Research: Transport, nutrient restriction, and effects on health and performance of cattle

This is the last of my posts covering the research currently underway at the EOARC. I’m starting to get really excited to go there, a week from Tuesday I get to leave and start working. So after this post I’ll put in some updates on what I’m doing over there, and return to my normal coverage of article reviews as I have time to read them.

The goal of this proposal is to see if a large part of the stress involved with cattle transport is caused by food and water deprivation, independent of the actual act of transport. I wished I had read this one first, as it contains a glimpse into the overall goals at the station.

“the long-term goal of our research program is to elaborate strategies that prevent stress-related illnesses elicited by routine cattle management procedures and, consequently, promote cattle welfare and productivity.”

Which is pretty much exactly what I want to promote in my later career, wherever that leads me. Its the idea of promoting welfare by working with the system, instead of digging trenches.

I actually learned a bit of immunology from this proposal, it was interesting. I always knew that chronic stress weakened the immune system, but apparently acute stress responses help fend off disease. Proinflammatory cytokines are released with acute stress, with the body assuming a response to a pathogen. The problem there, is that chronic stress (like that associated with transport or feed restriction) causes an unnecessary immune response that depletes resources and opens the animals up to infections like Bovine Respiratory Disease (BRD). The purpose of this study is to find new strategies in transport to reduce associated chronic stress and thus incidences of BRD.

54 steers will be separated into three groups, one will be transported continuously for 24 hours, another deprived of food and water for 24 hours at the station, and the last kept at the station with normal food and water access. Stress will be quantified by plasma chem profiles, cortisol, prostaglandin E2,  and various proinflammatory cytokine concentrations.

If it turns out the restriction of feed and water causes a significant amount of similar stress to transport, a discussion can open on new techniques in cattle transport that could potentially alleviate some of this stress. Thus, everyone wins, the cows are less stressed, and the industry loses less money dealing with cases of BRD.

You can read the full proposal here.

 

I’m ready to get over there and get into the thick of the work. I imagine I’ll learn tons more about the previous research carried out at the station that led to these current conclusions. Especially the stuff that hasn’t been published online yet. In addition to my article reviews, I’ll also post a few updates on what it’s like to work over there, and I’ll try to keep them somewhat interesting. There will probably be a gap between posts for a couple weeks while I get all situated (and finish a guest post for another blog). So check back here mid August.

Research: Incorporation of Sexed Semen into the 7‐day CO‐Synch + CIDR Estrous Synchronization Protocol

Sexed semen has the potential to completely change the industry. If pregnancy rates with altered semen continue to improve, we could see not only major efficiency upgrades in cattle production, but the reduction of many practices animal rights groups would like to see end. A great example is the veal industry, which is perpetuated not so much from a consumer demand for veal, but for a need to recuperate costs from unneeded male calves in the dairy industry. Being able to avoid the negative public image of producing veal calves by using sexed semen would be an appealing option for many milk producers. This proposal is exploring the financial benefit of using sexed semen in beef cattle production (in which weaned steers sell for 15% more than heifers).

The study will be simple, but with an awesome sample size of 450 cattle. We will synchronize estrus using a controlled intravaginal drug-releasing device (CIDR), along with other synchronization methods I need to do some more research to explain. For an overview of several CIDR methods you can look here. Serum concentrations of progesterone will be used to determine if normal estrous cycles are occurring, after which we will use standard AI techniques to inseminate the cows with either the sexed semen or the control semen.

When all is said and done, we will not only examine pregnancy rates, but the performance of the offspring in growth and carcass quality. The overall picture will provide the best financial perspective when examining the feasibility of using this technology in the future.

It’s a cool study, and I’m excited to see if the pregnancy rates with the sexed semen are high enough to start incorporating it into mainstream production. The large sample size is great because that makes the conclusions from this study have weight for producers that take financial risk in the future trying to incorporate sexed semen into their programs. Few studies examining sexed semen have had large enough sample sizes to validate their results. Additionally, this study is the first of its kind to examine a direct cost-benefit relationship of using the new technology in comparison to the established methods.

You can read the full proposal here.

Research: Effects of Bovine Somatotropin Treatment on Performance, Reproductive, and Physiological Responses of Replacement Beef Heifers

Oh yes, rBST (or BST, rBGH, “hormone injections”, “chemicals”, or any lay term the media can come up with), clearly the reason we are all getting cancer with every steak we eat and glass of milk we drink (second only to cell phone radiation and airport scanners). Animal science faces many of the same problems as food science. If the media can report on it and with scary images, all the while promoting ignorance of the processes of food production, then they will gladly jump on any and all practices in food production. This is super effective because everyone eats, and so we are sensitive to news that what we eat may harm us. I’ll discuss a little more about rBST use in Oregon, but fist I want to examine this proposal we’ll be examining at the EOARC.

The premise of the proposal is that in cow-calf operations, replacement heifers become less and less financially viable if they take longer to reach puberty, or miss their first breeding season. Previous research done at the EOARC has shown that higher IGF-1 (insulin like growth factor 1) concentrations are found in heifers that reach puberty by 12 months compared to non-pubertal heifers of the same age (Cooke et al., 2007). These levels are usually encouraged by using a high plane of nutrition; however, in eastern Oregon we generally run our cow-calf operations on poor forage because it’s economical, it’s what we have, and what we can take advantage of. The idea of the study then, is to see if rBST administration will result in higher IGF-1 levels which will hasten puberty compared to untreated cattle. Additionally, because the normal high plane of nutrition would also raise levels of insulin, blood glucose, and leptin which could also affect onset of puberty, this study will single out IGF-1 levels and determine if the absence of those other factors plays a role in puberty onset.

The procedures are pretty standard, so I won’t rewrite them all here, I’ll post the proposal below so you can read them yourself if you want to examine the methods. One thing I’m impressed by is the rotation of bulls between the treatment and control groups to account for bull effects. I’ve learned about estrus synchronization and other pheromone effects in repro, but the effects a specific bull might have are even more interesting. I wrote about one of these effects when looking at stallions kept on home pasture with pregnant mares a while ago, and was fascinated by the idea of spontaneous (or conscious!) abortion in the presence of specific stallions.

One thing I was a little concerned about is the sample size of the proposal. I’m told anything over 20 is considered viable, but you can’t really lock in any trends you may find with a sample size that small. This particular study will use 40 cattle, which makes the control and treatment groups composed of 20 animals. I think that we’ll still get good data, but that more research with more animals will be necessary to fortify the conclusions that come out of this study.

So that’s pretty much all I have for this one, it’s pretty straightforward. The only problem I have is that, while I support the use of rBST, the current trend is to abandon its use, which may end up making this research obsolete.

This needs to be said in any discussion about the hormone, and it isn’t said enough: the FDA has not found any significant effects resulting from the ingestion of milk from rBST treated cattle. It’s clever advertizing! And we as consumers have to start making the harder choices. We either have to start paying more for our food, or allow our farmers to use safe treatments to increase yields. We can’t have it both ways. I admire people who buy organic items because by purchasing them at a higher price they acknowledge that our agriculture industry needs to make money, and that the margins for small farms are incredibly slim. It’s the ones who want to limit the industry by preventing the use of tools that increase production, but still want to pay 2 dollars for a gallon of milk that make it harder and harder to strengthen the industry.

Coincidentally, this is why student fees and current national budget are so hard to set. No one ever wants to pay more, but we certainly can’t take away any of our provided services either. Something has to give there.

 

You can read the full research proposal here.

You can read a statement from the FDA on “rBST free” labeling here.

You can read a short statement (followed by a list of stores that sell rBST free milk) from the Oregon Physicians for Social Responsibility here. This group has worked hard to discourage use of rBST in small dairy’s across Oregon.