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Surgical castration of piglets without pain relief is still common practice in many countries. Possible alternatives for surgical castration are application of pain relief or anaesthesia or production of boars (entire males) and immunocastrates. Each of these alternatives faces advantages and disadvantages which may result in different citizen attitudes and consumers acceptability. Understanding which practice is acceptable to whom and why may further stimulate implementation. Consumer (n = 3251) and stakeholder (n = 1027) attitudes towards surgical castration without pain relief, surgical castration with anaesthesia, immunocastration, and production of boars were surveyed from April to June 2020 via an online questionnaire in 16 countries (&gt, 175 respondents per country). Surgical castration without pain relief was separated from each of the alternatives due to animal welfare and showed the lowest acceptability (32%). Within the alternatives, a further partitioning between the alternatives was based on perceived quality and food safety, with an acceptance of 85% for applying anaesthesia, 71% for immunocastration, and 49% for boar production. Differences depending on professional involvement and familiarity with agriculture could be observed, mainly for the acceptance of surgical castration without anaesthesia, immunocastration, and boars. Castration with anaesthesia was highly accepted by all types of respondents.

This study investigated meat quality and consumer preference after ageing beef gluteus medius in a water vapour-permeable dry-ageing bag or in vacuum for 14 days. Higher ageing and trim losses but lower thawing loss, cooking loss and water content were found in samples aged in dry ageing bags compared to those aged in vacuum. Samples aged in dry ageing bags had higher total bacteria and yeast counts but lower lactic acid bacteria counts than those aged in vacuum, both before and after trimming. Meat aged in dry ageing bag was more tender and juicier and overall preferred by consumers compared with samples aged in vacuum. Female participants outperformed the males in detecting differences in palatability. No differences were found in pH, smell, shear force, colour, Enterobacteriaceae, and mould counts. Thus, by using a dry ageing bag, it is possible to produce dry-aged meat in a more controlled condition without negative effects on sensory or other quality attributes.

This study evaluated the effect of supplement of raw potato starch (RPS) on the levels of skatole, androstenone, testosterone and oestrone sulphate in plasma from entire male pigs. The study also evaluated relationships between plasma levels of skatole and testicular steroids at three different live weights (LW) of approximately 90, 100 and 115 kg. A total of 111 entire male pigs of a crossbred (Yorkshire dams×Swedish Landrace sires) were used. Animals were raised either in mixed pens, with females and males, or single-sex pens. Each pen contained seven or nine pigs. The most fast-growing three pigs from the pens with nine pigs were slaughtered when they reached 90 kg LW, and the remaining pigs were slaughtered at 115 kg LW. All pigs were fed the same commercial diet until the average pen weight reached 100 kg. Then, 33 out of 80 remaining pigs received RPS, 0.6 kg per pig and day, for 2 weeks prior to slaughter. Blood samples were taken from the pigs at three occasions: first, the day prior to first slaughter occasion, low-weight group; second, the day prior to change in diet, middle-weight group; and third, the day prior to second slaughter occasion, high-weight group. Plasma was analysed for the levels of skatole, androstenone, testosterone and oestrone sulphate. Fat samples were taken at slaughter and analysed for the levels of skatole and androstenone. The levels of skatole and testicular steroids in plasma were significantly higher in entire male pigs from the high-weight group fed no RPS compared to those from low- and middle-weight groups. The levels of the investigated compounds did not differ between low- and middle-weight groups (P>0.1). The diet with RPS induced a decline in skatole levels in plasma and fat (P 0.05). Skatole levels were positively correlated to testosterone and oestrone sulphate levels in the middle- and high-weight pigs fed no RPS as well as to testosterone in the low-weight group. In the high-weight group fed RPS, skatole levels were not correlated to any of the analysed compounds. Approximately 26% of the entire male pigs (11 out of 43) from the high-weight group fed no RPS produced skatole levels in fat above 0.20 μg/g, whereas the pigs from the low- and high-weight group fed RPS did not produce skatole levels above 0.20 μg/g in fat. Androstenone levels in fat were high in all groups. In total 47% (52 out of 111) pigs expressed androstenone levels above the rejection levels in fat of 1.0 μg/g and 88% (98 out of 111) had androstenone levels above 0.5 μg/g. It was concluded that a lower slaughter weight and the supplement of raw potato starch to the diet could be used to reduce skatole levels in entire male pigs. Androstenone levels in fat, however, could not be reduced by either a lower weight at slaughter or dietary manipulation.

Contents Relationship between free oestrone and boar taint compounds in adipose tissue were studied in two groups of entire male pigs of different breeds. Group A consisted of 33 entire crossbred male pigs (dam Yorkshire and sire backcross Yorkshire × Wild Boar, generation seven). Group B consisted of 194 entire male pigs of crossbreeds between Swedish Hampshire (H) and Finnish Landrace (L), LH × H, H × LH, LH × LH (dam × sire). The measurements of free oestrone in adipose tissue were performed with a new method developed and validated in our laboratories. The standard curve was linear for concentrations of free oestrone ranging from 0.13 to 5.10 ng/g. The method exhibited parallelism of results between serial dilutions and a mean recovery of 97 ± 13.7%. Intra-assay variations for samples with concentrations of free oestrone from 0.67 to 2.08 ng/g were from 9.23 to 11.94%. Inter-assay variations for the samples with concentrations of free oestrone from 0.89 to 2.96 ng/g were from 3.78 to 10.11%. The levels of free oestrone in fat from group A were well correlated with fat levels of androstenone (r = 0.66; p

High skatole and to a lesser degree indole levels in some entire male pigs result in occurrence of off-flavor in meat, called boar taint. In this study, plasma samples from 117 Yorkshire, 134 Landrace, 184 Hampshire and 75 Duroc entire male pigs collected at different ages were analyzed for skatole and slightly fewer samples for indole concentrations. For each breed, a distinct age-related distribution of plasma skatole levels was observed. Skatole levels were increased at approximately 180–200 days of age, reaching very high levels is some individuals. Afterwards, the levels decreased; in Yorkshire and Landrace at approximately 240–260 and in Hampshire and Duroc at 310–360 days of age. The decrease of skatole levels was also observed in samples collected from 15 Landrace boars at two different ages: 16.8 μg/L (SD=17.36) vs. 5.9 μg/L (SD=3.48, p =0.016) in samples taken at the mean age of 210 and 314 days, respectively. Indole levels showed similar age- and breed-related variations to skatole. At the time of increased skatole concentrations (age from 180 to 360 days, depending on breed) 25.5% of Yorkshire, 31.6% of Landrace, 20.3% of Hampshire and 61.1% of Duroc entire male pigs had skatole levels above 12.6 μg/L of plasma, which corresponds to the threshold level of 0.20 μg/g of fat that is used for selecting tainted carcasses. The results indicate that increased levels of skatole in entire male pigs are related to puberty and taking skatole measurements at that age could be advantageous when considering genetic selection to reduce boar taint level in entire male pigs. Breed differences should be also taken into account.

The objectives of the study were to investigate the age-associated variations of plasma skatole and androstenone levels and their relationship to testosterone, estrone sulphate and thyroxine in plasma from entire male pigs. Effect of photoperiod on boar taint compounds in plasma was also investigated. In total, 47 uncastrated crossbred male pigs, siblings from 13 litters, were divided into three groups: Control group (natural photoperiod), Spring/Summer group (artificial spring conditions) and Autumn/Winter group (artificial autumn conditions). Blood samples were collected every 2 weeks at the average age from 8 weeks until slaughter at the age of 20–24 weeks. Neither skatole nor androstenone levels in plasma were affected by photoperiod. Skatole concentrations in plasma varied with age and were high at the age of 8–10 weeks. The early increase of skatole levels related to no other investigated compounds. At the older age, skatole levels in plasma were positively correlated to androstenone ( r =0.30; 20 weeks of age), testosterone and estrone sulphate levels ( r =0.43 and 0.54, respectively; 22 weeks of age) and negatively to thyroxine levels ( r =−0.44; 22 weeks of age, and r =−0.72; 24 weeks of age). Plasma androstenone levels were positively correlated to levels of testosterone and estrone sulphate from approximately 14 to 24 weeks of age, not at younger age, with correlation coefficients ranging from 0.34 to 0.79. Negative correlations between androstenone and thyroxine levels in plasma were found at the ages of 16, 18 and 20 weeks ( r =−0.42, −0.35 and −0.30, respectively). Skatole and androstenone levels in fat at slaughter, 20–24 weeks of age, were highly correlated ( r =0.68; P

A sensory study was conducted to determine consumer responses to meat from entire male pigs in order to evaluate different factors involved in causing boar taint, including 16-androstene steroids, skatole, size of accessory sexual glands and live weight. Pork chops from 33 entire Yorkshire male pigs were divided into three groups according to the levels of 16-androstene steroids in salivary glands, high (H; 56–114 μg/g), medium (M; 35–55 μg/g) and low (L; 26–6 μg/g), and were distributed among 59 families. Pork chops from gilts were used as control (C). The families were asked to rate liking of cooking aroma, flavour and texture, and overall liking. Consumer ratings were best related to the size of bulbourethral gland and salivary gland, followed by the levels of 16-androstene steroids in salivary gland. Meat from the L group received similar ratings to the C group, except the ratings for texture and overall liking were better than the C group. M samples were liked similarly to C, with the exception of some samples that had high fat skatole levels and which were liked less. H samples were liked less than C. The samples evaluated at the beginning of the experiment were liked more than those evaluated afterwards indicating sensitization of consumers to boar taint. The results indicate that levels of 16-androstenes in salivary glands can be used to estimate boar taint due to 16-androstenes; however, skatole measurements also need to be included. In addition, consumers are sensitive to some other maturity-related factors, which need to be considered when estimating the levels of boar taint. The effect of sensitization of consumers to boar taint requires more study.

Twelve intact male pigs (101.3 ± 1.8 kg liveweight [LW]) were divided into two groups, with six pigs receiving nine daily i.m. injections of skatole (1 mg kg−1 LW). Enzymatic activities were measured in liver tissues taken at slaughter. These included the rate of phase I skatole metabolism and the rate of glucuronidation and sulphation of 2-naphthol and(or) p-nitrophenol. Fat skatole concentration was higher (P = 0.001) in pigs injected with skatole (0.41 ± 0.04 ppm) than in control pigs (0.10 ± 0.04 ppm); however, enzymatic activities did not differ between the treatments. The results indicate that increased levels of skatole in backfat do not affect the enzymatic activities involved in skatole metabolism in the liver. Key words: Pigs, skatole, indole, boar taint, liver metabolism

The objective of this study was to evaluate the effect of 16-androstene steroids, skatole, size of accessory sexual glands and live weight on the development of boar taint in entire male pigs. In Trial I, 35 Yorkshire entire males were slaughtered at 116 ± 3.0 kg live weight. Levels of 16-androstene steroids in the salivary gland (STs), 16-androstene steroids in the fat (STf), skatole in the fat (SK), length of the bulbourethral gland (BG) and weight of the salivary gland (SG) were 44.2 ± 4.7 μg/g, 0.47 ± 0.06 μg/g, 0.20 ± 0.03 μg/g, 11.7 ± 2.2 cm and 63.50 ± 6.73 g, respectively. Samples of loin chops from the animals were evaluated by a trained sensory panel for the presence of boar odour and boar flavour. Sensory scores were correlated with all the investigated factors (P ⩽ 0.05). Boar odour was particularly well correlated with SG (r = 0.61) and BG (r = 0.60); the correlation with STs was r = 0.53, with SK was r = 0.46 and with STf was r = 0.44. Similar results were obtained for boar flavour. Therefore, both skatole and 16-androstene steroids had significant effects on boar taint. The best explanation of boar taint was obtained by combining measurements of skatole levels in fat and bulbourethral gland length. Trial II involved 36 Yorkshire pigs, 12 each of entire males, gilts and castrates, slaughtered at 104.6 ± 1.1, 102.8 ± 1.8 and 101.0 ± 1.6 kg, respectively. Entire males were chosen which had low levels of 16-androstene steroids (in salivary gland: 13.4 ± 1.5 μg/g; in fat: 0.49 ± 0.09 μg/g) and low levels of skatole in the fat (0.10 ± 0.01 μg/g) but long bulbourethral glands (11.3 ± 0.2 cm). Sensory evaluation performed by a trained panel revealed stronger boar odour and boar flavour from meat from entire males than from other genders (P ⩽ 0.05). The present results indicate that, although both 16-androstene steroids and skatole are important, they cannot completely account for the occurrence of boar taint detected by a trained sensory panel. Other factors, due to sexual maturity as indicated by the length of bulbourethral gland, are involved and should be considered when estimating boar taint in entire male pigs.

The objective of this study was to investigate beef quality of longissimus muscle after ageing in dry ageing bags, traditional dry ageing or vacuum for 8 or 19 days. Lower ageing weight loss, odour score and microbial growth were found in meat aged in dry ageing bags than after traditional dry ageing. The sensory panel detected no differences for most of the sensory attributes between samples using the two dry ageing methods, except for the odour of the cutting surface. The dry-aged steaks had more umami and butter fried meat taste compared with vacuum-aged steaks. Ageing time affected most of the sensory traits in this study, which improved as ageing time increased from 8 to 19 days. In a consumer test, meat aged for 21 days in dry ageing bags was preferred than the samples aged in vacuum. This may be due to the higher tenderness and juiciness obtained during storage in dry ageing bags than meat aged in vacuum.

Egg and production traits are of considerable economic importance in chickens. Using a White Leghorn x red junglefowl F(2) intercross, standard production measures of liver weight and colour, egg size, eggshell thickness, egg taste and meat quality were taken. A total of 160 markers covering 29 autosomes and the Z chromosome were genotyped on 175-243 individuals, depending on the trait under consideration. A total of nine significant quantitative trait loci (QTL) and three suggestive QTL were found on chicken chromosomes 1, 2, 4, 5, 7, 8, 10, 12, E47W24 and E22C19W28.

This study describes the age-related variation in boar taint compounds, skatole and androstenone, and testosterone, oestradiol-17 beta (E17 beta), oestrone sulphate (ES), dehydroepiandrosterone sulphate (DHEAS), triiodothyronine (T(3)) and insulin-like growth factor-1 (IGF-1) in six boars. Three pairs of littermates of crossbred entire male pigs (from three Yorkshire x Duroc dams and one Hampshire sire) were included. Blood samples were taken at the age of 9-15 weeks and thereafter at weekly intervals from the age of 20-32 weeks. Plasma concentrations of skatole, androstenone, testosterone, E17 beta, ES, DHEAS, T(3) and IGF-1 were measured. We found that skatole levels in boars increased at the age around puberty after an increase in the levels of testicular steroids. Levels of skatole were not associated with the levels of sex steroids, T(3) and IGF-1. However, the increased level of testicular steroids is probably the underlying factor needed for high skatole levels to occur although the specific mechanism leading to increased skatole levels remains unknown.

The objective of this study was to investigate the polar and neutral lipid fatty acid composition of pig muscle as influenced by rearing conditions and sex. A total of 120 Hampshire crossbreeds were divided in two groups, one reared free-range in a strip grazing fashion and one reared indoors in a large pen (120 m(2)). Free-range rearing produced a more unsaturated fatty acid composition (M. biceps femoris) in the neutral lipids, although the effect was small. In the polar lipids the effect of rearing condition was sex dependent. In the muscle of free-range gilts, there was a higher level of C18:2 n-6, compared with indoor gilts, indoor castrates, and free-range castrates. Moreover, muscle of gilts irrespective of rearing condition, had a higher level of the C⩾20 polyunsaturated fatty acids in the polar lipids (16.75 and 14.60, respectively). Thus, we suggest that the difference between castrates and gilts with respect to fatty acid composition in the polar lipids, might be affected by rearing condition.

The influence of free-range rearing, RN genotype and sex on different pig meat quality traits, including intramuscular fatty acid composition and levels of lipid oxidation products, were studied. A total of 60 Hampshire crossbred pigs were reared outdoors for two months with access to green feed, while 60 others were kept indoors, in a 120-m 2 -large pen, throughout the rearing period. From these 120 animals a subsample of 44 animals was chosen for meat quality analysis. Of the three factors studied, the RN genotype had the largest influence on basic technological meat quality traits, whereas the rearing conditions and sex had limited effects. However, outdoor rearing resulted in higher levels of polyunsaturated fatty acids in the intramuscular fat ( P =0.026) and in an increased level of vitamin E ( P =0.030) compared with the pigs that had been reared indoors. The sex and RN genotype of the animals also had an effect on the fatty acid profile: females had higher levels of unsaturated fatty acids ( P =0.003) as well as lower levels of saturated fatty acids ( P =0.011) than castrated males. Carriers of the RN − allele expressed a higher sum of omega-3 fatty acids ( P =0.047) and C22:5 ( P =0.012) than did the non-carriers. In a storage study where meat from free-range and indoor reared pigs was stored for 3 months at−20°C, it was shown that the lipid oxidation product malondialdehyde was formed at increased levels in animals that had a higher lean meat percentage than others, i.e. females that were carriers of the RN − gene and that were reared outdoors.

The relationship between the metabolism of androsterone and skatole, the major compounds responsible for boar taint, was investigated in F 4 Swedish Yorkshire x European Wild Pig intact males. The metabolism of androstenone and skatole were studied in liver microsomes, and the testicular steroid production was measured in testes microsomes. Including androstenone in the assays of skatole metabolism reduced the formation of 6-hydroxyskatole (pro-MII), and three other skatole metabolites (P

High concentrations of skatole in fat of some intact male pigs are a major cause of boar taint. In this study, we investigated the effect of oxidative and conjugative metabolism of skatole in liver on the concentrations of skatole in the fat of intact male pigs. In Trial 1, 18 Yorkshire intact males were equally divided into two treatments with high (mean, .42; SD, .26 ppm) and low (mean, .06; SD, .02 ppm) fat skatole levels. There was an increased rate of skatole metabolism, an increased glucuronidation activity, and a decreased sulfation activity toward 2-naphthol in liver from pigs with high skatole levels (P < .05). In Trial 2, Swedish Yorkshire x F4 European Wild Pig intact males were used. Among skatole metabolites that were produced in incubations with liver microsomes, pro-MII was conjugated with glucuronic acid and sulfate, and metabolite F-1 was conjugated with glucuronic acid. The rates of formation of various skatole metabolites and conjugation of pro-MII were evaluated for 22 pigs with different levels of cytochrome P4502E1 in the liver. The formation of F-1 and sulfation of pro-MII were negatively correlated with fat skatole levels (r = -.59, and r = -.56, respectively) and were decreased in pigs with high fat skatole levels and low P4502E1 levels (P < .01). The results indicate that oxidation and conjugation reactions of skatole in pig liver have a dramatic effect on skatole levels in the fat. In particular, the formation of F-1 and formation and subsequent sulfation of pro-MII are related to low levels of skatole in the fat, presumably due to rapid metabolic clearance of skatole.

High concentrations of skatole in fat are a major cause of boar taint in intact male pigs. Skatole is metabolized in the liver, and this metabolism could affect concentrations of skatole in fat. In this study, we evaluated the involvement of cytochrome P450, in particular cytochrome P4502E1, in skatole metabolism in pig liver. Liver microsomes from F4 European Wild Pig x Swedish Yorkshire intact male pigs were incubated in a buffer containing NADPH, NADH, and skatole. Several skatole metabolites were detected by HPLC, including 6-hydroxyskatole (pro-MII), 3-hydroxy-3-methyloxyindole (MIII), and five others not identified in this study. Inhibitors of P450 were added to microsomal incubations, and their effect on the formation of skatole metabolites and skatole disappearance was evaluated. The general cytochrome P450 inhibitors SKF 525A, at a concentration of .2 mM and metyrapone, at a concentration of .1 mM decreased the formation of pro-MII (P = .001) to 38.2 and 11.6%, respectively, of that of controls. The SKF 525A also reduced the synthesis of MIII and three other metabolites, whereas metyrapone only reduced the disappearance of skatole and synthesis of pro-MII. Inhibitors specific for cytochrome P4502E1 were more effective in reducing the formation of skatole metabolites than SKF 525A and metyrapone. Chlorzoxazone and diallyl sulfide reduced (P = .001) the synthesis of pro-MII to 9.7 and 30.9% of the control rate. The formation of most of the other skatole metabolites and disappearance of skatole were also reduced with these inhibitors. These results indicate that skatole is metabolized in pig liver to pro-MII and other metabolites by cytochrome P4502E1.

The measurement of 16-androstene steroids in submaxillary salivary glands is a potentially good way to estimate boar taint. The objective of this work was to identify factors regulating the concentrations of these steroids in salivary glands. Large White x Pietrain male pigs were divided into four treatments: T-1, intact untreated (n = 18); T-2, intact treated with porcine somatotropin (pST, n = 18); T-3, intact immunized against LHRH (n = 20); and T-4, castrated untreated (n = 19). The pigs were slaughtered at 105 mg of live weight. The mean concentrations of the compounds measured after slaughter for T-1 were as follows: 16-androstene steroid binding protein (pheromaxein) in salivary glands, 2.08 +/- .19 micrograms/g; 16-androstene steroids in salivary glands, 43.3 +/- 2.9 micrograms/g; androstenone in fat, .67 +/- .07 micrograms/g. In all other treatments, the concentrations were reduced (P = .001); T-2 and T-3 had intermediate and T-4 had the least concentrations of the measured compounds. The reduction of 16-androstenes in salivary glands was less than androstenone in fat, probably due to pheromaxein. The overall correlation between androstenone and 16-androstenes was r = .602 (P < .001) and for T-1 was r = .613 (P < .001). The overall correlation between pheromaxein and 16-androstenes was r = .777 (P < .001) and r = .928 (P < .001) for T-1. Only in T-3 was the estimation of the relationship between androstenone and 16-androstenes improved by measuring pheromaxein. These results indicate that pheromaxein is more closely related to the concentration of 16-androstene steroids in salivary glands than in fat. Synthesis of pheromaxein is dependent on mature, functional testes. We conclude that boar taint can be estimated by measuring the concentrations of 16-androstene steroids in salivary glands.

The authors wish to make the following corrections to this paper [...].