Ferber's syndrome, a viral disease that frequently affects cattle

Could you help me to analyze and point out the gap of this argument ? Thanks!

Ferber’s Syndrome
 
Step 1: Identify the Question

This is a fill in the blank question. The word since just before the blank indicates the need for another premise to support the conclusion, so this is a Strengthen the Argument question.
 
Step 2: Deconstruct the Argument

Feed → FS in cattle
Same feed → but FS rare in chick
© Chick not immune b/c ____.
 
Step 3: Pause and State the Goal

On Strengthen questions, the goal is to find a piece of information that would make the conclusion more likely. Besides immunity, what other reason could there be that Ferber’s syndrome is NOT found frequently in chickens?
 
Step 4: Work from Wrong to Right

(A) The conclusion relates to the immunity of chickens. Whether other animals eat the same feed is not relevant.
(B) This answer suggests that there may be other causes of Farber’s Syndrome; it does not help explain why chickens do not often get Farber’s syndrome from feed.
(C) This information could help explain how chickens acquire immunity to Farber’s syndrome. But the conclusion, which the correct answer should support, states that chickens are not immune to Farber’s syndrome.
(D) CORRECT. This answer provides information about why symptoms of Ferber’s syndrome would not be observed in chickens even though the chickens are not immune; the chickens do not live long enough to show symptoms.
(E) If the food is a more important component of the chickens’ diet than the cows’ diet, it seems more likely that the chickens would acquire Ferber’s syndrome if they lack immunity. This answer actually weakens the argument.

hello experts

i have a doubt regarding OPTION C
i think immunity is what the body has naturally
while the option is discussing about something acquired i.e resistance to the disease.
this resistance to the disease acquired from infected closely related animal(although not mentioned in the passage) is providing an alternate explanation.
please correct me where i am going wrong,because option D is logical too.

The correct option says that chickens commercially raised for meat are generally "brought to market" during the first year of life.

Is everyone supposed to know what "brought to market" means? I understand that this could be very natural to some people, but I had to spend quite a lot of time, to just make sense of what this option was trying to say..

According to this logic, the last sentence would translate to: "The fact that Ferber's syndrome is only rarely observed in chickens does not indicate that most chickens have a NATURAL immunity to the virus, since they could have DEVELOPED the resistance by exposure to a closely related infectious organism."

But the word "natural" changes the meaning entirely. Immunities are not ony what the body has naturally. We are given many immunizations by doctors. For example, many children in the US receive a shot (immunization) that protects them against diphtheria, tetanus, and pertussis. Now the children are immune to those infections despite not having a NATURAL immunity.

We need something that explains why the syndrome is rarely observed in chickens if they are NOT immune to it. If the chickens developed resistance by exposure to a closely related infectious organism, then the chickens WOULD be immune to it. In other words, if choice (C) were the answer, the passage would boil down to:

• Why don't we observe the syndrome in chickens if they are not immune to it?
• (choice C) - because they are immune to it.

Clearly we have not addressed the discrepancy. Instead, we have altered the facts given in the passage.

Choice (D) is a much better answer.


The best clue here is the word "commercially", which tells us that the meat is going to be sold. With that context, we should recognize "market" as a place where the meat can be sold. Thus, even if you think of "brought to market" as literally meaning "brought to where it will be sold", you'd be able to answer the question.

Yes, this question would be easier if you immediately recognized the meaning of that phrase, but if you find yourself in that predicament again, try to use contextual clues to determine the meaning.

I hope that helps!

how do we tackle complete the argument questions?

Which of the following most logically completes the argument?

Ferber’s syndrome, a viral disease that frequently affects cattle, is transmitted to these animals through infected feed. Even though chickens commercially raised for meat are often fed the type of feed identified as the source of infection in cattle, Ferber’s syndrome is only rarely observed in chickens. This fact, however, does not indicate that most chickens are immune to the virus that causes Ferber’s syndrome, since ________.

this is a question from og17, when I read it seems like an inference question. but really is it? or do we simply treat this question type as a strengthen/assumption question?

It doesn't look like an inference question. It looks more like the argument is trying to weaken this conclusion that most chickens are immune to the virus that causes Ferber’s syndrome.

Hi GMATNinja,

I have a question about choice B:

We want to prove that chicken is not immune to the virus that causes Ferber's syndrome. And what I thought is that maybe there are some other factors other than feed that cause the virus (note that the clause before the underline didn't specify what factor, so I thought another factor that cause the virus would makes sense here, like what B is saying).

Could you help me with this, please? I hope I make myself clear, but please let me know if any more explanation is needed. Thank you so much!

I initially chose B but now I see why it is wrong:

We want to prove that chicken is not immune to the virus that causes Ferber's syndrome. And what I thought is that maybe there are some other factors other than feed that cause the virus (note that the clause before the underline didn't specify what factor, so I thought another factor that cause the virus would makes sense here, like what B is saying).

However, for people who chose B, you need really need to look at the words the test writers use.

In the stimulus, the "chicken commercially raised" are the focus. Therefore, in the conclusion, "most chickens" refers to "commercially raised" chickens. And in the stimulus, we know that for these chickens, they are fed by the specific type of feed (leads to virus). Therefore, in B, "animals that have not been fed the type of feed" is irrelevant. If it is changed to "animals that have been fed the type of feed", then this choice would work.

Let's take a look at the passage before we take a closer look at (B).

The passage tells us:

• Cattle are frequently infected with Ferber's syndrome
• Ferber's syndrome is transmitted to cattle through their feed
• Chickens grown for food are regularly given the same feed that infects cattle, BUT
• These chickens are rarely observed to have Ferber's syndrome.

We're then asked to complete the sentence that tells us that the information above does NOT tell us chickens are immune to Ferber's syndrome, since_________

We don't want to prove that chickens are not immune to the virus -- we need something that explains why the syndrome is rarely observed in chickens if they are NOT immune to it.

(B) tells us:

Remember, we're trying to find an explanation for how the chickens can eat the same contaminated feed as the cows, yet we do not see them suffering from Ferber's syndrome. Also, this explanation cannot be that the chickens are immune to Ferber's syndrome.

You're right that (B) does tell us that there is some other factor, other than the feed, that causes the virus in some animals. However, knowing this doesn't help us address the discrepancy given above.

Maybe lions can get Ferber's syndrome if they eat the wrong type of wildebeest -- this doesn't explain why chickens are NOT observed to have Ferber's syndrome despite eating contaminated feed.

Since (B) doesn't help us resolve the discrepancy, it cannot be the answer to this question.

Compare this to (D):

Both (D) and the passage talks about "chickens commercially raised for meat", so we can be sure we're talking about the same animals.

(D) then tells us Ferber's syndrome can take more than a year to be noticeable BUT these chickens are "brought to market" in their first year of life. We cannot observe Ferber's syndrome in these chickens because they do not live long enough to display symptoms.

(D) provides information that helps us address the discrepancy given in the passage, so (D) is the answer to this question.

I hope that helps!

Conclusion: “This fact, however, does not indicate that most chickens are immune to the virus that causes Ferber's syndrome”
Prethink: Is there another factor we’re not seeing? What if these chickens take an immune shot each year? What if there’s no opportunity for the chickens to get sick?

(A) chickens and cattle are not the only kinds of farm animal that are typically fed the type of feed liable to be contaminated with the virus that causes Ferber's syndrome
Out of scope – we don’t care about what other kinds of farm animals are fed this feed too. We want to know why chickens aren’t getting sick that often.

(B) Ferber's syndrome has been found in animals that have not been fed the type of feed liable to be contaminated with the virus that can cause the disease
Out of scope – we don’t care about what other animals that have NOT been fed the feed. We want to know why chickens are rarely observed to be sick even though they eat the feed.

(C) resistance to some infectious organisms such as the virus that causes Ferber's syndrome can be acquired by exposure to a closely related infectious organism
Out of scope – first, it doesn’t even impact our conclusion. What if there were? Do the chickens have this exposure, leading to resistance? What if there weren’t and thus chickens didn’t have exposure? Our conclusion is not necessarily affected either way.

(D) chickens and cattle take more than a year to show symptoms of Ferber's syndrome, and chickens commercially raised for meat, unlike cattle, are generally brought to market during the first year of life
This is it. In chickens, “Ferber’s syndrome is only RARELY observed” because it goes to market quickly and presumably (thus) ate more quickly than cattle. Hence, you rarely observe chickens with this syndrome because it’s already in eaten.

(E) the type of feed liable to be infected with the virus that causes Ferber's syndrome generally constitutes a larger proportion of the diet of commercially raised chickens than of commercially raised cattle
Opposite, if anything. There are more chickens proportionally than cattle proportionally that eat the feed? So wouldn’t it make more sense for them to be sick more frequently?

A Complete the Argument type of question requires us to add a premise to support the conclusion. In most questions, the passage ends in the word ‘since’ or ‘because’, implying that we should find a reason to support the conclusion. This passage also has the typical ending.

We are looking not for a conclusion but for an extra premise.

The conclusion of the argument is that even though Ferber’s syndrome is only rarely observed in chickens, this fact does not indicate that chickens are immune to the virus that causes Ferber’s syndrome.

We are looking for a reason for this conclusion.

Option A does not give us the reason to support the conclusion. So, Option A can be eliminated.

Option B states that the disease has been found in animals that have not been fed the type of feed liable to be contaminated with the virus that can cause the disease. But the argument states that chickens commercially raised for meat are fed with this type of feed. Therefore, Option B is irrelevant.

The passage states that though chickens commercially raised for meat are fed with this type of feed, Ferber’s syndrome is only rarely seen in chickens. But the conclusion states that this fact does not mean that chickens are immune to the disease. Option C provides information to show that chickens could actually be immune to the disease, so Option C can be eliminated.

If the information provided by Option E is true, the disease should not be rarely seen in the chickens since the feed constitutes a larger part of the feed of the chickens. However, the passage states that it is rarely seen in chickens. So, Option E doesn’t provide a strong reason to show that chickens may not be immune to the disease. So, E can be eliminated too.

Option D is the only one that provides a clear reason for the fact that even though chickens are given the same type of feed as cattle, the disease is rarely seen in chickens. If the disease takes more than a year to manifest and the chickens are sold in the first year itself, the chickens are not necessarily immune to the disease; they simply may not have the time to manifest the disease. Therefore, Option D is the most appropriate.

Jayanthi Kumar.

Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.