单选题 Things in the henhouse changed practically overnight when McDonald's announced in 1999 that it would no longer buy eggs from producers who didn't meet its guidelines for care of chickens. Those guidelines included limiting the (51) of birds that could be kept in one (52) and prohibiting beak removal, (53) trimming just the tips.
Once McDonald's had (54) the way in issuing animal care guidelines for the company's suppliers, many other giants of the fast food industry rapidly followed suit, including Burger King, Taco Bell, Pizza Hut, Wendy's, A＆W, and KFC. Now, the American Meat Institute has (55) welfare guidelines and audit (56) for cattle, pigs, and chickens. And the European Union, representing our foreign customers, is also weighing in with, among other things, legislation banning (57) use of crates to house pregnant sows, effective in 2013.
Questions about animal care (58) with the explosive growth in large scale livestock farms, (59) spurred customers to complain about animals being treated as "factory parts." That spurred ARS and the livestock industry to take a proactive approach to addressing animal welfare issues, making sure that guidelines are based on facts (60) through scientific research. The goal is to share research findings with the retail food industry and others so that the livestock industry can improve its (61) guidelines.
Ten years ago, to address these concerns, ARS started a research program on livestock behavior and stress. The scientists involved were tasked with finding out whether modem farming practices were (62) stressing animals. And if so, could scientific methods be developed lo measure this stress so that (63) could be evaluated objectively rather than subjectively?
A decade later, the (64) answer is "yes" to both questions. Many had expected the answer to be "no" on both counts, but science works independently (65) people's opinions.