A Comparative Analysis of Gross and Histopathologic Lesions of Gizzard Erosions in Antibiotic Free and Conventionally Raised Broiler Flocks
Hockaday, Jessica Kehoe Brown
Magee, Danny L.
Armour, K. Natalie
Embargo TypeMSU Only Indefinitely
This study was conducted to compare the gizzard integrity between two broilers flocks, one under a no antibiotics ever (NAE) program and the other from a conventionally raised flock (CONV). One-hundred Ross 708 x Ross YPM broiler chickens from two flocks of the same company but raised under two distinct management systems were allocated for this study. At 1, 14, 28 and 42 days of age, birds from both flocks were received at the Poultry Research and Diagnostic Laboratory. Gross and histopathologic evaluations of gizzard lesions and microbiological determinations of the gizzard mucosa were conducted and body and gizzard weights were recorded. Birds under both programs showed very similar growth rates, however gizzards were heavier in the birds under the CONV program. The birds under the NAE program had higher gross gizzard lesion scores at days 1, 14, 28 and 42, with statistical significance at day 42 (P<0.05). Histopathologically, the birds under the NAE program had greater gizzard lesion scores compared to the CONV flock at days 14 and 28, however no statistical significance was established. Escherichia coli was more frequently isolated from the birds under the CONV program. According to these observations, gross and microscopic gizzard lesions appeared to be more associated with the NAE program.