Inger Edfors-Lilja

Effect of halothane genotype on muscle metabolism at slaughter and its relationship with meat quality: A within-litter comparison

The effects of halothane genotype on muscle metabolism at slaughter and its relationship with meat quality were studied within 16 litters. Heterozygous boars and sows were mated and the offspring were halothane tested and bloodtyped to reveal the halothane (Hal) genotype of the 120 animals used (NN, Nn or nn). Following slaughter at 100kg live weight, muscle samples from M. longissimus dorsi (LD) and M. quadriceps (Qu) were taken immediately after exsanguination and analysed for glycogen, glucose-6-phosphate, lactate, creatine phosphate (CP), and adenosine triphosphate (ATP), as well as for enzyme activities representing both the oxidative and glycolytic pathways. The enzyme activities were similar for all genotypes. All muscle metabolites differed significantly between samples from NN and nn animals, with higher lactate and glucose-6-phosphate and lower glycogen, CP and ATP in the nn muscles. The heterozygote animals were intermediate or close to either of the homozygotes. Meat quality characteristics (drip loss, surface and internal reflectance and dielectric loss factor) were studied only in the LD muscle. Meat quality of the muscle from the heterozygote (Nn) animals was inferior to that from NN animals (no difference for internal reflectance) but better than that from nn animals. When reflectance and drip loss were combined into an index, very few values from the nn-animals were better than the total mean. Indexes from the dominant homozygotes were generally better than the mean and those of heterozygotes were approximately normally distributed around the mean.

Genetic variation in parameters reflecting immune competence of swine

Abstract Genetic variation in total and differential white blood cell (WBC) counts, phagocytic capacity of polymorphonuclear leukocytes (PMNL), virus induced interferon-α (IFN-α) production, mitogen induced proliferation and interleukin 2 (IL-2) production of mononuclear cells (MNC) in vitro was studied in blood collected from 124 Yorkshire piglets, aged 8 weeks. The piglets were the offspring from 12 sires and 31 dams. Data from an earlier experiment, including 96 piglets of seven sires and 24 dams, were added when estimating heritabilities for Con A induced proliferation and IL-2 production. The highest heritability (h 2=0.87±0.41) was estimated for the total number of PMNL. Medium high heritabilities (h 2=0.3−0.4) were estimated for the phagocytic capacity of PMNL, Con A induced proliferation and IL-2 production and the total number of WBC, while the heritability estimates were lower (h 2=0.00−0.08±0.12) for the total number of lymphocytes, serum concentrations of Ig and IFN-α production. Pronounced differences between litters from various dams were found for total number of lymphocytes, IFN-α production, Con A induced proliferation and IL-2 production. The Con A induced proliferation was positively correlated (r=0.48, P<0.001) with the IL-2 production and both these parameters were correlated (r=0.44 and 0.37, respectively, P<0.001) to the virus induced IFN-α production. Despite these positive correlations, no parental offspring group was uniformly superior across all traits measured. However, the heritabilities estimated for the immune parameters are sufficiently high to be used as genetic markers in selection for general immune competence of swine.

Performance of pigs with or without the intestinal receptor for Escherichia coli K88

The adhesion of Escherichia (E.) coli K88ac to epithelial cells of the small intestine was studied after slaughter in 564 crossbred pigs (Swedish Landrace x Swedish Yorkshire). E.coli K88ac adhered to epithelial cells obtained from different parts of the small intestine in 40·8% of the pigs studied. Performance data indicated that presence of the receptor resulted in poorer daily gain during the 1st weeks of life, but that it had a beneficial influence on daily lean growth during the fattening period (24 to 100 kg live weight).

Major Histocompatibility Genes in Egg‐Laying Hens*

ABSTRACT: A common base population of White Leghorn was “synthesized” for a joint project on the genetics of egglaying, undertaken by animal breeding geneticists in 4 Scandinavian countries. After 6 to 7 generations of line selection for various egg‐laying parameters, MHC typing was undertaken of both the selection lines in Denmark, Norway, and Sweden and the respective control lines representing the common base population. Ten MHC haplotypes were defined which jointly accounted for about 95% of the MHC gene pool of the base population. The 2 haplotypes which were predominant in the base population, B15 and B19, responded very differently to the selection pressures applied.

Structure and organization of pigMHC class IIDRB genes: evidence for genetic exchange between loci

The pig major histocompatibility complexDRB genes were studied by polymerase chain reaction (PCR) amplification of exon 2 from eight domestic pigs and two European wild boars. Sequence comparisons together with a phylogenetic analysis showed the existence of at least threeDRB genes of which only one appears to be expressed. The two putativeDRB pseudogenes contained delections in exon 2, making it possible to confirm the presence of three non-allelicDRB genes by analyzing the length polymorphism of the amplified PCR products. The expressed gene shows allelic polymorphism at the same positions as in the humanDRB1 gene. In addition this pig gene shows extensive allelic polymorphism at positions 84–88, whereas, e.g., humanDRB genes do not. Surprisingly, the the two putativeDRB pseudogenes also display a considerable amount of allelic polymorphism, albeit of a different character as compared with the expressedDRB gene. Short stretches of sequences are shared between individual alleles at different loci. These sequence similarities cannot be due to natural selection, since two of the threeDRB genes involved are polymorphic pseudogenes constituting allelic series that have diverged after the inactivation event. Instead, the results indicate that the sequences have been exchanged between theDRB genes by intergenic recombination.

Genetic variation in Con A-induced production of interleukin 2 by porcine peripheral blood mononuclear cells

Genetic variation in concanavalin A (Con A)-induced proliferation and interleukin 2 (IL-2) production by peripheral blood mononuclear cells (PBMC) was studied in blood collected from 96 piglets, aged 7 weeks. The piglets were the offspring of seven sires and 24 dams. Pronounced differences between litters from various dams were observed in the immune parameters measured. Also, large individual differences in the magnitudes of Con A-induced proliferation and IL-2 production were seen for PBMC collected from individual pigs within each litter. Both the time course and magnitude of IL-2 activity showed genetic variation, as results from the offspring of the seven sires differed significantly. However, only the time course, not the magnitude, of proliferation differed among the offspring groups. It was possible to establish a rank order for the sires based on the IL-2 production of PBMC by their offspring. As IL-2 has a key role in regulating the immune response, mitogen-induced IL-2 activity seems to be a good candidate as a general marker for cell-mediated immunity in pigs.

A large linkage group on pig chromosome 7 including the MHC class I, class II (DQB), and class III (TNFB) genes

A large linkage group on pig chromosome 7 including the MHC class I, class II (DQB), and class III (TNFB) genes

A within-litter comparison of the three halothane genotypes. 2. Performance, carcass quality, organ development and long-term effects of transportation and amperozide.

The aim of the investigation was: (1) to compare the three Hal genotypes with respect to performance, carcass quality and organ development at slaughter, (2) to study long-lasting effects of transportation and treatment with amperozide. The study comprised 120 (23 NN, 69 Nn and 28 nn) crossbred pigs, offspring of heterozygous boars and sows. The Hal genotype was revealed by combining the halothane test and blood typing. At an average age of 12 weeks, the pigs were subjected to one of four treatments (with and without transport × with and without amperozide treatment). The pigs were kept in groups of four pigs ( 1NN, 2Nn and 1nn) originating from different litters and were fed individually. Four nn pigs died during the experiment, one owing to fighting on the first day and three on the way to the slaughter house. The nn pigs had higher daily weight gain and lower feed to gain ratio than the NN and Nn animals. Carcass lean content was higher, but meat colour paler for the nn compared with the NN and Nn pigs. The heterozygotes were intermediate to the homozygotes for carcass lean content and meat colour. Organ weights were lower for the nn compared with the NN animals, and those of the Nn pigs were intermediate or close to the NN animals. Pigs subjected to a 5-h transport at 12 weeks had lower carcass lean content than non-transported ones. Amperozide treatment at the same age resulted in increased crude fat content of the liver at slaughter 3 months later. Adrenal weight at slaughter was higher for the amperozide-treated but nontransported animals compared with the other three treatment groups.

A within-litter comparison of the three halothane genotypes. 1. Piglet performance and effects of transportation and amperozide treatment at 12 weeks of age.

The aim of the investigation was to compare the three Hal genotypes within litter, with respect to: (1) piglet performance; (2) effects on agonistic behaviour and weight gain of transport and amperozide treatment at 12 weeks of age. The animals were offspring of heterozygous boars and sows, and the Hal genotype was revealed by the halothane test combined with blood typing. One hundred and twenty pigs, kept in groups of four (1 NN, 2 Nn and 1 nn from different litters), were allotted to the four treatments in an experiment with a 2 × 2 factorial design: with and without transport (5 h) × with and without amperozide treatment. Each transport treatment comprised 15 pens and the animals in seven of these were treated with amperozide. Piglet weight at birth and at 9 weeks did not differ between the Hal genotypes. Amperozide treatment decreased the agonistic behaviour, but the effects on weight gain were inconsistent. Overall, daily weight gain in the first 13 days after the transport/amperozide treatments did not differ, neither between treatment groups nor between Hal genotypes, but interactions between Hal genotype, sex and amperozide treatment were found. Gilts attacked more than castrates, and interactions between Hal genotype and sex were indicated for agonistic behaviour. Creatine kinase (CK) activity was higher in nn compared with NN and Nn pigs. Transport increased the CK activity.

Quantitation of repetitive epitopes in glycosaminoglycans immobilized on hydrophobic membranes treated with cationic detergents

Glycosaminoglycans (GAGs) are linear carbohydrate polymers containing repetitive sequences of differently sulfated uronic acid and glycosamine residues that are recognized by antibodies raised against proteoglycans. We have developed a method to demonstrate such repetitive sequence motifs in isolated GAG chains immobilized on hydrophobic membranes derivatized with cationic detergents. Six monoclonal antibodies directed against Cs (2B6, 3B3, Cs56, and 1B5), Hs (HepSS), and Ks (5D4) were used to detect native and chondroitinase-generated epitopes in the immobilized GAGs. All antibodies, except 1B5, were able to detect epitopes in both proteoglycans and isolated GAGs. Type of detergent and buffer composition affected the accessibility and the retention of immobilized GAGs. The epitope density, i.e., the number of repetitive epitopes per GAG mass, was estimated as the ratio between antibody (epitope) and Alcian blue (mass) staining measured simultaneously. The epitope profiles, using six antibodies, were different for each sample (CsA, CsC, Ds, Hs, intact cartilage, and human serum). The epitope profile may be used as a structural characteristic of a GAG population. Electrophoretic separation of GAGs based on their glucuronic/ioduronic acid content and O-sulfate/N-sulfate ratio was performed using a diethylene glycol-diaminobutanol agarose gel. The electrophoretic populations were characterized by immunoblotting to detergent-treated membranes.