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Animal Sciences

Purdue University

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Full-Text Articles in Medicine and Health Sciences

Impact Of Dietary Modification On Aflatoxicosis In Poultry, Xi Chen Dec 2016

Impact Of Dietary Modification On Aflatoxicosis In Poultry, Xi Chen

Open Access Dissertations

Aflatoxin contamination in feed and feed ingredients is of high worldwide prevalence, posing serious risks to the livestock industry. A series of studies were conducted to better understand the comprehensive impact of aflatoxicosis and its interrelationships with dietary modifications in broiler chicks and ducks. Results of these studies emphasize the many factors that the severity of aflatoxicosis depends on, including animal species, age, presence of mycotoxin adsorbent, and concentration of major dietary nutrients. Exposure to 2 mg/kg cultured AFB1 led to reduced feed intake, BW gain, depressed feed efficiency, increased relative liver weight, negatively affected serum measures and complement activity, …


The Impact Of Tickling Rats On Human-Animal Interactions And Rat Welfare, Megan Renee Lafollette Dec 2016

The Impact Of Tickling Rats On Human-Animal Interactions And Rat Welfare, Megan Renee Lafollette

Open Access Theses

Rats initially fear humans which can lead to negative affect, poor welfare, and difficult handling. Also, modeling and measuring positive affect states in rats can pose an additional challenge. Heterospecific play, or “tickling,” is a handling habituation technique that mimics rat rough-and-tumble play that is being used to study positive affect. It can also be used to reduce fear of human, improve welfare, and elicit a positive affect state. However, current studies implementing the technique in laboratory rats use a wide variety of protocols to achieve differential results. Unlike in laboratory environment, pet store rats experience high levels of novelty …


Gonadal Intersex In Teleosts: Mechanisms, Molecular Biomarkers And Diagnostic Assays, Ahmed M.E. Abdel-Moneim Mohamed Dec 2016

Gonadal Intersex In Teleosts: Mechanisms, Molecular Biomarkers And Diagnostic Assays, Ahmed M.E. Abdel-Moneim Mohamed

Open Access Dissertations

Natural and synthetic estrogenic and androgenic compounds are continuously released into aquatic ecosystems. Exposure of teleost fishes to these contaminants can negatively impact sex differentiation and reproductive output. Specifically, development of gonadal intersex in gonochoristic (fixed sex) fish species has been studied extensively in relation to exposure to this class of compounds. The main objectives of this dissertation were to: 1) conduct field and laboratory studies to investigate the molecular signaling pathways behind the development of gonadal intersex; and 2) establish molecular biomarkers and assays for testing the ability of environmental pollutants to develop this condition using a battery of …


Evaluating The Physical Welfare Of Dogs In Commercial Breeding Facilities In The United States, Moriah J. Hurt Aug 2016

Evaluating The Physical Welfare Of Dogs In Commercial Breeding Facilities In The United States, Moriah J. Hurt

Open Access Theses

Despite high levels of public concern, the state of commercial breeding (CB) dog welfare is largely unknown. Therefore, this study aimed to characterize the physical welfare of dogs in CB facilities and their environment in Indiana. This study specifically aimed 1) to characterize dog foot health in CB facilities as a function of the length of time dogs were housed on a given flooring substrate, 2) to characterize visual dog body cleanliness and visual kennel cleanliness as a function of the flooring substrate, 3) to determine the efficacy of kennel cleaning procedures and 4) to characterize the dog dental and …


Influence Of Dietary Component Manipulation And Feed Management Strategies On Growth And Rumen Development Of Weaned Dairy Heifers, Tana Shea Dennis Aug 2016

Influence Of Dietary Component Manipulation And Feed Management Strategies On Growth And Rumen Development Of Weaned Dairy Heifers, Tana Shea Dennis

Open Access Dissertations

Well-developed replacement heifers provide a central foundation for the continued success of the dairy industry. Emphasis on improving pre-weaned calf nutrition has predominated in the industry, but opportunities exist to improve post-weaning heifer nutrition and management. We aimed to evaluate common feed management strategies seen in the industry and their effects on growth, feed efficiency (G:F), and rumen development of calves from birth to 8 mo of age using pen- and individually-fed animal trials. Little information exists regarding post-weaning performance and rumen development of calves fed conventional or high planes of nutrition pre-weaning; therefore, we evaluated two milk replacer feeding …


Evaluation Of Negative Energy And Mineral Balance In Periparturient Holstein-Friesian Cattle, Ameer Ahmed Abdelhameed Apr 2016

Evaluation Of Negative Energy And Mineral Balance In Periparturient Holstein-Friesian Cattle, Ameer Ahmed Abdelhameed

Open Access Dissertations

Most cows experience a state of negative energy and mineral balance during the periparturient period. This imbalance is a major problem in the dairy industry and it is more frequently seen in multiparous cattle due to their high milk production. A large amount of fat and protein is mobilized in order to address the energy deficit during the periparturient period. The ability to accurately monitor energetics and electrolytes status using accurate, rapid, and low cost point-of-care instruments will assist in optimizing animal health and productivity.

This dissertation contains three studies that evaluated point-of-care instruments for measuring blood and plasma glucose, …


The Effects Of Heat Stress On Immunity In Laying Hens And Dairy Cattle, Rebecca Ann Strong Oct 2014

The Effects Of Heat Stress On Immunity In Laying Hens And Dairy Cattle, Rebecca Ann Strong

Open Access Theses

With the increase in global climate change and the population growth driving the high demand for additional food production, heat stress (HS) is a major concern in the livestock industry across all species. Animals experience HS when exposed to high environmental temperatures outside their thermal neutral zone. The level of the effects can vary due to the length and intensity of HS to which the animal is exposed to. In experiment one, laying hens with access to cooled perches during HS had a lower heterophil to lymphocyte ratio compared to the control hens after 4 h of acute heat stress, …