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Biomedical subjects

T C Daniel

Publications and source records attributed to T C Daniel.

12 recordsLinked to original sources
PubMed1999

Reducing phosphorus runoff and improving poultry production with alum.

This is a review paper on the effects of aluminum sulfate (alum) on ammonia volatilization and P runoff from poultry litter. Initially, laboratory studies were conducted that showed P solubility could be reduced in poultry litter with Al, Ca, and Fe amendments, indicating that these amendments may reduce P runoff. These results were confirmed in small plot studies in which alum applications to litter were shown to decrease P concentrations in runoff by as much as 87%, while improving tall fescue yields. Leaf tissue analyses indicated that the yield improvements were due to increased N availability, which we hypothesized was due to reduced NH3 volatilization. This result was confirmed in laboratory studies that showed that alum was one of the most effective (and cost-effective) compounds for reducing NH3 volatilization. Field trials conducted at commercial broiler farms in conjunction with the Environmental Protection Agency showed that alum additions to poultry litter lowered litter pH, particularly during the first 3 to 4 wk of each growout, which resulted in less NH3 volatilization and lower atmospheric NH3. Ammonia volatilization rates were reduced by 97% for the first 4 wk of the growout. Broilers grown on alum-treated litter were heavier than the controls (1.73 vs 1.66 kg) and had lower mortality (3.9 vs 4.2%) and better feed efficiency (1.98 vs 2.04). Electricity and propane use were lower for alum-treated houses. As a result of these economic benefits to the integrator and grower, the benefit:cost ratio of alum addition was 1.96. Phosphorus concentrations in runoff from small watersheds were 75% lower from alum-treated litter than normal litter over a 3-yr period. Long-term small plot studies on alum use have shown that alum-treated litter results in lower soil test P levels than normal litter and does not increase Al availability in soils or uptake by plants.

Agriculture↗
PubMed1998

Effect of dietary phytase and high available phosphorus corn on broiler chicken performance.

Two trials were conducted to determine the effects on broiler chicken performance and health of reducing dietary phosphorus levels by treating feed with the enzyme phytase, formulating diets using high available phosphorus (HAP) corn, or when diets were formulated with HAP corn and treated with phytase. Cobb x Cobb male broiler chickens were placed in an experimental design consisting of four dietary treatments with six replicate pens of 50 broilers per pen. The dietary treatments consisted of untreated control feed, phytase-supplemented feed (500 U/kg), diets prepared with HAP corn, and diets prepared with HAP corn and supplemented with phytase. The chickens were maintained on these dietary treatments from 1 to 49 d of age with feed and water made available for ad libitum consumption. When the two trials were combined, there was a significant (P < or = 0.05) increase in body weight in the broilers fed the phytase treated diets at 49 d of age. The serum activity of alkaline phosphatase was significantly decreased in the diets supplemented with phytase, and serum cholesterol was significantly decreased in the diets prepared with HAP corn. These data indicate that total phosphorus can be reduced by at least 11% in diets prepared with HAP corn, or in diets supplemented with phytase, without affecting the performance or health of broiler chickens. When diets are prepared with HAP corn and supplemented with phytase, the dietary addition of total phosphorus can be reduced by at least 25% without affecting broiler chicken performance or health.

6-Phytase↗
PubMed1996

Evaluation of chemical amendments to reduce ammonia volatilization from poultry litter.

Ammonia volatilization from poultry litter often causes high levels of atmospheric ammonia in poultry houses, which is detrimental to both farm workers and birds. Ammonia emissions from houses also aggravate environmental problems, such as acid rain, and result in a loss of fertilizer nitrogen. The objectives of this study were to determine the effect of litter amendments on ammonia volatilization and to determine the effect of these amendments on nitrogen and phosphorus content in litter. The results of this research indicate that alum [Al2(SO4)3.18H2O], ferrous sulfate (FeSO4.7H2O), and phosphoric acid (H3PO4) dramatically reduce ammonia volatilization form litter. The amount of ammonia lost from litter treated with sodium bisulfate (NaHSO4) and a proprietory product made of Ca-Fe silicate with a phosphoric acid coating was not different from the control (untreated litter). Aluminum sulfate (alum) and ferrous sulfate also reduced water soluble P concentrations in litter, whereas phosphoric acid greatly increased water-soluble P levels. The most effective compound evaluated with respect to reducing both ammonia loss and P solubility was alum.

Air Pollution↗
PubMed1976

Recognition gradients for random shapes following distinctive or equivalent verbal association training.

The effect of distinctive and equivalent verbal label training on a subsequent test of recognition memory for random shapes were assessed. Shape continua, systematically relating the labeled shapes, were used in the memory test so that gradients of recognition memory were obtained. Distinctive-nonrepresentative-label training produced symmetrical recognition gradients with a single mode at the correct target shape. Equivalent-label training produced symmetrical gradients that were as steep as the distinctive-label gradients, but the mode of the equivalent-label gradients was shifted to a distractor shape that varied from the target in the direction of the equivalent-label shape. The results offered support to a Gestalt/configurational account of the effects of verbal labels on memory for form, but the data were also consistent with an extension of Ellis' conceptual coding hypothesis. It was concluded that, rather than being a competing alternative account, the conceptual coding hypothesis may be viewed as an updated, more analytic statement of the older Gestalt view.

Association Learning↗
PubMed1975

Recognition latency for pictures and words as a function of encoded-feature similarity.

In separate trials of a same-different recognition task, a single target item presented as either a picture or a word was followed after a 30-sec delay by a single test item, either a picture or a word. Test items were either nominal matches for the target (same) or one of five related distractor items. Distractors were selected to resemble the target item on one of five dimensions: orthographic, acoustic, conceptual (functional or categorical), schematic (similar in shape), or neutral. Same-different reaction times were found to vary systematically as a function of depiction mode of target and/or test items and by distractor type. Verbally related distractors (orthographic and acoustic) produced longer reaction times when target or test items or both were presented as printed words. When target or test items were presented as pictures, schematic and conceptual distractors produced the longest rejection latencies.

Acoustic Stimulation↗
PubMedDate not supplied

Effects of alum and aluminum chloride on phosphorus runoff from swine manure.

Phosphorus (P) runoff from fields fertilized with swine (Sus scrofa domesticus) manure may contribute to eutrophication. The objective of this study was to evaluate the effect of aluminum sulfate (alum) and aluminum chloride applications to swine manure on P runoff from small plots cropped to tall fescue (Festuca arundinacea Shreb.). There were six treatments in this study: (i) unfertilized control plots, (ii) untreated manure, (iii) manure with alum at 215 mg Al L(-1), (iv) manure with aluminum chloride at 215 mg Al L(-1), (v) manure with alum at 430 mg Al L(-1), and (vi) manure with aluminum chloride at 430 mg Al L(-1). Manure application rates were equivalent to approximately 125 kg N ha(-1). Alum and aluminum chloride additions lowered soluble reactive phosphorus (SRP) levels from about 130 mg P L(-1) to approximately 30 mg P L(-1) at low rates. At high rates, SRP levels in swine manure were around 1 mg P L(-1). Soluble reactive P concentrations in runoff were 5.50, 3.66, 3.00, 0.87, 0.87, and 0.55 mg P L(-1), for normal manure, low alum, low aluminum chloride, high alum, high aluminum chloride, and unfertilized control plots, respectively. Hence, high alum and aluminum chloride reduced SRP concentrations in runoff by 84% and were not statistically different from SRP concentrations in runoff from unfertilized control plots. These data indicate that treating swine manure with alum or aluminum chloride could result in significant reductions in nonpoint-source P runoff.

Alum Compounds↗