Halothane-catecholamine arrhythmias in swine (Sus scrofa)

The arrhythmogenic dose of epinephrine (ADE) was determined in 6 pigs during steady-state anesthesia (1.5% halothane in O2) and steady-state anesthesia plus xylazine (1.1 mg X kg-1 X hr-1; IV infusion) and after either prazosin (alpha 1) or metoprolol (beta 1) adrenergic blockade during halothane-xylazine (H-X) anesthesia. A constant infusion (1, 2, 3, 5, and 10 micrograms X kg-1 X min-1) of freshly mixed epinephrine (100 micrograms X ml-1 in saline solution) was used to determine ADE. The ADE was defined as the total dose of epinephrine which produced 4 or more continuous or intermittent, premature, ventricular contractions within a 15-s period. The mean epinephrine total dose values during 1.5% halothane anesthesia, H-X anesthesia alone, or H-X anesthesia after either prazosin (0.1 mg X kg-1) or metoprolol (0.5 mg X kg-1) adrenergic blockade were 3.60 +/- 0.844, 2.68 +/- 0.402, 11.85 +/- 3.804, and 5.17 +/- 0.587 micrograms X kg-1, respectively. Xylazine administration did not significantly decrease ADE, although mean arterial pressure significantly increased. Prazosin administration significantly increased ADE and was associated with an increased heart rate and a decreased mean arterial pressure. We conclude that alpha 1-blockade with prazosin is more protective to epinephrine-induced arrhythmias in H-X-anesthetized pigs than is beta 1-blockade with metoprolol.     

Identification of Brucella spp. in feral swine (Sus scrofa) at abattoirs in Texas,USA

Various tissues, nasal swabs, urine and blood samples were collected from 376 feral swine at two federally inspected abattoirs in Texas during six separate sampling periods in 2015. Samples were tested for Brucella spp. by culture and serology. Brucella spp. were cultured from 13.0% of feral swine, and antibodies were detected in 9.8%. Only 32.7% of culture‐positive feral swine were also antibody positive, and 43.2% of antibody‐positive feral swine were culture positive. Approximately, the same number of males (14.0%) and females (12.1%) were culture positive, and slightly more males (10.5%) than females (8.7%) were antibody positive. Our results indicate that serology likely underestimates the prevalence of feral swine infected, and that those who come in contact with feral swine should be aware of the symptoms of infection with Brucella spp. to ensure prompt treatment.     

Anesthetic potency of nitrous oxide in young swine (Sus scrofa)

Determination of nitrous oxide (N2O) potency was accomplished by extrapolation using the concepts of minimum alveolar concentration (MAC) and additivity among inhalation anesthetics. Halothane and isoflurane anesthetic requirement (alveolar concentration) necessary to achieve MAC in 9 pigs decreased with each successive increase in the percentage of inspired N2O (25%, 50%, 75%). Halothane and isoflurane MAC was determined to be 0.94 +/- 0.03 and 1.75 +/- 0.01 volumes percent, respectively. Halothane and isoflurane requirements decreased to 0.74 +/- 0.02, 0.66 +/- 0.02, and 0.58 +/- 0.02; and to 1.56 +/- 0.02, 1.38 +/- 0.02, and 1.08 +/- 0.03 volumes percent with 25%, 50%, and 75% N2O, respectively. The line of best fit derived from regression analysis of the combined data (isoflurane and halothane MAC values) had a correlation coefficient of 0.987 and an X intercept equivalent to 195% N2O. The potency of N2O in pigs was similar to that of other domesticated mammals and reduced halothane and isoflurane anesthetic requirements by approximately 50% of the reduction observed in human beings.     

利用锌指核酸酶对猪基因组进行定向遗传修饰（续完）

4利用ZFN修饰猪的基因组 早期通过ZFN获得遗传修饰动物的研究开始于将其注射到非洲爪蟾（Xenopus laevis）的卵母细胞中（Bibikova等,2001）。虽然最终没有得到活着的基因敲除蟾蜍,但是这个研究证明了ZFN在活体内具有活性,以及可以通过同源重组介导基因组修饰。     

Vaccination of feral pigs (Sus scrofa) using iophenoxic acid as a simulated vaccine

OBJECTIVES: To develop an encapsulation method for delivery of vaccines to feral pigs, and quantify the effect of iophenoxic acid on captive feral pig blood iodine concentrations to assist in investigation of factors affecting vaccine uptake. DESIGN AND METHODS: Feral pigs were administered iophenoxic acid by oral gavage, and consumption was assessed for different encapsulation methods in baits. Blood iodine concentrations were monitored for eight days after consumption. The relationship between dose rate, time since dosing and blood iodine concentration was assessed for gavaged and baited captive feral pigs. Wild feral pigs were baited with PIGOUT baits containing 20 mg of encapsulated iophenoxic acid to simulate a vaccination program. Using knowledge from the pen studies, bait uptake and factors affecting bait uptake were investigated. RESULTS: Bait-delivered iophenoxic acid led to variable and inconsistent changes in blood iodine concentrations, in contrast to pigs receiving iophenoxic acid by gavage. This precluded accurate assessment of the quantity consumed, but still allowed a conservative determination of bait uptake. Iophenoxic acid in smaller capsules was consumed readily. Increasing baiting intensity appeared to increase bait uptake by wild feral pigs, and pigs of varying sexes, ages and weights appeared equally likely to consume baits. CONCLUSIONS: Encapsulated liquids can be delivered to feral pigs within baits, should the need to vaccinate feral pigs for fertility or disease management arise. High baiting intensities may be required.     

Monitoring of classical swine fever in wild boar (Sus scrofa) in Slovenia

Classical swine fever (CSF) is a highly contagious multi-systemic haemorrhagic viral disease of pigs. Not only domestic pigs, but also wild boar appear to play a crucial role in the epidemiology of CSF. Spleen (n = 739) and blood coagulum (n = 562) sampled from wild boars (Sus scrofa) shot in 2002, and serum samples from 746 wild boar shot in 2003 and 2004, were tested throughout Slovenia. In 2002, 17 samples were positive on enzyme-linked immunosorbent assay (ELISA) test for antibodies against classical swine fever virus (CSFV). Positive ELISA test was confirmed by a virus neutralization test. All other samples were negative. This is the first report that describes the epidemiology of CSFV from 2002 on, and the monitoring of the wild boar population in Slovenia at present.     

Functional significance of musculature of the external nose in swine (Sus scrofa f. domestica)

The origin and attachments of the muscles of the external nose were examined in 17 pigs comprising both sexes and different age groups. The modification of the porcine nasal apex to the snout-disc leads to different functional aspects of the muscles of the external nose. Accordingly, all these muscles are attached to the snout-disc. Only the nasolabial levator and caninus muscles are also attached to the upper lip. In addition, the snout-disc includes an intrinsic muscle, the nasal muscle. With regard to morphological and functional aspects, the nostrils can be divided into two parts. The superficial part consists of muscle and connective tissue and is dilated by the cooperative contraction of all muscles of the external nose. In contrast, the second and cartilaginous part of the nostrils dilates less readily, through contraction of the rostrally located deep fibres of the levator nasolabial muscle. As an adaptation for rooting, a special supportive system for muscles of the external nose has developed in pigs, including osseous (eminentia canina) and muscular (muscular slip of the m. levator labii superioris attached to the nasal bone, species-specific development of the m. levator nasolabialis) structures. The observed cartilaginous connection between the ventral lateral nasal and the vomeronasal cartilages suggests another transport mechanism for odours into the vomeronasal organ. Due to this connection, movement of the snout-disc and the cartilages of the external nose could imply passive movement of the vomeronasal cartilage and therefore of the vomeronasal organ.     

Cell Biology Symposium: Zinc finger nucleases to create custom-designed modifications in the swine (Sus scrofa) genome

Engineered zinc finger nucleases (ZFN) are rapidly gaining popularity as a means to enhance the rate and specificity of DNA modifications in plant and animal cells. Repair-mediated gene modification by ZFN is driven by introducing DNA double-strand breaks via a nonspecific nuclease domain linked to a sequence-specific zinc finger nucleotide recognition domain. This review examines the use of ZFN to produce genetically modified swine and the potential of this technology for the future. By combining conventional gene targeting methods with somatic cell nuclear transfer, several genetically modified pig models have been produced. These conventional techniques are inefficient in mammalian somatic cells and provide little control over the site specificity and rate of exogenous DNA integration. The use of engineered ZFN that bind and cleave genomic DNA at specific loci can enhance targeting efficiencies by orders of magnitude. Recent publication of the first genetic modification in pigs by combining ZFN technology with somatic cell nuclear transfer has opened the door to genome targeting with a precision that was not previously possible in a large animal model. Since that time, model pigs with selective knockout of endogenous genes have been produced. This review will examine the use of ZFN to generate these pig models and the potential of ZFN to accelerate the production of genetically modified pigs of agricultural and biomedical importance. Current methods of ZFN design, important considerations for their safe and effective use in modification of the swine genome, and future innovative applications of this technology in pigs will be discussed.     

Trichinella spiralis in wild boars (Sus scrofa)

During the period 1.7. 1972--31.6. 1977 muscle samples from 137 wild boars were examined for Trichinella spiralis. Larvae of T. spiralis were demonstrated in 4 animals. The major part (83) of the wild boars examined, including the 4 positive ones, originated from one particular game park. The rate of infection with T. spiralis in the game park concerned was 4.8%. Calculated on the basis of the total of animals examined, the rate of infection was 2.9%.     

Isolation of Campylobacter from feral swine (Sus scrofa) on the ranch associated with the 2006 Escherichia coli O157:H7 spinach outbreak investigation in California

We report the isolation of Campylobacter species from the same population of feral swine that was investigated in San Benito County, California, during the 2006 spinach-related Escherichia coli O157:H7 outbreak. This is the first survey of Campylobacter in a free-ranging feral swine population in the United States. Campylobacter species were cultured from buccal and rectal-anal swabs, colonic faeces and tonsils using a combination of selective enrichment and antibiotic-free membrane filtration methods. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS, Bruker Daltonics, Inc., Billerica, MA, USA) was used to identify species followed by confirmatory multiplex PCR or 16S rRNA sequencing. Genetic relatedness of Campylobacter jejuni and Campylobacter coli strains was determined by multilocus sequence typing (MLST) and porA allele sequencing. Altogether, 12 (40%) of 30 feral swine gastrointestinal and oral cavity specimens were positive, and six species were isolated: Campylobacter coli, Campylobacter fetus, Campylobacter hyointestinalsis, Campylobacter jejuni, Campylobacter lanienae and Campylobacter sputorum. Campylobacter jejuni subtypes were closely related to MLST sequence type 21 (ST-21) and had identical porA sequences. Campylobacter coli subtypes were unrelated to isolates in the pubMLST/porA database. This feral swine population lived in close association with a 'grassfed' beef cattle herd adjacent to spinach and other leafy green row crop fields. The findings underscore the importance of protecting raw vegetable crops from faecal contamination by wild or feral animals. The study also illustrates a potential risk of Campylobacter exposure for hunters during handling and processing of wild swine meat.     

Morphological changes in the pineal body of domestic swine (Sus scrofa domesticus) depending on light]

The cerebral epiphysis of twelve gilts, aged 6.5 months, was histologically, histochemically, and histometrically tested, after the animals had been kept permanently under artificial light, 100 lux, or in darkness, interrupted twice a day by two hours of lighting, over ten weeks altogether. The parenchymal cells of the epiphyses of the animals kept in darkness changed clearly from those of the other group with constant exposure to light. Changes in the darkness animals included significant enlargement of the cell nuclear volume by 33 per cent, increase in nucleoli count as well as increases of lipids and ribonucleic acid in cytoplasm.     

A systematic study of brain base arteries in the wild boar (Sus scrofa scrofa)

This study aimed at describing and systematizing the arteries of the base of the brain of the wild boar (Sus scrofa scrofa). Thirty-three heads were used, of which 30 were injected with latex, and three with acrylic dental resin through the common carotid arteries. The brain carotid artery arose from the rostral epidural rete mirabile, and divided into a rostral and a caudal branch. The rostral branch gave off the middle cerebral artery and then continued as rostral cerebral artery. The latter branched into lateral rhinal, internal ethmoidal and medial rhinal arteries. The rostral cerebral artery joined its contralateral homologue, becoming the single rostral inter-hemispheric artery. The caudal branch emitted the caudal cerebral artery and the tectal arteries, and then fused with the branch of the opposite antimere, joining the basilar artery. The rostral cerebellar arteries derived from this point. The basilar artery originated from the anastomosis between the arteries derived from the caudal epidural rete mirabile of each antimere. The basilar artery extended rostrally, giving off as main collateral branch the caudal cerebellar artery. The basilar artery presented a significant decrease in diameter before joining the caudal branches of the brain carotid arteries. The cerebral arterial circle was rostrally and caudally closed.     

Morphological Investigations of the Glandulae Profundae Plicae Semilunares Conjuctivae in the Domestic Swine (Sus scrofa domesticus) and the Wild Hog (Sus scrofa ferus)

Samples of glandulae profundae plicae semilunares (Harderian glands) from five domestic swine and five wild hogs were used for this research. The gland samples were fixed in Bouin solution and mounted in paraffin. The paraffin slices were stained with haematoxylin and eosin, according to the periodic-acid-Schiff (PAS) method, with alcian blue (pH 2.5), with toluidine blue (pH 4.0), and applying a combination of staining with alcian blue (pH 2.5) and the PAS method. In domestic swine and wild hogs, these glands are tubular-alveolar with wide glandular lumina. A great deal of acid mucopolysaccharides and PAS-positive substances were noted within swines’ glandular cells, while, in wild hogs, PAS-positive substances were not frequent, acid mucopolysaccharides being noted in only a few glandular-acini cells. The appearance of the metachromatic phenomenon was not noted either in domestic swine or in wild hogs. In domestic swine, the level of acid mucopolysaccharides is probably due either to the housing method or to the influence of the alkaline substances that may appear on an eye's mucous conjunctive membrane during intensive breeding, such that the Harderian glands protect the mucous membrane by extracting acid mucopolysaccharides.     

Histomorphologic and Histochemical Characteristics of Carpal Glands (Glandulae Carpeae) in Domestic Swine (Sus scrofa domesticus) and Wild Swine (Sus scrofa ferus)

Investigations were carried out on samples from carpal glands of domestic and wild swine of different ages. The anatomic position of carpal glands is identical in domestic and wild swine. Glandular acini in domestic swine are bigger and more scarce than in wild swine. LDH activity is more intense in wild swine, while the activity of the investigated diaphorases is almost even. The activity alkaline and acid phosphatase is stronger in domestic swine, while the activity of non-specific esterases is present only in wild animals. The more or less manifest presence of all investigated enzymes indicates that carpal glands in domestic and wild porcine specimens are very active metabolically. Regarding the intensity of enzymatic reactions, some differences are probably due to different sexual maturity, as well as to the method of feeding and housing in these groups of animals.     

Validating the effectiveness of alternative euthanasia techniques using penetrating captive bolt guns in mature swine (Sus scrofa domesticus)

Euthanasia of mature swine is challenging. Temporal and behind-the-ear locations are two sites that have been identified as alternatives to the more commonly used frontal placement. In stage one, the effectiveness of two penetrating captive bolt gun styles (cylinder or pistol) was evaluated using frontal, temporal, and behind-the-ear placement in anesthetized mature swine (n = 36; weight: 267 ± 41 kg). For stage one, when evaluating treatment efficacy by sex, the cylinder-style equipment was 100% effective in achieving death when applied to all cranial locations (frontal, temporal, and behind-the-ear) for sows; however, the pistol-style equipment was only 100% effective when applied at the behind-the-ear location for sows. For boars, the cylinder-style equipment was 100% effective when applied to the frontal and behind-the-ear location, but the pistol-style equipment was not effective for any cranial location in boars. Therefore, the pistol–frontal, pistol–temporal, pistol–behind-the-ear, and cylinder–temporal were not included for boars, and pistol–frontal and pistol–temporal were not included for sows in stage two. In stage two, commercial, mixed-breed, mature swine (n = 42; weight: 292 +/− 56 kg) were randomly assigned to one of four treatments based on the inclusion criteria described in stage one. A three-point traumatic brain injury (TBI) score (0 = normal; 1 = some abnormalities; 2 = grossly abnormal, unrecognizable) was used to evaluate six neuroanatomical structures (cerebral cortex, cerebellum, hypothalamus, thalamus, pons, and brain stem), and the presence of hemorrhage was also noted. All treatments were 100% effective in stage two. A significant interaction between gun style and placement was determined on predicting total TBI as the cylinder style produced a higher total TBI score compared with the pistol type of the magnitude of +2.8 (P < 0.01). The cylinder style tended to produce a greater TBI score than the pistol in the temporal location (+1.2; P = 0.08). No difference was noted for TBI score behind-the-ear between the cylinder- and pistol-style gun (P > 0.05). TBI tended to be less in boars compared with sows (−0.6; P = 0.08). Hemorrhage was observed in frontal, parietal, occipital, and temporal lobes. This study demonstrated that the cylinder-style captive bolt gun more effectively resulted in brain trauma and death compared with a pistol-style gun and the behind-the-ear and temporal placement showed promise as an alternative placement site for euthanizing mature pigs on-farm.     

Technical note: adipose tissue blood flow in miniature swine (Sus scrofa) using the 133xenon washout technique

The purpose of this study was to examine the 133xenon washout technique as a viable method for measuring adipose tissue blood flow (ATBF) in swine. Using a total of 32 female Yucatan miniature swine (Sus scrofa), the partition coefficient for 133xenon in swine subcutaneous adipose tissue was determined and ATBF was measured at rest and under various physiological conditions. These conditions included feeding, anesthesia, epinephrine infusion, and acute exercise. The effects of epinephrine and acute exercise were examined in both sedentary and exercise-trained swine. The partition coefficient value for 133xenon in swine subcutaneous adipose tissue was 9.23+/-0.26 mL/g (mean +/- SD, n = 10). The average value for resting ATBF in swine was 3.98+/-2.72 mL/(100 g tissue-min) (n = 19). Feeding increased ATBF by approximately fivefold over fasting values, and isoflurane anesthesia significantly decreased ATBF compared to rest (1.64+/-1.12 vs 3.92+/-4.22 mL/[100 g x min], n = 10). A 30-min epinephrine infusion (1 microg/[kg BW x min]) significantly increased ATBF from a resting value of 3.13+/-2.61 to 10.35+/-5.31 mL/(100 g x min) (n = 12). Epinephrine infusion into exercise-trained swine increased ATBF to the same extent as when infused into sedentary swine. An acute, 20-min bout of exercise significantly increased ATBF in swine, and the sedentary swine showed a larger increase in ATBF than their exercise-trained littermates relative to rest: 7.83 vs 2.98 mL/(100 g x min). In conclusion, the 133xenon washout technique appears to be a viable method for measuring ATBF in swine; our findings are comparable to swine ATBF values reported using the microsphere method and are consistent with values reported in animal and human studies.     

Reciprocal translocations in the pig (Sus scrofa): a review

The incidence and effect of 29 different reciprocal translocations in the pig are reviewed. It is concluded that heterozygosity for these translocations causes major reproductive loss. The chromosome anomaly appears to occur spontaneously and between 42 per cent and 50 per cent of hypoprolific boars are carrier animals. The incidence in the general population is calculated to be 0.6 per 1000.