percent of the vehicles recorded, were on or above the high water mark (in the dunes). Of the beach-users interviewed, 74% suggested that only registered vehicles should be allowed on the beach. Most (80%) anglers had no problem determining the position of the high water mark. There is an overlap in area and seasonal use between beach-users and breeding birds. With specific areas along the beach being heavily impacted and vehicles utilising the area above the high water mark the potential for impact on the fauna and flora of these areas is high. There is a need to educate beach users as to the vulnerability of dune systems and to develop appropriate management guidelines to minimise the impacts of beach users on the dune fauna.     

Ion detection by Fourier transform ion cyclotron resonance: the effect of initial radial velocity on the coherent ion packet

Ion detection by Fourier transform ion cyclotron resonance (FT-ICR) is accomplished by observing a coherent ion packet produced from an initially random ensemble of ions. The coherent packet is formed by excitation with a resonant oscillating electric field. Ions that are out of phase with the applied radio frequency (rf) electric field experience a continuous misalignment of the electric field vector. The misalignment creates a net force of the electric field perpendicular to ion motion. The perpendicular component of the rf electric field creates a frequency shift resulting in phase synchronization of the ion ensemble. The phase coherence of the ion packet affects both the sensitivity and the resolution of FT-ICR.     

Theoretical equation of state for aluminum

Theoretical methods for calculating equations of state are discussed and applied to aluminum. The model includes a treatment of melting, vaporization, and thermal electronic excitation. The thermal electronic terms are shown to cause a plasma phase transition in the hot expanded fluid, affecting the unloading behavior from shocked states. The calculations give good agreement with experimental Hugoniot data, the melting curve, and isobaric expansion measurements.