Scientists from the University of Illinois, Urbana, Pancosma SA (Switzerland), and Purdue University report that the turmeric oil supplements had the added benefit of improving feed efficiency in pigs challenged with PRRSV.
Porcine reproductive and respiratory syndrome virus (PRRSV) is an economically important disease that causes respiratory tract illness in young pigs and reproductive failure in breeding sows. The disease was first reported in 1987 in parts of North Carolina, Iowa, and Minnesota.
According to a report by scientists from Iowa State University in the Journal of Swine Health and Production, PRRSV costs the US swine industry about $664 million annually.
“Results indicate that supplementation with plant extracts reduce the adverse effects of PRRSV by improving the immune responses of pigs, and the 3 plant extracts tested here show different effects,” wrote the researchers in the Journal of Animal Science.
Led by Illinois’ Professor James Pettigrew, the researchers used 64 weaned pigs and randomly assigned them to one of 4 groups. Each group was further divided into two sub-groups – one subgroup was challenged with PRRSV, while the other was not. The four main groups were then given one of four diets: a control diet, or the control diet supplemented with 10 mg/kg capsicum oleoresin, garlic botanical, or turmeric oleoresin.
Twenty-eight days later the results indicated that the unchallenged pigs were all free of PRRSV. In the PRRSV pigs, decreases in average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency were observed.
Feeding garlic increased the number of B cells and CD8+ T immune cells, compared to controls.
In addition, all of the plant extracts reversed the increases in viral load, and inflammatory markers, such as TNF-alpha and C-reactive protein (CRP) that were observed in the control animals.
There were also indications that the plant extracts delayed fever caused by PRRSV infection in the pigs.
Not only did the researchers report benefits in the immune function of the animals, but the turmeric oil supplements were associated with improved feed efficiency in PRRSV-challenged pigs, they added.
Source: Journal of Animal Science
Published online ahead of print, doi: 10.2527/jas.2013-6495
“Dietary plant extracts improve immune responses and growth efficiency of pigs experimentally infected with porcine reproductive and respiratory syndrome virus”
Authors: Y. Liu, T. M. Che, M. Song, J. J. Lee, J. A. S. Almeida, D. Bravo, W. G. Van Alstine, and J. E. Pettigrew