Castration Of Piglets Research Articles

Genetic relationship between boar taint compounds, human nose scores, and reproduction traits in pigs1

A reduction in boar taint, an unpleasant odor arising in pork from some intact males, is desirable if routine castration of piglets needs to be stopped. Commercial slaughter pigs are typically crosses between sire lines mainly selected for finishing traits and dam lines mainly selected for reproduction traits. Previous studies suggest the possibility of reducing boar taint in sire lines due to favorable genetic correlations between boar taint and finishing traits. However, there are indications of unfavorable genetic associations between boar taint and female reproduction traits, but a lack of genetic correlation estimates remain a major roadblock in reducing boar taint in dam lines. This study was conducted to estimate genetic correlations between boar taint traits and female reproduction traits, investigate differences in these genetic relationships among sire and dam lines, and evaluate possible consequences of selection against boar taint in dam lines. The data consisted of 32,549 reproduction records from a Landrace dam line, 23,874 records from a Yorkshire dam line, and 3,745 records from a Pietrain sire line. Androstenone, skatole, and indole were measured on 1,896 carcasses, and human nose scores were recorded on 7,742 carcass samples. In general, the level of boar taint was significantly greater (P < 0.05) in the two dam lines than in the sire line. A majority of genetic correlations of boar taint compounds with reproduction traits were either low or nonsignificant, except for those of skatole and indole, with age at first insemination in dam lines that were -0.32 and -0.46, respectively. Genetic correlations also differed (P < 0.05) between sire and dam lines. The consequences of selection against boar taint in dam lines were evaluated, using selection indexes based on reproduction traits only, boar taint traits only, and both boar taint and reproduction traits. Selection on an index of only reproduction traits increased the number of carcasses with boar taint from 4 to 7.3% in 5 generations. Selection on a combined index reduced carcasses with boar taint from 4 to <0.1% in 19 generations at the cost of a 10% less economic gain in reproduction traits. In markets for intact males, overall economic gain is 78% greater than with selection for reproduction only. Breeding programs for boar taint in commercial production should include boar taint in breeding goals of dam lines as the levels of boar taint and the risk of a further increase are greater.

Animal welfare versus food quality: Factors influencing organic consumers' preferences for alternatives to piglet castration without anaesthesia

Surgical piglet castration without pain relief has been banned in organic farming in the EU since the beginning of 2012. Alternative methods therefore need to be implemented that improve animal welfare and solve the underlying problem of boar taint. This paper explores German organic consumers' preferences for piglet castration without pain relief and three alternative methods. In an innovative approach using a multi-criteria decision making procedure, qualitative data from focus group discussions were compared with quantitative results from Vickrey auctions. Overall, participants preferred all alternatives to castration without pain relief. Different aspects influenced willingness-to-pay for the methods. Animal welfare was important for the evaluation of castration without pain relief and castration with anaesthesia. Food safety played a major role for willingness-to-pay for immunocastration, while taste and, to some extent, animal welfare were dominant factors for fattening of boars. These differences should be considered when communicating the alternatives.

Application of whole genome resequencing in the dissection of QTLs affecting boar taint

Meat products obtained from some intact male pigs often produce offensive smell or odour which is recognized as a complex trait known as boar taint. A surplus deposition of androstenone and skatole in the fat is a primarily source of boar taint. Castration of young male piglets is typically used to remove boar taint despite it resultant in loss of male specific sex steroids which are necessary for proper reproduction. Dissection of boar taint quantative trait loci using whole genome resequencing approach could unravel functional polymorphism(s) which may be useful in selection.

Genetic parameters for androstenone and skatole as indicators of boar taint and their relationship to production and litter size traits in Danish Landrace1

Boar taint is an offensive odor that affects the smell and taste of cooked pork, resulting mainly from the accumulation of skatole and androstenone in the back fat of intact males. The aim of the study was to estimate genetic parameters for skatole and androstenone and their genetic relationship to production and litter size traits. Concentrations of skatole and androstenone in the back fat were available for approximately 6,000 and 1,000 Landrace boars, respectively. The concentrations were log-transformed to align phenotypic measures to a normal distribution. Heritability estimates for Log(skatole) and Log(androstenone) were 0.33 and 0.59, respectively. The genetic correlation between the 2 measures of boar taint was 0.37, suggesting that genetic selection against boar taint based on only 1 of the chemical compounds could be insufficient. The boar taint compounds had low and mostly favorable genetic correlations with the production traits. Most noticeable, a favorable genetic correlation of -0.20 between meat percentage and Log(skatole) was estimated and hence continued selection for lean pigs can also slowly reduce the level of boar taint if the desired carcass weight is kept constant. The relationship between litter size traits (measured on sows related to boars) and boar taint compounds was low and not significantly different from 0. In conclusion, skatole and androstenone can be reduced through selection without affecting important economical production and litter size traits. Therefore, animal breeding offers an effective and sustainable solution to surgical castration of male piglets.

Pain behaviour after castration of piglets; effect of pain relief with lidocaine and/or meloxicam

Behavioural responses and the effect of lidocaine and meloxicam on behaviour of piglets after castration were studied. A total of 144 piglets of 2 to 5 days of age were allocated to one of six treatments: castration (CAST), castration with lidocaine (LIDO), castration with meloxicam (MELO), castration with lidocaine and meloxicam (L + M), handling (SHAM) and no handling (NONE). Behaviour was observed for 5 days after the procedure, growth until weaning was recorded and characteristics of the castration wound noted. MELO piglets showed significantly (P < 0.05) more no pain-related behaviour than CAST and LIDO at the afternoon after castration, and were not significantly different from SHAM and NONE. LIDO piglets showed an increase (P < 0.001) in tail wagging, lasting for 3 days. This increase was not seen in L + M piglets. The occurrence of several behaviours changed with age, independent of treatment. A treatment effect on growth was not found. Wound healing was rapid in all treatments, but thickening of the heal was observed in several piglets, suggesting perturbation in the cicatrization process. Our study showed a pain-relieving effect of meloxicam after castration. Local anaesthesia resulted in piglets performing more tail wagging during the first few days after castration, which was prevented by administering meloxicam in combination with local anaesthesia.

A single nucleotide polymorphism in the CYP2E1 gene promoter affects skatole content in backfat of boars of two commercial Duroc-sired crossbred populations

The prevention of unpleasant boar taint is the main reason for castration of male piglets. This study aimed to investigate how the malodorous compound skatole is affected by a single nucleotide polymorphism (g.2412 C>T at −586 ATG) in the porcine cytochrome p450 II E1 (CYP2E1) gene. 119 boars of two commercial Duroc-sired crossbred populations raised at different farms were investigated. Skatole and androstenone in backfat averaged 114±125ng/g and 1206±895ng/g melted fat, respectively. The frequency of the genotypes CC, CT, and TT was 25, 52, and 23%, respectively. CC boars had the highest average skatole levels (175ng/g) compared to CT (92ng/g) and TT (93ng/g). Applying suggested sensory threshold levels for skatole (>150ng/g) and androstenone (>2000ng/g), 30% of the carcasses may be unacceptably tainted while the proportion of tainted carcasses is significantly higher within genotype CC (56.7%) compared to genotypes CT (24.3%) and TT (14.8%). Effective reduction of tainted carcasses appears feasible applying marker assisted selection.

Castration of piglets under general anaesthesia: a possible approach

Since January 2010 the castration of piglets without pain relief has been forbidden in Switzerland. Swiss pig farmers now have two choices, either vet-performed anaesthesia and analgesia by intramuscular injection or farmer-administered isofluran anaesthesia by an inhalation device. Many smaller pig producers, with less than 60 sows, have chosen injected anaesthesia for economic, user safety and environmental reasons.

Castration of piglets under general anaesthesia: a possible approach

Since January 2010 the castration of piglets without pain relief has been forbidden in Switzerland. Swiss pig farmers now have two choices, either vet-performed anaesthesia and analgesia by intramuscular injection or farmer-administered isofluran anaesthesia by an inhalation device. Many smaller pig producers, with less than 60 sows, have chosen injected anaesthesia for economic, user safety and environmental reasons.

Different scalding techniques do not affect boar taint

The prevention of unpleasant boar taint is the main reason for castration of male piglets. For animal welfare reasons, castration is announced to be banned in the European Community. This study aimed to investigate whether androstenone, skatole and indole in backfat of boars may be reduced by different scalding technologies. To discriminate ante and post mortem effects, carcasses were sampled before and after scalding in two abattoirs using either horizontal (TANK) or vertical (TUNNEL) scalding. Backfat samples were analysed using gas chromatography (androstenone) and liquid chromatography (skatole, indole). Neither TANK nor TUNNEL scalding did significantly reduce malodorous compounds. Skatole and androstenone in backfat obtained after scalding averaged 112±123ng/g and 1196±885ng/g melted fat, respectively; significant differences between abattoirs were observed for skatole. Increased skatole levels were tentatively assigned to longer transport duration. Concluding from recent consumer research and subsequent application of suggested sensory rejection thresholds for androstenone (2000ng/g) and skatole (150ng/g), nearly 30% of the carcasses may be unacceptably tainted.

Belgian Consumers’ Opinion on Pork Consumption Concerning Alternatives for Unanesthetized Piglet Castration

Male piglets in Belgium are still castrated unanesthetized in the first week of life, but animal rights organizations, supermarkets, and some consumers no longer accept this method in terms of animal welfare, and are pushing the pig industry to apply available alternative methods. This major change in pig husbandry will increase production costs without a guarantee for return of investment by consumers. Therefore, it is important to know the opinion of consumers on this matter. A questionnaire was used to collect data from 1,018 people through face to face interviewing in Flanders. A Chi-square test and Fisher’s exact test were used to analyze the data. Results show that in spite of several media campaigns of animal welfare organizations over the past few years, still half of the Flemish respondents were not aware of the problem of unanesthetized piglet castration. However, after being informed, the majority wanted unanesthetized castration to be banned. Although the concern about animal welfare implications was very high, the willingness to pay extra for alternatives was low.

Genetic parameters for androstenone, skatole, indole, and human nose scores as measures of boar taint and their relationship with finishing traits1

The purpose of this study was to evaluate measures of boar (Sus scrofa) taint as potential selection criteria to reduce boar taint so that castration of piglets will become unnecessary. Therefore, genetic parameters of boar taint measures and their genetic correlations with finishing traits were estimated. In particular, the usefulness of a human panel assessing boar taint (human nose score) was compared with chemical assessment of boar taint compounds, androstenone, skatole, and indole. Heritability estimates for androstenone, skatole, and indole were 0.54, 0.41, and 0.33, respectively. The heritability for the human nose score using multiple panelists was 0.12, and ranged from 0.12 to 0.19 for individual panelists. Genetic correlations between scores of panelists were generally high up to unity. The genetic correlations between human nose scores and the boar taint compounds ranged from 0.64 to 0.999. The boar taint compounds and human nose scores had low or favorable genetic correlations with finishing traits. Selection index estimates indicated that the effectiveness of a breeding program based on human nose scores can be comparable to a breeding program based on the boar taint compounds themselves. Human nose scores can thus be used as a cheap and fast alternative for the costly determination of boar taint compounds, needed in breeding pigs without boar taint.

Effects of a local anaesthetic and NSAID in castration of piglets, on the acute pain responses, growth and mortality

The present study addresses the questions whether on-farm use of local anaesthesia with lidocaine leads to a reduction in pain responses during castration, and whether the non-steroidal anti-inflammatory drug meloxicam improves technical performance after castration of piglets. Five treatments were included in the study: (1) castration without anaesthesia or analgesia (CAST), (2) castration after local anaesthesia with lidocaine (LIDO), (3) castration after administration of meloxicam (MELO), (4) castration after lidocaine and meloxicam (L + M) and (5) sham castration (SHAM). To reduce litter influences, each treatment was present in each of the 32 litters (n = 32 per treatment). During castration, vocalizations were recorded continuously. Blood samples were collected 15 min before and 20 min after castration for determination of plasma levels of total cortisol, glucose, lactate and creatine kinase (CK). Mortality was registered and piglets were weighed several times to calculate growth. Several aspects of vocalizations during castration showed consistent and significantly different levels in CAST compared with LIDO, L + M and SHAM. CAST piglets squealed longer, louder and higher. Vocalizations of MELO piglets most resembled those of CAST. An increase in cortisol was seen in all treatments. However, in SHAM piglets this increase was significantly lower than in the other treatments. LIDO piglets showed a significantly smaller increase in plasma cortisol levels compared with CAST and MELO. L + M piglets differed significantly only from the SHAM group. Lactate levels differed significantly between LIDO and MELO, the level in LIDO being decreased after castration. In the other treatments an increase was measured. No treatment effects were found in plasma glucose and CK levels, nor in growth and mortality of the piglets. In conclusion, on the basis of vocalizations and plasma cortisol, local anaesthesia with lidocaine reduces pain responses in piglets during castration. A positive effect of meloxicam on technical performance was not found.

Consumer Attitudes Towards Alternatives to Piglet Castration Without Pain Relief in Organic Farming: Qualitative Results from Germany

In order to avoid the occurrence of boar taint, castration of piglets without pain relief is a common practice in pork production. Due to increasing animal welfare concerns, the practice will be banned in organic agriculture from 2012 and alternative methods will have to be implemented. An important factor for the successful implementation of such alternatives is consumers’ acceptance of the methods, as consumers’ daily buying decisions are crucial to the further development of the organic pork sector. Thus, this paper explores organic consumers’ attitudes towards piglet castration without pain relief and three alternative methods and examines which aspects of these alternatives are important to consumers of organic products. The analysis of nine focus group discussions in Germany conducted in fall 2009 and involving a total of 89 participants, shows that castration without pain relief in organic farming was unacceptable for participants. Animal welfare, food safety, taste, and costs were principal aspects that participants used to assess the three alternatives. Participants had mainly favorable attitudes towards castration with anesthesia and analgesia. Although participants had some concerns regarding the fattening of boars (taste), there was openness towards this alternative due to its perceived naturalness. Immunocastration was seen quite critically because participants feared that this alternative might lead to (hormone) residues in meat. Overall, the results suggest that fattening of boars and castration with anesthesia and analgesia could be acceptable alternatives to consumers of organic pork.

Effect of local anaesthesia and/or analgesia on pain responses induced by piglet castration

BackgroundSurgical castration in male piglets is painful and methods that reduce this pain are requested. This study evaluated the effect of local anaesthesia and analgesia on vocal, physiological and behavioural responses during and after castration. A second purpose was to evaluate if herdsmen can effectively administer anaesthesia.MethodsFour male piglets in each of 141 litters in five herds were randomly assigned to one of four treatments: castration without local anaesthesia or analgesia (C, controls), analgesia (M, meloxicam), local anaesthesia (L, lidocaine), or both local anaesthesia and analgesia (LM). Lidocaine (L, LM) was injected at least three minutes before castration and meloxicam (M, LM) was injected after castration. During castration, vocalisation was measured and resistance movements judged. Behaviour observations were carried out on the castration day and the following day. The day after castration, castration wounds were ranked, ear and skin temperature was measured, and blood samples were collected for analysis of acute phase protein Serum Amyloid A concentration (SAA). Piglets were weighed on the castration day and at three weeks of age. Sickness treatments and mortality were recorded until three weeks of age.ResultsPiglets castrated with lidocaine produced calls with lower intensity (p < 0.001) and less resistance movements (p < 0.001) during castration. Piglets that were given meloxicam displayed less pain-related behaviour (huddled up, spasms, rump-scratching, stiffness and prostrated) on both the castration day (p = 0.06, n.s.) and the following day (p = 0.02). Controls had less swollen wounds compared to piglets assigned to treatments M, L and LM (p < 0.001). The proportion of piglets with high SAA concentration (over threshold values 200, 400 mg/l) was higher (p = 0.005; p = 0.05) for C + L compared to M + LM. Ear temperature was higher (p < 0.01) for controls compared to L and LM. There were no significant treatment effects for skin temperature, weight gain, sickness treatments or mortality.ConclusionsThe study concludes that lidocaine reduced pain during castration and that meloxicam reduced pain after castration. The study also concludes that the herdsmen were able to administer local anaesthesia effectively.

Behavior of piglets after castration with or without carbon dioxide anesthesia1

Surgical castration of male piglets without anesthesia is a routine management practice conducted on commercial pig farms. For animal welfare reasons, it would be beneficial to develop methods of practical pain relief. The objective of this study was to evaluate the effect of providing CO₂ anesthesia before castration on the behavior of piglets for up to 8 d after castration in comparison with piglets castrated without anesthesia. In 3 successive replicates, the behavior of 186 male piglets castrated with (n = 95) or without (n = 91) anesthesia was observed for up to 8 d after castration. All piglets in a given replicate were castrated on the same day, before 8 d of age. Behavioral observations were carried out in accordance with a continuous focal sampling procedure that began immediately after castration and continued for a period of 1 wk. Barrows anesthetized with CO₂ before castration displayed more interactive behaviors during the overall observation period than the other barrows (P = 0.0412), which may indicate better welfare. Assessing all observation periods separately, differences in activity at the udder, lying, walking, and interactive behaviors appeared to support the beneficial effect of providing CO₂ anesthesia before castration. However, these differences varied over time between treatment groups. The most important conclusion was that piglets castrated with or without CO₂ anesthesia displayed behaviors indicative of pain and discomfort for up to 6 d after castration. Therefore, additional analgesia may be necessary to eliminate the long-term pain caused by castration even in piglets anesthetized with CO₂ before castration.

Effect of information provisioning on attitude toward surgical castration of male piglets and alternative strategies for avoiding boar taint

Pork consumers know little about boar taint and the methods used to avoid it. As such, relevant information is necessary to assist consumers to judge the acceptability of different strategies to avoid boar taint. The effect of basic (T1) or extensive (T2) written information or T2 with supplementary audio–visual information (AV) on the opinion concerning immunocastration (IC), raising entire male pigs (EM) and surgical castration with anaesthesia (SA) as compared to castration without anaesthesia (SC) was investigated in a student population. Overall, IC was significantly preferred over SC. The information condition influenced the preference for IC and EM as compared to SC. Participants exposed to AV were more positive to IC than participants exposed to T1 and T2, and more positive to EM than participants exposed to T2. The impact of information condition was not affected by gender, farming experience, knowledge about the boar taint issue or personal relevance of pig welfare. Potential effects of providing background information and media campaigns on public surveys ought to be considered. Supplementary audio–visual information increased the impact of information provisioning.

Consumer response to the possible use of a vaccine method to control boar taint v. physical piglet castration with anaesthesia: a quantitative study in four European countries

In most European countries, male piglets being reared for meat are physically castrated without anaesthesia in order to avoid boar taint and to safeguard sensory meat quality. This method is increasingly criticised for its violation of piglet welfare. Alternative methods are being researched and castration with anaesthesia or analgesia and vaccination (immunisation) against gonadotropin-releasing hormone (using Improvac®, Pfizer GmbH) have been proposed as possible solutions. In addition to efficacy, the successful introduction and adoption of the vaccine method by stakeholders in pig supply chains are expected to depend on a favourable reception by consumers. This large-scale quantitative cross-country study (n = 4031) involving representative samples of consumers in France, Germany, the Netherlands and Belgium does not support the reserved attitude of stakeholders who fear potential low market acceptance. The vaccine method was actually preferred by the majority of consumers surveyed (69.6% of the participants) and it was perceived as equally effective in terms of avoiding boar taint; 43.8% of the consumers reported an intention to seek out pork from pigs where the vaccine had been used to control boar taint, whereas 33.7% reported an intention to avoid pork from pigs physically castrated with anaesthesia. Consumers’ favourable dispositions to the vaccine method were independent of dominant ethical, health or price orientations when purchasing pork.

Impact of single-sex and mixed-sex group housing of boars vaccinated against GnRF or physically castrated on body lesions, feeding behaviour and weight gain

Physical castration of male piglets is common practice in many countries for the control of boar taint. A vaccine against GnRF (Improvac ®) is licensed in Europe as an alternative to this painful procedure. Vaccinated pigs are known to behave like entire males up to the second vaccination, exhibiting more aggressive behaviour towards each other, which is of welfare concern. Previous studies showed that feeding behaviour is influenced by the level of competition and therefore possibly also by agonistic interactions in pig groups. The aim of this study was to evaluate if mixed-sex or single-sex housing as well as the castration method would influence skin lesions, feeding behaviour and weight gain. A total of 160 pigs were raised in four treatment groups (in four replicates): (1) single-sex physical castrates (C, n = 10 per pen), (2) single-sex vaccinates (V, n = 10), (3) physical castrates (CF, n = 5) housed with females (FC, n = 5), and (4) vaccinates (VF, n = 5) housed with females (FV, n = 5). The fattening time started at 11 wks and vaccinations were applied at 12 and 23 wks of age. Data were analyzed as repeated mixed models with Tukey HSD tests. A shorter feeding duration (FDV, P < 0.001) and lower feed intake (FIV, P = 0.009) per visit of V compared to C pigs, before the second vaccination (wk 20 of age), could be a consequence of more aggressive interactions at the feeder. This is confirmed by higher shoulder lesion scores in V pigs before effective castration (period 3, P = 0.036). This disadvantage is not apparent in VF groups, in which shoulder lesions were not higher and FIV/FDV were not lower compared to C and CF pigs. Feeding duration (FDD) and intake (FID) per day were lower for V ( P < 0.001/ P < 0.001), as well as for VF pigs ( P = 0.005/ P = 0.013) in wk 20 compared to C pigs. However, ADG did not differ between treatments before the second vaccination. Considerable changes occurred after the second vaccination, with a higher FID for V ( P < 0.001) and a higher ADG for V ( P < 0.001) and VF pigs ( P < 0.001) than for C pigs; the other feeding parameters and lesion scores did not differ between treatments anymore. Although lesions were mostly superficial scratches and not severe wounds, it seems likely that agonistic interactions impair welfare. Our results suggest that for welfare improvement the second vaccination should be applied earlier in the fattening phase and GnRF-vaccinated males should be raised together with females to reduce agonistic interactions.

Semiquantitative detection of male pork tissue in meat and meat products by PCR

Consumer awareness has increased concerning castration of piglets without analgesia or anaesthesia. On the other hand the occurrence of boar taint is not tolerated by consumers. Currently no reliable methods exist for the on-line detection of boar taint in the slaughterhouse or for genetic sexing of pigs. Therefore, as an alternative the detection of male pork meat was sought. Based on detection of a length polymorphism of the sex chromosomal amelogenin gene a reliable, specific and highly sensitive PCR method for qualitative and semi-quantitative determination of male pork tissue in meat and meat products was determined. A set of 25 male and 25 female meat samples could be correctly identified and mixtures with as little as 0.1% male meat content could be detected. Therefore the method can be used for production and control of specific meat products containing low amounts of male pork meat and thus avoiding boar taint.

Salmonella in fattening pigs in Reunion Island: Herd prevalence and risk factors for infection

Our objective was to identify the risk factors for Salmonella infection in fattening pigs in Reunion Island. Sixty pig farms were studied from April to August 2008 on the whole island. A questionnaire was submitted to the farmers, and samples of fresh faeces and gauze socks were taken to assess the Salmonella status of each herd. 40% of the herds tested positive for Salmonella spp. The most prevalent serovars were S. Typhimurium and S. Derby. The risk of Salmonella infection for the fattening pigs was increased when there was no disinfection at the farrowing stage (OR = 5.2), when large numbers of cockroaches were present on the premises (OR = 5.5) and when these facilities were not resistant to feral birds (OR = 4.5). The risk for Salmonella infection of the herd was decreased when the number of visits from technical personnel was limited (<1 per month) (OR = 0.38), when castration of piglets was done after 1 week of age (OR = 0.38) and when the all-in all-out system was respected (OR = 0.13).