Major implications on a country's economy, food source, and public health. With recent concern over the highly pathogenic avian influenza outbreaks around the world, government agencies are carefully monitoring and inspecting live bird markets, commercial flocks, and migratory bird populations. However, there remains limited surveillance of non-commercial poultry. Therefore, a cross-sectional study was conducted in backyard poultry flocks using a convenience sampling method across three regions of Maryland from July 2011 to August 2011. The objective of this study was to develop a better understanding of the ecology and epidemiology of avian influenza by investigating the prevalence and seroprevalence in this potentially vulnerable population and by evaluating biosecurity risk factors associated with positive findings. Serum, tracheal, and cloacal swabs were randomly collected from 262 birds among 39 registered premises. Analysis indicated bird and flock seroprevalence as 4.2% (11/262) and 23.1% (9/39), respectively. Based on RT-qPCR analysis, none of the samples were found to be positive for AI RNA and evidence of AI hemagglutinin subtypes H5, H7, or H9 were not detected. Although no statistically significant biosecurity associations were identified (p≤0.05), AI seroprevalence was positively associated with exposure to waterfowl, pest control, and location. AI seropositive flocks exposed to waterfowl were 3.14 times as likely to be AI seropositive than those not exposed (p = 0.15). AI seropositive flocks that did not use pest control were 2.5 times as likely to be AI seropositive compared to those that did and AI seropositive flocks located in the Northern region of Maryland were 2.8 times as likely to be AI seropositive than those that were located elsewhere.

Seventy-two-week-old Single Comb White Leghorn hens were induced to molt by 11 different methods 1) to determine the utility of molt-inducing procedures that employ full feeding, limited feeding, and fasting and 2) to determine the postmolt performance of hens induced to molt by fasting to varying degrees of body weight reduction (BWR) then fed postfast, prelay (PF-PL) diets varying in nutrient density. Induced molt treatments were full feeding of 10 and 15% guar meal diets to 30% BWR; limited feeding by withholding feed to 30% BWR, except for 6-hr feeding periods on every 3rd, 4th, and 5th recurring day; fasting to 25, 30, or 35% BWR then feeding either a pullet developer ration or a fortified molt ration (FR) for 21 days. Egg production, egg weight, shell quality, Haugh unit, feed consumption, and mortality were recorded for 33 weeks. Molt treatments produced few significant differences; nonmolted control hens had overall poor performance. Full feeding of the 15% guar meal diet caused a slow cessation and reinitiation of lay with acceptable lay performance. The 10% guar meal diet reduced livability. All recurring day, limited-feeding treatments conserved feed during the first 35 days of molt induction. The 3rd and 5th recurring day-feeding treatments were particularly effective and had acceptable lay performance and feed efficiency. Neither level of BWR nor type of PF-PL diet significantly affected postmolt performance. The 30% BWR-FR induced-molt method produced superior (but not significantly) postmolt lay performance.

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Two experiments were conducted to evaluate dietary and environmental factors involved in skin tensile strength of commercial broilers. In Experiment 1 the effect of added dietary fat (4 or 7%), environmental temperature (25 or 20.5 C after 21 d), and anticoccidial drug (halofuginone or salinomycin fed continuously) were examined factorially using male and female chicks. Skin tensile strength was measured at 21, 35, and 40 d of age. Thickness of the dermal layers was measured from skin taken at Day 35. In Experiment 2, the effect of added dietary fat (0 or 7%), environmental temperature (25 or 18.5 C after 21 d), and anticoccidial drug (halofuginone or salinomycin) were examined factorially using female chicks. Skin strength and collagen content of the skin were measured at 21, 38, and 42 d of age. Skin tensile strength increased with age in both experiments, but female skin strength was subject to periodic decline. Males had significantly strong skin than females. Levels of added fat or environmental temperature did not affect skin strength in either experiment. Continuous feeding of halofuginone significantly (P < .0001) decreased skin strength compared with that of birds fed salinomycin in both experiments. Halofuginone reduced skin strength in females more than males (25 and 9%, respectively). Dermis thickness was correspondingly reduced in the birds consuming halofuginone. In Experiment 2, soluble collagen contents were reduced at all ages in birds consuming halofuginone; insoluble collagen was significantly decreased at 21 d of age. Birds with weakened skin exhibited increased incidence of skin tears during slaughter in a commercial processing plant (P < or = .0043). These results suggest that halofuginone interferes with collagen synthesis, causing decreased collagen formation and reduced skin strength. Neither added dietary fat nor ambient temperature were involved.