Effects of nonanoic acid on performance and hematological and biochemical parameters for weaned piglets

Abstract

Nonanoic acid (NA) is one of a group of straight-chain aliphatic aldehydes, acids and their derivatives with a long and established history of use as flavors in human food and animal feed. The use of this group of flavors in feed was evaluated by the European Food Safety Authority (EFSA) in 2013 and in the absence of data in the target species, maximum safe levels were derived from available toxicology studies of 12 mg for piglets, and 20 mg for grower/finisher pigs and sows per kg complete feed containing 120 g/kg moisture. These established safe levels limit the practical use of NA as a flavoring in swine diets and the objective of this study was to evaluate the tolerance to piglets of NA at significantly higher dietary levels that are relevant to commercial feeding practices. Three hundred eighty four (192 males, 192 females), cross bred [Tempo x (Large White x Landrace)] post-weaned piglets with an initial body weight (BW) of between 6.5 and 8.5 kg and age of 26 days were used in a 42-day tolerance study. Piglets were randomly assigned to one of 64 pens containing either 6 males or 6 females. One of 4 dietary treatments were fed to the piglets containing NA at 0, 100, 300 or 1000 mg/kg complete feed. General health and performance were monitored for the duration of the study. At day 42, blood samples were taken and piglets were sacrificed and necropsied for pathological examination of the digestive tract. NA supplementation had no effect (P > 0.05) on the daily feed intake (DFI), average daily gain (ADG), feed conversion ratio (FCR) or fecal consistency over the 42-day period. No treatment related effects (P > 0.05) on hematology or blood biochemistry parameters were reported and all values fell within normal ranges. There were no treatment-related findings from macroscopic and microscopic examination of digestive tissues. The results of the study support the tolerance to piglets of NA in feed treated with 1000 mg/kg complete feed of which 720 mg/kg was recovered, which is considerably higher than anticipated practical conditions of use as a feed flavoring.