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Biomedical subjects

C W Wood

Publications and source records attributed to C W Wood.

9 recordsLinked to original sources

Peanut hulls as a litter source for broiler breeder replacement pullets.

Broiler breeder pullets were reared on either peanut hulls or pine shavings to determine effects of litter type on growth performance and litter characteristics. Pullets were reared to 20 wk of age in rooms initially bedded with 8 cm of clean shavings or hulls. Heating and ventilation were standardized in all rooms. Restricted skip-a-day feeding was used to attain recommended growth curves. Water was continuously provided for ad libitum consumption. Litter and environmental variables were measured throughout rearing and 2 wk after pullets were removed from the litter materials. Feed consumption, BW, mortality, and uniformity at 20 wk were not affected by litter type; however, gizzard weights were decreased in pullets reared on hulls. Litter bulk density increased with use and was greater for shavings through 11 wk, but not thereafter. Particle size decreased with use in both litter types. Through 11 wk, there were more particles in the > 4 mm range and less in the < 1.7 mm range with hulls. Litter moisture increased with use but was not affected by litter type. Litter pH was greater in unused shavings, but during and after use was generally greater in hulls. With both litter types, litter and environmental ammonia levels increased to 11 wk then decreased; however, this effect was more pronounced for hulls. Bacteria populations were not affected by litter type; however, greater fungal populations were observed in shavings at 7 and 15 wk. Aflatoxins were detected in unused hulls but not shavings. Because aflatoxin levels decreased during use and Aspergillus flavus and Aspergillus parasiticus populations were not detected in samples collected during use, aflatoxins observed were presumed to have been formed prior to use. Peanut hulls performed similarly to pine shavings as a litter source for breeder pullets; however, the specific influence of the aflatoxins contained in this litter source on bird performance deserves further study.

Aflatoxins↗

Bartonella henselae bacteraemia in domestic cats from Auckland.

Bartonella henselae causes most cases of cat scratch disease, a self-limited localised lymphadenopathy illness of humans. Bartonella henselae also causes disseminated cutaneous and visceral disease in immunocompromised people. Cat blood (1-5 ml) collected from cats in the Auckland area was processed and plated on to 5% sheep blood brain heart infusion agar and incubated at 35 degrees C in 5% CO2 for 14 days. Bartonella henselae was identified by colony morphology, Gram's stain, twitching motility, biochemical tests and molecular methods. Eight of 48 cats (17%) had Bartonella bacteraemia. Species-specific probes and biochemical profiles identified all isolates as B. henselae. Infected cats pose a risk to humans they lick, scratch or bite. People should be made aware of the risk cats pose.

Journal Article↗

Comparison of pressure differential procedures for dipping turkey hatching-eggs in gentamicin solution.

Studies have shown that antibiotics introduced into hatching eggs can destroy certain egg-borne bacterial pathogens. An investigation was made to determine an effective procedure to introduce gentamicin solutions into turkey eggs. The findings showed that a pressure differential (PD) method using a reduced pressure of 38 cm. (15 inches) Hg for 15 minutes followed by an absorption period of 15 minutes at atmospheric pressure was an effective method which did not cause excessive egg cracking nor adversely effect hatchability. In excess of two times more fluid was absorbed using a PD method compared to an established temperature differential procedure. For maximum absorption, eggs should be washed at collection time and stored for a period of up to two weeks prior to dipping.

Animals↗

Trace element speciation in poultry litter.

Trace elements are added to poultry feed for disease prevention and enhanced feed efficiency. High concentrations are found in poultry litter (PL), which raises concerns regarding trace element loading of soils. Trace metal cation solubility from PL may be enhanced by complexation with dissolved organic carbon (DOC). Mineralization of organo-As compounds may result in more toxic species such as As(III) and As(V). Speciation of these elements in PL leachates should assist in predicting their fate in soil. Elemental concentrations of 40 PL samples from the southeastern USA were determined. Water-soluble extractions (WSE) were fractionated into hydrophobic, anionic, and cationic species with solid-phase extraction columns. Arsenic speciation of seven As species, including the main As poultry feed additives, roxarsone (ROX; 3-nitro-4-hydroxyphenylarsonic acid) and p-arsanilic acid (p-ASA; 4-aminophenylarsonic acid), was performed by ion chromatography-inductively coupled plasma-mass spectrometry (IC-ICP-MS). Total As concentrations in the litter varied from 1 to 39 mg kg(-1), averaging 16 mg kg(-1). Mean total Cu, Ni, and Zn concentrations were 479, 11, and 373 mg kg(-1), respectively. Copper and Ni were relatively soluble (49 and 41% respectively) while only 6% of Zn was soluble. Arsenic was highly soluble with an average of 71% WSE. Roxarsone was the major As species in 50% of PL samples. However, the presence of As(V) as the major species in 50% of the PL samples indicates that mineralization of ROX had occurred. The high solubility of As from litter and its apparent ready mineralization to inorganic forms coupled with the large quantity of litter that is annually land-applied in the USA suggests a potential detrimental effect on soil and water quality in the long term.

Agriculture↗