Laurits Lydehøj Hansen

Influence of chicory roots ( Cichorium intybus L ) on boar taint in entire male and female pigs

Boar taint is an off-flavour of pork caused primarily by a microbial breakdown product, skatole and a testicular steroid, androstenone. As skatole is produced in the large intestine from tryptophan, it is possible that some ‘bioactive’ ingredients could modify protein fermentation and, in the process, diminish boar taint. The aim of this study was to examine the effect of inulin-rich chicory roots (Cichorium intybus L.) on boar taint. In the first of three trials individually penned, entire males and females were given an organic concentrate in which 0·25 of the daily energy intake was replaced with crude chicory roots for 9 or 4 weeks prior to slaughter. In the second trial, entire male pigs were given diets that included, either crude chicory roots, dried chicory roots, or inulin (extracted from chicory roots) for 6 weeks pre-slaughter. In the third trial, intact male pigs were given the dried chicory diet for either 2 or 1 week before slaughter. In all trials the chicory diets were offered on a scale at 0·95 of the Danish recommendation for energy intake, and pig performance was compared with a control group given the organic concentrate at 0·95 of recommended energy intake plus silage ad libitum. In trial 1 an additional control group was offered the organic concentrate at a daily energy intake level of 1·0 of Danish recommendations. The pigs in trials 1, 2, and 3 were slaughtered at an average live weight of 118, 124, and 110kg, respectively, in order to ensure that they had achieved sexual maturity. Overall, skatole concentrations in blood plasma and backfat at slaughter were reduced to almost zero levels by including crude or dried chicory or inulin in the diet. This occurred irrespective of sex and length of feeding period (1 to 9 weeks). In trial 3 a significant effect on blood plasma concentration was observed after 3 days of feeding a diet containing dried chicory. The only significant reduction in plasma androstenone levels was detected in pigs given the crude chicory for a 9 week duration in trial 1. The production and proportion of lean was generally not affected by the addition of either form of chicory to the diets in trials 1 and 2. Therefore, dried chicory may be the most suitable form for commercial use because it: had no initial adverse effects on food intake, consistently reduced skatole without reducing performance, was easy to handle throughout the entire year and is relatively inexpensive.

Influence of Keeping Pigs Heavily Fouled with Faeces plus Urine on Skatole and Indole Concentration (Boar Taint) in Subcutaneous Fat

Abstract The aim of this study was to investigate the effect on indole and skatole concentrations in subcutaneous fat (boar taint) of two housing conditions: keeping pigs heavily fouled with faeces on a concrete floor versus keeping pigs clean on a wholly slatted floor. Both groups of pigs were kept at a high stocking rate (0.6 m2 per pig) and high temperatures (≥25[ddot]C). This study also aimed to show if changing the treatment a week prior to slaughter is sufficient to change the concentration of indole and skatole in subcutaneous fat. The experimental material consisted of 158 LY (Danish Land-race x Large White) zigzag crossbred and LYD (Danish Land-race x Large White x Duroc) crossbred entire male, castrate, and female pigs. With the exception of the first delivery, where half of the pigs were kept constantly clean and the other half constantly dirty from the start of the experiment, both treatments were changed to the opposite treatment one week before delivery to the abattoir. Post-slaughter the co...

Influence of aromatic components from pig manure on odour and flavour of cooked chicken meat.

An experiment with 96 broilers distributed across six treatments was carried out. Each treatment consisted of four cages each with four broilers. The six treatments were: the control (treatment 1), broilers placed in cages with a welded wire bottom hanging over smelling pig manure (treatment 2), or placed on a pig manure mat (treatment 3), combined with two intervals, i.e. 1 week (group a) and 2 weeks (group b) before slaughter. The content of skatole in the abdominal fat was measured, and the odour and flavour impressions after cooking were evaluated by a taste panel. The treatments were compared with two control treatments: broilers produced traditionally in cages either without (treatment 1a) or with (treatment 1b) contact with their own manure for a fortnight. A higher skatole level in abdominal fat of broilers in physical contact with pig manure (treatment 3) was measured, compared with broilers without physical contact with pig manure for at least 1 week (treatments 1 and 2) (p<0.05). The consumer taste panel evaluation was not affected by the fact that the broilers had been lying on pig manure. However, the evaluation of the odour of the cooked meat, when opening the cooking bag, was to some extent negatively affected by the experimental treatments of broilers, which had physical contact with the pig manure (p<0.05). Furthermore, physical contact with the manure, regardless of whether it was broiler or pig manure, proved to affect the odour of the meat (p<0.01). For broilers placed in cages without physical contact with the pig manure (treatments 2a and 2), the smell had no negative influence on either the odour or on the flavour of the meat, and the content of skatole was not different from that of the broilers on the control treatment. A taste panel evaluation performed on four broilers of the treatments 1a, 2b, and 3b showed no flavour differences among treatments. Whether the broilers had been exposed to a given treatment for 1 or 2 weeks made no difference, either to the skatole concentration or to the odour or flavour impression of the newly cooked chicken meat.