Current control strategies for avian influenza and other highly contagious poultry diseases often include quarantine, depopulation, and disposal of infected birds. For biosecurity reasons, on-farm depopulation and disposal methods are preferred. The options for mass depopulation are limited, as reported by the "2000 Report of the AVMA Panel on Euthanasia." Current depopulation techniques may have excessive labor requirements, are not appropriate for all house types, and may not be suitable for large-scale emergency implementation. A procedure has been developed that uses foam to rapidly form a blanket over the birds. The procedure requires relatively few people, can be performed in a variety of house types, and is compatible with in-house composting. Results from 2 experiments using foam for depopulation are presented in this paper. These studies have shown that foams are comparable to the CO(2) polyethylene tent procedure in time to death in small groups and that the foam is faster as group size increases. Adding CO(2) to the foam does not enhance its efficacy. Based on corticosterone levels, the study also showed that the foams are no more stressful than the CO(2) depopulation method. Necropsy and histological examination of birds indicated that blood was present to some degree in the trachea, syrinx, and bronchial tree in broilers subjected to foam with CO(2), foam without CO(2), and CO(2) polyethylene tent methods of depopulation. Foam caused a rapid onset of airway occlusion. In both foam- and CO(2)-euthanized broilers, lesions are consistent with anoxia or hypoxia. This suggests that foam acts by physically induced hypoxia, whereas CO(2) causes chemically induced hypoxia.

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The suitability of three types of recycled paper products for use as broiler litter was studied in three trials using a total of 9,600 broilers. Litter, consisting of hardwood sawdust (SD) as a control, shredded newspaper (SN), processed newspaper (PN), or processed cardboard (PC), was placed in each of four replicate pens in the first trial and reused in subsequent trials.Body weights at 28 and 49 days were significantly influenced by treatment with broilers reared on SN weighing more than SD controls. Broilers on PC were the lightest. Statistically, the PN broilers were heavier than SD broilers at 28 days but similar to controls by market age. Feed conversion was improved with SN at 28 days but did not differ by 49 days. Mortality was not significantly affected by litter material.The moisture content of paper litters was numerically higher than that of the SD control with significantly greater litter caking occurring in the paper litters. However, only broilers on PC had a greater incidence of breast blisters. Overall and total disease condemnation were not influenced by litter material. Skin color scores were improved with the PN treatment.

The eviscerated yields and carcass characteristics of five commercial broiler crosses were evaluated. In each of four trials, processed in December, March, June, and September, 33 birds from each cross and each sex were used. Individual live weights were recorded at 56 days of age, prior to feed withdrawal, and immediately before processing (plant weight). The fresh eviscerated carcass weight, neck, abdominal fat, liver, gizzard, and heart weights were evaluated as a percentage of the plant weight. The relative yields of parts, breast, back, wings, legs, and thighs were determined for both sexes of each cross.No significant differences were observed in the loss of weight from the 56 day to the plant weight between crosses in any trial. In all trials, differences in plant weights between crosses were statistically significant (P<.01) when weights for both sexes were combined. When data from the four trials were combined, the cross X trial interaction for plant weights was significant (P<.01). The fresh eviscerated carcass yields were not significantly influenced by the cross or sex of broilers in any trial. The amount of abdominal fat was the largest single significant (P<.01) source of variation among the commercial yield of broiler crosses. When cut into parts, carcasses from female broilers had a significantly (P<.01) greater proportion of breast and back than male carcasses. (

Litter-Aid, a product consisting primarily of ferrous sulfate but also containing propionic acid and magnesium and copper sulfate was incorporated into litter at three application rates (0, .73, and 1.46 kg/m2) to determine its effects on broiler chicken performance and various aspects of litter quality. In Trial 1, litter treatments were applied to litter used for two previous flocks with a 10-week layout period. In Trial 1, there were 10 replicate pens of 175 birds per treatment. In Trial 2, litter used in Trial 1 was retreated, after a 26-week layout period, at the same application rates as Trial 1 with five replicate pens of 175 birds per treatment. This product in Trial 1 at .73 kg/m2 and in Trial 2 at 1.46 kg/m2 significantly (P less than .05) increased body weight without affecting feed conversion or mortality. The product did not significantly (P less than .05) affect litter moisture or litter nitrogen levels, but significantly (P less than .05) decreased litter pH. However, even at the application rate of 1.46 kg/m2, litter pH values rose above 8 as the birds reached 7 weeks of age. This product had no effect on bacteria counts and significantly (P less than .05) increased mold counts. These data indicate that Litter-Aid can be used without detrimental effects on broiler performance or litter quality.

Broilers reared in cages have a high incidence of wing breakage during processing. Three trials were conducted to determine the effects of cage dimensions and floor types on bone breaking strength and wing breakage during processing. Broilers were fed commercial-type diets and processed through the pickers at a commercial processing plant or a research facility. Broken bones were detected by palpation, and humeri and tibia were removed. Breaking strength was determined for the humeri and tibia with a testing instrument. Incidence of breast blisters, crooked keels, follicle infection, fleshing downgrades, and slabsidedness were determined in one trial. Cage height was the major factor affecting wing breakage and humerus strength. Incidence of wing breakage for broilers on wire floors with cages .64 m high was not significantly different from that of control broilers reared on litter with ceiling 2.54 m high. Humerus breaking strength was significantly reduced in two of three trials by the .64-m-high ceiling. Cage rearing increased the incidence of crooked keels and feather follicle infections.