Economics of boar taint prevention without surgical castration in the pork chain

An economic analyses of boar taint prevention without surgical castration is lacking. This paper explores currently feasible alternatives to surgical castration along the pork chain. The considered alternatives include genetic selection (pig breeding stage); altering management strategies (pig growing stage); slaughter at younger age and lower weight (slaughtering stage). Control measures relevant to these alternatives were designed and examined, using costeffectiveness and cost-benefit analysis. Results show that the option of single-sex raising of entire males is more cost-effective compared to the mixed-sex option. The breeding programs combining selection on boar taint and economics are more cost-effective than programs focusing on boar taint only, and also much more cost-effective than slaughtering at a younger age and lower weigh

Moving towards boar taint-free meat: an overview of alternatives to surgical castration from a chain perspective

The objective of this study is to review important issues in boar taint prevention without surgical castration, namely alternatives to surgical castration, factors influencing boar taint development and economic considerations associated with the presently feasible alternatives to surgical castration. The paper looks at these issues from the pig production chain perspective and suggests a framework for the analysis of boar taint prevention without surgical castration within the whole-chain contex

Sensory emphasis on pork quality related to the diet content of fermentable fibre-rich feedstuffs (chicory and lupine) with special emphasis on the effect on boar taint

Boar taint in entire male pork is caused by skatole and andros-tenone and other compounds such as indole. However, female pigs also pro-duce skatole and indole. The purpose was to minimise boar taint related to skatole by feeding entire male and female pigs with fibre-rich feedstuffs. An organic, 10% dried chicory or 25% lupine diet was applied for either 7 or 14 days before slaughter. Lupines significantly reduced skatole in backfat for both genders whilst chicory showed no significant differences in this re-spect. From a sensory perspective, chicory and lupine reduced boar taint since odour and flavour of manure related to skatole and urine associated to androstenone were minimised. The level of boar taint in the entire male pigs was mainly reduced after 14 days by both chicory and lupine while the “boar” taint in female pigs was mainly reduced by lupine

Ban on castration of boars in the Netherlands: modeling economic consequences of options

As a result of social criticism on castration, the Netherlands intend to start fattening boars. The great obstacle to a ban on castration is the expected negative effect on international trade because of the fear of boar taint. Consumers’ perception of boar taint is investigated, and a summary is presented of the knowledge gained up to the present to reduce boar taint. Advantaged and drawbacks of several alternatives are assessed. An economic chain- and import/export model has been developed to estimate economic consequences. The total added value of the pig farmers' chain will significantly reduce, but there is much uncertainty of the estimation of market acceptance and prices. A further elaboration of the model is proposed, with an assessment of the optimal mix of alternative

Effect of feeding fermentable fibrerich feedstuffs on meat quality with emphasis on chemical and sensory boar taint in entire male and female pigs

Skatole, androstenone and other compounds such as indole cause boar taint in entire male pork. However, female pigs also produce skatole and indole. The purpose of this experiment was to minimise boar taint and increase overall impression of sensory quality by feeding entire male and female pigs with fibrerich feedstuffs. The pigs have been fed three organic diets for either 1 or 2 weeks prior to slaughter of which two diets contained different fermentable fibre-rich feedstuffs – 10–13.3% dried chicory roots or 25% blue lupines. These two treatments were compared with pigs fed with an organic control diet for either 1 or 2 weeks prior to slaughter. Lupines significantly reduced skatole in blood and backfat for both genders after 1 week. Moreover, lupines showed negative impact on growth rate and feed conversion whilst chicory showed no significant differences in this respect. However, the indole concentration was significantly lower in chicory than lupine fed pigs. From a sensory perspective, chicory and lupine feeding reduced boar taint since odour and flavour of manure related to skatole and urine associated to androstenone were minimised. The level of boar taint in the entire male pigs was most effectively reduced after 14 days by both fibre-rich feeds while lupine had the largest influence on ‘‘boar” taint reduction in female pigs

Monitoring of behavior, sex hormones and boar taint compounds during the vaccination program for immunocastration in three sire lines

Immunocastration (vaccination against boar taint) is an alternative method to prevent boar taint without the need for surgical castration. This study investigates the evolution of boar taint compounds in serum and fat, serum steroid compounds as well as behavior in immunocastrated pigs from 3 sire lines: 15 stress positive Belgian Pietrain (BP), 20 stress negative French Pietrain (FP), and 20 stress negative Canadian Duroc (CD). Hormone and boar taint compounds in serum were determined at 4 time points; boar taint compounds in fat were determined at 3 time points. Behavior, skin lesions, animal and pen fouling were also recorded before the first vaccination ( V2). Aggressiveness, eating and drinking and general activity behavior declined from V2 for all sire lines. Pigs from BP were cleaner than FP and CD pigs. Even though immunocastration was effective in general (reduced testosterone, estradiol as well as androstenone in serum) for all sire lines, some individual pigs showed either androstenone or skatole levels in fat above cutoff values. While the immunocastration mechanism works as intended for androstenone, and also for skatole for the three sire lines, the risk of carcasses with boar taint compounds above cutoff levels (respectively 1.9 and 3.7%) still remains to some extent

Organic pig production 2014 -without castration

Organic pork is a clear alternative to conventional pork because organic pig production, with outdoor access and roughage, is quite different. The low market share (1 %) for organic pork provides a promising development potential. Consumer expectation for a natural product means that a stop for castration could provide new marketing possibilities. A recent pilot study on production of entire males on commercial organic farms indicates that the proportion of organic produced entire male pigs with boar taint is so high that it is a major barrier for a marked orientated growth in organic pig production. In this project we develop a management concept for future organic pig production without castration, with a documented low level of entire male pigs with a high level of skatol and androstenone in back fat and therefore a minimum risk for boar taint. The risk of boar taint can be reduced by feeding the right feeds in the right combination. The best feed rations are selected based on their ability to minimize boar taint and tested for consequences for productivity, nutrient utilization and natural disease resistance. Subsequently the best feeding is combined with the best decisions concerning, pig weight when taken from pasture, group size and grouping strategy and slaughter weight and the concept is tested for the overall effect on skatole and androstenone level in male pig. The consequences for economy and working conditions are demonstrated for farmers and citizens

Chicory roots improves the taste and odour of organic pork

The carbohydrate inulin is known to reduce the production of skatole in pigs. This is caused by inulin changing the intestinal flora, so that the bacteria that produce skatole are held in check. This change in intestinal flora also reduces the number of intestinal parasites in the pigs. However the high cost of inulin makes its use in pig feed impractical. Chicory root contains inulin and a series of other carbohydrates and secondary metabolites. Therefore we have examined whether chicory root can replace pure inulin and thereby reduce boar taint, improve the taste of pork and reduce the infection of pigs with pathogenic parasites and bacteria

Effect of feeding fermentable fibrerich feedstuffs lupin and chicory prior to slaughter with special emphasis on the effect on chemical boar taint in organic entire male and female pigs and technological meat quality

Boar taint is an off-flavour of pork caused primarily by skatole and, androstenone. Pig off-odour and flavour mostly caused by higher skatole concentrations in backfat. It is a problem in all types of pork production and is not restricted to entire male pigs. If uncastrated, 5-10% of Danish entire male pigs (100 kg liveweight) have > 0.25 ppm skatole in backfat and are then classified as boar tainted, having a markedly reduced value. Even backfat skatole values above 0.15 ppm enhance the off-odour for skatole sensitive consumers. An alternative way to reduce high skatole concentrations may be feeding with fibre-rich feedstuffs. This idea is based on previous studies which have demonstrated that 10% dried chicory or more in the feed reduces skatole in entire male pigs significantly after 7, 14 and 21 days of feeding, resulting in a significant reduction in perceived boar taint and thus an improvement in the flavour and taste of meat. Significantly decreased skatole concentrations and a tendency to increased eating quality have also been demonstrated by feeding 25% lupines to female and castrated male pigs during the whole fattening period. The question remains, however, whether the effects of lupines on skatole and other sensory characteristics of female and entire male pigs can be obtained when used only in the last 1 or 2 weeks before slaughter. Two experimental replicates each consisting of 24 pigs (12 entire male and 12 female) was divided into three treatments according to litter and initial weight and kept in pairs (pens) of either female or entire male pigs. The male and female pigs were kept in different stables. The pairs of pigs have been fed three organic diets for either 1 or 2 weeks prior to slaughter of which two diets contained different fermentable fibre-rich feedstuffs (10% dried chicory root plus 90% organic control feed and 25% blue lupine seed plus 75% other organic feed components). These two treatments were compared with a control; where the pairs of pigs were fed organic control concentrate (“conventional”) either 1 or 2 weeks prior to slaughter (at approx. 104 kg liveweight). Levels of skatole and indole in blood plasma from Vena jugularis were monitored at the start of the experiment and just before slaughter, and skatole in backfat was measured at slaughter. Production results were registered (daily weight gain, FUp per kg gain, slaughter weight, carcass meat percentage, warm and cold carcass weight), and after slaughter at Research Centre Foulum the following technological meat quality attributes were measured on M. Longissimus dorsi (LD): meat colour (L*, a*, and b* values), drip loss, pH measurements, temperatures and glycogen at 45 minutes and 24 hours post mortem. There was a significant reduction in skatole in blood and backfat for both sexes by feeding 25% blue lupine one or two weeks prior to slaughter (P<0.001). The 10% (and 13.3%) dried chicory roots showed no significant effect. This is possibly due to error in the heat treatment of the roots during the drying process. A majority of the meat quality parameters were not significantly affected by either of the two dietary treatments. However, glycogen contents tended to be higher 45 minutes and 24 hours post mortem (P<0.10) and the drip loss lower in the lupine-fed pigs. There were clear tendencies to significant differences in production results as the 25% lupines showed negative impact on growth rate, feed conversion ratio, slaughter weight and carcass weight. Newly mixed entire male pigs showed worse performance than newly mixed female pigs during the short time experiment

Feed interventions and skatole deposition

Skatole produced in the large intestine of the pig and the testicular steroid androstenone are the main substances contributing to boar tainted meat from entire male pigs. Boar taint decreases the quality of the meat and is not accepted by consumers. Until now boar taint has been avoided by castrating male pigs. Surgical castration reduces lean meat percentage, growth rate and feed efficiency, and it causes pain to the animal. This constitutes a problem in relation to productivity and welfare. Different attempts on avoiding surgical castration were either not fully effective, not accepted by the market, or they have a long time horizon for implementation. However, when focusing on the effect of feed interventions on boar taint, previous studies have showed a reducing effect through reduced skatole production in the large intestine after a one week application period. Skatole is produced from the microbial fermentation of L-tryptophan in the large intestine. In the literature it is well documented that skatole production in the large intestine is positively correlated with skatole deposition in adipose tissue. Moreover skatole production can be decreased by adding non-digestible and easy fermentable carbohydrates to the feed. However, little is known about skatole producing bacteria from the large intestine of pigs, and how these bacteria can be affected. This thesis reviews skatole production and metabolism in the pig, and how skatole production can be reduced by affecting the microbial production of skatole in the large intestine. A skatole producing bacterium SK9 K4 was isolated from the gastrointestinal tract of pigs. No such bacterium has previously been described. The bacterium was characterised by 16S RNA sequencing, gram stain, analysis of DNA G-C content, cellular fatty acids composition and DNA hybridisation with closely related bacteria. The fermentation of different carbohydrate sources, the growth pattern, the production of organic acids and the skatole production were studied in vitro. The production of skatole in the large intestine was correlated with skatole deposition in adipose tissue. Skatole production could be reduced when adding a minimum of 20 % raw potato starch or 9 % inulin to the feed. The problem concerning deposition of skatole in adipose tissue seems to be solved through the introduction of feed interventions. However high concentrations of androstenone deposited in adipose tissue remains a challenge. Thus, the feed interventions were not fully effective against boar taint. SK9 K4 was described as cells being strictly anaerobic, occurred singly or in pairs and were gram positive. It was identical with an Olsenella sp. strain isolated from the rumen, an uncultured Olsenella sp. clone isolated from sludge and an uncultured bacterium colon isolated from the oral cavity. Moreover SK9 K4 was closely related to Olsenella uli, Olsenella profusa, Olsenella umbonata and Atopobium parvulum. SK9 K4 and O. uli produced skatole from idole-3-acetic acid but not from L-tryptophan. The major fermentation products were lactic acid together with acetic acid and formic acid. SK9 K4 was not able to ferment raw potato starch, inulin and raw corn starch. Thus, when feeding resistant starch or inulin, the growth of skatole producing bacteria might be reduced followed by a reduced ability to produce skatole. The characterisation of a skatole producing bacterium isolated from the gastrointestinal tract of pigs gives the opportunity to further study the bacterium in vivo. Studies should be conducted to investigate the effect of a control diet compared to a diet added a non-digestible and easy fermentable carbohydrate on the growth of SK9 K4 in the large intestine of the pig