Comparison of broiler performance and carcass yields when fed diets containing transgenic maize grains from event DP-O9814O-6 (Optimum GAT), near-isogenic control maize grain, or commercial reference maize grains

A genetically modified maize (Zea mays L.) line that contains the Optimum GAT trait (event DP-Ø9814Ø-6; 98140) was produced by integration of the gat4621 and zm-hra genes. The expressed GAT4621 and ZM-HRA proteins confer tolerance to the herbicidal active ingredient glyphosate and acetolactate synthase-inhibiting herbicides, respectively. The objective of this study was to compare the nutritional performance of 98140 maize grain to nontransgenic maize grain in a 42-d feeding trial in broiler chickens. Diets were prepared using grain from untreated 98140 plants and from plants treated with an in-field application of herbicides (98140 + Spray). For comparison, additional diets were produced with maize grain obtained from the nontransgenic near-isogenic control (control) and nontransgenic commercial reference Pioneer brand hybrids 33J56, 33P66, and 33R77. Diets were fed to Ross x Cobb broilers (n = 120/group, 50% male and 50% female) in 3 phases: starter, grower, and finisher containing 58.5, 64, and 71.5% maize grain, respectively. No statistically significant differences were observed in mortality, growth performance variables, or carcass and organ yields between broilers consuming diets produced with maize grains from unsprayed or sprayed 98140 and those consuming diets produced with near-isogenic control maize grain. Additionally, all performance and carcass variables from control, 98140, and 98140 + Spray test maize treatment groups were within tolerance intervals constructed using data from reference maize groups. Based on these results, it was concluded that 98140 maize grain (unsprayed or sprayed with a herbicide mixture) was nutritionally equivalent to nontransgenic control maize with comparable genetic background.

Comparison of broiler performance when fed diets containing event DP-3O5423-1, nontransgenic near-isoline control, or commercial reference soybean meal, hulls, and oil

DP-3Ø5423-1 (305423) is a genetically modified soybean that was produced by biolistic insertion of the gm-fad2-1 gene fragment and gm-hra genes into the germline of soybean seeds. Expression of gm-fad2-1 results in greater concentrations of oleic acid (18:1) by suppressing expression of the endogenous FAD2-1 gene, which encodes an n-6 fatty acid desaturase enzyme that catalyzes desaturation of 18:1 to linoleic acid (18:2). The GM-HRA protein expressed by the gm-hra gene is a modified version of the soybean acetolactate synthase enzyme that is used as a selectable marker during transformation. A 42-d feeding trial was conducted with broiler chickens to compare the nutritional performance of 305423 soybeans with nontransgenic soybeans. Diets were prepared using processed fractions (meal, hulls, and oil) from 305423 soybean plants. For comparison, additional diets were produced with soybean fractions obtained from a nontransgenic near-isoline (control) and nontransgenic commercial Pioneer brand varieties (93B86, 93B15, and 93M40). Diets were fed to Ross x Cobb broilers (n = 120/group, 50% male and 50% female) in 3 phases. Starter, grower, and finisher diets contained 26.5, 23, and 21.5% soybean meal, respectively. Soybean hulls and oil were added at 1.0 and 0.5%, respectively, across all diets in each phase. No statistically significant differences were observed in growth performance (BW, mortality, feed efficiency), organ yield (liver and kidney), or carcass yield (breast, thigh, leg, wing, and abdominal fat) variables between broilers consuming diets prepared with isolated fractions from 305423 or near-isoline control soybean. Additionally, all performance and carcass variables from control and 305423 soybean treatment groups fell within tolerance intervals constructed for each response variable using data from broilers fed diets prepared with reference soybean fractions. Based on the results from this study, it was concluded that 305423 soybeans were nutritionally equivalent to non-transgenic control soybeans with a comparable genetic background.

Comparison of broiler performance when fed diets containing event DP-356Ø43-5 (Optimum GAT), nontransgenic near-isoline control, or commercial reference soybean meal, hulls, and oil

Event DP-356Ø43-5 (356043; Optimum GAT) is a genetically modified soybean (Glycine max) that was produced by insertion of the gat4601 and gm-hra genes. The expression products of these genes are the glyphosate acetyltransferase 4601 and acetolactate synthase proteins, respectively. Expression of the glyphosate acetyltransferase 4601 protein confers tolerance in planta to the herbicidal active ingredient glyphosate, whereas expression of the acetolactate synthase protein confers tolerance to sulfonylurea and imidazolinone herbicides. The objective of this study was to compare the nutritional equivalence of 356043 soybeans to nontransgenic soybeans in a 42-d feeding trial in broiler chickens. Diets were prepared using processed fractions (meal, hulls, and oil) from untreated 356043 soybean plants or from soybean plants treated with a mixture of glyphosate, chlorimuron, and thifensulfuron (356043 + Gly/SU). For comparison, additional diets were produced with soybean fractions obtained from a nontransgenic near-isoline (control; 091) and nontransgenic commercial Pioneer varieties (93B86, 93B15, and 93M40). Diets were fed to Ross x Cobb broilers (n = 120/group, 50% male and 50% female) in 3 phases. Starter diets contained 30% soybean meal, grower diets 26% soybean meal, and finisher diets 21.5% soybean meal. Soybean hulls and oil were added at 1.0 and 0.5%, respectively, across all diets in each phase. No statistically significant differences were observed in mortality, growth performance variables, or carcass and organ yields between broilers consuming diets produced with 356043 or 356043 + Gly/SU soybean fractions and those consuming diets produced with near-isoline control soybean fractions. Additionally, all performance and carcass variables from control, 356043, and 356043 + Gly/SU soybean treatment groups fell within the tolerance intervals constructed using data from reference soybean groups. Based on the results from this study, it was concluded that 356043 soybean was nutritionally equivalent to nontransgenic control soybean with a comparable genetic background.

Evidence for the classification of a crayfish pathogen as a member of the genus Coxiella

AIMS

The study aimed to provide characterization of a potential new species of Coxiella, identified following a series of outbreaks of disease in Australian native freshwater crayfish.

METHODS AND RESULTS

PCR primers designed for amplification of Coxiella burnetii genes including 16S rDNA, com1 and sodB were used to amplify homologues in the Coxiella-like crayfish pathogen. Products were then cloned and sequenced. The organism demonstrated a high degree of sequence homology in the highly conserved 16S rDNA (96%) and sodB (99%) genes, as well as the Coxiella sp. specific com1 (100%) gene. Regions flanking the sodB coding sequence demonstrated homology to C. burnetii antioxidant AhpC/Tsa family protein and dihydrodipicolinate reductase gene.

CONCLUSIONS

The degree of homology between the genes selected and flanking regions suggested the two organisms were sufficiently closely related to belong to the same genus.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provided evidence for a potential new species in the currently monospecific genus Coxiella, with the only described member being C. burnetii, a category B biological warfare agent.

[Development of a synthetic positive control which also detects plasmid contamination in diagnostic polymerase chain reaction]

This paper describes a technique for the development of a positive control for use in a nested PCR to show that the PCR has worked correctly with both outer and inner primers designed for diagnostic amplification of 618 bp and 317 bp products respectively. This positive control produces a larger product than the diagnostic sample that can be discriminated on an agarose gel. This technique is advantageous over traditional cloning of the diagnostic PCR product itself by: 1) making it visually easy to detect plasmid contamination and thus, prevent false positives from the plasmid; 2) develop a positive control when the target organism is at a very low prevalence so initial detection is not relied on for cloning positive controls. This will ensure the PCR is working correctly prior to diagnostic sampling, reducing false negatives; or 3) for developing a PCR and determining the sensitivity prior to the use of diagnostic samples. The methods used to produce this nested positive control demonstrates how to use large oligonucleotide primers in PCR without non-specific binding occurring.

Observations on the collection and handling of blood samples for N.E.F.A. estimation

The effect upon the results of estimating plasma or serum non-esterified fatty acids (N.E.F.A.) assay by different methods of collecting blood samples and subsequent differences in sample storage and time of assay have been studied. Standardization of technique is advised and the use of chilled heparinized tubes, with separation of the sample within one hour of collection and assay on the day of collection is advocated.