Ask the Vet

Stocker Density for Transport

(Progressive Farmer image by Becky Mills)

READER: How many stockers, or mother cows, can I put in a livestock trailer? I realize trailers vary in length and width, but as a general rule, how do you estimate what is safe and responsible?

Dr. McMillan: That's a great question. My first recommendation is that you consider going through your local Beef Quality Assurance (BQA) program sometime in the future. They will do a thorough job of answering that question while addressing other transportation issues like low-stress handling and working in the heat.

There are hauling guidelines based on animal weights and trailer size you can look at to help you determine number of animals to load. To give you an idea, let's look at a stock trailer with a compartment weight of 8,000 pounds. If you are hauling cows that weigh 1,200 each, you could put six head in that trailer. This doesn't include their calves, just the cows. Logically, the bigger the trailer and the higher the compartment weight, the more animals you could carry. I recommend erring to the side of underloading, especially when conditions are hot. Never exceed the gross vehicle weight rating for your truck and stock trailer.

The BQA Master Cattle Transporter Guide contains all the details on this subject, including charts that look at eight different trailer compartment weights with corresponding number of cattle that can be safely and humanely carried. You can find the information at

Of course, all of this means you need to know weights on the cattle you're intending to haul. We'll talk about the importance of a good set of on-farm scales in another column.

READER: This spring, we were hit with the worst pink eye we've ever had. We vaccinate every year, but this season, we saw pink eye in 90% of the herd. We treated with Oxytet 200 and a pink eye spray. We could not understand why there was such a wide range in price on the Oxytet 200 products. We saw for the same 500cc bottle prices from $25 to $75. The dosages for all the different products were the same (4.5ml to 5ml per 100 pounds of body weight). Are all the products of equal quality?

Dr. McMillan: There can be a lot of price disparity when comparing name-brand products to generics. It's true the FDA requires generic versions of products contain the same active ingredient(s), but it does not require they have the same inactive ingredients. The thinking is inactive ingredients should have no effect on the drug's therapeutic action. I believe it can make a difference.

Also, consider some generics are imported from countries that do not have the same manufacturing standards the FDA requires of companies here. When choosing whether to use a brand-name or a generic, or even selecting between generics, I say look for a company that will stand behind its products.

Specific to oxytetracycline, I do have concerns about many of the generics. With all injectable products, it's important to follow the label regarding amount to be given at one site. These products do cause inflammation at the injection site, and giving the whole dose or more than the recommended amount in one place will increase the reaction and may decrease the effectiveness. My experience has been that the generics are generally more reactive than the brand-name products. Additionally, I feel Bio-Mycin 200 is less painful and reactive than the generics I have used. I particularly like it for sheep and goats. But, yes, it does cost more.

Among generics, I wish I could tell you a higher price guarantees better quality. I do not think that is necessarily the case. Your herd veterinarian is a good resource to help in your selection of the best product. He or she can also do a lot to help you prevent another outbreak. As we have discussed before, pink eye is not just a costly disease to treat, it also brings with it long-term costs in reduced fertility and future eye diseases, especially squamous cell carcinoma, or "cancer eye."

Please contact your veterinarian with questions pertaining to the health of your herd. Every operation is unique, and the information in this column does not pertain to all situations. This is not intended as medical advice but is purely for informational purposes.

Write Dr. Ken McMillan at Ask The Vet, 2204 Lakeshore Dr., Suite 415, Birmingham, AL 35209, or email


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