Nickolas G. Zimmermann

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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,(More)
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(More)
Turkey hens were allowed to incubate eggs and to hatch and rear young. Plasma prolactin (Prl) levels increased prior to the start of continuous incubation and rose sharply as incubation progressed to reach a peak of 1178.2 +/- 221.8 ng/ml (mean +/- SEM) just before hatching. Prl levels then fell precipitously before the hens left the nest, and returned to(More)
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(More)
A neuropharmacologic approach was utilized to investigate the catecholaminergic influence on the hypothalamic regulation of growth hormone (GH) secretion in young (6-week-old) male domestic fowl. The selective inhibition of norepinephrine (NE) and epinephrine (E) synthesis or activity by diethyldithiocarbamate (DDC), FLA63 (dopamine-beta-hydroxylase(More)
Three trials were conducted to determine if modern energy-efficient light sources, which vary in wavelength emission, affect broiler growth performance. The effect of light source on growth performance was determined by measuring body weight, feed conversion, and livability at intervals throughout rearing and at market age in three flocks of approximately(More)
Domesticated poultry are susceptible to infectious and zoonotic diseases and can serve as a transmission source to other bird and human populations. In recent years, the number of noncommercial poultry has been on the rise in the United States. To evaluate potential risks of this growing population, a descriptive epidemiologic survey was conducted among(More)
Continuous feeding of the anticoccidial halofuginone to broilers is associated with reduced skin tensile strength and increased skin tearing during processing. The possible mitigating effect of shuttle administration of halofuginone and salinomycin to female broilers was evaluated. Halofuginone or salinomycin were included in the starter and grower diets in(More)
Two experiments were conducted to determine whether supplemental levels of L-proline in the diets of broiler chickens would mitigate the skin weakening effect caused by continuous feeding of the anticoccidial halofuginone. In Experiment 1, tensile strength and collagen levels in thigh apteria skin were determined at 21 and 42 d of age in male broilers fed(More)
Three electronic devices used to treat drinking water were compared with untreated city well water in a broiler growth performance trial. In each treatment feed conversion and BW were measured in 16 replicate pens of 60 female broilers at 29, 42, and 49 days of age. Two of the devices increased dissolved oxygen content of the water and reduced conductivity(More)