美国国家公共电台 NPR As Milk Production Cools In Summer, Farmers Try To Help Cows Take The Heat

 

SCOTT SIMON, HOST:

Climate change disrupts our lives in all kinds of ways, including in the icebox. It turns out, global warming is hurting global milk production. As part of our summer series on heat, Mose Buchele of member station KUT has this.

(SOUNDBITE OF CICADAS CHIRPING)

MOSE BUCHELE, BYLINE¹: The morning I visit Mill-King dairy farm in McGregor, Texas, the cicadas are loud, but the cows are silent.

CRAIG MILLER²: It's starting to warm up, so they're starting to get a little bit less frolicy (ph).

BUCHELE: That's Craig Miller. His grandfather started this farm. Now he runs it. And hot cows are exactly what I've come to talk to him about.

MILLER: Any dairy farmer - commercial, small, local - are experts in dealing³ with heat.

BUCHELE: That's because the way cows digest food takes a lot of energy and generates a lot of heat. When it gets too warm outside, cows want to cool down, So they spend their energy panting, increasing blood flow to their skin and...

MILLER: They just stop eating. It's hard to get feed into them.

BUCHELE: In the case of beef cattle, that means less beef - with dairy cows, less milk.

MILLER: Right now, this time of year, you just expect in any farm in Central Texas, it will produce about two-thirds of the milk they will in January.

BUCHELE: That means less money for his family business. And Miller says he's noticed summers are getting longer and hotter. So you can see the problem. One study finds the nation's dairy industry already loses $900 million a year thanks to what it calls heat stress. Another says global warming has already decreased U.S. milk production from Holstein cows by about 2 percent. Geoffrey Dahl is the chair of the Department of Animal Sciences at the University of Florida, Gainesville.

GEOFFREY DAHL: There are a lot of cows that are going to be living in hotter climates, and that number's probably going to increase in the future.

BUCHELE: And the problem is bigger than just hotter summers. Dahl's research shows how pregnant cows that suffer heat stress give birth to calves⁵ that also produce less milk.

DAHL: It's kind of a negative cascade⁶ that occurs from those early - well - in utero, really - insults.

BUCHELE: He and his colleagues are working on one solution. They've bred a new kind of dairy cow. It includes the DNA⁷ of a South American cow breed that's adapted to better withstand heat. It's called a slick cow.

DAHL: That's really in reference to their hair coat. They have a very, very fine hair coat, and that's all part of their improved ability to handle higher temperatures.

BUCHELE: He says these cows also seem to sweat more and transfer heat off their bodies more efficiently⁸, so their milk production does not decline when it's warmer out. Heat-tolerant slick cows just went on the market about six months ago.

DAHL: There are actually some bulls now that are available through a couple of the semen companies out there that have this slick gene⁴.

BUCHELE: Meanwhile, other researchers are looking at more traditional techniques to help cows cope with the heat.

BARBARA JONES: We have fans here, and we also have sprinklers.

(SOUNDBITE OF SPRINKLER)

BUCHELE: Barbara Jones directs the Southwest Regional Dairy Center in Stephenville, Texas, where 400 cows are milked, studied and kept cool. They munch⁹ on feed in their barn while pipes overhead spray them with water.

(SOUNDBITE OF WATER SPRAYING)

JONES: It should wet the cow to her skin. Then those sprinklers will shut off, the fans will keep going, and we're going to employ that evaporative cooling to cool the cows.

BUCHELE: Jones is researching what different dairy farm designs and cooling techniques do to milk production. She says these water and fan setups are pretty common in the South and Southwest, but they could be used more. Geoffrey Dahl at the University of Florida says they're also becoming more widely used in other parts of the country as those places get hotter.

(SOUNDBITE OF CICADAS CHIRPING)

BUCHELE: Back at Mill-King dairy farm, that doesn't surprise Craig Miller. But he points out that all of these things cost money.

MILLER: You know, there's only so much that you can do and be economically feasible.

BUCHELE: That could mean yet another consequence of a warming climate - more expensive milk.

(SOUNDBITE OF COW MOOING)

BUCHELE: For NPR News, I'm Mose Buchele in Austin.

1 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

2 miller   

n.磨坊主

参考例句：

• Every miller draws water to his own mill.磨坊主都往自己磨里注水。
• The skilful miller killed millions of lions with his ski.技术娴熟的磨坊主用雪橇杀死了上百万头狮子。

3 dealing   

n.经商方法，待人态度

参考例句：

• This store has an excellent reputation for fair dealing.该商店因买卖公道而享有极高的声誉。
• His fair dealing earned our confidence.他的诚实的行为获得我们的信任。

4 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

5 calves   

n.(calf的复数)笨拙的男子，腓；腿肚子( calf的名词复数 )；牛犊；腓；小腿肚v.生小牛( calve的第三人称单数 )；（冰川）崩解；生（小牛等），产（犊）；使（冰川）崩解

参考例句：

• a cow suckling her calves 给小牛吃奶的母牛
• The calves are grazed intensively during their first season. 小牛在生长的第一季里集中喂养。 来自《简明英汉词典》

6 cascade   

n.小瀑布，喷流；层叠；vi.成瀑布落下

参考例句：

• She watched the magnificent waterfall cascade down the mountainside.她看着壮观的瀑布从山坡上倾泻而下。
• Her hair fell over her shoulders in a cascade of curls.她的卷发像瀑布一样垂在肩上。

7 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

8 efficiently   

adv.高效率地，有能力地

参考例句：

• The worker oils the machine to operate it more efficiently.工人给机器上油以使机器运转更有效。
• Local authorities have to learn to allocate resources efficiently.地方政府必须学会有效地分配资源。

9 munch   

v.用力嚼，大声咀嚼

参考例句：

• We watched her munch through two packets of peanuts.我们看她津津有味地嚼了两包花生米。
• Getting them to munch on vegetable dishes was more difficult.使他们吃素菜就比较困难了。