Zugl.: Halle (Saale), Univ., Diss., 2008

Hohenheim, Univ., Diss., 2006.

Tierärztl. Hochsch., Diss., 2004--Hannover.

In times of economic hardship, everyone must find ways to adapt, and the poultry industry is no exception. The majority of the cost in an integrated poultry operation is feeding the birds. Distillers dried grains with solubles (DDGS) has been around for decades as a by-product of the beverage industry and more recently as a co-product of the ethanol industry. Over the past decade, there has been a dramatic increase in the production of DDGS from U.S. ethanol biorefineries, making the co-product a very economical choice. DDGS have not held a common place in the poultry industry for long though, as issues with nutritional variability, storage, transportation, etc. all have led to the product being avoided by nutritionists much of the time. Even now, DDGS are fed at a relatively low inclusion level compared to other major feed ingredients such as corn, wheat and soybean meal. With the often volatile price of corn grain, DDGS are receiving more attention as a feasible alternative in commercial poultry diets as research, such as that presented in this dissertation, continues to elucidate the nutritional, economical and dietary inclusion aspects of this once neglected ingredient. The primary purpose of this research has been to determine the efficacy of DDGS as an ingredient in poultry diets, and also to further elaborate on the suitable inclusion rates in a ration. In the end it is clear that DDGS are an effective and suitable choice for inclusion into both broiler and layer diets. DDGS can be incorporated into layer diets at up to one-third of the ration with no deleterious effects on performance or egg quality. DDGS can be added to broiler diets at varying inclusion levels, depending on bird age, as the research points towards increased tolerance of the co-product as the bird ages, without harming bird health or performance. It is also shown that further processing of DDGS, primarily fiber separation, can have a positive effect on bird performance. In conclusion, DDGS inclusion in poultry rations is a sound choice provided attention is paid to the nutritional profile of this co-product.

The prevalence of Salmonella within poultry environments and on poultry products has been well documented. However, there has not been a study documenting the effect of utilizing used litter in newly constructed commercial broiler houses on Salmonella status or on the rate and source of Salmonella contamination within new houses. Objectives of this study are to 1) determine environmental source and rate of Salmonella spp. colonization in two newly constructed broiler houses 2) to evaluate the effect of mixing used broiler litter with clean litter in a new broiler house. Results of this study suggest that Salmonella contamination of the poultry house environment occurred within the first 2-4 weeks of bird placement and that the source of contamination may have been the chicks themselves. Litter inoculation may be beneficial in reducing Salmonella levels within the first flock if it is known that the chicks are already contaminated with Salmonella spp.

Litter is a possible source of Campylobacter colonization for broilers as well as contamination of crops when used as fertilizer. A survey of Arkansas broiler litter indicated that Campylobacter recovery rates were higher in pine shavings and rice hulls than sand. Two experiments utilized three types of litter, which were artificially contaminated with Campylobacter. After 24 hours no Campylobacter could be recovered from any sample. Campylobacter growth was also examined for used pine shaving litter in varying conditions: aerobic atmosphere, micro aerobic atmosphere (6% O2), and moisture content. Campylobacter was recovered for all treatments at the initial sampling, and by the 12 hour sampling time, only the added moisture and micro aerobic atmosphere yielded recoverable Campylobacter. This research suggests that without birds present in the house to shed fresh Campylobacter cells onto the litter, that the litter itself is incapable of harboring the bacteria long enough to colonize sequential flocks.

A randomized complete block design with three replications (n=432, 72 broilers per treatment) was utilized to evaluate the effects of electrical (ES) and low atmosphere pressure stunning (LAPS) on the quality of broiler breast meat deboned at 0.75, 2, and 4h postmortem. The L* values were lower (P<0.05) for LAPS than ES at 4 h and 2 h deboning times. Shear force did not differ (P>0.05) between stun methods but decreased (P<0.05) as deboning time increased. Consumers were clustered into 8 groups based on preference and liking of samples. Sixtyive percent of consumers (3 clusters) liked all broiler breast treatments. Within these three clusters, some consumers preferred (P<0.05) 4 h deboned samples over those deboned at 2 h (Cluster 7), and other consumers preferred (P<0.05) those deboned at 2 h over 4 h samples (Cluster 6). Data reveals that both stunning methods provide high quality breast meat with minimal product differences.

Litter is a possible source of Campylobacter colonization for broilers as well as contamination of crops when used as fertilizer. A survey of Arkansas broiler litter indicated that Campylobacter recovery rates were higher in pine shavings and rice hulls than sand. Two experiments utilized three types of litter, which were artificially contaminated with Campylobacter. After 24 hours no Campylobacter could be recovered from any sample. Campylobacter growth was also examined for used pine shaving litter in varying conditions: aerobic atmosphere, micro aerobic atmosphere (6% O2), and moisture content. Campylobacter was recovered for all treatments at the initial sampling, and by the 12 hour sampling time, only the added moisture and micro aerobic atmosphere yielded recoverable Campylobacter. This research suggests that without birds present in the house to shed fresh Campylobacter cells onto the litter, that the litter itself is incapable of harboring the bacteria long enough to colonize sequential flocks.

Master of Science / Department of Animal Sciences and Industry / R. Scott Beyer / Over the decades much has been discovered about the appropriate lighting management strategies for raising commercial meat-type poultry. Our knowledge of light preference, wavelength, intensity, intermittent lighting, and avian spectral sensitivity continues to improve our management strategies. In this work, a total of 5 experiments were conducted. The first 2 experiments investigated the effects of Light emitting diodes (LED) lights on growth performance of broiler chicks. Broiler chicks were raised under LED lights at different intensities: 5, 10, 15, 20, and 25 lux. A significant linear relationship (P < 0.05) was found in experiment 1 between body weight gain and light intensity. In experiment 2, a linear trend was noticed between body weight gain and light intensity. As the light intensity increased, chick weight increased. Feed: gain ratios were not affected by light intensity. The third experiment also examined growth performance using LED lighting as well as the effects of feed form and different lighting intensities upon behavior. The broilers fed a pelleted diet had significantly better performance than those fed crumbles. Under more intense light it was discovered that broilers spend significantly more time (P< .05) consuming feed compared to dim light. The fourth experiment focused on broiler preference for light color, and feed form during feeding. The broilers were offered either pelleted or crumbled feed and served under 4 different light colors: red, white, blue, and green. It was found that broilers statistically preferred pelleted feed, and white lighting, with red being the 2nd color choice of preference while green and blue were statistically not chosen. The fifth experiment focused on chick preference for feed color, when under different light color. One day old chicks were offered dyed feed: red, yellow, blue, green or light brown iv (control) under 5 different colors of light: red, yellow, blue, green, and white. It was found that chicks significantly preferred red dyed feed, especially under blue light. In conclusion, it was found that LED lights can have positive effects on broiler performance. Broilers show a preference for white lighting and pelleted feed. Young chicks show a preference for red dyed feed.

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