A study conducted from 2010 to last year by an animal research institute in Taiwan found that pigs fed a controversial leanness-promoting drug suffered from side effects that included mobility difficulties, according to an agricultural official.
An Animal Technology Institute Taiwan (ATIT) study showed that about 25 percent of Taiwan black pigs and 50 percent of crossbreed Landrace, Yorkshire and Duroc (LYD) pigs suffered side effects after being fed ractopamine, said the deputy director of the Bureau of Animal and Plant Health Inspection and Quarantine (BAPHIQ), Huang Kuo-ching (黃國青).
The side effects observed included fatigue, difficulty getting up and slow movements, ATIT assistant researcher Liu Chang-yeu (劉昌宇) said.
The institute’s study involved ractopamine experiments on 32 LYD pigs and 32 Taiwan black pigs from Aug. 1 to Dec. 31, 2010, Liu and ATIT head Yang Ping-cheng (楊平政) said.
LYD is the most common type of pig found in Taiwan, accounting for 85 percent of all pigs raised by farmers in the country, while the Taiwan black pig accounts for 15 percent of the hog population.
The pigs in the study weighed 80kg before the experiment started. Half of them were put in a control group, while the other half were fed ractopamine additives on a daily basis, Liu said.
The pigs in both groups were given 2.64kg to 2.91kg of feed per day. The concentration of ractopamine was diluted to 10 parts per million (ppm) in the experimental group, Liu said.
By the end of the experiment, the pigs in the two groups weighed about the same, having grown to between 116kg and 119kg, Liu said, but differences were observed in the percentage of lean meat.
LYD pigs on a diet without ractopamine had a lean-meat percentage of 61.39 percent, while those given ractopamine had a lean-meat percentage of 65.58 percent, according to Liu.
In Taiwan black pigs, the control group had a lean-meat percentage of 42.5 percent, while in the ractopamine group it was 44.6 percent, Liu said.
The differences were less than those announced by Huang, who said the experiment showed that ractopamine boosted lean meat in LYD pigs by 6 percentage points and in Taiwan black pigs by 5 percentage points.
Liu attributed the difference in the results to different ways of calculating the data, but he said that even a 2.1 percentage point differential in lean meat would have a high economic payoff and was statistically significant.
The use of ractopamine has been the focus of a trade dispute with the US.
Taiwan, along with the EU, China and many other countries, bans the use of the drug in animal feed, but the US does not and Washington hopes Taiwan will ease its restriction on ractopamine, which is used as a feed additive.
The government is currently considering whether to give in to US pressure and lift the ban on residue of the drug in US beef, but local pig farmers are concerned that if regulations are changed for beef, they might also be changed for pork.
The dispute has also focused attention on the effect of the feed additive on animals.
The issue caught the attention of Taiwan’s media after a report by Helena Bottemiller of Food Safety News — an Internet-based food safety newspaper — cited US Food and Drug Administration (FDA) records that the drug has caused sickness and death in more animals than any other drug.