Bob Collier

Jennifer Dush Author

10/19/2018 Added

41 Plays

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Bob Collier talks about Frontiers in Thermal Biology of Cattle.

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[00:00:00.400]I'm Rick Stoll for those of you who don't know
[00:00:02.282]in animal science, biological systems engineering.
[00:00:07.510]And you might be wondering why I'm introducing
[00:00:10.229]Dr. Collier here, so I'll introduce it this way.
[00:00:15.590]I got to keep this short by the way.
[00:00:17.230]And let him introduce himself and his wife.
[00:00:22.510]When I was a PhD student at Michigan state back before
[00:00:26.290]many of you graduate students were probably born.
[00:00:29.480]Sorry about that.
[00:00:31.931]It's all good, I won't hold it against you.
[00:00:35.390]Do what you're supposed to do,
[00:00:37.160]and doing the literature reviews that I could.
[00:00:42.037]And my work was ventilation, and how ventilations
[00:00:47.050]mitigate heat stress in the gray panel.
[00:00:49.797]And as I'm going through if you're doing this,
[00:00:52.850]or as you did this you probably would recognize
[00:00:55.700]that there's probably a handful of names that keep
[00:00:57.560]popping up, over, and over, and over.
[00:00:59.640]And for me at that time it was Dr. Bob Collier,
[00:01:04.850]who's name kept popping up and the work
[00:01:07.183]that they were doing at the University of Florida
[00:01:09.660]back at that time was just obviously cutting edge.
[00:01:14.150]And so Dr. Collier's work focuses on environmental effects.
[00:01:20.340]Especially heat stress on gene function.
[00:01:23.470]And he began his career at the University of Florida.
[00:01:29.114]Then was hired by Masaito Company to be the director
[00:01:32.630]during the research program.
[00:01:35.106]Since 1999 he's been at the University of Arizona.
[00:01:39.320]Served as department head for awhile.
[00:01:41.086]Of the Animal Science department there.
[00:01:43.410]And now he's Professor Americus.
[00:01:45.640]And along the way he's taught anatomy and physiology
[00:01:51.424]of domestic animals, so he can relate to students obviously.
[00:01:54.689]And teaching as well as research.
[00:01:56.900]So with that I'll let you.
[00:01:58.300]Thank you.
[00:02:01.626]I want to thank the department and the students
[00:02:03.600]for the opportunity to talk to you today.
[00:02:08.124]The general topic area I'm gonna be talking about is
[00:02:11.581]frontiers of thermal biology.
[00:02:13.890]In order to get to the frontier
[00:02:16.160]we have to kind of go through the history of the field
[00:02:19.500]so you understand how these areas developed.
[00:02:26.378]Let's see if I can get this deal to advance.
[00:02:34.285]Hit the escape button.
[00:02:36.264]It's this arrow right?
[00:02:39.830]Do I just click it?
[00:02:45.710]I think you just hit the escape button.
[00:02:48.000]Didn't show, there we go.
[00:02:49.726]Oh I'm sorry.
[00:02:51.270]That's alright, I'll pop us to the slide.
[00:02:54.142]Yep, then you should be good to go.
[00:02:56.832]Okay good, so the topic areas
[00:02:59.910]that I wanna talk about.
[00:03:00.760]The progression of understanding, which is
[00:03:03.810]how we began the evolution of our thinking about
[00:03:09.950]animals interacting with the environment,
[00:03:12.110]especially in this case cattle.
[00:03:14.780]Which is kinda split into we first began to look at
[00:03:18.860]the impact of the environment on cattle.
[00:03:21.601]Then we realized that cattle were effecting the environment.
[00:03:24.750]So there was a component that we've added to this
[00:03:29.220]in the biology of our domestic animal industries.
[00:03:34.710]Then we'll talk about current and future trends.
[00:03:39.000]Just to put it in perspective
[00:03:40.360]you know we domesticated livestock about 8,000 BC.
[00:03:43.757]But we didn't start identifying breeds
[00:03:46.410]until about the 1500s.
[00:03:48.550]So a long time was in there where we didn't really
[00:03:51.950]pay much attention to what animals were doing.
[00:03:54.900]To just whether you owned one or not.
[00:03:57.541]And we really didn't think about starting to measure
[00:04:00.180]differences between animals
[00:04:01.778]and their production until the 1900s.
[00:04:05.740]So things have really progressed pretty rapidly after that.
[00:04:10.010]Around the 1940s with two major labs,
[00:04:16.890]the Brody Lab at Missouri, and the lab of
[00:04:26.000]Curt I can't remember his last name, but he wrote
[00:04:28.970]The Fire of Life.
[00:04:33.261]At the University of California Davis.
[00:04:36.320]I'll come back to those guys but they were the first
[00:04:39.700]to really establish factors that regulate metabolism.
[00:04:43.820]And then once we started looking at that we began to look at
[00:04:47.540]the impact of the environment on metabolism.
[00:04:50.670]And the controlled environment facilities built
[00:04:54.860]in the '50s were able to give us that kind of capacity.
[00:05:00.850]And then we really started moving into
[00:05:04.430]how do we reduce the effects
[00:05:06.380]of the thermal environment on production?
[00:05:09.320]Because we know if an environment
[00:05:12.310]is stressful it's gonna increase
[00:05:16.490]the maintenance cost of the animal.
[00:05:18.224]Which means it's altered the basal metabolism.
[00:05:21.176]And when you do that that cost
[00:05:22.990]has to be paid out of production.
[00:05:26.130]So the energy for milk and the energy for meat
[00:05:29.450]is reduced in order to support the increased
[00:05:32.420]basal metabolic rate required to meet the stress.
[00:05:35.860]So because we measured metabolism and we could
[00:05:39.570]accurately define how much was being diverted, we began
[00:05:43.143]to understand the value of the various cooling methods.
[00:05:47.340]Or warming.
[00:05:50.040]So that's where the heat stress indices abatement
[00:05:53.310]we've been working on since the '60s.
[00:05:56.620]And then climatology began in the '70s where
[00:05:59.490]we started to think our climate's changing
[00:06:03.670]and is this induced by activities of humans?
[00:06:10.956]And there's a lot of evidence to support that.
[00:06:16.917]And that's really not the topic of my talk today.
[00:06:20.680]But it is a part now.
[00:06:24.110]Reducing the carbon footprint of our ag industries
[00:06:28.400]is part of what we do in agriculture to meet the requirement
[00:06:35.228]to not have an adverse effect on the environment.
[00:06:39.710]So if you look at the origin of cattle
[00:06:43.479]there's basically three centers.
[00:06:49.300]The Bos Taurus cattle came out of the Fertile Crescent.
[00:06:53.950]And the Bos Indicus cattle in India.
[00:07:01.560]And there's another group called the Sanga that was
[00:07:05.640]really kind of a cross between you notice here the
[00:07:11.020]Bos Indicus and Bos Taurus, and these African Sanga cattle
[00:07:16.740]which were evolving to become heat tolerant
[00:07:20.440]are also considered a separate group.
[00:07:26.280]But the Bos Taurus cattle of course are the basis
[00:07:30.250]for the U.S. dairy industry.
[00:07:33.770]Are all Bos Taurus.
[00:07:36.030]There are some Bos Indicus breeds that are used
[00:07:38.770]for milk production, but they are not of any importance
[00:07:44.140]to the U.S. dairy industry.
[00:07:46.150]They are in some other dairy industries.
[00:07:48.860]Primarily Latin America and the Caribbean.
[00:07:52.690]As we'll as India, 'cause India's a lacto vegetarian culture
[00:07:59.570]Where they do not eat meat as a whole.
[00:08:02.820]But they do get their protein source with milk.
[00:08:06.820]Milk is a major product, source of protein in India.
[00:08:14.470]So there are a lot of obviously,
[00:08:16.450]a lot of Bos Indicus breeds there.
[00:08:19.970]Just wanna point out down here the cattle to the New World
[00:08:24.980]was about 500 years ago.
[00:08:28.280]Now once we started identifying breeds, around the 1500s
[00:08:36.310]we did this in many cases based on hair coat.
[00:08:41.750]Different breeds had different hair coat.
[00:08:45.000]So the coat characteristics
[00:08:48.300]often were an identifying component of a specific breed.
[00:08:53.932]But what we didn't know is that we were also selecting for
[00:08:58.540]differences in their interaction with the environment.
[00:09:01.330]Because the hair coat has a big effect on the ability
[00:09:06.000]of animals to be able to dissipate heat level.
[00:09:08.150]Especially evaporate heat levels.
[00:09:12.180]So these shaggy, these are Scottish cattle,
[00:09:16.480]obviously a shaggy hair coat is favorable
[00:09:19.150]in a cold environment, but it certainly
[00:09:20.780]isn't favorable in a hot environment.
[00:09:23.820]Especially in a hot, humid environment.
[00:09:27.550]So measuring metabolism in the '40s.
[00:09:31.888]Max Kleiber was the name I couldn't remember.
[00:09:35.530]But him and Samuel Brody were pioneers in this.
[00:09:38.690]And they both wrote books that everyone should read.
[00:09:44.730]I've got copies of Bioenergetics and Growth,
[00:09:47.740]which was Brody's book, and then Fire of Life:
[00:09:49.890]An Introduction to Animal Energetics, by Kleiber.
[00:09:53.560]They were contemporaries, they worked at the same time.
[00:09:57.320]And had a huge impact on our understanding
[00:10:01.990]on how basal metabolism is basically
[00:10:08.920]a component of body weight, and they have formulas
[00:10:12.720]if you know the body weight you could calculate
[00:10:15.240]not only the basal metabolic rate of an animal.
[00:10:17.617]But also it's surface area, and you could start
[00:10:20.680]to think about how much heat that you could move
[00:10:23.160]across that surface area based on the size of the gradient
[00:10:28.120]depending on the environment of the animal.
[00:10:29.850]So all of this came out of
[00:10:32.290]this pioneering work by these guys.
[00:10:34.900]And then a whole bunch of people contributed to
[00:10:40.220]the work that followed that, and some of these
[00:10:44.490]are listed below.
[00:10:46.410]Dennis Armstrong, and Frank Weirsma,
[00:10:48.200]who put together the first THI chart.
[00:10:52.320]Don Spiers at Missouri, John Gaughan who still works
[00:10:56.500]in Australia, at the University of Brisbane.
[00:10:59.420]Terry Mader here in Nebraska, on the beef side.
[00:11:04.050]And Leroy Hahn who I had the pleasure of interacting with
[00:11:07.860]here at a meeting this week.
[00:11:09.760]They've made very big contributions to this area.
[00:11:14.140]And we understand the factors that are important
[00:11:18.850]when calculating heat exchange.
[00:11:23.810]And basically a combined measure of the air temperature
[00:11:29.000]and of the humidity.
[00:11:32.890]The air temperature's important because three of the four
[00:11:36.050]routes of heat loss, conduction, conduction radiation,
[00:11:40.100]are sensible routes that require thermal gradients.
[00:11:43.670]So they go to zero when the air temperature
[00:11:46.520]or the environment is at the body temperature.
[00:11:50.020]Which in Arizona is about everyday.
[00:11:53.840]There leaves just one route of heat loss left,
[00:11:56.630]and that's evaporative, and that works
[00:11:58.480]under a vapor pressure gradient, that doesn't work
[00:12:00.810]on a temperature gradient.
[00:12:02.820]So relative humidity becomes important.
[00:12:04.580]And that's why the temperature humidity index
[00:12:08.480]is a pretty good way to evaluate the total effects
[00:12:10.620]of the environment on an animal.
[00:12:14.330]If you really want to take into account solar radiation,
[00:12:18.780]then you have to use what's called
[00:12:19.900]a black globe humidity index.
[00:12:22.030]See the air temperature is the temperature in the shade.
[00:12:25.580]It's the temperature of the air regardless of whether
[00:12:27.590]you're standing in the open, or standing in the shade.
[00:12:31.170]So if it's 100 degrees air temperature.
[00:12:34.260]That's a dry bulb thermometer, that means it's
[00:12:37.340]100 degrees under a shade, or 100 degrees out in the open,
[00:12:40.640]as far as air.
[00:12:41.890]But everyone knows that if you're standing in the open
[00:12:44.420]it's hotter.
[00:12:46.250]What you're feeling there
[00:12:47.690]is the infrared radiation from the sun.
[00:12:53.140]And dry bulb thermometers do not measure that.
[00:12:55.910]They can only measure the temperature of the air.
[00:12:58.770]So a black globe, which is really just
[00:13:02.254]a black, copper globe painted black
[00:13:06.308]will heat up relative to
[00:13:10.950]the amount of solar radiation it gets.
[00:13:13.630]And so the air temperature inside that black globe
[00:13:15.760]is a combined measure of solar radiation, air temperature,
[00:13:19.582]and also any cooling effects, the wind speed.
[00:13:23.650]So if you really wanna get a full evaluation
[00:13:27.590]of the heat load of animals in the sun you wanna use
[00:13:31.520]instead of just THI, you wanna use
[00:13:33.670]the black globe humidity index.
[00:13:35.730]Which gives you the full heat load on those animals.
[00:13:41.470]In Arizona we recently revised
[00:13:44.460]the temperature humidity index for lactating cows.
[00:13:47.980]The reason we did that is 'cause the original one
[00:13:50.090]was based on cows producing 15 kilos of milk a day,
[00:13:54.936]or 15 liters, about 35 pounds.
[00:13:58.150]Today's dairy cows are producing over 100 pounds of milk.
[00:14:02.694]At 15 liters a day cows are dried out.
[00:14:07.107]'Cause that's too low, so we use high producing cows.
[00:14:10.500]And the old THI, the threshold was around 72,
[00:14:16.560]and because of the heat associated with high production,
[00:14:22.980]that's been dropped down to 68.
[00:14:25.560]And we've also tried to tag in some other things
[00:14:29.753]that allow the producer to understand,
[00:14:34.300]one of them is respiration rate.
[00:14:38.860]Cattle respire in about 30, 40 breaths a minute
[00:14:41.630]under thermal neutral conditions.
[00:14:44.500]If they get to 60 breaths per minute,
[00:14:47.680]they are at the stress threshold.
[00:14:50.249]This is half maximal.
[00:14:52.510]It'll go to 120 breaths per minute
[00:14:55.010]at the maximal respiration rates.
[00:14:57.290]So for sometime now that Israeli's first started using it,
[00:15:01.910]but it's been adopted in the U.S. at 60 breaths per minute.
[00:15:05.370]When you look at THI of 68 for a lactating dairy cow,
[00:15:10.830]she's gonna get about 60 breaths per minute.
[00:15:13.920]And then it goes up from there.
[00:15:15.410]And then of course severe stress.
[00:15:18.997]That's a real problem.
[00:15:20.900]And you think animals could die of that, yes they will.
[00:15:25.308]In fact animals start dying at a relatively low THI.
[00:15:30.137]And that's been published by a group
[00:15:33.070]at the University of Tuscany.
[00:15:35.465]And they looked at the break point.
[00:15:37.640]You can see a minimum THI of only 70.
[00:15:40.840]And a maximum of THI of 80 they get a rapid increase
[00:15:44.220]in death rate, and where do you think
[00:15:46.930]most of those cows are dying?
[00:15:49.260]Anybody have a guess?
[00:15:52.910]Which cows are dying?
[00:15:55.340]Remember if stresses are additive, so if you have cows
[00:15:59.810]that have multiple stresses on 'em,
[00:16:02.165]where are those cows located?
[00:16:05.210]They're located in the sick barn,
[00:16:07.360]guess what you go to the average dairy,
[00:16:09.810]is there any cooling in the sick barn?
[00:16:11.580]Nope.
[00:16:12.850]Most dairies don't provide any cooling in the sick barn.
[00:16:16.060]Which is exactly the animals that need it the most.
[00:16:18.570]Because it's really an understanding when the stressors
[00:16:21.320]are additive, you got a cow that's got neutritis,
[00:16:23.982]stressitis, and she's off feed, 'cause maybe
[00:16:27.020]she's ketotic, and then you subject her to heat stress,
[00:16:32.650]that's the cow that's likely to die.
[00:16:35.000]And they confirmed that with this study.
[00:16:38.620]So we need to pay more attention, this is an area
[00:16:40.680]that needs a lot of work on protecting those animals
[00:16:44.470]that are most susceptible.
[00:16:47.441]A dairy cow's worth about $2,000.
[00:16:49.830]So it's not a lot of coolant for $2,000.
[00:16:54.758]I was in California in 2006
[00:16:56.163]when they had that 10 day heat wave and it cost
[00:16:58.927]the dairy industry in California a billion dollars
[00:17:01.490]for 10 days.
[00:17:03.240]And these dairy farmers would say well we can't justify
[00:17:05.920]spending that kind of money to cool animals.
[00:17:09.095]And I said, you could've cooled
[00:17:11.020]every dairy cow in California for a billion dollars.
[00:17:15.310]Pretty effectively, so it's all relative.
[00:17:20.271]The thing we have to worry about with climate change
[00:17:23.260]is not so much the average, but these rare events
[00:17:27.580]that become more severe.
[00:17:30.620]And are occurring more often.
[00:17:33.374]We have those like a 10 day period of extreme heat stress,
[00:17:37.950]on an industry that's not prepared for it,
[00:17:40.590]can basically wipe out that industry.
[00:17:43.020]And so that's the kind of thing
[00:17:45.380]we have to be concerned about.
[00:17:47.270]Heat abatement strategies.
[00:17:48.700]You wanna minimize heat gain, and you wanna
[00:17:50.780]maximize heat loss, and so we do these things
[00:17:54.460]like reduce air temperature.
[00:17:56.430]Provide shade, which is the cheapest form of protection.
[00:18:00.129]And then we want to allow animals to conduct
[00:18:04.660]heat away if we can, use forced convection.
[00:18:07.870]We wet cows to evaporate water from them.
[00:18:10.920]And we actually use evaporative coolant
[00:18:12.100]to drop the air temperature.
[00:18:14.470]All of this is designed to put the gradient back
[00:18:19.800]so the cows can move the heat out.
[00:18:21.955]When the air temperature is at the body temperature
[00:18:25.080]of the animal, the heat cannot flow out of the cow.
[00:18:27.890]It's actually gonna reverse and start flowing
[00:18:30.950]into the cow, and she's also producing a lot of heat.
[00:18:36.500]But so we have these fairly advanced
[00:18:39.140]cooling systems in Arizona.
[00:18:42.480]Just behaviorally I can tell you those cows are cool.
[00:18:46.240]And the reason you know that
[00:18:47.280]is 'cause they're all lying down.
[00:18:49.480]If an animal's heat stressed it has to stand up
[00:18:51.900]because once it starts breathing about 60 breaths per minute
[00:18:56.280]it can't do that lying down.
[00:18:57.610]It has to get up on it's feet.
[00:18:59.397]And it just rocks back and forth.
[00:19:01.850]So those cows are cool, I can tell that just by
[00:19:05.710]one look at 'em, and you can see the other thing
[00:19:09.740]is they'd be ruminating.
[00:19:12.530]Which they don't do if they're heat stressed.
[00:19:15.000]You look at respiration rate, if they're below
[00:19:18.210]60 breaths per minute, they're doing okay.
[00:19:22.217]But these systems are expensive, capital wise.
[00:19:28.050]The crop tool, this reverse chimney which is pulling air
[00:19:30.790]and mixing it with water at various fan speeds,
[00:19:33.800]but we'll go through 200 gallons per cow per day.
[00:19:37.710]And we're essentially near water rationing in Arizona
[00:19:42.780]'cause Lake Powell only has to drop like two more feet.
[00:19:45.690]And they're gonna institute water rationing.
[00:19:47.970]So we have to start coming up with systems that are passive.
[00:19:54.090]That don't require large amounts of water.
[00:19:56.570]And large amounts of electricity to assist in
[00:20:00.140]that scenario that is a frontier.
[00:20:03.070]We need new engineering to passively cool
[00:20:06.810]confinement animal operations.
[00:20:09.358]Because the cost of water and the cost of electricity
[00:20:12.160]keeps rising, if you can't even get it,
[00:20:17.120]obviously you're in big trouble.
[00:20:19.720]The concept of homeorhesis was developed by
[00:20:21.640]Bauman and Currie in 1980.
[00:20:23.813]Also plays into our understanding of animals
[00:20:28.670]in the environment because when animals undergo
[00:20:32.950]acclimatization or adaptation, two stressors
[00:20:37.720]of the process is homeorhetic.
[00:20:41.137]In other words metabolism is coordinated
[00:20:44.160]to support a new physiological state.
[00:20:46.420]And so if you look at acclimatization and homeorhesis
[00:20:52.340]why physiologist published in 1976 that
[00:20:56.210]when animals are acclimatized they have
[00:20:57.994]intracellular biochemical, biophysical changes,
[00:21:01.260]it's chronic.
[00:21:02.093]It takes weeks or months to establish.
[00:21:05.820]It's not homeostatic so it's not minute to minute.
[00:21:09.484]But there's a hormonal link in the pathway from
[00:21:11.350]the central nervous system to the effector cells.
[00:21:14.610]Which are multiple organs throughout the body.
[00:21:17.890]And it enhances the ability of the effector cell
[00:21:20.320]to respond to the disturbance.
[00:21:22.600]But basically Gail Bauman has been continuing
[00:21:26.170]his characterization of homeorhesis and acclimatization
[00:21:32.860]as squarely inside that process.
[00:21:36.057]So it's a homeorhetic process.
[00:21:39.200]Which means basically you change, the response
[00:21:44.700]of tissues to homeostatic signals.
[00:21:47.240]The one example would be, response to insulin.
[00:21:50.780]Response to epinephrin, is altered
[00:21:53.610]in the acclimatized animal.
[00:21:55.920]And so this is an area that's still
[00:22:00.200]being actively investigated.
[00:22:02.417]And the person there would be, and example would be
[00:22:05.480]Lance Vonguard's work looking at energy metabolism
[00:22:10.110]in the heat stressed animal.
[00:22:12.620]Heat stress carryover effects.
[00:22:16.510]When I was at Florida I was looking at this
[00:22:20.580]pattern of season in milk yield.
[00:22:25.440]Everybody knew there was a seasonal trend in milk yield,
[00:22:27.600]and in composition.
[00:22:30.510]But the yield curve if you look here, which is in red.
[00:22:35.490]Bottoms out here in September/October and the
[00:22:37.610]composition curve really bottomed out in July/August.
[00:22:42.640]This is peak temperature here,
[00:22:44.770]so it's actually cooling off here.
[00:22:48.304]Well if this is direct effect of heat stress on milk yield
[00:22:51.040]why would it be September/October when it's
[00:22:55.650]at its lowest point?
[00:22:57.420]And we looked at the birth weight pattern,
[00:23:00.720]and this is from 1,000 calves born at
[00:23:04.660]the University of Florida Dairy Research Unit
[00:23:08.010]over a 20 year period.
[00:23:09.777]And there was a pronounced 10 pound range in birth weight.
[00:23:14.520]So there is a relationship between the placenta
[00:23:17.307]and the mammary gland as far as
[00:23:19.910]the development of the mammary glands,
[00:23:21.190]controlling the placenta during pregnancy.
[00:23:23.910]There's also a relationship
[00:23:24.980]between the placenta and birth weight.
[00:23:27.640]When animals are heat stressed during late gestation
[00:23:31.340]they have lower birth weight calves.
[00:23:34.610]And the placenta is also reduced in size.
[00:23:38.430]We did a study we published in '82, over here the first one.
[00:23:42.890]Showing that if you just provided shade,
[00:23:46.350]that's all we did, is provide shade, to dry cows
[00:23:49.333]because at that time producers aborted
[00:23:52.530]and put their dry cows in an open pasture
[00:23:54.660]because they weren't producing milk,
[00:23:57.160]they didn't need protection they thought.
[00:23:59.993]And so they didn't provide anything for 'em.
[00:24:02.720]Other than a porch.
[00:24:06.180]So just providing shade we could show a measurable increase
[00:24:08.650]in birth weight and milk yield postpartum.
[00:24:11.850]Since then this is Wolfonson at Hebrew University.
[00:24:17.510]This is a study in Mexico.
[00:24:19.670]Then there's a bunch of 'em at Florida.
[00:24:23.100]And the more cooling you provide the bigger the difference.
[00:24:27.610]So now cow in 2012 published we got 3,000 pounds
[00:24:32.360]of additional milk in the next lactation
[00:24:35.770]by not only providing shade
[00:24:37.810]but also fans and misters to cool dry cows.
[00:24:42.210]So protecting the dry cow has big carryover effects
[00:24:46.410]in the next lactation.
[00:24:50.800]There's another new faculty member there
[00:24:53.230]who's working on the impacts on the fetus
[00:24:57.550]and carryover effects on its life.
[00:24:59.670]And she's been able to demonstrate
[00:25:01.610]reduced production in the calves that are born
[00:25:05.460]from heat stressed mothers.
[00:25:07.640]So this is an area that's going to continue
[00:25:11.140]to be investigated.
[00:25:13.440]And the the main hypothesis we have developed was that
[00:25:21.120]there was an association between placental and fetal weight
[00:25:25.520]and the association between
[00:25:26.710]placental, fetal, and mammary growth.
[00:25:32.578]And recently the Limesand Lab at Arizona developed a model
[00:25:37.250]where they can alter fetal catecholamines
[00:25:40.290]produced during gestation.
[00:25:43.750]And we have been able to demonstrate that that does affect
[00:25:49.240]mammary growth, and his model is he comes in,
[00:25:52.479]this just shows that the inner uterine growth retarded fetus
[00:25:57.050]which is the dashed line.
[00:25:59.990]You can see that from mid gestation on
[00:26:03.120]if you heat stress in this period
[00:26:08.120]you'll reduce the placenta which subsequently leads to
[00:26:11.070]reduced vasculature in the placenta and also reduced
[00:26:16.460]growth of the fetus.
[00:26:18.047]But not shown here is the mammary gland growth
[00:26:20.470]which is occurring over here, is also negatively impacted.
[00:26:25.540]So Shawn has developed a way to actually remove the adrenal
[00:26:31.360]from the fetus, and the sheep is unique in that you can
[00:26:34.760]actually take the fetus out during gestation,
[00:26:38.600]surgically manipulate it, put it back in the uterus
[00:26:41.212]and it won't abort, every other domestic animal will do that
[00:26:44.667]and the reason is the placenta is a primary source
[00:26:48.510]of progesterone from mid pregnancy on for the sheep.
[00:26:54.140]In the cow, in a horse, in a pig, it's still the ovary.
[00:26:58.390]So if you open up the uterus you get
[00:27:01.860]prostaglandins being produced.
[00:27:04.140]Which is trying to create an exchange between
[00:27:07.240]the ovary and the uterus, it knocks out the CO,
[00:27:12.720]so the animal is gonna abort eight days later.
[00:27:16.230]Bill Thatcher, probably did a couple 100 animals
[00:27:20.200]trying to figure a way to use a dairy cow
[00:27:23.250]and never found a way to do it.
[00:27:24.810]Because animals always abort.
[00:27:27.080]But the sheep is great model for this.
[00:27:30.330]So we know that heat stress during gestation reduces
[00:27:33.890]placental and fetal memory development.
[00:27:36.170]And then if de-medulate, and I know I'm trying to go
[00:27:40.330]through all that data that he's still collecting,
[00:27:42.870]but we can demonstrate, and you can restore
[00:27:44.690]mammary development in the mother by de-medullating,
[00:27:51.160]taking the catecholamine producing tissue out of the adrenal
[00:27:55.382]at mid the gestation and the sheep to use.
[00:27:58.630]So that appears to be one of the primary signals
[00:28:01.660]in reducing mammary growth.
[00:28:05.350]But there's still a lot of work to be done in that area.
[00:28:09.220]So the impact of cow on the environment, Don Johnson
[00:28:13.820]in Colorado, and Jude Capper and Dale Bauman at Cornell
[00:28:19.060]really got to work on this in the '80s.
[00:28:21.452]And really began to document
[00:28:24.460]what's been going on in the U.S.
[00:28:28.320]I like to use this slide because this is actually
[00:28:30.880]for all of agriculture, it doesn't matter
[00:28:32.580]what industry you talk about.
[00:28:34.552]Whether it's the beef industry, the diary industry,
[00:28:37.160]corn, wheat production, we for the last 50 years,
[00:28:42.900]have been increasing output while holding input costs
[00:28:46.290]basically the same or even lower.
[00:28:48.560]And so this has resulted in huge increases
[00:28:50.870]in agricultural productivity.
[00:28:53.860]So how does that play out in the dairy industry?
[00:28:57.870]We have reduced the carbon footprint
[00:28:59.890]of a gallon of milk by 2/3 since 1944.
[00:29:05.050]So the environmental impact of the dairy industry
[00:29:09.510]has been dramatically reduced.
[00:29:11.520]In all of agriculture we've seen the same kinds of trends.
[00:29:16.030]Which is really a lot of people don't understand
[00:29:18.740]how this was done.
[00:29:20.530]But practically here's the numbers.
[00:29:23.460]In 1944 we had 25 million dairy cows.
[00:29:27.690]Today we have 8.7 million dairy cows
[00:29:31.440]producing more milk than the 25 million cows did in 1944.
[00:29:37.110]So we're not feeding all those extra cows with all their
[00:29:40.089]basal metabolic rate cost.
[00:29:43.100]All of that food is going to another part
[00:29:45.260]of the ag industry, of our agriculture rather,
[00:29:49.420]and it increases profitability for the dairy producer.
[00:29:53.290]It lowers the cost of goods
[00:29:55.410]at the marketplace for a consumer.
[00:29:58.560]So practically you know in the U.S. we spend
[00:30:01.650]about nine cents out of every dollar for food.
[00:30:04.140]In Europe it's 20 cents, in Africa it's about 75 cents.
[00:30:09.030]Now if you were paying 75 cents out of every dollar you made
[00:30:12.760]to put food on your table, you wouldn't be sitting here.
[00:30:16.267]You wouldn't be in this classroom 'cause you wouldn't
[00:30:18.050]have the kind of money, additional money to do it.
[00:30:24.810]A cheap source of food is often
[00:30:28.060]unappreciated in this country.
[00:30:30.187]But it has great benefits for society.
[00:30:34.630]I go to Pakistan and this is something
[00:30:38.811]that I experienced firsthand in Pakistan.
[00:30:42.390]They've got about a tenth of the land mass of the U.S.
[00:30:45.840]They got about half the number of people that we do
[00:30:48.770]on that one tenth of land mass.
[00:30:51.160]But they have 45 million water buffaloes,
[00:30:54.070]38 million dairy cows, and they only produce
[00:30:58.430]29 million tons of volume.
[00:31:00.987]So we have 8.455 million dairy cows,
[00:31:06.060]196 million tons of milk.
[00:31:08.700]We're exporting milk and hay.
[00:31:11.730]In Pakistan there's chronically a shortage of milk
[00:31:16.100]and there's always a shortage of forage,
[00:31:18.760]'cause they're feeding too many animals
[00:31:21.440]to get a very low amount of milk.
[00:31:23.690]That's it in a basket.
[00:31:26.250]When you increase efficiency, you can get rid of,
[00:31:30.478]in the long run they should be able to get rid of
[00:31:32.570]half of the water buffalo and produce more milk
[00:31:36.680]than they're producing now.
[00:31:38.610]And they would not be short of milk
[00:31:40.280]and they won't be short of forage.
[00:31:42.620]But they have to institute the kind of
[00:31:45.396]agricultural practices that allow you to do that.
[00:31:48.520]Including improved genetic selection.
[00:31:52.380]Okay, so in vitro models came into play about in the 1980s.
[00:31:57.510]And I've got one example.
[00:31:58.910]We built, this is mammary epithelial cells.
[00:32:02.180]You can grow ecology gels, and grow three dimensions.
[00:32:05.910]And you can get those to undergo lacto genesis
[00:32:10.760]if you change the hormonal complex the ends of those ducts
[00:32:14.130]will develop into little bulbs and then they'll
[00:32:15.743]blow up into balloons as they start to secrete milk.
[00:32:19.670]So it's way to study factors regulating milk synthesis.
[00:32:25.895]But you can also look at heat stress effects.
[00:32:27.987]And on the top here these are different cultures
[00:32:32.440]but this is what you see in a ductile tree
[00:32:35.180]after about seven days in thermal neutral.
[00:32:37.900]24 hours of heat shock and this is what is happening.
[00:32:41.920]The cytoskeleton has collapsed.
[00:32:44.050]The cytoskeleton is made up of small, small proteins
[00:32:49.327]and there's a class of heat shock proteins
[00:32:51.640]that protect those structures.
[00:32:54.600]And this is basically what happens
[00:32:56.510]when the cytoskeleton collapses.
[00:32:59.930]The embryo is exquisitely sensitive to heat stress
[00:33:05.330]for this reason because if the cytoskeleton
[00:33:08.140]is collapsing on a developing embryo the cells
[00:33:11.540]are not in the right place at the right time.
[00:33:13.320]And so you know if you've ever taken embryotic development
[00:33:16.400]you know that's critical.
[00:33:18.040]Cells have to be in an exact location at a specific time
[00:33:21.620]in order for normal and embryogenesis to occur.
[00:33:25.194]So if this is going on you know the developing embryo
[00:33:30.910]is not gonna make it.
[00:33:32.750]So cells that can up regulate and maintain
[00:33:38.460]a high expression of heat shock proteins are considered
[00:33:41.300]thermal tolerant and those that cannot
[00:33:46.420]have lost their thermal tolerance
[00:33:47.980]and they're in the process of dying.
[00:33:50.646]And this just shows when we looked at
[00:33:52.310]heat shock protein gene expression,
[00:33:55.106]it's only about four hours before at 42 degrees centigrade
[00:33:59.430]the cells lose their ability.
[00:34:01.880]And you can extend this with certain molecules.
[00:34:05.037]I don't really have time go through it,
[00:34:06.477]but it can be extended.
[00:34:08.640]But the important thing is that thermal tolerance
[00:34:12.200]in a normal developing mammary cell only lasts for about
[00:34:16.770]four hours at that temperature.
[00:34:19.260]Well if you think about temperatures that dairy cows
[00:34:22.610]go through, they go to those temperatures
[00:34:25.030]every day in Arizona.
[00:34:27.061]And the mammary gland because of its metabolic rate
[00:34:30.520]has got more heat being produced there
[00:34:32.980]than other parts of the body.
[00:34:35.430]So an active area of investigation is how are those cells
[00:34:42.370]able to withstand that kind of stress and not die.
[00:34:48.110]We looked at gene expression at these time periods
[00:34:51.833]to see what's going on.
[00:34:53.020]And what we found, this is a Venn diagram
[00:34:56.440]showing the different pathways
[00:34:59.090]that were up and down regulated at two, four,
[00:35:03.367]and eight, and 16 hours.
[00:35:06.073]I keep wanting to use my finger to point it,
[00:35:08.233]instead of the pointer.
[00:35:11.430]So in the first two hours DNA repair is going on
[00:35:15.700]and there's a lot of transport secretion.
[00:35:18.872]I think one of the things that's being transported out
[00:35:21.460]are secreted heat shock proteins
[00:35:24.660]because these act as signaling to other cell types
[00:35:27.380]to indicate there's a major stress occurring.
[00:35:33.493]Then at four hours we see protein repair,
[00:35:37.465]up regulation of heat stress proteins.
[00:35:40.830]Cell cycle arrest proteins start going up.
[00:35:44.520]Down regulating transcription glycolysis,
[00:35:47.960]branching morphogenesis, that's the names
[00:35:51.710]that are associated with the structure being built
[00:35:55.720]as ducts grow, and then differentiations.
[00:36:00.430]And then the last, the cell death cycle by 16 hours
[00:36:05.010]they've already started going into
[00:36:06.470]the what's called apoptosis or cell death.
[00:36:10.390]And you're down regulating everything associated with
[00:36:14.460]the ability of withstanding stress.
[00:36:18.280]So up regulated genes, or ones that we looked at.
[00:36:23.227]And it turns out that several of these pathways
[00:36:25.350]they've looked up in these genome-wide association studies
[00:36:29.860]they've looked at heat tolerant cattle
[00:36:31.500]and less tolerant cattle
[00:36:33.830]a lot of these pathways are identical.
[00:36:36.757]And so the cellular story is matching up pretty well
[00:36:40.490]with the whole animal story.
[00:36:43.090]And we also looked at down regulated genes
[00:36:48.870]because maybe down regulation is more important
[00:36:51.050]than up regulation, I'm not sure?
[00:36:53.820]We do see a lot of things going on to shut down metabolism
[00:36:59.250]and develop the cytoskeleton, the synaptic protein
[00:37:02.960]are also down regulated.
[00:37:05.600]So how much of the milk yield loss
[00:37:07.800]that we get at heat stress, how much of that is actually
[00:37:12.220]direct effects of themselves?
[00:37:14.690]We know from Lance's work that only about half of it
[00:37:18.361]can be assigned to direct effects.
[00:37:20.867]And the other half is associated intake.
[00:37:26.740]One of the things that Lance found was that
[00:37:33.200]fatty acid metabolism was not an energy source
[00:37:36.610]in heat the stressed cow even though it was
[00:37:39.350]a negative energy balance.
[00:37:41.250]See typically when animals are at negative energy balance
[00:37:44.640]they start mobilizing lipids to burn as a fuel source.
[00:37:50.480]That doesn't happen in a heat stressed cow.
[00:37:52.350]Lance was the first to show that.
[00:37:54.390]Also glucose uptake is increased in heat stressed animals.
[00:38:02.550]We can show these same effects at the cellular level.
[00:38:04.860]So basically what we're showing at the cell
[00:38:07.990]is what he was able to show systemically in all animals.
[00:38:12.960]And so he's shown that this is turned off
[00:38:19.257]because he believes it's because insulin secretion remains
[00:38:26.590]relatively elevated, because more insulin's secreted.
[00:38:31.350]And that prevents adipose tissue from mobilizing
[00:38:35.800]non-esterified fatty acids.
[00:38:38.260]But this is still an active area of investigation.
[00:38:43.490]So this is another frontier,
[00:38:45.500]the intermediary metabolism in the heat stressed animal.
[00:38:49.210]And how that's integrated between the systemic
[00:38:51.550]and cellular components.
[00:38:55.600]Okay, now I mentioned you know three of the four routes
[00:38:58.820]of heat loss are sensible and they come to zero here
[00:39:04.050]at body temperature and the only thing left
[00:39:06.790]for the animal is adaptive heat loss,
[00:39:09.820]and that's why animals pant.
[00:39:12.340]These ruminants up.
[00:39:15.090]And they do sweat but they really
[00:39:18.080]don't do a very good job of it.
[00:39:20.170]And unfortunately in Arizona this is where dairy cows
[00:39:23.480]spend most of their time, right here.
[00:39:26.640]With this being the only route
[00:39:27.760]of available heat loss to 'em.
[00:39:31.141]When you look at surface temperature and rectal temperature
[00:39:38.040]you can see that animals can hold
[00:39:39.640]their rectal temperature constant till they get to about
[00:39:42.210]35 degrees centigrade surface temperature,
[00:39:46.610]then they start storing heat.
[00:39:49.440]They just can't dissipate it if the gradient is not there.
[00:39:53.160]So this is another measure I did when I tell producers
[00:39:58.250]he says how can I assess heat stress in my animal?
[00:40:00.420]And I said get an infrared gun,
[00:40:02.870]walk around your barn you don't even
[00:40:04.400]have to be within 10 feet, you can take an infrared
[00:40:08.130]surface temperature, if it's above 35
[00:40:11.600]those animals are getting hot.
[00:40:13.920]If the respiration rate's above 60,
[00:40:16.050]those animals are getting hot.
[00:40:18.090]So you don't have to touch an animal to really understand
[00:40:21.227]whether it's being heat stressed.
[00:40:23.870]We look at the sweating rate, the dairy cows,
[00:40:26.380]it's highly variable, there's a lot of genetic differences
[00:40:29.040]between animals and sweating rate.
[00:40:31.070]And this is that 35 degree breakpoint.
[00:40:34.570]And you know some animals hardly change their
[00:40:36.230]sweating rate at all some do a really good job of it.
[00:40:39.980]But, as a group that's pretty low.
[00:40:44.130]You're looking at grams per meter squared as around
[00:40:48.420]200 would be maximum.
[00:40:51.500]How does that compare to other animals?
[00:40:54.840]The champion sweater in animal kingdom is the horse.
[00:40:58.270]A horse can move three liters per square meter
[00:41:01.870]at peak sweating rates.
[00:41:03.930]Humans it's about half that, we're pretty good sweaters.
[00:41:07.899]A dairy cow's only 200 and no liters,
[00:41:13.025]with the very same sweat gland the horse has.
[00:41:16.320]A horse has a apocrine sweat gland just like the dairy cow.
[00:41:19.290]But it's able to move three liters, a dairy cow can
[00:41:23.020]just move 200 mils.
[00:41:24.930]If a dairy cow could sweat like a horse we would be able
[00:41:29.410]to really improve their thermal tolerance.
[00:41:33.160]And it wouldn't require messing with metabolism.
[00:41:37.475]It wouldn't require some of the things
[00:41:39.600]that people are talking about trying to achieve.
[00:41:42.430]Like up regulated heat shock proteins permanently.
[00:41:46.270]That's got some real high risk issues like cancer
[00:41:49.505]and immune issues.
[00:41:51.530]'Cause heat shock proteins also are involved
[00:41:54.860]in regulation of the immune system.
[00:41:57.430]So if we could just improve evaporate heat loss
[00:42:01.170]in dairy cows it would be a huge thing.
[00:42:04.901]So looking at the apocrine sweat gland
[00:42:06.933]there's one associated with each hair follicle
[00:42:10.710]and this should be thought of as a single unit.
[00:42:13.130]The hair follicle and the sweat gland.
[00:42:16.210]Because the hair fiber dictates how much
[00:42:20.270]sweat can be evaporated.
[00:42:22.760]So you can you can alter what's called sweating rate.
[00:42:26.220]It's really just altering evaporation rate
[00:42:28.470]by but changing the hair coat.
[00:42:30.551]You can also alter the activity of these cells.
[00:42:36.570]The secretory cells, and you could dramatically alter
[00:42:40.890]cooling activity.
[00:42:43.750]And how it gets to the surface is through
[00:42:46.051]contraction of myoepithelial cells
[00:42:48.360]just like the mammary gland.
[00:42:49.600]'Cause the mammary gland's a skin gland.
[00:42:52.970]And so is the sweat gland.
[00:42:55.080]So if we can get cows to produce 150 pounds of milk a day
[00:42:59.100]we can get cows to sweat 3 liters a day, I believe.
[00:43:03.340]Because it's very similar cell types.
[00:43:09.410]I did studies with Peter Hellman and Keith Lake
[00:43:13.110]at Cornell and Tim Lee at the University White,
[00:43:19.350]we did look at hair coat characteristics,
[00:43:22.400]sweating rate and airflow.
[00:43:24.630]And basically can show you that
[00:43:29.386]you can have some big impacts.
[00:43:32.840]Of course the color the hair coat makes a difference,
[00:43:34.816]this was all done in full sun.
[00:43:37.580]You can see the sweating rate was maximal
[00:43:40.870]with one meter per second of wind speed
[00:43:45.320]on a shaved hair coat.
[00:43:47.550]So we took away the hair factor to improve evaporation.
[00:43:53.810]And we got to 600.
[00:43:56.800]That's a fairly big increase, basically 200.
[00:44:00.093]You're tripling the heat loss from the animal.
[00:44:04.160]So if you didn't have time,
[00:44:06.380]I've advised some people to do this.
[00:44:07.770]Over the dairy at Bangkok that
[00:44:10.450]donated a big ship of the heifers from the U.S.,
[00:44:13.820]Wisconsin I believe.
[00:44:14.830]And they all had weird hair coats,
[00:44:16.820]and they were going to be calving in about 30 days,
[00:44:19.690]and they asked me what can we do
[00:44:22.080]to get them ready for the heat, when they calf?
[00:44:24.600]And I said shave 'em, shave everyone of 'em.
[00:44:27.407]And they did
[00:44:28.240]and they all they came in without problems
[00:44:30.840]because they were able to
[00:44:31.760]effectively get rid of their heat loads.
[00:44:35.320]So black is higher than white because
[00:44:38.010]the black hair coat's about 5 degrees centigrade hotter
[00:44:40.640]in the sun, which increases vapor pressure.
[00:44:44.320]Which means you evaporate more water.
[00:44:47.080]It's not an advantage because the black hair coat
[00:44:48.767]absorbs more heat, the animal gets hotter.
[00:44:54.150]So the white hair coat's preferred
[00:44:57.210]because you absorb less heat in the sun.
[00:45:01.860]This is a slick hair coat,
[00:45:03.820]how many people have heard of the slick gene?
[00:45:05.830]Anybody?
[00:45:06.663]Okay, a few of you have.
[00:45:08.000]The slick gene all it is is a mutation
[00:45:10.140]in the prolactin receptor which changes the hair follicle.
[00:45:15.120]It changes the type of hair produced by that follicle
[00:45:17.623]to make it a very short, smooth.
[00:45:20.530]You can see how much this glistens here,
[00:45:24.090]and you'll notice also you can see pigmented skin
[00:45:27.420]under the hair coat, and the other looks like
[00:45:30.290]it's been shaved, it hasn't been shaved.
[00:45:32.620]It's just they way it looks.
[00:45:34.840]This animal is about a degree centigrade cooler
[00:45:36.910]than one next to it.
[00:45:38.790]And all they did, they didn't modify
[00:45:41.380]the activity of the sweat gland, they changed the hair coat.
[00:45:45.620]Now the trouble with this is prolactin's
[00:45:47.870]a fairly important hormone from a reproduction standpoint.
[00:45:51.890]Homozygous animals don't appear,
[00:45:55.600]it appears to be a lethal.
[00:45:57.540]You gotta be heterozygous to have the advantage
[00:46:01.980]and still be able to reproduce.
[00:46:04.500]So it's a challenge.
[00:46:07.900]So we started, developed a method
[00:46:11.100]for isolating sweat glands.
[00:46:13.820]This is in situ, this is a sweat gland you can see.
[00:46:17.060]There's two cell types here.
[00:46:19.380]The green is the epithelial cells which secrete sweat
[00:46:23.700]and the red are the myoepithelial cells
[00:46:25.750]that contract and squeeze the sweat up to the surface.
[00:46:29.880]These are isolated and you can see we've disrupted
[00:46:32.730]some of that interaction.
[00:46:34.823]But these are myoepithelial cells
[00:46:36.609]and these are epithelial cells.
[00:46:41.070]It turns out sweat glands take up neutral red
[00:46:43.400]which is really advantageous 'cause you can't see 'em
[00:46:46.240]when you first start working up skin to find sweat glands,
[00:46:50.250]you can't even see 'em.
[00:46:52.269]But when they take up this neutral red
[00:46:53.293]they're pretty easily defined, especially
[00:46:56.410]after you've collagenase digested,
[00:47:00.040]and use a purple gradient that's separating out the layers.
[00:47:04.850]You'll see a red band that's loaded with these glands.
[00:47:08.490]We then take those and we have done a workup on receptors,
[00:47:15.040]we got serotonin receptors.
[00:47:17.460]Several important members of the serotonin receptor subtype.
[00:47:22.850]Only the short form of the prolactin receptor is present.
[00:47:26.490]And the growth hormone receptor is present.
[00:47:31.470]And we had done a study when
[00:47:33.610]I was at Monsanto in Missouri showing that
[00:47:36.390]we've got a very fairly big increase in sweating rate
[00:47:39.310]when we gave animals growth hormone.
[00:47:41.730]So growth hormone is a molecule
[00:47:44.450]that does regulate sweat gland function.
[00:47:47.160]And the last one is education perception.
[00:47:50.430]So there's there's a lot of future research here
[00:47:54.780]that needs to be done and hopefully someone
[00:47:59.160]will take the opportunity to find which ones
[00:48:02.100]are really regulating sweat gland activity,
[00:48:05.050]and getting that sweat to the surface.
[00:48:08.110]And how can we help cows stay cooler in the heat?
[00:48:12.527]So this is what needs to be done.
[00:48:15.859]We need to identify the factors
[00:48:17.042]regulating the sweating rate.
[00:48:18.430]Both in horses and cattle, so we can find out
[00:48:20.560]why the horse have evolved.
[00:48:23.720]Then we need that to start measuring evaporate heat loss
[00:48:26.690]which very few people do.
[00:48:28.540]But it should become a tool for genetic selection,
[00:48:32.520]we need to add it to our component of markers
[00:48:37.790]and phenotypic data.
[00:48:40.270]Okay, so all these things like
[00:48:43.442]the genome wide association studies.
[00:48:45.930]And metabolimics, passive forms of cooling,
[00:48:50.900]gene insertion, cloning,
[00:48:53.370]all of those became possible
[00:48:54.860]after the bovine genome was published.
[00:48:57.690]And now the porcine genome, the agean genome.
[00:49:00.820]These are all available and we could really start working on
[00:49:04.910]improving thermal tolerance
[00:49:07.280]of these domestic animal species.
[00:49:10.950]And what I see in the future is we're gonna take advantage
[00:49:14.395]of genomics to improve the animal.
[00:49:17.300]But we're also going to use things like,
[00:49:19.916]I didn't have time to go through it.
[00:49:20.880]But passive cooling like just providing water exchange,
[00:49:24.920]coolers underneath, sand beds, effectively cools animals.
[00:49:30.040]They can transfer heat to their bed that they're lying on.
[00:49:34.860]And when you combine that with convection
[00:49:38.150]and evaporation you can improve
[00:49:40.470]the productivity of these animals.
[00:49:42.660]Nice thing about this form of cooling
[00:49:44.550]as you don't use any water, that's recirculated,
[00:49:48.820]you don't evaporate it, and all you do is
[00:49:51.470]you remove the heat by cooling it.
[00:49:53.640]And you can use the plate cooler in the milk department,
[00:49:57.520]potentially to drive cooling in the dairy barns.
[00:50:01.390]So it's got a future.
[00:50:06.380]I have worked with some major
[00:50:12.100]milk housing operations and we estimate,
[00:50:19.830]when you put in a new dairy barn this trend is something
[00:50:22.250]you want to think about down the road.
[00:50:24.870]It's going to take about $100 per animal to install this
[00:50:29.330]to where you would have it underneath your sand bed,
[00:50:33.480]and keep the bedding that cool.
[00:50:36.260]Alright, thank you, I'll be glad to answer any questions.
[00:50:38.936](applause)
[00:50:50.035]We have any questions for Dr. Collier?
[00:50:58.027]I have a question but not quite about the research
[00:51:00.950]but more of just maybe projections.
[00:51:02.370]You said you think water rationing might become an issue
[00:51:05.380]in Arizona in the next couple of years?
[00:51:06.890]Oh I do, I mean we've been
[00:51:10.255]in a drought now for 30 years.
[00:51:11.950]Do you see dairy farmers moving out of Arizona
[00:51:14.870]in the next few years?
[00:51:15.703]To places like Nebraska, Kansas, South Dakota,
[00:51:17.710]like they have been?
[00:51:18.780]Well the way it works Arizona is you'd buy
[00:51:20.470]more rice and that's what they'll do, they'll buy more rice.
[00:51:27.520]The Indian tribes have a lot of water rights.
[00:51:30.060]Right now cities and producers compete for water rights.
[00:51:36.380]Cities tend to win out on those
[00:51:37.767]'cause they have more money.
[00:51:40.470]But you know the problem with milk is it's because of
[00:51:44.900]its cost of transport, dairies tend to be close to cities.
[00:51:49.670]So when you talk about transporting very far,
[00:51:54.335]and in Florida, the milk price of Florida's based on
[00:51:58.250]production cost in Florida, plus the cost of
[00:52:00.330]transporting milk from Wisconsin.
[00:52:03.250]So it's why it's $14 in Wisconsin, that's $17 in Florida,
[00:52:08.600]on your plate.
[00:52:10.120]So that's an example of a state that probably
[00:52:13.370]shouldn't even be producing milk,
[00:52:15.360]'cause milk's already priced to be shipped there.
[00:52:18.333]But they still have dairies down there.
[00:52:20.230]Okeechobee I always said,
[00:52:22.070]who owns a dairy cow, and what the hell
[00:52:23.450]are they doing in Okeechobee?
[00:52:24.557]'Cause that is a tough place to be a cow.
[00:52:27.918]It's really tough.
[00:52:33.840]Dr. Collier, I noticed you had some
[00:52:35.560]biological variation around the cow's ability to sweat,
[00:52:39.630]so has anyone looked at the hair's ability of that?
[00:52:42.360]No, I had a student, who was that was actually
[00:52:46.580]part of a method that he changed his bull to male dominant
[00:52:50.300]and there was not a noticeable difference.
[00:52:51.863]So it's survival cost
[00:52:53.343]that low hanging fruit that needs to be done.
[00:52:57.740]I think it's going to be fairly irritable.
[00:53:00.997]There are a lot of variants there to work with,
[00:53:02.720]which is a good thing.
[00:53:06.260]I think that's true with beef and dairy.
[00:53:09.690]I think it's just as big an opportunity in the beef industry
[00:53:12.417]as it is in the dairies.
[00:53:16.210]Even greater because they provide almost no shade
[00:53:19.960]to feedlots, it's rare to see.
[00:53:24.180]Even in Arizona, it's rare to see with a shade.
[00:53:29.110]I remember in Florida cows would line up behind,
[00:53:31.253]one cow to each fence post.
[00:53:33.890]Trying to get the shade
[00:53:34.740]from a single fence post on it's head,
[00:53:38.180]and that's where they always try to cool the head.
[00:53:44.010]The other thing you talked about was
[00:53:45.340]the sick bin being a high risk for death loss,
[00:53:48.560]what about the stressors related to milk production?
[00:53:53.860]In other words, are really high milk producers also?
[00:53:56.590]Yeah, and that's the paradox.
[00:53:59.583]Let me explain why.
[00:54:01.310]You cannot get to high production without removing
[00:54:04.421]stressors around the cows.
[00:54:06.529]The cows that set production records, I think we're at
[00:54:09.190]73, 74,000 pounds at 305 days, or 365 days.
[00:54:19.590]You can't get to that without having minimal stress.
[00:54:22.120]So it's a paradox to say that high production is a stress.
[00:54:26.800]You need to remove all the stressors
[00:54:28.510]in order to get to high production.
[00:54:30.460]So I contend that high production itself is not a stress.
[00:54:34.580]What's stressful is when a producer
[00:54:36.940]doesn't manage the cow properly.
[00:54:39.820]And because of that it cannot reach its genetic potential.
[00:54:43.570]And so it's under fed, or it's got poor housing for it.
[00:54:48.290]Not hygienic, the milking parlor's not good.
[00:54:51.466]But there's 1,000 ways to fail in the dairy industry.
[00:54:55.843]And the only way to succeed is
[00:54:57.540]all those things have to work.
[00:55:00.030]But there are many, many ways to create stressors on cows.
[00:55:04.710]Even social interactions can be stressful if they're not.
[00:55:09.090]If animals are constantly sorted and moved
[00:55:12.000]from pin to pin, it creates new pecking orders
[00:55:16.210]and so the animals have to go through the process
[00:55:18.170]of reestablishing who's at the top of the chain.
[00:55:22.840]So that management is not good for production.
[00:55:28.410]So putting heifers with older cows is also not very smart
[00:55:33.387]'cause they're never gonna compete for the feed box space.
[00:55:37.380]There's just a lot of things that can happen,
[00:55:40.230]that we don't, if we're not aware of it we don't.
[00:55:43.956]The key is education of producers, who then recognize
[00:55:48.420]what the stressors are.
[00:55:50.508]And if they could remove those,
[00:55:52.330]they could have high production.
[00:55:54.230]But if you look at the normal distribution
[00:55:55.950]of milk yield in the United States with a mean
[00:55:58.320]that's around 22, 23,000 pounds,
[00:56:03.239]you go down to the low end and then compare that group
[00:56:08.170]to the high end, to which cows are most stressed?
[00:56:11.570]It's not the high end cows, it's those cows
[00:56:14.690]in the low end that have the most issues.
[00:56:18.820]So I don't see high production as a stress.
[00:56:28.360]A couple of the genes that you were talking about
[00:56:30.430]this prolactin receptor mutation, this slick gene,
[00:56:34.350]is that a mutation where the receptor is not functional?
[00:56:39.646]Yes, that's correct.
[00:56:41.880]There are several things around that prolactin receptor,
[00:56:44.793]around the hair follicle.
[00:56:48.007]That specific mutation was discovered in New Zealand.
[00:56:52.220]There's another mutation that's been
[00:56:53.800]discovered in Puerto Rico that
[00:56:59.333]results in a different hair type
[00:57:00.870]but also is more efficient in cooling.
[00:57:04.780]And then there's the case of ergot poisoning.
[00:57:10.630]If you go to the Midwest, like Kentucky,
[00:57:14.270]where ergots grow within the grasses,
[00:57:18.470]if a cow gets ergot poisoning, it suppresses prolactin.
[00:57:23.560]And she maintains a winter coat in the summer.
[00:57:26.810]And as a result she's a very heated cow.
[00:57:30.027]They lose a lot of cows to heat stress.
[00:57:33.220]And Don Spier's spent a lot of time
[00:57:35.330]working on that in Missouri.
[00:57:37.680]So if that's a mutation the receptor,
[00:57:40.020]you also said that growth hormone, you were talking about
[00:57:44.220]growth hormones in the sweat?
[00:57:45.494]There is a growth hormone is present in the
[00:57:47.015]Sweat glands?
[00:57:48.337]Secretory cell.
[00:57:50.492]And so if you are going to increase sweat
[00:57:53.890]are you going to activate that receptor
[00:57:57.150]or do you want to mutate it?
[00:57:58.080]You wanna activate it.
[00:58:00.660]So just injecting growth hormone, which is what we did.
[00:58:03.630]We increased evaporative heat loss about 25%
[00:58:09.355]in these animals.
[00:58:11.306]And we were measuring evaporative heat loss in
[00:58:14.900]thermal neutral and in heat stress environments.
[00:58:19.780]It was Herald Johnson's work.
[00:58:21.960]But they work through the same
[00:58:23.600]signal transduction pathway.
[00:58:25.350]Prolactin and growth hormone, but it looks like they're
[00:58:27.990]very diverse actions?
[00:58:30.730]There is no prolactin receptor
[00:58:32.420]in the secretory cell, only the growth hormone.
[00:58:34.907]The prolactin receptor's in the hair follicle.
[00:58:38.130]That's the difference.
[00:58:45.130]Yes.
[00:58:46.660]Assuming the animal doesn't die, over the long term
[00:58:51.070]what's the greater cost of production?
[00:58:53.340]More of acute severe stress, or chronic moderate stress?
[00:59:00.500]Oh so if you were comparing the two.
[00:59:04.580]So with chronic stress the animals undergo acclimatization,
[00:59:10.000]so it will reduce the effects, and they'll attempt
[00:59:14.160]to get back to where they were on production.
[00:59:17.370]If they were really high levels production
[00:59:18.930]they'll never get there, but in lower levels they will
[00:59:21.900]get back to where they were.
[00:59:24.380]But the problem of the acute stress there's no time
[00:59:26.050]to acclimatize and they're gonna drop.
[00:59:29.180]I didn't have time to show it but we recently summarized
[00:59:32.690]heat intake responses to three days of heat shock,
[00:59:36.964]and broke it out by levels of milk yield.
[00:59:40.290]And at the highest levels of milk yield
[00:59:44.840]they drop like a rock.
[00:59:46.600]So there's a pretty substantial
[00:59:47.740]carrying over effect from acute?
[00:59:49.650]Yeah, and the other thing,
[00:59:52.120]so there's immediate loss in production.
[00:59:54.690]And what's driving that drop in intake?
[00:59:58.530]I'm not sure, but I'm pretty sure I think,
[01:00:01.620]it's some signal from the mammary glands,
[01:00:03.410]and we're shutting it down.
[01:00:05.690]You've got to drop intake.
[01:00:07.660]Interestingly water intake drops too.
[01:00:10.460]Because they're drinking way excessive maintenance water.
[01:00:14.392]When their intake drops everybody says well water intake
[01:00:16.830]will increase, not in high producing dairy cows.
[01:00:20.230]I'm gonna present that at the Conference
[01:00:23.410]this next February, this data which really surprised us.
[01:00:30.593]There was one other thing I was gonna point out.
[01:00:34.210]Now I have to think of it, it slipped in and slipped out.
[01:00:36.790]Maybe I'll remember here in a minute.
[01:00:38.500]It's part of the problem with aging, if you don't grab it,
[01:00:42.195]it disappears.
[01:00:44.450]Is there any inflammatory response to heat stress?
[01:00:47.841]In other words, what happens?
[01:00:48.990]Well that's a area Lance has been working on.
[01:00:50.800]The leaky gut syndrome, and his contention is that
[01:00:56.240]gut cells are extremely sensitive to heat shock.
[01:01:00.080]And as a result they become leaky which allow
[01:01:04.280]these inflammatory peptides or compounds,
[01:01:09.140]help put the polysaccharides in.
[01:01:10.840]Which then have all their side effects.
[01:01:18.050]I think potentially that contributes
[01:01:21.330]but we've been watching another phenomenon
[01:01:26.400]in the mammary gland.
[01:01:30.250]And I ran a study where we were looking at data.
[01:01:33.450]We were looking at milk somatic cells.
[01:01:36.440]And during the thermal neutral heat stress period
[01:01:40.070]there was no change in somatic cells.
[01:01:43.170]And suddenly when we put 'em back in thermal neutral
[01:01:46.090]they had this huge spike in both dietary.
[01:01:51.410]At first I thought, I blamed it on the grad student,
[01:01:53.560]I said somebody contaminated the milking equipment.
[01:01:57.595]Or one of the milk culture, you know couldn't find a bug.
[01:02:01.502]And it came back down, it was only elevated for only a day.
[01:02:08.070]Repeated the study got the exact same results.
[01:02:12.300]So now I'm beginning to think that these
[01:02:15.530]mammary epithelial cells that are heat shocked,
[01:02:18.690]actually they're sloughed off
[01:02:20.720]when the animal gets back to thermal neutral.
[01:02:23.540]And so the next study what we're gonna do is actually
[01:02:27.250]separate out the cell types.
[01:02:31.270]Which, it's really difficult to tell a phagocyte from
[01:02:36.640]a engorged mammary epithelial cell.
[01:02:41.020]But if you use RNA targets, like if you look for genes
[01:02:46.760]associated with low perceptive cells.
[01:02:49.817]Like Glycosynthase or KC genes.
[01:02:53.490]Those cells only light up if they're producing milk.
[01:02:56.640]So we're gonna do an analysis on the cell types.
[01:03:03.840]But if the same thing is going on in the gut,
[01:03:06.670]it wouldn't necessarily be during the stress,
[01:03:08.445]it'd be immediately after you might see something.
[01:03:14.500]Of course it's all conjecture at this point,
[01:03:16.020]I haven't proved anything, I've got a hypothesis.
[01:03:19.353]So what's the incidence of secondary infections?
[01:03:22.930]Is it greater in acute stress than chronic stress?
[01:03:28.240]Secondary infections
[01:03:29.073]are gonna be greater than chronic stress.
[01:03:31.900]Acute stress, I'm talking, that's really the first
[01:03:37.300]three days we don't see much in the way of infections.
[01:03:44.881]From a heat stress standpoint it makes sense
[01:03:47.889]why a animal would increase heat intake,
[01:03:52.077]but from a pathogen standpoint,
[01:03:55.530]from an evolutionary standpoint
[01:03:57.360]why would pro inflammatory cytokine cause a reduction
[01:04:02.060]in caloric intake when indeed those animals need it?
[01:04:05.325]I agree, I don't quite accept that yet.
[01:04:10.140]And also why would it be related to level of milk yield?
[01:04:14.824]'Cause I can show you that we can break it down
[01:04:16.890]in five kilogram increments
[01:04:18.340]and there's definitely different slopes
[01:04:21.010]and it's not even significant until you get
[01:04:25.130]above 30 pounds of milk a day.
[01:04:28.161]If that was just leaky gut I don't think that
[01:04:31.720]relationship would hold.
[01:04:38.335]I think something is coming from the mammary gland
[01:04:40.684]and it drops different.
[01:04:44.781]It was an Israeli scientists who claimed to have found that.
[01:04:49.722]He claimed it was a partially digested casing.
[01:04:54.390]No one's been able to duplicate it the work.
[01:04:58.530]Including themselves.
[01:04:59.363](laughter)
[01:05:00.723]Which is always a bad sign.
[01:05:01.661](laughter)
[01:05:03.399]I hate it when that happens.
[01:05:05.980]That sounds like a good time to transition.
[01:05:09.740]It's a little after 1:00, so I know a lot of folks
[01:05:12.029]have some more places to go.
[01:05:13.680]Dr. Collier will be with us for about an hour or so.
[01:05:18.912]And we're getting ready to grab lunch.
[01:05:20.400]Are we in this room?
[01:05:21.416]No.
[01:05:23.093]We're in a different room.
[01:05:24.730]Do you remember which one?
[01:05:25.960]It's 822, but yeah.
[01:05:28.010]Okay.
[01:05:30.309]If you have questions if you wanna
[01:05:33.397]email me I'd be glad to answer any questions
[01:05:36.520]through email that we will get to.
[01:05:39.218]If you need my email address I will put it up.
[01:05:41.516]Let's show some appreciation for him.
[01:05:42.925](applause)

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Bob Collier

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