James H. Wilson

EFFECTS OF BORON ON GROWING PULLETS

The effects of dietary boron on bone ash content and on the ultimate shear force, stress, and fracture energy of the tibia, femur, humerus, and radius from white Leghorn pullets were investigated. There was a significant increase in the shear force of the tibia and femur for pullets supplemented with 50 and 100 mg/kg of dietary boron. There was a significant increase in the shear stress of the tibia at 50 and 100 mg/kg of boron, and also an increase in shear fracture energy at 50 and 100 mg/kg boron for the femur. Tibia bone ash content increased significantly at 50, 100, and 200 mg/kg boron with the highest value at 50 mg/kg. Even though there was not a significant increase in body wt at 50 and 100 mg/kg boron, the pullets fed these supplements were consistently heavier than the control group.

Dietary nickel improves male broiler (Gallus domesticus) bone strength

The effects of dietary nickel (0, 25, 50, 75, 100, and 150 mg/kg) on the bone strength characteristics and performance parameters of male broilers were investigated. Broilers were housed in either cages or floor pens. At 6 wk of age, the shear fracture energy of the tibia from the caged birds increased when the basal diet was supplemented with 25 mg of dietary nickel per kilogram of feed. The shear force, stress, and fracture energy of the radius from the caged birds also increased at 25 mg/kg nickel. Dietary nickel had no effect on bird body weight, but the caged broilers (2161 g) were heavier than the floor birds (2005 g). Nickel had no effect on the strength characteristics of the tibia from the floor birds. Percent tibia bone ash, a measure of bone density, was not influenced by dietary nickel, but the tibia ash of the floor birds was greater than that of the caged birds. Overall, the data indicates that adding 25 mg/kg of dietary nickel to a poultry diet will have a positive influence on bone strength characteristics and performance.

The effects of an oil spill on the macroinvertebrates and fish in a small southwestern Virginia creek

Abstract Plum Creek, a small 4th order tributary of the Clinch River in southwestern Virginia, experienced an oil spill in May, 1973. Approximately 13,000 liters of No. 2 fuel oil entered the creek 4.2 km above the confluence with the Clinch River. Collections of benthos and fishes made at eight stations over a five‐month period indicated minimal mortality. Immediate mortality of water snakes and waterfowl appeared relatively high. Fishes did not exhibit significant decreases in numbers of taxa or specimens collected at the site of the spill for the length of the survey.

Comparison of Stomach Contents and Condition of Two Catfish Species Living at Ambient Temperatures and in a Heated Discharge

The lower condition factors for two catfish species in water heated by effluents from APCos Glen Lyn, Virginia plant as compared to control areas probably is not due to lack of food as evidenced by macroinvertebrate sampling and the fact that only 4.3 percent of the catfish stomachs were empty. Results suggested that young-of-the-year channel catfish were nonselectively eating food organisms present at both control and heated stations. The difference between stomach contents of flatheat catfish from the heated site and fauna available at that site indicated that fish were either moving out of the heated area to feed or were selectively feeding on organisms (particularly mayflies) which were in the substrate or drifted into the heated area. Stomach contents of the two species and distribution and abundance of the macroinvertebrate benthos community are detailed. (RFC)

Influence of Body Weight and Cage Height on the Ultimate Bending Force and Stress of the Radius and Tibia of Layers

ABSTRACT THE effects of body weight and cage height on the ultimate bending force and bending stress of the radius and tibia of layers were investigated. An increase in cage height produced an increase in the ultimate bending force of the radius but not of the tibia when using analysis of variance. With analysis of covariance and body weight considered as a covariant, there was no statistical difference observed in the ultimate bending force of the radius. No statistical differences were noted when evaluating the effects of cage height on the ultimate bending stress of the radius or tibia. This indicated that the cross-sectional area of the bone changed proportionally with the cage height and body weight. The study showed that body weight could not be used as a means of predicting bone strength using a linear regression model.

GROWTH PERFORMANCE AND BONE CHARACTERISTICS OF FEMALE BROILERS AS INFLUENCED BY DIETARY NICKEL

The effects of dietary nickel (0, 25, 50, 75, 100, and 150 mg/kg) on growth performance parameters and bone strength characteristics of female broiler chicks were investigated. Broilers were housed in either cages or floor pens. At 7 weeks of age, the shear force, stress, and fracture energy of the tibia and radius for both the floor and caged birds all increased but not statistically when the basal diet was supplemented with 25 milligram of dietary nickel per kilogram of feed (mg/kg). Dietary nickel had no effect on bird body weight, but the caged broilers (2420 g) were heavier than the floor birds (2128 g). Percent tibia bone ash, a measure of bone density, was not influenced by dietary nickel, but the tibia ash of the floor birds (40.1%) was greater than that of the caged birds (36.4%). Overall, the data suggest that there is an optimum amount of dietary nickel, near 25 mg/kg, that will have a positive influence on bone strength characteristics and performance of female broilers.

The effect of humidity and preloading on the torsional fatigue of aluminium

Since very little work has been done with aluminium in reversed torsion and no work with a torsional preload, the purpose of this investigation was to compare the fatigue life of 2024-T351 aluminium at high (86 to 91%) and low (20 to 25%) relative humidity tested in torsion with a static preload (R=0). For comparison, tests on 2024-T3 aluminium were conducted in completely reversed torsion (R=−1). Tests were also conducted in argon on 2024-T351 aluminium in order to compare low humidity (20 to 25%) with a dry environment. All tests were replicated five times