Stability of glutathione peroxidase in swine plasma samples under various storage conditions.

The stability of plasma glutathione peroxidase under different temperatures (4 degrees C vs. -15 degrees C), various durations of storage (0, 1, 2, 3, 7, 14, 28 and 56 d), and storage under inert gas (nitrogen (N2)) vs air is described. The glutathione peroxidase activity of swine plasma decreased consistently with storage at either 4 degrees C or -15 degrees C 1-56 d after collection, and differed (P less than or equal to 0.01) from the initial values. Storage under N2 at -15 degrees C slowed the rate of enzyme activity decrease but did not maintain the initial activity. For absolute measurements, it is suggested that swine plasma glutathione peroxidase activity be measured immediately after separation from the blood cells or be assayed within 24 h in plasma samples stored at -15 degrees C with air space displaced by N2. If relative treatment differences in enzyme activity are satisfactory, then assays can be conducted after controlled periods of storage.     

The crossbred sire: experimental results for swine

Experiments aimed at comparing crossbred and purebred boars were reviewed. These experiments showed that crossbred boars matured sexually more quickly than corresponding purebred boars: they exhibited greater testis weight, large ejaculate volume and had better semen quality. Young crossbred boars were more aggressive sexually and achieved a higher conception rate, particularly on first service. Differences between the two types of boars for litter size and weight were generally small and variable in direction. Growth rate, feed efficiency and carcass characteristics of progeny of purebred and crossbred boars were generally similar. In addition, there was little evidence that use of crossbred sires had any effect on variability of pig performance.     

The behavior of calves under various housing conditions]

Investigations were performed regarding the length of rest, sucking and feeding and the daily rhythm of these activities in calves kept with their mothers on pasture or in stables and the motility of the calves. Length of rest and feeding in breeding calves kept in groups and length of rest and sucking in breeding and fattening calves (automatic feeding and bucket feeding) were examined too. The examinations were performed starting from the morning feeding to the end of the day over a period of appr. 10.5 to 12 hours. During this time, calves 2--4 weeks of age ran about 550,7 m, 6--8 weeks of age 423.7 and 10--12 weeks of age 388.1 m. The length of sucking under automatic feeding conditions was comparable to the datas obtained from calves kept with their mothers. Bucket feeding took 2--4 minutes regardless whether rubber teats were used or not. Fattening calves in groups or single showed feint sucking or licking activities of 70.0 and 114.0 minutes/day respectively, breeding calves 39.8 and 20.8 minutes/day resp. Feint sucking in connection with a deficit of real sucking was observed regularly under bucket feeding conditions but only in those cases of automatic feeding, where the calves pushed each other aside from the feeding facilities. Feint rumination was observed in all fattening calves when kept strawlessly and lasted for about 31 minutes/day. Neither the feint rumination nor the feint sucking ever reached physiological lengths. Both behavioural patterns may be important in regard to animal welfare considerations of special maintenance conditions.     

Salmonella and Erysipelothrix infection in swine: a laboratory summary.

The occurrence of salmonellas and Erysipelothrix rhusiopathiae in tissues of swine was determined by bacteriologic and fluorscent antibody examination of 5,297 specimens from herds investigated for hog cholera. Of the specimens examined, 35.5% were positive for salmonellas, 21.1% were positive for E rhusiopathiae, and 8.3% were positive for both salmonellas and E rhusiopathiae.     

Porcine myelomonocytic markers: summary of the second international swine CD workshop

Forty five mAbs submitted to the Second International Swine CD workshop were analyzed by six different laboratories for their possible reactivity with porcine myelomonocytic cells using flow cytometry and immunohistochemistry. As a result of these analyses, a new swine workshop cluster, SWC9, composed of two mAbs that recognize an antigen selectively expressed on mature macrophages, was defined. In addition, several mAbs were identified, allowing the differentiation of granulocytes from monocytes/macrophages, or monocytes from macrophages. Further work is required to identify the antigen recognized by these mAbs. Nevertheless, they should already prove useful for the identification of different stages in the macrophage maturation/differentiation, and will certainly aid analyses on the complexity of the mononuclear phagocyte system in the pig. Finally, the cross-reactivity of three anti-human CD14 mAbs with porcine myelomonocytic cells was established in this workshop.     

Nutrient management practices among swine operations of various sizes

OBJECTIVE: To determine feeding, cropping, and manure-handling practices of swine operations of various sizes. DESIGN: Producer survey. SAMPLE POPULATION: 85 sow units and 132 finish floors. PROCEDURE: Swine producers were surveyed by mail and during farm visits for information regarding herd characteristics and management practices, with emphasis on the 3 components of the nutrient cycle: cropping, feeding and nutrition, and manure handling. Farms were categorized by operation type as sow units or finish floors and, subsequently, stratified by size as small sow units (< 600 head), large sow units (> or = 600 head), small finish floors (< 2,000 head), and large finish floors (2 > or = 2,000 head). RESULTS: Large sow units and large finish floors were approximately twice as likely to use environmentally sound nutrient management practices as small sow units or small finish floors. These large operations were more likely to use progressive feeding practices, to be aware of their nutrient flows, and to be capable of using these nutrients properly. CONCLUSIONS AND CLINICAL RELEVANCE: There is a need for greater environmental awareness among all swine producers, especially among small producers. This provides a possible growth area for large-animal veterinary consultants. Economy of scale and increased governmental regulations allow large farms to use environmentally sound practices. Thus, large swine farms are not necessarily harmful to the environment.     

铅在猪不同组织和器官中的富集状态

本试验旨在研究饲料中铅含量与猪组织和器官中铅含量的关系,及铅在猪各组织和器官中的分布规律,为制定猪可食用器官中铅含量限量标准提供理论依据.将24头大约克夏仔猪随机分为4组,分别饲喂含铅量为0.398mg/kg(对照组),6.095 mg/kg(低剂量组),17.49 mg/kg(中剂量组),51.674 mg/kg(高剂量组)的饲料,持续喂养90 d,屠宰、取其心脏、肝脏、脾脏、肺脏、肾脏、小肠、猪毛、猪皮、脂肪、猪血、骨髓、猪耳、猪舌、猪尾、里脊、臀尖、小排、后腿内,测定其中的铅含量.结果表明,随着饲料中铅含量的增加,猪体内各组织和器官中的铅含量均有不同程度的升高.对照组组织和器官中铅含量由高到低的次序为肾脏>脾脏>肝脏>毛发>其他组织和器官,其中肾脏、脾脏铅含量超标;3个给铅组组织和器官中铅含量由高到低的次序为骨髓>肾脏>脾脏>肝脏>毛发>猪尾>其他组织和器官;其中肾脏、脾脏、肝脏、猪尾均超标,但各组猪的肌肉、脂肪、猪皮、小肠等组织或器官中的铅含量较低,均符合国家标准<食品中污染物限量,GB 2762-2005>.表明随着饲料中铅含量的增加,猪组织和器官中铅的富集有所不同,其中骨髓、肝脏、肾脏和脾脏中的铅含量较高,猪皮、肌肉、脂肪、小肠、猪舌、猪心、猪肺等可食用组织和器官中铅的含量较低.     

Susceptibility of colostrum-deprived swine of various ages to streptococcic lymphadenitis

The effect of age on susceptibility of young pigs to streptococcic lymphadenitis was investigated. Twenty-nine cesarean-derived, colostrum-deprived pigs were allotted to 7 groups exposed to type IV group E Streptococcus (GES) at 5, 14, 28, 35, 56, 70, and 84 days of age. Four cesarean-derived, colostrum-deprived pigs were maintained as nonexposed controls. Six naturally farrowed, susceptible controls were exposed to GES at 63 to 84 days of age. All exposed pigs were killed and necropsied 28 days after exposure. Lesions of streptococcic lymphadenitis were not observed in pigs exposed at 5 or 14 days of age, except for 1 microabscess in a mandibular lymph node in a pig exposed at 14 days, but GES was recovered from 11% of lymph nodes examined from pigs of those age groups. Lesions and GES-positive lymph nodes were frequent in cesarean-derived, colostrum-deprived pigs exposed at 28 days and older and in susceptible controls. Serologic response to exposure, as determined by microtitration agglutination test and bactericidal test, was observed only in pigs exposed at 14 days and older. The absence of abscess development in pigs exposed at 5 or 14 days of age was not caused by antibody or failure of infecting organisms to reach the target organs.     

The influence of cellulose and various starches in feed on nitrogen metabolism in growing swine

In N-balance experiments with a total of 49 female fattening pigs with a live weight between 33 and 47 kg the influence of cellulose supplements (exchanger principle) and changing quotas of maize starch and maize soak starch in semisynthetic feed mixtures on parameters of N-utilization was studied. The results show that there may be a positive influence of the supplement of cellulose on total N utilization (b-value, Gebhardt, 1963). One can conclude that, apart from a shift of the ways of N-excretion through faeces and urine, the utilization of products of microbial protein synthesis for N-retention is possible to a nutrition-physiologically relevant degree. The influence of the kind of starch on N-utilization was small.     

猪饲喂甜菜碱和肉碱的研究结果

1.甜菜碱 对在猪日粮中添加甜菜碱(0.1%～0.2%)的大量研究主要集中在育成阶段考察甜菜碱对猪胴体品质的影响。最初Cadogan等(1993)试验报道,在屠宰前35天添加0.125%的甜菜碱,背膘降低14.8%。由于很多重要的试验细节(例如日粮中胆碱和蛋氨酸水平)不能提供,这妨碍了对现在试验结果的对比。然而,Shurson等(1994)对早期的研究进行总结得出结论,在屠宰前30     

The correlation between passage rate of digesta and dry matter digestibility in various stages of swine

The relationship between passage rate of digesta (PRD) and apparent faecal dry matter digestibility (DMD) was investigated in five trials. In trial 1, 2, and 3, 36 weanling (16.9 ± 3.0 kg), 24 growing (51.3 ± 8.8 kg), and 23 finishing (104.8 ± 5.2 kg) barrows were housed in metabolic crates. The beginning and end of 5-day collection periods were marked by the addition of 0.5% indigo carmine to the feed for total faeces collection and PRD determination by observing the time required for the marker to appear. In trial 4 and 5, 21 gestating gilts (215.0 ± 15.0 kg), and 19 lactating sows were individually penned. Addition of 0.5% chromic oxide to the feed enabled indirect determination of DMD and PRD. The PRD, which ranged from 12 to 80 h, was positively correlated with DMD in weanling (R² = 0.483, P < 0.001), growing (R² = 0.425, P < 0.01), and finishing (R² = 0.553, P < 0.001) pigs. Body weight and DMD were not significantly correlated in weanling (R² = 0.001, P = 0.893), growing (R² = 0.000, P = 0.995), or finishing (R² = 0.092, P = 0.156) pigs. A positive correlation between PRD, which ranged from 27 to 102 h, and DMD occurred in gestating gilts (R² = 0.231, P < 0.05), but not in lactating sows (R² = 0.014, P = 0.633). The results indicate that longer retention times of digesta improve DMD in swine. Also the results indicate the importance of PRD as a potential independent variable in digestibility assessments.     

Airborne transmission of classical swine fever virus under experimental conditions

Sixty-one pigs were housed in an isolation unit with three compartments and five pens. Each compartment had its own ventilation system resulting in air currents flowing from compartment A (pens 1 to 3) towards compartment B (pen 4), but not towards compartment C (pen 5). Classical swine fever virus was introduced by the experimental inoculation of one pig in the middle pen (pen 2) of compartment A. The virus infected the pigs in pen 4, following the prevalent air currents, and the compartmentalisation had only a retarding effect on the transmission of the virus. The absence of infection in the pigs in pen 5, which was not different from pen 4 except for the ventilation system, indicates that the spread of virus was affected by the air currents.     

Plasma concentration curves of catecholamines and corticosteroids as well as PBI in swine kept under various conditions and acutely exposed to cold]

The response to acute cold (-5 degrees C) of swine kept single was found to differ from that of animals kept in groups. Such difference in reaction was reflected in significant variation of plasma concentration curves in catechol amines and 11-OHKS during and after acute exposure to cold. The response to cold stimulation of animals kept single was primarily and pronouncedly via the sympathicoadrenal system, whereas animals kept in groups responded to acute cold exposure, with the hypothalamic-adrenocortico-pituitary system playing the major role. Significant rise in PBJ in response to 30 and 90 minutes of exposure to cold was recorded only from animals kept single and interpreted as an expression of strong adrenergic reaction of such probands. Such difference in response to one and the same acute stimulus supported the conclusion that there was a difference in adaptation capacity between animals in those two keeping conditions. The results also suggested that type and degree of organic response to a specific stimulus were likely to depend not only on the intensity of the given stimulus, but also on the control potential produced by all closely interconnected control circuits at the time of stimulation.