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Rupture of the gastrocnemius tendon is a costly challenge for the poultry industry due to bird culling from clinical lameness and leg condemnations at the processing plant. In this case, a broiler chicken producer experienced a dramatic increase in leg condemnations at processing, coinciding with a temporary increase in processing age and weight (from 62 days at 10.25 pounds or 4.66 kg to 67 days at 11 pounds or 5 kg body weight). Gross lesions in the condemned limbs included acute rupture of the gastrocnemius tendon with corresponding hemorrhage and edema. Histologic analysis, however, revealed that the “tendon rupture” observed grossly was in fact due to rupture of the gastrocnemius muscle at the myotendinous junction. The myopathic lesions, as well as the venous inflammation (phlebitis) and lipid infiltrates, observed in the affected tissues were consistent with wooden breast syndrome (WBS), which more typically manifests in the pectoral (breast) muscle. WBS in breast muscle and meat is well recognized as a significant problem in the poultry industry due to economic losses from breast meat condemnation. This report demonstrates that the negative bird health effects and economic impact of WBS are likely far greater than previously understood. Moving forward, WBS myopathy and vasculopathy must now also be considered as a potential cause for clinical lameness, gastrocnemius muscle-tendon rupture, and economic losses from leg condemnation in broiler chickens, particularly in birds raised to roaster weights.

The purpose of the present study was to use an Eimeria maxima light microscopic lesion scoring (MLS) system to measure magnitudes of E. maxima infection in sections of broiler chick intestine, and to help make decisions regarding the efficacy of an E. maxima abatement programme. Chicks with whole-body pallor, elevated feed conversion ratios (10 points higher than normal) and reduced body sizes (0.1 kg smaller than normal) had light microscopic lesions caused by E. maxima infections. These intestine segments had high Eimeria maxima MLSs. High scores, coupled with the fact that there was no microscopic evidence for the presence of gastrointestinal pathogens other than E. maxima, allowed us to conclude that E. maxima was the cause of the signs observed. When changes in the pharmacotherapy of the coccidiosis abatement programme were made (substitution of one ionophore coccidiostat for another ionophore coccidiostat), the MLSs were significantly (P0.01) reduced, and chicks returned to their normal colour (yellow) and normal target body size (2.091 kg) on a normal feed conversion ratio (2.06). It was decided that the MLS is suitable for use in health programmes that depend upon detection of E. maxima in broilers.

The search for a solitary cause of spiking mortality (so-called spiking mortality syndrome [SMS]) among broiler chicks has been thwarted by the fact that many agents will cause similar mortality histograms. Recently, severe hypoglycemia has been said to be a characteristic finding in chicks that die with SMS. In the present case study, we report adenovirus inclusions in the pancreas, small intestines, and liver of chicks with hypoglycemia and spiking mortality. We attributed the hypoglycemia and mortality to hepatic insufficiency.

SUMMARY A micromethod was used in order to quantitate intestinal D-xylose absorption in young and extremely small birds. This test was performed in broilers collected from two farms from which birds were extremely uneven in body size and were passing poorly digested or undigested feed. A similar syndrome had been seen on all grow-outs during the 6 months before this investigation. Broilers were also collected and tested from three farms where no clinical signs of disease were seen. D-Xylose absorption peaks and curves for normal broilers closely resembled those observed in normal humans. Mean plasma D-xylose concentrations for virus-infected broilers and for broilers with pale-bird syndrome were consistently lower than concentrations for normal broilers (P = 0.009). Reoviruses, small coronaviruslike particles, small round virus particles, and abundant bacterial flagellar fragments were seen in fecal samples from broilers with pale-bird syndrome. Production performance was lowest on farms showing clinical signs of this syndrome. RESUMEN