Jackson Sezibwa is just one man, but Uganda’s economy is made up of millions like him. Agriculture accounts for 30 percent of the country’s gross domestic product, and 10 percent of that comes from the livestock sector. The World Bank’s October report claimed that “G.D.P. growth originating in agriculture is at least twice as effective in reducing poverty” as other types of growth. The report pointed out that the industrialization of Europe and North America that began in the late 18th century was preceded by a period of farming innovation, and that the Green Revolution that took place between the 1940s and 1960s catalyzed Asia’s fantastic economic growth.

During the Green Revolution, scientists invented high-yielding strains of corn, wheat and rice and planted them around the third world, and they also promoted the introduction of better livestock. But then, broadly speaking, foreign-aid donors moved away from such interventions, which were viewed as meddling with the free market, and shifted financing priorities to areas like education and AIDS. Today, even after recent increases, the World Bank devotes less than 10 percent of its development assistance to agriculture, down from 30 percent a quarter-century ago. Recently, the notion of helping poor farmers by making farming more lucrative has been dusted off by a new generation of economists. And Bill Gates and the Rockefeller Foundation have promised to finance a second Green Revolution. But governmental aid agencies have been slower to rediscover the importance of agriculture. Farming initiatives now account for just 4 percent of the assistance distributed by the Organization for Economic Cooperation and Development, a group of the world’s most developed nations.

The U.S. Agency for International Development budgeted $392 million for agricultural programs last year, including a significant proportion to promote milk production. Crossbreeding is an important component of its strategy. In Uganda, where the agency recently completed a five-year, $8 million dairy-modernization project, about half the money went toward artificial insemination. One partner in the program was Land O’Lakes International Development, the aid arm of the Minnesota butter company. “We should be able to do farming as a business, not sentimentally,” said Dr. Paul Kimbugwe, the Land O’Lakes country manager. “Making money means you have to crossbreed. And crossbreeding means that you are doing away with the genetics of that cow,” meaning the Ankole, “which I also encourage.”

Not everyone in Uganda, however, agrees that the foreign breeds are an upgrade. President Yoweri Museveni once imposed a ban on imported semen. Museveni belongs to the Bahima ethnic group. When he was a baby, in a sort of Bahima baptism ritual, his parents placed him on the back of an Ankole cow with a mock bow and arrow, as if to commit him symbolically to the defense of the family’s herd. Museveni, now in his 60s, still owns the descendants of that very cow, and he retains a strong bond to the Ankole breed. Two years ago, I accompanied a group of Ugandan journalists on a daylong trip to one of the president’s private ranches, where he proudly showed us his 4,000-strong herd of Ankole cattle. At one point, a reporter asked if the ranch had any Holsteins. “No, those are pollution,” Museveni replied. “These,” he said, referring to his Ankoles, “the genetic material is superior.”

If the Ankole cattle are able to mount a comeback, it will be because circumstances have endowed them with a unique set of defenses, both evolutionary and political. Members of President Museveni’s ethnic group populate the upper ranks of Uganda’s government. Some prominent Bahima have started an organization devoted to preserving Ankoles, under the patronage of a one-eyed army general who spends his free time painting rapturous portraits of cows. One afternoon, at a pricey restaurant in Kampala, I had lunch with the organization’s chairman, Samuel Mugasi. Dressed in a dapper gray suit and a French-cuffed pale blue shirt, he told me he was a civil servant and part-time rancher.

“They have tasted the money,” Mugasi said of the farmers who switched to Holsteins. “They are excited about having these big earnings, and they are forgetting the cultural aspect.”

Kimbugwe, the Land O’Lakes representative, has a ready reply to such arguments. “Culture  fine, it’s good to have,” he said. “But first, the stomachs.” He views the Ankole as an atavistic indulgence for the country’s elite. Once, cattle were like currency, and the wealthy displayed their status by maintaining huge free-ranging herds. Competition for land is forcing cows onto smaller pastures. Uganda has one of the highest birth rates in the world, and despite its poverty and diseases like AIDS, the population has more than doubled since 1980. There’s a long history of tension between the Bahima and an agriculturalist ethnic group, the Bairu, which coexist in western Uganda, at times less than happily.