Halothane Sensitivity Research Articles

Genetic variation at a pig serum protein locus, Po-2 and its assignment to the Phi, Hal, S, H, Pgd linkage group.

Two-dimensional agarose gel (pH 5.4)-polyacrylamide gel (pH 9.0) electrophoresis of pig serum samples revealed a new serum protein (postalbumin-2, PO-2) polymorphism. Family data supported the hypothesis that the three PO-2 phenotypes observed were controlled by two codominant, autosomal alleles (Po-2F and Po-2s) at a single locus. The frequency of Po-2F in Swedish Landrace and in Swedish Yorkshire breeds was estimated at 0.74 and 0.65, respectively. Evidence was presented for close genetic linkage between Po-2 and the red cell phosphohexose isomerase locus (Phi). A recombination frequency of 3.2% was obtained from double backcross material. Data obtained in a Danish Landrace material showing linkage between the Po-2 locus and the H blood group locus, the Pgd locus and Hal (locus for halothane sensitivity) are also given. A total of seven recombinants were observed. They show that Po-2 is a new locus in a previously established linkage group. The likely sequence of the loci is: Phi, Hal, S, H, Po-2, Pgd.

Effects of halothane sensitivity on growth and body composition traits in pigs

Effects of halothane sensitivity on growth and body composition traits in pigs

Organoleptical qualities of pork in relation to halothane sensitivity

Organoleptical qualities of pork in relation to halothane sensitivity

Carcass characteristics and meat quality of halothane negative and halothane positive pietrain pigs

One hundred and seventy-six Pietrain pigs were tested for halothane sensitivity by means of a 5-min halothane anaesthesia in two experiments. One hundred and twenty were halothane negative (HN) and 56 were halothane positive (HP). In one experiment pigs were slaughtered under commercial (stress) conditions; in the other experiment pigs were killed under minimal stress conditions. The carcasses of HP pigs were meatier and shorter and contained 2·2% more muscle than the carcasses of HN pigs. Halothane positive pigs gave a meat of poorer quality, as assessed in the fresh state. When the pigs were slaughtered under commercial conditions, hams from HP pigs were not inferior in curing ability and had a higher total processing yield of Paris ham due to their higher trimming yield. When the pigs were killed under minimal stress conditions, there was no difference in the total processing yield betwen HN and HP pigs, because the technological yield was markedly reduced in HP pigs. However, in both cases, HP pigs produced more cooked ham per pig. It is suggested that different physiological mechanisms may account for either PSE (pale soft exudative) or DFD (dark firm dry) meat. The former is the consequence of an excessively high rate of post mortem glycolysis which is clearly manifest in HP pigs when they are killed under minimal stress conditions and the latter appears to be unrelated to halothane sensitivity as the ultimate pH of HP and HN pigs is similar when the animals are slaughtered under stress conditions.

Linkage of genes for PHI, halothane sensitivity, A-O inhibition, H red blood cell antigens and 6-PGD variants in pigs.

SummaryData from one apparent crossover between S and H, two between PHI and HAL on one side and S on the other, and one between PHI on one side and HAL, S and H on the other, indicate a gene order in pigs of Phi‐Hal‐S‐H‐Pgd for genes for PHI, halothane sensitivity, inhibition of expression of A and O, H red blood cell antigens and 6‐PGD types.Rasmusen et al. (1980) provided data for a gene order in pigs ofPhi‐Hal‐H‐Pgd for genes for phosphohexose isomerase (PHI) isozyme variants, halothane sensitivity (HAL), H red cell antigens and 6‐phosphogluconate dehydrogenase (6‐PGD) variants, and suggested that there might be a locus for a gene for inhibition of expression of A and O separate from the locus for H. This is contrary to an earlier proposal by Rasmusen (1972) that the H‐system genotype directly influences expression of A and O. Imlah (1980) suggested that the recessive gene for halothane sensitivity has a suppressant effect on the expression of A and O. Andresen (1981) proposed that the locus for inhibition of A and O (for which Rasmusen, 1964, proposed the symbol S) was between the loci for HAL and H types. Data presented in Table 1, which includes haplotypes for three recombinant offspring described by Rasmusen et al. (1980) (883‐1, 233‐3 and 3864‐1) as well as one other recombinant (296‐2) provide evidence for the gene order for five genes proposed by Andresen. Types for 6‐PGD are listed for all pigs, although they do not provide evidence for gene order in these cases.Male 883‐1 (Table 1, and Rasmusen et al., 1980, Table 5) provided the original evidence for recombination between S and H. His phenotype, as well as his genotype as revealed by progeny test (Rasmusen et al., 1980, Table 6) indicated that recombination had occurred between the genes for PHI, HAL and S and the gene for H type in his dam, so that the S locus mapped between H and the loci for the other three traits. The phenotype of one of his sons (233‐3, Table 1, and Rasmusen et al., 1980, Table 6) indicated that there had been a recombination between genes for PHI and HAL types on one side and S and H types on the other, providing evidence that the S locus was separate from PHI and HAL as well as H. Another pig listed in Table 1,3864‐1, was also described by Rasmusen et al. (1980, Table 9) as a recombinant. This pig provides evidence for recombination between PHI on one side and HAL, S and H on the other, establishing a gene order of Phi‐Hal‐S‐H‐Pgd. The last pig listed in Table 1,296‐2, is a recombinant comparable to 233‐3. The H type of his dam provides markers indicating the recombination was between PHI and HAL on one side and S and H on the other, although the unusual expression of HAL phenotype in both parents of 296‐2 makes her haplotypes somewhat uncertain. (Recombination may have been between PHI and HAL rather than as indicated in Table 1.)In spite of incomplete penetrance for HAL (Ollivier et al., 1975; Smith & Bampton, 1977) which makes haplotypes for HAL questionable in some cases, the other genetic markers available are useful to show that recombination has taken place. Without considering the results of halothane testing, if the apparent recombinants are accepted as being as indicated, the order of the genes at the other four loci seems established. Alleles for S types appear to be separable by recombination from those for PHI and H, and the S locus appears to be between the loci for PHI and H. For the five loci, data obtained thus far are cohsistent with a gene order of Phi‐Hal‐S‐H‐Pgd.

Exertional myopathy in Finnish Landrace pigs a survey of the situation and evaluation of different control methods

The exertional myopathy situation is surveyed for the top of the breeding pyramid of the Finnish Landrace breed by testing 2,003 pigs and from material on the Norwegian Landrace (86 pigs). The usefulness of the different methods as well as practical measures with regard to the breeding programme are discussed. The halothane sensitivity frequency in the Finnish Landrace breed was found to be 12.4%, indicating that about 58 % of all Finnish Landrace pigs at the top of breeding pyramid have the halothane sensitivity gene (Haln). In contrast, a frequency of only 3.2 % was found in the Norwegian material. Of the Finnish Landrace pigs 60.7 % had the H blood group factor a, 38.0 % factor c and 16.7 %none of these factors. In the Norwegian material 62.0 % had factor a and 55.6 % factor c. Of the Finnish hal+ pigs 91.1% had the H blood group factor a and 3.2 % factor c, while 6.1 % had none of these factors. About 96.6 % of the hal+ pigs had the Phi enzyme type BB and 3.4% the Phi-type AB. None of the Phi-type AA pigs were sensitive to halothane. Phi AA was found to be rare in the Finnish Landrace, with only 1.5 % of the animals having this Phi type. The water-holding capacity measurements from muscle biopsies taken from the pigs at the end of the halothane test did not show statistically significant differences between groups of hal+ and hal— pigs. It was concluded from the results of the present study that the measurement of CK serum activity in nonstressed pigs is not very useful for identification of the hetcrozygotic carriers of the Haln gene.The iterativeness of the CK test in non-stressed pigs was found tobe poor, but muscle tissue might have infected some of the serum samples taken from the vena cava and so caused false high serum CK activity. The halothane test is reliable for the identification of Haln gene homozygotes when conducted on pigs older than 50 days. The Phi AA type is so rare that Phi enzyme typing in Finland is of limited value at present for the breeding programme. A determination of the H blood group factors a and c of all pigs intended for breeding is advised. By increasing the number of pigs with the H blood group factor c it should be possible to reduce the exertional myopathy problem in the Finnish Landrace breed. Preferential use of the desirable genotype c of the H blood group system should be more attractive to breeders than selecting against the undesirable H blood group factor a, especially as many of the H a/a and H a/ pigs have a high K index and a high percentage of lean meat on the carcase. The best a/a and a/pigs may be kept as breeding animals but have to be mated only to H c/ pigs. Because some H c/ pigs are carriers of the Haln gene and a high K index and percentage of lean meat on the carcase favour carriers of the Haln gene, it is most probable that the existing low frequency of H c/ pigs sensitive to halothane will change in the future in an unfavourable direction. It is therefore advisable to stipulate a halothane test based on a progeny test for all H c/ boars with a high K index. Halothane-sensitive sows would be especially suitable for these test matings.

The incidence of halothane sensitivity in British pigs

ABSTRACTAn adverse reaction in pigs to the anaesthetic halothane at approximately 8 weeks of age appears to be controlled by a single recessive gene affecting stress susceptibility, lean content and reproductive performance. In a survey of British nucleus herds, a total of 2998 pigs between 5 weeks of age and 28 kg live weight were given 3-min halothane tests during visits to 17 breeders or companies. There were no positive halothane reactions among 764 Large Whites from 7 herds. The frequency of positive reaction among 1538 Landrace from 14 herds averaged 11%, with a range from 0 to 23 % in individual herds. Frequencies in other pure breeds or synthetic lines varied from 0 to 88%. British and foreign breeds are compared, and the possibility of eliminating the halothane gene is discussed.

Testing methods for PSE syndrome: Current research in the U.K.

Pale, soft, exudative (PSE) pigmeat is not common in the U.K. There is, therefore, no great pressure for the introduction of tests to identify potentially affected animals. Commercial and research organisations are, however, anxious to keep a watching brief and to evaluate the established and novel tests for predicting and monitoring porcine stress syndrome (PSS) and PSE in pig populations. Of these, serum enzyme measurements, halothane sensitivity, blood grouping and mitochondrial calcium efflux have received the greatest attention. Most of the tests examined readily predict the worst examples of the syndrome, but are not sufficiently precise to be able to identify tendencies towards it, which restricts their value in breeding programmes. There are no plans to incorporate any of the tests in the national (MLC) testing programme.

Halothane sensitivity and linkage of genes for H red blood cell antigens, phosphohexose isomerase (PHI) and 6-phosphogluconate dehydrogenase (6-PGD) variants in pigs.

Data from matings appropriate to test linkage in pigs of genes for halothane sensitivity (HAL), H red cell antigens, phosphohexose isomerase (PHI) and 6-phosphogluconate dehydrogenase (6-PGD) red cell isoenzyme variants were consistent with a gene order of Phi-Hal-H-Pgd. There was no unequivocal evidence for a Hal locus separate from Phi, although the phenotype of one pig not tested for halothane sensitivity suggested recombination between Hal and Phi. Breeding tests confirmed that in two cases there had been recombination between Hal and H. Offspring of one of these recombinant types provided evidence for a locus for a gene for inhibition of expression of A and O separate from the locus for H.

Hitch-hiking effect and linkage disequilibrium: the example of two closely linked loci in the pig, Halothane Sensitivity (HAL) and Phosphohexose Isomerase (PHI)

Hitch-hiking effect and linkage disequilibrium: the example of two closely linked loci in the pig, Halothane Sensitivity (HAL) and Phosphohexose Isomerase (PHI)

Halothane Sensitivity, The H Blood Group System and Phosphohexose Isomerase (PHI) in Pigs

Previous investigations have clearly shown the existence of associations between halothane sensitivity, the H blood group system and the PHI enzyme system in pigs (Rasmusen & Christian 1976, Jorgensen et al. 1976). These associations which have considerable practical interest are most probably linkage phenomenons (Jorgensen 1977, Andresen & Jensen 1977). The major recessive locus for halothane sensitivity (HAL) comprises the two alleles N and n, n being responsible for halothane sensitivity. The distances between this locus and the loci for H and PHI are still not known exactly. This communication aims at clarifying these problems.

Halothane sensitivity as a field test for stress-susceptibility in the pig

ABSTRACTThe possible use of a pig's reaction to the anaesthetic halothane as a field test for Porcine Stress Syndrome in genetic improvement pro-grammes was investigated. A standard 3-min halothane test gave incidences of positive reaction of 20% in a composite Pietrain/Hampshire line, 5% in Norwegian Landrace, 1% in Hampshires and zero in Durocs, Large Whites and N. American Yorkshires. In the Pietrain/Hampshire population, two generations oftwo-way selection on the test gave a divergence in incidence of positive reaction of 85%, and the frequencies of affected progeny supported the hypothesis of monogenic recessive inheritance. From second tests made 20 days after the first, the probability of misclassifying a pig's reaction on one test was 5 ± 1%. Positive reactors had significantly shorter and leaner carcasses, fewer pigs born alive, poorer meat quality, higher mortality and greater plasma creatine phosphokinase activity than negative reactors.

Halothane Sensitivity, Blood CPK-Values and Meat Quality Characteristics in Pigs Selected for Rate of Gain and Backfat Thickness

(1978). Halothane Sensitivity, Blood CPK-Values and Meat Quality Characteristics in Pigs Selected for Rate of Gain and Backfat Thickness. Acta Agriculturae Scandinavica: Vol. 28, No. sup21, pp. 432-440.

Halothane Sensitivity in a Positive and a Negative Selection Line

Halothane Sensitivity in a Positive and a Negative Selection Line

Halothane Sensitivity and pH1 Testing In Irish Pigs

(1978). Halothane Sensitivity and pH1 Testing In Irish Pigs. Acta Agriculturae Scandinavica: Vol. 28, No. sup21, pp. 451-456.

The Relationship Between Halothane Sensitivity and Blood Group Systems in Pigs

The Relationship Between Halothane Sensitivity and Blood Group Systems in Pigs

Polymorphic Systems in Blood Associations with Porcine Halothane Sensitivity and Meat Quality

(1978). Polymorphic Systems in Blood Associations with Porcine Halothane Sensitivity and Meat Quality. Acta Agriculturae Scandinavica: Vol. 28, No. sup21, pp. 386-395.

A possible mechanism of anesthetic-induced myocardial depression

Summary Evidence showing that anesthetic-induced myocardial depression is caused by direct interaction of the anesthetic with the tropomyosin-troponin complex is presented. A clinical concentration (1% v/v gas) of halothane, a general anesthetic, was found to depress ATPase activity of myofibrils prepared from cat heart. Depression was significant at low [Ca ++ ], but was antagonized by increasing [Ca ++ ]. The antagonism was proved to be competitive. Halothane sensitivity of ATPase was lost after the tropomyosin-troponin complex was removed from myofibrils with mild alkaline washing, but was restored by adding the complex back to the desensitized myofibrils.