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1.
    
Male piglets are castrated to reduce boar taint and also to reduce aggressive and sexual behaviour. However, the procedure as traditionally performed is painful and negatively affects performance. Large-scale results about the consequences of implementing alternatives on farms are lacking. We, therefore, investigated the practical applicability of the following five alternatives that can be implemented in the short term: surgical castration (1) without pain relief (CONT, control group), (2) with analgesia (MET, Metacam, 0.2 ml, 10 to 15 min before castration), (3) with general anaesthesia (CO2, inhalation, 100% CO2, 25 s, 3 l/min), (4) vaccination against boar taint (IM, two injections with Improvac) and (5) production of entire males (EM). The study consisted of the following two trials: (1) an experimental farm trial with 18 animals/treatment and (2) a large field trial on 20 farms with ~120 male pigs/farm per treatment and all treatments performed on each farm. Performance results as well as data on carcass traits, boar taint (hot-iron method) and testes development and weight were collected in both trials. Neither castration nor administration of analgesia or anaesthesia had an effect on daily gain of the piglets in the farrowing crates (P>0.05). Farmer records indicated that mortality in the farrowing crates (1.1%), nursery pens (1.8%) and fattening stable (2.2%) was not influenced by MET or CO2 compared with EM, IM or CONT (P>0.05). No significant differences were found for daily gain (P>0.05) nor slaughter age (P>0.05). Immunocastrates and EM had a better gain-to-feed ratio (P<0.05) compared with the groups of barrows (CONT, MET and CO2). Lean meat percentage was higher for EM compared with the barrows, and intermediate for IM (P<0.05). Carcass yield was lowest for IM (P<0.05). The hot-iron method indicated that boar taint was eliminated in barrows and IM compared with EM (P<0.001). Average prevalence of strong boar taint was 3% for EM, but varied from 0% to 14% between farms. As the effect of treatment on performance as well as the level of boar taint of EM was farm dependent, farmers should be encouraged to pre-test the different alternatives in order to make a well-considered choice for the best practical and profitable alternative for their farm.  相似文献   

2.
    
The use of an anti-gonadotropin-releasing hormone vaccine for immunocastration of male pigs has been recently approved in the European Union. This technique is potentially useful for avoiding both castration-associated pain for the animal and boar taint in pork. However, some animals may escape immunocastration and be slaughtered as entire males, potentially exhibiting boar taint. Therefore, it is important to check the efficacy of immunocastration on the slaughter line. To achieve that, the currently proposed method, based on testis weight, is not fully reliable because there is some overlap in the distributions of testis weight between immunocastrates and entire males. On the basis of literature data on the effect of immunocastration on the development of accessory sex glands, this paper provides evidence that the weight of seminal vesicles might be a much better criterion for checking the efficacy of immunocastration, because their size decreases more rapidly, and to a greater extent, than that of the testis.  相似文献   

3.
    
Feed intake behavior was studied between 9 weeks of age and slaughter in a total of 36 gilts, 32 immunocastrates, 33 surgically castrated barrows and 33 boars from 36 litters. Consequences for the concentration of substances contributing to off odor of pork (skatole, indole) were evaluated. Animals were kept in groups of 12 pigs of the same sex and treatment and fed ad libitum (13.4 MJ ME, 17% CP, 1.1% lysine). Individual feed intake behavior was recorded continuously by an electronic feeder. Immunocastration was carried out with two injections of Improvac with at least 4 weeks between both injections (1st: 12 to 17 weeks of age, 2nd: 19 to 21 weeks of age). Feed intake/day increased from an average of 0.91 ± 0.02 kg/day up to 3.15 ± 0.04 kg/day before slaughter. This increase was associated with a 50% reduction in the number of meals/day (from 15.8 ± 0.44 to 7.2 ± 0.29 meals/day). The larger meal sizes resulted from an increase in both, the duration of feed intake/meal and the feed intake rate (g/min). In addition, sex and treatment differences were observed: Feed intake in boars was lower than in all other groups due to a reduction in the number of meals/day and in the time spent feeding/day. In females, time spent feeding/day was quite similar to boars, but resulted from a higher number of meals of shorter duration. Barrows had a significantly higher feed intake because of a higher number of meals/day resulting in more time spent feeding/day. The feed intake rate was similar in boars, gilts and barrows and showed an increasing trend during the study, starting from about 15 g/min up to four times the amount. Immunocastration affected feed intake behavior severely, especially the meal size increased dramatically because of higher feed intake rate, which exceeded that of all other groups by 25% at the end of the study. The number of meals/day was not influenced by immunocastration and was almost identical to that of boars. Highest skatole concentrations were measured in fat of boars, whereas indole concentrations were higher in immunocastrates than in all other groups. In gilts and barrows, skatole concentrations were related to growth rate. Additionally, the feeding rate was an important factor explaining the variability in skatole/indole concentrations in adipose tissue. The physiological mechanisms however need further clarification.  相似文献   

4.
    
Tannins have long been considered ‘anti-nutritional’ factors in monogastric nutrition, shown to reduce feed intake and palatability. However, recent studies revealed that compared with condensed tannins, hydrolysable tannins (HT) appear to have far less impact on growth performance, but may be inhibitory to the total activity of caecal bacteria. This in turn could reduce microbial synthesis of skatole and indole in the hindgut of entire male pigs (EM). Thus, the objective of this study was to determine the impact of a group of dietary HT on growth performance, carcass traits and boar taint compounds of group housed EM. For the study, 36 Swiss Large White boars were assigned within litter to three treatment groups. Boars were offered ad libitum one of three finisher diets supplemented with 0 (C), 15 (T15) or 30 g/kg (T30) of HT from day 105 to 165 of age. Growth performance, carcass characteristics, boar taint compounds in the adipose tissue and cytochrome P450 (CYP) isoenzymes CYP2E1, CYP1A2 and CYP2A19 gene expression in the liver was assessed. Compared with C, feed efficiency but not daily gain and daily feed intake was lower (P<0.05) in T15 and T30 boars. Except for the percentage carcass weight loss during cooling, which tended (P<0.10) to be greater in T30 than C and T15, carcass characteristics were not affected by the diets. In line with the numerically lower androstenone level, bulbourethral and salivary glands of T30 boars were lighter (P<0.05) than of T15 with intermediate values for C. Indole level was lower (P<0.05) in the adipose tissue of T30 than C pigs with intermediate levels in T15. Skatole levels tended (P<0.10) to be lower in T30 and C than T15 pigs. Hepatic gene expression of CYP isoenzymes did not differ between-treatment groups, but was negatively correlated (P<0.05) with androstenone (CYP2E1 and CYP1A2), skatole (CYP2E1, CYP2A) and indole (CYP2A) level. In line with the numerically highest androstenone and skatole concentrations, boar taint odour but not flavour was detected by the panellists in loins from T15 compared with loins from C and T30 boars. These results provide evidence that HT affected metabolism of indolic compounds and androstenone and that they affected the development of accessory sex glands. However, the effects were too small to be detected by sensory evaluation.  相似文献   

5.
    
Pig farms in the Netherlands producing boars have different levels of boar taint prevalence, as assessed by sensory evaluation with the human nose at the slaughter line. With a questionnaire to 152 Dutch pig producers (response rate 59%), farm and management characteristics were identified that are potentially associated with farm-level boar taint prevalence. Lower farm-level boar taint prevalence was associated with a smaller group size, a smaller pen surface per boar, newer housing equipment, not practicing restricted feeding in the last period before delivery, a longer fasting period before slaughter, a higher stocking weight and a lower fraction of boars from purebred dam line sows or from Pietrain terminal boars. These characteristics can be used to develop farm-level intervention strategies to control boar taint. More research effort is needed to establish causal relationships.  相似文献   

6.
Boar taint is a major meat-quality defect in pigs and is due to excessive accumulation of skatole and androstenone in adipose tissue. The present work investigated the relationship between carcass weight, levels of skatole and androstenone in adipose tissue, and expression of the hepatic androstenone-metabolising enzyme 3β-hydroxysteroid dehydrogenase (3β-HSD), in 22 entire male and 22 entire female crossbred pigs (Large White (40%) × Landrace (40%) × Duroc (20%)). Animals of each gender were divided into two subgroups (11 pigs in each subgroup): (i) conventional weight (carcass weight 59 to 77 kg) and (ii) heavy weight (carcass weight 84 to 95 kg). No relationship between carcass weight and adipose tissue skatole level was found for entire male pigs (r2 = 0.013, P > 0.05). There was a significant negative relationship between carcass weight and expression of the hepatic 3β-HSD protein (r2 = 0.502, P < 0.001) and a significant negative relationship between 3β-HSD protein expression and androstenone level in adipose tissue (r2 = 0.24, P < 0.05) in entire males. No relationship was found between carcass weight and 3β-HSD protein expression in female pigs (r2 = 0.001, P > 0.05). 3β-HSD expression was 59% higher in conventional-weight male pigs when compared with heavy-weight animals (P < 0.05) and 36% higher in heavy-weight females when compared with heavy-weight males (P < 0.05). It is concluded that an increase in slaughter weight of entire commercial crossbred Large White pigs is accompanied by inhibition of expression of the hepatic 3β-HSD protein, which might result in a reduced rate of hepatic androstenone clearance with its subsequent accumulation in adipose tissue. It is suggested that regulation of pig hepatic 3β-HSD expression is under the control of sex hormones.  相似文献   

7.
    
Societal pressure to ban surgical castration of male piglets is rising due to animal welfare concerns, thus other methods to prevent boar taint need to be explored. Genetic selection against boar taint appears to be a long-term sustainable alternative. However, as boar taint is linked to reproductive hormones, it is important to consider possible negative side effects such as delayed sexual maturity or changes in behaviour. We reported earlier that the melanocortin-4 receptor (MC4R) marker can be used to reduce boar taint levels in fat of boars. The objective of this study was to evaluate whether MC4R marker-assisted selection for lower boar taint prevalence affects plasma levels of boar taint compounds and testosterone; sexual maturity; behaviour; skin lesions; and lameness in boars and gilts. Using an intervention study with a 2×2 design, 264 boars and gilts differing on position 893 of the MC4R gene (AA v. GG) were compared. The MC4R polymorphism did not affect the plasma concentration of either androstenone or testosterone at different time points, whereas the concentration of skatole was significantly lower (P=0.003) and the concentration of indole tended to be lower (P=0.074) in GG compared with AA boars. A higher percentage of gilts of the GG genotype were in puberty at slaughter age compared with AA gilts (P<0.001). The age of the boars at sexual maturity (as indicated by the first positive preputial smear test) did not differ between AA and GG boars. In contrast, weight of GG boars at sexual maturity tended to be lower (P=0.065). During the period from 6 weeks of age to slaughter, boars and gilts of the GG genotype showed more playing behaviour (P=0.015) and less passive and feeding behaviour (P=0.003). They showed more skin lesions on their back and caudal area (P=0.022), and tended to show more skin lesions on their head and anterior area (P=0.093) compared with AA animals. In conclusion, the polymorphism in the MC4R gene can be used as a marker without negative effects on reproduction characteristics in boars and gilts. Genetic selection towards a lower prevalence of boar taint will lead to more active pigs with more skin lesions. Management strategies may therefore be necessary to reduce skin lesions in the selected animals.  相似文献   

8.
    
Androstenone production increases during pubertal development and plays a major role in boar taint. The objective of the present study was to evaluate the effect of a subclinical inflammation on the pubertal development of boars and hence on fat androstenone. Contrasted hygiene conditions were applied during rearing to increase the variability of the inflammatory status. Boars from a commercial cross line were allocated at 139±0.9 days of age (Day 0) and 81.3±5.9 kg of live weight either to Good (n=61) or Poor (n=54) hygiene conditions until slaughter at 172.9±4.8 days of age and 116.7±4.5 kg live weight. Inflammatory status, growth and pubertal development were evaluated on Day 0, Day 27 and at slaughter by analysing the blood formula, plasma inflammatory proteins; testosterone and oestradiol, salivary cortisol, rectal temperature, live weight, back fat thickness, weight of reproductive organs and clinical scores of organs (lungs, stomach, snout). Fat was collected on Day 27 by biopsy and at slaughter to measure androstenone concentration. A principal component analysis including inflammatory indicators followed by a clustering procedure was performed to identify pigs with a high (Infl+, n=50) or a low (Infl−, n=65) inflammatory status. Infl+ pigs had more granulocytes/ml, higher concentrations of haptoglobin, C-reative protein and cortisol (P<0.05), lower growth rate and higher lung pneumonia score. However, regardless of stage, the inflammatory status had no significant effect on plasma testosterone or oestradiol, fat androstenone or sexual organ development. Present data suggest that a mild inflammatory status has no influence on pubertal development or fat concentration of androstenone in boars.  相似文献   

9.
'Boar taint' is a strong perspiration-like, urine-like unpleasant odour given off upon heating or cooking of meat from some intact (uncastrated) male pigs. Data from the F(2) generation of a Large White (LW) x Meishan (MS) crossbred population were analysed to detect quantitative trait loci (QTL) for traits associated with boar taint. Fat samples from 178 intact male pigs slaughtered at 85 +/- 5 kg were analysed for the major contributors to boar taint (androstenone, indole and skatole). Fat and lean samples from cooked meat were scored for boar, abnormal and pork flavour and odour by a trained sensory panel (SP). A scan with 117 markers covering the whole genome was performed in the F(2) individuals, together with their F(1) parents and purebred grandparents. At the 5% chromosomal significance threshold (approximately equal to the genome-wide suggestive significance threshold), QTL were detected for the laboratory estimate of androstenone on chromosomes 2, 4, 6, 7 and 9. However, only on chromosome 6 were there QTL for boar flavour (BF) traits in the same or adjacent marker intervals as a QTL for the laboratory estimate of androstenone. On chromosome 14, QTL were detected for the laboratory estimates of indole and skatole, the SP score for skatole and the scores for BF in lean and BF in fat. In all five cases, the MS allele generally increased the estimate or score, compared with the LW allele, but it appeared that desirable and undesirable alleles were present in both breeds. This locus on chromosome 14 has considerable potential for use to reduce the incidence of boar taint, especially if further research can identify the causative polymorphism or strongly associated markers.  相似文献   

10.
    
The objective was to determine the effects of immunization against gonadotropin-releasing hormone on reproductive characteristics in boars. A total of 72 boars were used in a randomized design with three treatments: single immunization (SI) (10 weeks of age) or double immunization (DI) (10 and 15 weeks of age) with Improvest® and intact controls (no Improvest®; CNT) (n=24/group). At 10, 15, 20, 25 and 40 weeks of age, blood was collected and serum harvested to evaluate testosterone concentrations. Testosterone concentrations were less for DI boars compared with CNT boars and SI boars at 20 and 25 weeks (P<0.001), but not at 40 weeks of age. At week 25, 18 pigs (n=6/group) were sacrificed and testes were removed, weighed and measured, and seminiferous tubules were examined and scored using histological slides of testes parenchyma. A sample of neck fat was assessed for boar taint aroma. All testicular measurements and weights and seminiferous tubule scores were less for DI boars compared with SI and CNT boars (P<0.001). More (P<0.05) SI and CNT boars had detectable boar taint aroma than DI boars. Libido was assessed at 32, 36, 47, 60 and 63 weeks of age and semen collected at 60 weeks of age was analyzed for indicators of quality. There were no effects of treatment (P=0.41) or treatment by week (P=0.71) on libido. Semen volume, gel weight and total number of sperm cells, determined in a subset of boars (n=3/treatment), were not different among treatments. Sperm concentration was greater for DI than SI (P=0.01), and tended to be greater for DI compared with CNT (P=0.10). Sperm motility tended to be greater for DI boars compared with CNT boars (P=0.066). In conclusion, our results show that there are no long-term effects of immunocastration on reproductive characteristics in boars.  相似文献   

11.
    
Piétrain (P), Large White (LW) and Belgian Landrace stress negative (BN) boars were slaughtered at 50, 70, 90 or 110 kg live weight to investigate breed differences and the effect of slaughter weight on boar taint prevalence. Boar taint was quantified by four different methodologies: sensory evaluation of neckfat heated with a hot iron in the slaughterhouse, sensory evaluation of meat by consumer panels, sensory evaluation of fat and meat by expert panels and laboratory analysis of indole, skatole and androstenone in backfat. Skatole levels in backfat were significantly higher for LW and BN than for P boars. The androstenone levels and the hot iron method revealed a significant interaction between breed and slaughter weight. On the other hand, experts detected an effect of weight on the androstenone odour perception, which was significantly higher in fat from boars slaughtered at 90 kg compared with 50 kg, and significantly higher in meat from boars slaughtered at 110 kg compared with 50 kg. Consumers did not detect differences in the sensory characteristics among breeds or slaughter weight. These results indicate opportunities to minimise the risk of boar taint in entire male pigs by carefully selecting a combination of breed and slaughter weight. Along with the optimal slaughter weight, the effectiveness of reducing boar taint by lowering slaughter weight appeared to be breed dependent.  相似文献   

12.
    
There is a commitment by the European pig sector to ban surgical castration of male piglets in the European Union in 2018. One alternative to castration is to raise entire male pigs, with an increased risk of boar taint. A field study was performed to: (1) evaluate inter- and intra-farm variation in boar taint prevalence, (2) investigate factors measured at slaughter influencing boar taint and (3) evaluate the relationship between sensorial scoring by a trained panel and the concentration of boar taint components. From 34 farms, neck fat samples were collected from all entire male pigs in at least two slaughter batches per farm (78 batches; 9167 animals). In addition to olfactory boar taint analysis, data were also collected on fresh skin lesions (score 0 to 3) at the slaughter line, slaughter weight, lean meat percentage, duration of transport, time spent in lairage, total delivery duration, day length, shortening of days and outdoor mean temperature. Using the hot iron method, neck fat samples were scored (eight-point scale) for boar taint. Average boar taint prevalence (score ≥3) was 5.6±2.5% and the mean difference between the maximum and minimum prevalence per farm was 4.3±3.2%. Androstenone (AND), skatole (SKA) and indole concentrations were measured for a subset (n=254) of the samples. According to binomial univariate mixed models, entire male pigs with a higher skin lesion score had higher odds of having boar taint (P=0.031), as did fatter entire male pigs (P<0.001). In the binomial multivariate mixed model lean meat percentage (P<0.001) and outdoor mean temperature (P=0.005) remained as only significant factors. Based on our results, we can conclude that these statistically significant at least partially influence the prevalence of boar taint. According to the binomial univariate mixed models SKA concentration in liquid fat seems a better predictor for boar taint than AND. There were no significant synergetic effects between boar taint compounds.  相似文献   

13.
    
The aim of this study was to evaluate the performance of various boar taint detection methods, measure the relationship between them and identify possible points of improvement for boar taint detection. The methods used to evaluate boar taint in the carcasses of 448 entire male pigs and 17 barrows were the hot iron method (n = 442), a standardised (n = 323) and home (n = 58) consumer meat-evaluation panel, an expert panel assessment of meat and fat (n = 464) and laboratory analysis of skatole, androstenone and indole in fat (n = 464). The axillary odour of a number of slaughtered entire male pigs was also investigated (n = 231). As correlation coefficients were generally weak, a positive result for one of these detection methods did not per se result in a positive result for all other methods. Results of one detection method could not be generalised. The choice to use one or more detection methods deserves consideration depending on the aim of the study. In this paper, we suggest some possible improvements for evaluating boar taint with a consumer panel based on our results and experience. The home consumer evaluation was correlated with the concentration of indole (r = 0.27) but not with skatole or androstenone. We therefore recommend that lab analyses include indole testing. The hot iron method seems to be an easy and fast detection method, which yields comparable or better correlation coefficients with the other detection methods than an expert panel evaluating fat samples. However, the reliability of the hot iron method depends on the training and reliability of one or two assessors. Efforts should be made to further optimise this method by evaluating the effect of testing conditions. The axillary odour score was moderately correlated with the other detection methods (up to 0.32). More research is needed to evaluate the possibilities of axillary odour as a boar taint detection method.  相似文献   

14.
    
Genetically reducing boar taint using low-taint lines is considered the most sustainable and economic long-term alternative to surgical castration of male pigs. Owing to the high heritability of the main boar taint components (androstenone, skatole and indole), breeding is an excellent tool for reducing the number of tainted carcasses. To incorporate boar taint into breeding programmes, standardized performance testing is required. The objective of this study was to develop and formally present a performance test for the main boar taint compounds on live breeding candidates. First, a standardized performance test for boar taint was established. A biopsy device was developed to extract small tissue samples (200 to 300 mg) from breeding candidates. Quantification of boar taint components from these small samples using specialized chemical extraction methods proved accurate and repeatable (r = 0.938). Following establishment of the method, biopsy samples of 516 live boars (100 to 130 kg live weight) were collected in the second step. Various mixed linear models were tested for each boar taint compound; models were ranked in terms of their information content. Pedigree information of 2245 ancestors of biopsied animals was included, and genetic parameters were estimated using univariate and multivariate models. Androstenone (in μg/g liquid fat (LF): mean = 0.578, σ = 0.527), skatole (in μg/g LF: mean = 0.033, σ = 0.002) and indole (in μg/g LF: mean = 0.032, σ = 0.002) levels obtained by biopsy were plausible. Heritability estimates for androstenone calculated with univariate (0.453) and multivariate (0.452) analyses were comparable to those in the literature. Heritabilities for skatole (0.495) and indole (0.550) were higher than that for androstenone. Genetic and phenotypic correlations were similar to those published previously. Our results show that data on boar taint compounds from small adipose samples obtained by biopsy provide similar genetic parameters as that described in the literature for larger samples and are therefore a reliable performance test for boar taint in live breeding candidates.  相似文献   

15.
    
Today, different analytical methods are used by different laboratories to quantify androstenone in fat tissue. This study shows the comparison of methods used routinely in different laboratories for androstenone quantification: Time-resolved fluoroimmunoassay in Norwegian School of Veterinary Science (NSVS; Norway), gas chromatography coupled to mass spectrometry in Co-operative Central Laboratory (CCL; The Netherlands) and in Institut de Recerca i Tecnologia Agroalimentàries (IRTA; Spain), and high-pressure liquid chromatography in Agroscope Liebefeld-Posieux Research Station (ALP; Switzerland). In a first trial, a set of adipose tissue (AT) samples from 53 entire males was sent to CCL, IRTA and NSVS for determination of androstenone concentration. The average androstenone concentration (s.d.) was 2.47 (2.10) μg/g at NSVS, 1.31 (0.98) μg/g at CCL and 0.62 (0.52) μg/g at IRTA. Despite the large differences in absolute values, inter-laboratory correlations were high, ranging from 0.82 to 0.92. A closer look showed differences in the preparation step. Indeed, different matrices were used for the analysis: pure fat at NSVS, melted fat at CCL and AT at IRTA. A second trial was organised in order to circumvent the differences in sample preparation. Back fat samples from 10 entire males were lyophilised at the ALP labortary in Switzerland and were sent to the other laboratories for androstenone concentration measurement. The average concentration (s.d.) of androstenone in the freeze-dried AT samples was 0.87 (0.52), 1.03 (0.55), 0.84 (0.46) and 0.99 (0.67) μg/g at NSVS, CCL, IRTA and ALP, respectively, and the pairwise correlations between laboratories ranged from 0.92 to 0.97. Thus, this study shows the influence of the different sample preparation protocols, leading to major differences in the results, although still allowing high inter-laboratory correlations. The results further highlight the need for method standardisation and inter-laboratory ring tests for the determination of androstenone. This standardisation is especially relevant when deriving thresholds of consumer acceptance, whereas the ranking of animals for breeding purposes will be less affected due to the high correlations between methods.  相似文献   

16.
The objective of the study was to compare growth performance, carcass characteristics, meat quality and fatty acid composition of the adipose tissue of group-penned barrows, immunocastrated boars and entire males. Furthermore, the effect of housing of entire males on the aforementioned parameters was evaluated. At 55.2 days of age, 52 Swiss Large White pigs were blocked by litter and assigned by BW to four experimental groups: barrows (C), immunocastrated boars (IC), entire males (EMG) reared in group pens and entire males (EMP) reared in individual pens. In experiment 1, the effects of the method of castration were investigated (experimental groups C, IC and EMG). In experiment 2, the effects of housing on entire male pigs were evaluated (experimental groups EMG and EMP). All pigs had ad libitum access to standard diets from weaning to 107 kg BW. The two vaccinations (Improvac®) were applied to the IC pigs at an average BW of 22.6 and 73.0 kg. In experiment 1, average daily gain (ADG) did not (P > 0.05) differ among the experimental groups. However, EMG consumed less feed and had a better feed-conversion ratio than C (P < 0.001 for each). For IC, intermediate values were observed, which differed (P < 0.001) from EMG and C. Lean meat percentage decreased (P < 0.05) from EMG to IC, and from IC to C. The androstenone and skatole levels were higher (P < 0.05) in the adipose tissue of EMG than IC and C. Shear force values were higher (P < 0.01) in the longissimus muscle of C and EMG, compared to IC. The concentration of saturated fatty acid in the adipose tissue increased (P < 0.001) from EMG to IC, and from IC to C pigs, and that of polyunsaturated fatty acid decreased (P < 0.001). In experiment 2, ADG did not (P > 0.05) differ between EMP and EMG. However, EMP pigs consumed more feed than EMG pigs and had a poorer feed efficiency (P < 0.01 for each). In conclusion, EMG pigs had a better feed efficiency than IC pigs and their carcasses were leaner, but the risk of boar tainted pork was elevated. Group-housing negatively affected average daily feed intake but not ADG of entire males. At the moment, immunocastration offers a good approach to avoid castration and minimize the risk of boar taint.  相似文献   

17.
    
The aim of this study was to evaluate the effectiveness of a gonadotropin-releasing hormone (GnRH) vaccine, Improvac™ (Pfizer Ltd), in suppressing aggressive and sexual behaviour of male pigs. One hundred and thirty-six pigs were assigned to three treatments: entire male pigs (n = 64), immunocastration against GnRH (n = 48) and surgical castration (n = 24). Surgical castration was performed before the age of 1 week. Vaccination comprised two injections: the first injection was given 8 to 11 weeks before slaughter and the second injection 4 weeks before slaughter. After the second injection, immunocastrated pigs showed less non-violent social and aggressive behaviours than entire male pigs of the same age. Mounting was reduced to the same low level as observed in surgically castrated pigs, and more immunocastrated pigs were without skin lesions compared with entire male pigs. Pigs that received the second injection only 1 week before the observation day did not differ significantly in behaviour from those that received the injection 3 weeks before the observation day. Thus, the behaviour seems to change soon after the second injection and these changes remain until slaughter.  相似文献   

18.
    
Knowledge of tissue and cuts growth depending on the sex could be used to improve performance and efficiency. Computed tomography (CT) is a non-invasive technology that enables the study of the body composition of live animals during growth. The aims of the present study were (1) to evaluate variation in the body composition of four sex types (SEX) of pigs (castrated males (CM), immunocastrated males (IM), entire males (EM) and females (FE)) at the live weight of 30, 70, 100 and 120 kg, assessed using CT; (2) to model the growth of the main tissues and cuts; and (3) to predict the mature BW (MBW) of the four SEX and establish the relationships between the growth models and the MBW. There were significant phenotypic differences in the allometric growth of fat and lean among SEX. For the lean tissue, FE and EM showed higher values of the b coefficient than CM and IM (1.07 and 1.07 v. 1.00 and 1.02, respectively) all of them close to unity, indicating a proportional growth rate similar to live weight and that this tissue developed faster in FE and EM than in CM and IM. However, these differences were not related to differences in estimated MBW. There were significant differences in estimated MBW among SEX, being higher in IM and EM than in CM and FE (303 and 247 v. 219 and 216 kg), however, the MBW may have been overestimated, especially for the IM. The poorer accuracy of the MBW estimate for the IM could be due to a maximum live weight of 120 kg in the experiment, or to the fact that this particular SEX presented two clear behaviours, being more similar to EM from birth to the second injection of the vaccine (130 days) and comparable with CM from that point to the final BW.  相似文献   

19.
    
Economic margins on pig farms are small, and changing slaughter weights may increase farm profitability. However, one can question if the optimal slaughter weight is the same for each sex. On three farms, crossbred pigs (n = 1128) were used to determine the effect of sex and slaughter weight on performance, carcass quality and gross margin per pig place per year. On each farm, an equal number of entire males (EMs), barrows (BAs), immunocastrates (IC) and gilts (GIs) were housed separately in group pens. Pens were randomly divided into three categories of different slaughter weights: 105, 117 and 130 kg BW. In BA, the high average daily feed intake (ADFI) and the lower capacity to gain muscle led to a higher feed conversion ratio (FCR) and lower lean meat percentage in comparison to EM and IC. In all sexes, ADFI and FCR increased with an increasing slaughter weight but the effect of slaughter weight on carcass quality varied between sexes. In BA and GI, slaughter weight had no effect on carcass quality, but in EM and IC, carcass quality improved at higher slaughter weights. Gross margin per pig place per year was calculated as gross margin per pig × barn turnover per year, taking into account fixed costs per round, feed costs and output price per pig. The slaughter weight that gained the highest gross margin per year differed between sexes. Slaughtering BA and GI at 130 kg BW, compared to 105 or 117 kg BW, decreased the gross margin per pig place per year due to the lower margin per pig and barn turnover at higher weights. In IC and EM, no difference in gross margin per pig place per year could be demonstrated between slaughtering at 105, 117 or 130 kg BW. In IC, the increasing gross margin per pig with increasing slaughter weights counteracted with the lower barn turnover. In EM, gross margin per pig did not differ between slaughter weights, but the effect of barn turnover was too small to demonstrate significant differences between slaughter weights on gross margin per pig place per year. In conclusion, slaughter weight has an impact on profitability in BA and GI: they should not be slaughtered at 130 kg BW but at lower weights, but no effect could be demonstrated in EM and IC.  相似文献   

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