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The demographics of incoming univer-sity animal science majors have shifted from students with a farm background to urban students with no his-tory of direct livestock contact. Research completed before the Internet was a central source of information indicated that incoming urban students tend to express no opinion or a neutral opinion regarding livestock agriculture issues. Due to the changing background of incoming students enrolled in introductory university-level animal science classes, we sought to determine 1) if livestock background (self-identified as raised in a farm or urban setting), sex, or animal science career interest influenced the opinions of incoming students regarding critical issues involving livestock farming practices and 2) if 15 wk of introductory animal science instruction changed student opinions. A total of 224 stu-dents were given 2 identical anonymous surveys (start and end of 15 wk) with 5 demographic questions and 9 animal issue statements. For each statement, students marked their opinion by placing a vertical line on a con-tinuous 130 mm horizontal line, where a vertical line placed at 0 mm = strongly agree and 130 mm = strong-ly disagree. Data were analyzed by ANOVA to determine any significant effects of instruction, background, sex, and future career preference on survey responses. Before instruction, urban students were less agreeable than farm students that animal farming was moral and humane and that farmers are concerned about animal welfare and livestock are of value to society (P < 0.05). Urban students were more likely than farm students to purchase organic foods or food based on environmen-tal/welfare standards (P < 0.05). Introductory animal science instruction resulted in students becoming more agreeable that animal fanning was humane, farmers are concerned about animal welfare, and animal agriculture is a value to society (P < 0.05). Postinstruction, students were more likely to buy food products based on price (P < 0.05). Males found farm practices more humane than females (P< 0.05), but sex differences were not evident for other questions. Future professional career plans did not affect student opinions. Data showed that incoming urban students tend to be more neutral with regards to animal farming issues, and introductory animal science instruction fosters a more agreeable attitude towards animal farming practices, especially in students with urban backgrounds. [ABSTRACT FROM AUTHOR]

In this review, the science used to develop host-targeted therapies for improving animal growth and feed efficiency is presented. In contrast to targeting the microbiota of the host, endogenous host proteins are targeted to regulate an overactive inflammatory response in the host. Activation of the immune/inflammatory systems of an animal is costly in terms of growth and feed efficiency. For example, reduced rates of BW gain and poorer feed efficiency in vaccinated animals compared with nonvaccinated animals have been well documented. Also, the growth rate and feed efficiency of animals colonized by microorganisms is only 80 to 90% of their germ-free counterparts. Further evidence of a cost associated with immune activation is that strategies that enhance the immune capability of an animal can reduce animal growth and feed efficiency. Research now indicates that the growth-promoting effects of antibiotics are indirect, and more likely the result of reduced immune activation due to decreased microbial exposure. Studies of mechanisms by which immune/inflammatory activation reduces animal growth and feed efficiency have shown that cytokines of the acute inflammatory response (i.e., IL-1 and tumor necrosis factor α) are key triggers for host muscle wasting. Cytokine-induced muscle wasting is linked to PG signaling pathways, and it has been proposed that regulation of the PG signaling pathways provide host targets for preventing an overreactive or unwarranted inflammatory event. Intestinal secretory phospholipase A2 (sPLA2) has been found to be a useful and accessible (i.e., found in the intestinal lumen) host target for the regulation of an overreactive inflammatory response to conventional environments. This review presents the science and strategy for the regulation of intestinal sPLA2 using orally administered egg yolk antibody against the enzyme. Clinically healthy animals fed egg antibodies to sPLA2 had improved growth and feed efficiency. Literature presented indicates that use of host-targeted strategies for regulating the overexpression of inflammatory processes in an animal may provide new mechanisms to improve animal growth and feed efficiency. [ABSTRACT FROM AUTHOR]

The effects of conjugated linoleic acid (CLA) in animals are reviewed. In most of the CLA preparations that have been investigated to date for biological activity, two CLA isomers are present in about equal concentrations: cis-9,trans-11 CLA, and trans-10,cis-12 CLA. The occurrence of these isomers in foods and their production by rumen microorganisms are discussed. Potential mechanisms of action as regards the effects of CLA on cancer and body composition are reviewed, including recent evidence that body composition changes are produced by the trans-10,cis-12 CLA isomer. Evidence is presented indicating that CLA may modulate cellular response to tumor necrosis factor-alpha (TNF-α). The mechanistic implications of this finding are considered. [ABSTRACT FROM PUBLISHER]