Organic acids in diets for entire male pigs: Effect on skatole level, microbiota in digesta, and growht performance
Øverland, M., Kjos, N. P., Borg, M., Skjerve, E., Sørum, H. (2007) Livestock Science. Article in press, doi: 10.1016/j.livsci.2007.07.007
08-Nov-2007 (18 years 6 months 30 days ago)One problem in meat obtained from entire males is the boar taint, since restrictions
on castration practices on male pigs in some European countries are now present,
the study of factors that reduce the presence of skatole in the meat are gaining
attention. Nutritional factors may influence the presence of skatole, for example,
diets with low digestible carbohydrates that result in a higher production of
butyrate in the hindgut, reduce the formation of skatole, by reducing the colonocytes
apoptosis and therefore the availability of tryptophan to bacteria. In the same
way, by reducing the skatole producing bacteria activity the formation of skatole
can be reduced. The objective of this study was to investigate the effect of
the addition of different organic acids in diets of growing-finishing entire
male pigs on skatole levels.
In this experiment 60 entire male pigs were used, blocked by litter (12 litters) and initial weight (31.7kg). The experimental treatments were 6 diets: basal diet (BD); BD + 0.85% formic acid (Fo), BD + 0.85% benzoic acid (Be), BD + 0.85% sorbic acid (So), BD + 1.2% normal coated Ca-butyrate (nBu), or BD + 1.5% inulin coated butyrate acid (iBu). During the experimental period it was recorded the average daily gain (ADG), average daily feed intake (ADFI), and feed conversation ratio (FCR). With 113.2kg of body weight, the pigs were slaughtered and carcass characteristics were measured. In the adipose tissue it was determinated skatole and adrosterone levels, which were also measured in blood samples 2-4 days prior to slaughter. Digesta samples were studied for microbiological counts, including different groups of bacteria, and in colon descendent digesta it was determinated skatole, indole and short chain fatty acid concentration.
During the overall period (growing and finishing periods) the experimental treatments had no effect of ADG, and ADFI of pigs, but FCR tended to be improved in Fo, Be, and So diets compared to BD, nBu and iBu (2.07 vs 2.14). No differences on carcass characteristics were obtained, except that dressing percentage was higher in pigs fed Be diet compared to the other diets. In general, the addition of organic acids in the diets resulted in a lower number of microbial counts in the gastrointestinal tract, being the effect of iBu and nBu lower than that reported with the other acids. No differences in the skatole content of gastrointestinal tract digesta, or in the adipose tissue were observed, however, skatole levels in plasma were lower in pigs fed Fo and So diets.
The addition of organic acids resulted, as expected, in a reduction of microbial counts in the gastrointestinal tract, which did not lead to a reduction in the skatole concentration in the digesta or in the adipose tissue. In the same way, the addition of butyrate (normal coated or inulin coated) did not represent an effective mean to reduce skatole formation.
In this experiment 60 entire male pigs were used, blocked by litter (12 litters) and initial weight (31.7kg). The experimental treatments were 6 diets: basal diet (BD); BD + 0.85% formic acid (Fo), BD + 0.85% benzoic acid (Be), BD + 0.85% sorbic acid (So), BD + 1.2% normal coated Ca-butyrate (nBu), or BD + 1.5% inulin coated butyrate acid (iBu). During the experimental period it was recorded the average daily gain (ADG), average daily feed intake (ADFI), and feed conversation ratio (FCR). With 113.2kg of body weight, the pigs were slaughtered and carcass characteristics were measured. In the adipose tissue it was determinated skatole and adrosterone levels, which were also measured in blood samples 2-4 days prior to slaughter. Digesta samples were studied for microbiological counts, including different groups of bacteria, and in colon descendent digesta it was determinated skatole, indole and short chain fatty acid concentration.
During the overall period (growing and finishing periods) the experimental treatments had no effect of ADG, and ADFI of pigs, but FCR tended to be improved in Fo, Be, and So diets compared to BD, nBu and iBu (2.07 vs 2.14). No differences on carcass characteristics were obtained, except that dressing percentage was higher in pigs fed Be diet compared to the other diets. In general, the addition of organic acids in the diets resulted in a lower number of microbial counts in the gastrointestinal tract, being the effect of iBu and nBu lower than that reported with the other acids. No differences in the skatole content of gastrointestinal tract digesta, or in the adipose tissue were observed, however, skatole levels in plasma were lower in pigs fed Fo and So diets.
The addition of organic acids resulted, as expected, in a reduction of microbial counts in the gastrointestinal tract, which did not lead to a reduction in the skatole concentration in the digesta or in the adipose tissue. In the same way, the addition of butyrate (normal coated or inulin coated) did not represent an effective mean to reduce skatole formation.