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Agriculture 221: Animal Nutrition

A guide to assist students in the course Animal Nutrition, including a writing guide for the midterm research assignment on animal diseases.

Choosing a Topic and Background Information

It can be hard separating these two, since they both tie in with each other.  It works like this:

Let’s say that Andy is thinking about all the diseases he knows that livestock get, and out of all of them, mad cow disease is the most interesting to him.  Andy knows little about it, only that it’s deadly, and it can be spread to humans by eating infected beef.  It could be interesting, only Andy isn’t interested in a cattle disease.  He’d like to do something more exotic…like cheetahs.  But do cheetahs get mad cow disease?  Time to Google!

This is now the background information part—you have an idea but you don’t necessarily know if it’s viable yet.  Andy will need to do a little research to find out a few things:

  • Do cheetahs get mad cow disease?
  • If not, do they get a similar disease?
  • If it’s a similar disease, how is it related?
  • Is this disease interesting enough for Andy to want to research it?
  • Is there enough information available on the disease for Andy to research it?

The process below is how Andy will get his background information; you might approach this differently, and that’s OK.  Different people will have different approaches and different starting levels of understanding regarding their topic, so some people will need more background information than others.  It’s not bad or wrong—it just is. 

Andy decides to Google “mad cow disease and cheetahs”, which brings up some web articles and pages from various sources.  The top hit is the livescience.com one, and the summary it gives under the page’s title mentions mad cow disease, so he decides he might as well start there. 

Google Scholar Find It @ Marian

The article talks about a disease called AA amyloidosis, which seems to be similar to mad cow disease because a misfolded protein makes other normal proteins misfold, too, and that damages tissues.  So that’s how mad cow disease works!  Andy now has a name, AA amyloidosis, for his disease in cheetahs, and it is just as fascinating as mad cow disease.

Andy now decides to check out Wikipedia—yes, Wikipedia—for more background information specific to AA amyloidosis.  The nice thing about background information is that you can use any semi-reliable source, including Wikipedia, because you won’t be using the sources you find for background information in your actual paper--you're just using them to get a feel for your topic.  I use the term “semi-reliable” because you should double-check your background info with multiple sources, just to make sure what you’re finding is legitimate and you don’t spend a lot of time running around trying to find information on a disease that doesn’t exist.  Andy knows his disease exists—he’s found several legit sites that talk about it.  And while anyone can add or change pages in Wikipedia and maybe not get caught by proofers for some time, Wikipedia does have a very cool, useful thing most other general websites don’t:  references.

Andy Googles AA amyloidosis and looks at the Wikipedia article.  Apparently, humans can get AA amyloidosis too.  It’s not a huge article, but it does have one very small paragraph that mentions cheetahs (along with cattle, mice, and chickens) and a concern about people getting it from animals when they’re eaten, so Andy looks at the next section—References—and sees one in particular that may be useful--that last one that talks about AA amyloidosis in animals.  It not only looks useful for his paper, but it also looks like it’s a peer-reviewed source, and it’s got a download PDF link!  Thank goodness he set up LibKey so he can get articles Marian students have access to directly through web searches!

(Want to learn how to set this up, too?  See the LibKey links below!)

At this point, Andy could do more background research, but he decides his basic questions are answered, and that he understands enough to move forward.  He has his topic—AA amyloidosis in cheetahs—and now he can move forward with his abstract.

Abstracts

Abstracts are nothing more than a summary of what an article, paper, or book is about.  Usually a paragraph or two, abstracts provide the reader with a general idea of what they will be reading in the full text.  You will be using abstracts in 2 ways in this project:  you can use them to help determine if a source is good for you to use, and you’ll write your own abstract to summarize your paper.

First, using the abstract of published articles helps you decide if the article might be useful to you.  Here are two article citations with their abstracts that Andy found in EBSCO databases when searching for cheetahs and amyloidosis:

Mitchell, Emily P., et al. “Pathology and Epidemiology of Oxalate Nephrosis in Cheetahs.” Veterinary Pathology, vol. 54, no. 6, Nov. 2017, pp. 977–85. EBSCOhost, https://doi.org/10.1177/0300985817728556.

ABSTRACT

To investigate cases of acute oxalate nephrosis without evidence of ethylene glycol exposure, archived data and tissues from cheetahs ( Acinonyx jubatus) from North America ( n = 297), southern Africa ( n = 257), and France ( n = 40) were evaluated. Renal and gastrointestinal tract lesions were characterized in a subset of animals with ( n = 100) and without ( n = 165) oxalate crystals at death. Crystals were confirmed as calcium oxalate by Raman spectroscopy in 45 of 47 cheetahs tested. Crystals were present in cheetahs from 3.7 months to 15.9 years old. Cheetahs younger than 1.5 years were less likely to have oxalates than older cheetahs ( P = .034), but young cheetahs with oxalates had more oxalate crystals than older cheetahs ( P < .001). Cheetahs with oxalate crystals were more likely to have renal amyloidosis, interstitial nephritis, or colitis and less likely to have glomerular loop thickening or gastritis than those without oxalates. Crystal number was positively associated with renal tubular necrosis ( P ≤ .001), regeneration ( P = .015), and casts ( P ≤ .001) but inversely associated with glomerulosclerosis, renal amyloidosis, and interstitial nephritis. Crystal number was unrelated to the presence or absence of colitis and was lower in southern African than American and European animals ( P = .01). This study found no evidence that coexisting chronic renal disease (amyloidosis, interstitial nephritis, or glomerulosclerosis), veno-occlusive disease, gastritis, or enterocolitis contributed significantly to oxalate nephrosis. Oxalate-related renal disease should be considered as a potential cause of acute renal failure, especially in young captive cheetahs. The role of location, diet, stress, and genetic predisposition in the pathogenesis of oxalate nephrosis in cheetahs warrants further study.

Franklin, Ashley D., et al. “Serum Amyloid A Protein Concentration in Blood Is Influenced by Genetic Differences in the Cheetah (Acinonyx Jubatus).” The Journal of Heredity, vol. 107, no. 2, Mar. 2016, pp. 115–21. EBSCOhost, https://doi.org/10.1093/jhered/esv089.

ABSTRACT

Systemic amyloid A (AA) amyloidosis is a major cause of morbidity and mortality among captive cheetahs. The self-aggregating AA protein responsible for this disease is a byproduct of serum amyloid A (SAA) protein degradation. Transcriptional induction of the SAA1 gene is dependent on both C/EBPβ and NF-κB cis-acting elements within the promoter region. In cheetahs, 2 alleles exist for a single guanine nucleotide deletion in the putative NF-κB binding site. In this study, a novel genotyping assay was developed to screen for the alleles. The results show that the SAA1A (-97delG) allele is associated with decreased SAA protein concentrations in the serum of captive cheetahs (n = 58), suggesting genetic differences at this locus may be affecting AA amyloidosis prevalence. However, there was no significant difference in the frequency of the SAA1A (-97delG) allele between individuals confirmed AA amyloidosis positive versus AA amyloidosis negative at the time of necropsy (n = 48). Thus, even though there is evidence that having more copies of the SAA1A (-97delG) allele results in a potentially protective decrease in serum concentrations of SAA protein in captive cheetahs, genotype is not associated with this disease within the North American population. These results suggest that other factors are playing a more significant role in the pathogenesis of AA amyloidosis among captive cheetahs.
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Andy can sort through the abstracts to determine if any are too technical for him or not a good fit for his topic.  Abstracts that have a lot of unfamiliar words and jargon (technical language used in a field of study) may indicate that Andy might not be able to understand the content of the article (though not necessarily--sometimes the introduction and discussion sections take all the technical language and calculations and puts them into less technical language).  Still, it can help him sort through and find the articles he thinks will be most useful to him.  He decides, based on what he reads, that the first article isn't focused on the amyloidosis; most of the information the authors are providing are on another condition, oxalate nephrosis.  Even though the abstract in the second one has some medical and technical language, he decides that one is his better option, and he brings up the full text.  He'll use some of the tips he's learned about how to research to make the most of his time and effort.

Of course, Andy has to also write an abstract for his own paper, too.  He knows there are certain expectations regarding content for this paper; they are outlined in the syllabus.  He knows he’s expected to include things like the disease's symptoms, how it spreads, how it’s treated, and whether it can spread to humans.  He knows a little about some of this, other areas are complete blanks.  Because it’s a summary, and not packed with a lot of details, Andy can write his abstract with what his instructor says should be included in the paper, and what he’s learned from his initial background search.  He creates an abstract that looks like this:

AA amyloidosis in the captive cheetah population is a serious concern, especially as cases have risen sharply since the 1980s.  The fatal disease does not help this endangered species' outlook for survival, as it seems to spread easily among individuals living in zoos and similar facilities, usually resulting in death through renal failure, though inflammatory conditions, particularly in the gastrointestinal tract, were fairly common as well.  Unlike most prion diseases, AA amyloidosis seems able to spread through means other than eating contaminated meat, and transmission through feces seems particularly likely.  While the likelihood of an outbreak in the human population is almost nonexistent, the strains put on this species, already struggling to edge away from the brink of extinction, is great.

From just what little he's already read, Andy was able to create a short paragraph that hints at the full content of his upcoming paper.