Two experiments were conducted to compare effects of housing temperatures and bird density on the airborne microflora of poultry houses. Temperatures of 15.6 and 26.7 C were used with birds housed at densities of .42 or .84 m3 per bird. Air samples were taken using a New Brunswick STA 200 microbiological air sampler. Numbers of aerobic, anaerobic, coliform and lactic acid bacteria, and molds were determined by plate counts with numbers of Escherichia coli and Staphylococcus aureus determined by most probable numbers procedures. Microorganisms were identified by picking representative colonies from plates and inoculating into differential media for biochemical tests. Higher bird density (.42 m3/bird) resulted in greater numbers of airborne microorganisms in both experiments. Fifteen genera of bacteria were identified with two or more species identified for eight genera. Among the most commonly identified aerobic genera were Bacillus, Micrococcus, Proteus, Pseudomonas and Staphylococcus, while four species of Clostridia were the most frequently identified anaerobes. Nine genera of molds were identified with over one-half of all isolates being either Aspergillus or Penicillium. Microorganisms represented only a small fraction of the airborne particulate matter in the study.

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Nitrogen corrected metabolizable energy values were determined for 4-week old broiler chicks and 60-week old Leghorn hens. Feed ingredients tested included corn, wheat, barley, bailey hulls, wheat bran, alfalfa meal, fish meal, meat scraps, soybean meal, safflower meal and peas. Significant differences in energy values were obtained for most feeds with higher energy values resulting in 8 of 11 feeds when fed to hens. Hens in general utilized more energy than chicks when fed feed ingredients with higher fiber levels.

Ninety-six White Leghorn pullets housed in individual laying cages were used to study effects of low level pesticide in feed on fertility and hatchability of eggs in a 10 week experiment. Pullets housed under similar conditions in a separate building served as controls. Hens were fed a commercial breeder ration. Feed samples were negative when analyzed for pesticides. DDT, Diazinon, lindane or malathion were added to the feed at rates of 0.1, 1.0 or 10.0 p.p.m. Commercially produced wettable powders were used to incorporate the insecticides in the feed. Hens were artificially inseminated twice each week using pooled semen from 10 males. Two test hatches at an interval of four weeks were incubated to determine levels of fertility and hatchability prior to pesticide feeding. Eggs produced were incubated beginning on the third day of pesticide feeding. Settings were made at weekly intervals with fertility determined on the seventh day of incubation. Pre-test fertility averaged 95% and hatchability 92% of fertile eggs. Fertility during the experimental period ranged from 96.1 to 99.0%. Hatchability of the control group during the experiment was 94.1%. All pesticides used except 0.1 p.p.m malathion significantly (P < .05) reduced hatchability. Embryonic mortality was increased throughout the incubation period. Egg shell thickness was significantly reduced by lindane and DDT. Egg production was reduced by all pesticides fed.