Mother Sows Research Articles

Yeast-based nucleotide supplementation in mother sows modifies the intestinal barrier function and immune response of neonatal pigs.

In the present study, we aimed to evaluate the effects of maternal yeast-based nucleotide (YN) supplementation on the intestinal immune response and barrier function in neonatal pigs, as well as the diarrhoea rate and growth performance in suckling piglets. Sixty-four late-gestation sows were assigned to the following groups: the CON (fed a basal diet) and YN groups (fed a basal diet with 4 g YN/kg diet). The experiment started on d 85 of gestation and ended on d 20 of lactation. Diarrhoea rate and average daily gain of the piglets were recorded, and samples of blood and intestines from neonatal piglets were collected before they consumed colostrum during farrowing. Compared with the CON group, maternal YN supplementation increased the weaning weight of litter and decreased the diarrhoea rate (P < 0.01). In addition, maternal YN supplementation promoted the ileal villus development in the neonates compared with that in the CON group (P < 0.01). Maternal YN supplementation also increased the ileal secretory immunoglobulin A (sIgA) level compared with that in the CON group (P < 0.05). The real-time PCR results showed that maternal dietary YN supplementation increased the jejunal and ileal expression of interleukin (IL)-17, IL-8, IL-1β, IL-10 and tumor necrosis factor (TNF)- α in the neonates compared with that in the CON group (P < 0.05). Overall, maternal nucleotide supplementation improved the villus development and innate immunity of neonatal piglets during late pregnancy. This may be associated with the decrease in diarrhoea and the increase in weaning weight of the litter of suckling piglets.

How does animal welfare taste? Combining sensory and choice experiments to evaluate willingness to pay for animal welfare pork

Although consumers show considerable interest in higher animal welfare, the market share for such products remains low. To provide consumers with a choice regarding different levels of animal welfare, animal welfare labels have been developed. Such product options are intended to serve as intermediate products between conventional products and more expensive organic options that are often associated with high animal welfare standards. This study aims to evaluate whether information about animal welfare practices affects consumers’ liking and willingness to pay (WTP) for a pork product. Using a within-subject design with three evaluation rounds (blind, expectation, and full information) we combine hedonic liking where subjects rate four different types of ham with a choice experiment. Hams differ in the animal husbandry conditions during the rearing and fattening process: conventional rearing, a specific treatment of mother sows, a general animal welfare label, and organic production. Results show an effect of information on consumers’ sensory evaluation of the different products, although products were evaluated to be similar in the blind condition. Consumers rated the organic product higher than those with animal welfare labels while the conventional option had the lowest liking scores. Results from the choice experiment concur with the hedonic rating. Estimates indicate that consumers are willing to pay more for ham bearing a general animal welfare or organic label in the expectation and full information condition. Consequently, information regarding animal welfare affects both consumers’ hedonic liking and WTP for ham.

Early vocal ontogeny in a polytocous mammal: no evidence of social learning among sibling piglets, Sus scrofa

Animals living in social proximity often have similar vocalizations. For many bird and several mammal species, at least part of the vocal similarity is socially learned during ontogeny. Little is known, however, about the ontogenetic origin of vocal similarities among siblings in polytocous mammals. We investigated the influence of social environment and genetic relatedness on the development of acoustic similarities among suckling piglets. To examine whether the common acoustic features are innate or learned by postnatal vocal convergence in the same litter, we cross-fostered piglets among pairs of mother sows immediately after birth and recorded contact calls (grunts) of both the cross-fostered and the noncross-fostered piglets during the suckling period. Acoustic distances of the cross-fostered piglets to their new littermates remained longer than those among noncross-fostered siblings and were as long as those between piglets from different litters. The results show that after being neonatally cross-fostered to another litter, the piglets did not converge acoustically with their new littermates even after several weeks of cohabitation. This is in contrast to the presence of vocal plasticity during the ontogeny of other mammals including other ungulates, indicating that use of vocal learning may vary even in closely related species, perhaps in relation to its adaptive utility within the life history and social organization of the species.

El comportamiento bioproductivo de cerdas reproductoras y su descendencia alimentadas con aditivo probiótico

Los aditivos probióticos contienen microorganismos benéficos vivos que incluidos en la dieta en cantidades adecuadas repercuten de manera positiva en la salud del huésped. Sin embargo, los altos costos han limitado su uso en los productores de carne de cerdo en los países en desarrollo. Con el objetivo de evaluar el comportamiento bioproductivo en cerdas reproductoras y su descendencia al suplementar biopreparado en la dieta. Se emplearon 12 cerdas reproductoras híbridos CC21 (Yorkshire-Landrace/L35 Duroc) y su descendencia, distribuidas en dos grupos de síes animales cada uno, T1 Control y T2 tratamiento. T2, contenía Lactobacillus acidophilus, Streptococcus thermophilus y Kluyveromyces fragilis (L-4 UCLV). Se utilizó un Diseño Completamente Aleatorizado, donde se evaluó la ganancia de peso y el comportamiento productivo en la descendencia; ganancia de peso en las crías a partir del nacimiento hasta la pre-ceba, casos diarreicos y mortalidad, y la caracterización morfo-tintorial de los microrganismos provenientes del hisopado rectal. La ganancia de peso en cerdas madres y su descendencia fue mayor (P&gt;0,05) en el T2. Los casos diarreicos y mortalidad fue menor (p&lt;0,05) en el T2; con la caracterización morfo-tintorial se observó mayor (P&lt;0,05) carga microbiana principalmente de cocos en cadena y aislados, bacilos cortos y en cadena Gram positivo y levaduras. Se concluye, que la inclusión de biopreparado en la dieta de cerdas reproductoras y su descendencia mejora el comportamiento bioproductivo, reduce los trastornos diarreicos y muertes, y aumenta la carga microbiana con característica morfo-tintorial correspondientes a bacilos, cocos Gram positivo y levaduras.

Condition of sows during reproductive activity depending on lipid metabolism gene (DGAT1) polymorphism

Abstract Mutations at gene loci associated with body lipid metabolism may affect not only carcass and meat quality traits in young animals but also the production results of mother sows. The objective of the study was to determine the effect of mutations in the DGAT1 gene, found in Polish populations of maternal breeds, on condition of gilts and later on condition and reproductive performance of sows during three reproductive cycles. The study involved 118 gilts of maternal breeds (Polish Large White (PLW ) and Polish Landrace (PL)). Gilts and subsequently sows were monitored for body weight (BW) and P2 backfat thickness over three reproductive cycles and their litters were analysed for the number and body weight of the piglets. A total of 354 litters of pigs were evaluated. In the analysed pig populations, a single mutation (A/G) in the DGAT1 gene (rs45434075) had a significant effect on deposition of subcutaneous fat only in the PLW gilts (P2G, AA,AG&lt;GG P≤0.05 and P2F r=214 P≤0.01). As regards the G/A 3’UTR polymorphism of the DGAT1 gene (rs342152658), this mutation is negatively correlated only in the PL sows with fatness during their reproductive life and with BW of the piglets reared to 21 d of age. Sows of the DGAT1GG 3’UTR genotype had significantly lower P2F backfat thickness (P≤0.05) and, during a 21-d lactation, reared lighter piglets (P≤0.01) compared to sows of the same breed with the DGAT1AG 3’UTR genotype. The analysed traits were also affected by the interaction between mutations in the DGAT1 gene of the sows of maternal breeds (DGAT1/DGAT1 3’UTR). Sows of the DGAT1GG/GG genotype were characterised by the highest backfat thickness on selection day, and during three reproductive cycles they reared significantly more piglets compared to sows of the DGAT1AA/AG genotype. Heterozygous sows (AG/AG) reared significantly heavier piglets than sows of the AA/GG and AG/GG genotypes (P≤0.05).

Thermophile-fermented compost extract as a possible feed additive to enhance fecundity in the laying hen and pig: Modulation of gut metabolism

Recently, we reported that the oral administration of an extract of compost fermented with marine animal resources and thermophilic Bacillus species should confer health benefits in fish, pigs and rodents. Herein, the relations between fecundity and gut metabolites in laying hens and pigs on farms after oral exposure to compost were investigated. On the hen farms, the egg production of hens continuously administered the extract was maintained at significantly higher levels compared with the hens not administered the extract. On the swine farms, after the compost treatment, the shipping dates of fattening pigs were shortened, with an improvement in the death rate of the pigs. When the levels of fecal organic acids, such as short-chain fatty acids, lactate, and ammonium, as indicators of gut metabolism and energy sources for peripheral tissues, were examined, the levels of the acetate, propionate, and butyrate in the feces of the hens and pigs in the compost-treated group were not always different from those in the untreated control group. However, the levels of lactate were consistently low in the feces of both animals after the compost treatment. The fecal ammonium concentrations in old hens (age 597-672 days) and 2-month-old piglets from the compost-fed mother sows were low when compared with the untreated groups. The concentrations of free organic acids and their related compounds in the animal products (eggs and pig loins) were nearly equal to those in the untreated control products. Thus, the oral administration of the thermophile-fermented compost should improve the fecundity of hens and pigs by modifying their gut metabolism.

Genetic diversity of livestock-associated MRSA isolates obtained from piglets from farrowing until slaughter age on four farrow-to-finish farms.

During a previous longitudinal study, performed on four farrow-to-finish farms (A to D), samples were taken from twelve sows, their offspring, and the environment on various occasions over six months to study the MRSA presence. During the present study, a selection of the obtained MRSA isolates were typed by multiple-locus variable-number tandem-repeat analysis (MLVA), Pulsed Field Gel Electrophoresis (PFGE), spa typing, and SCCmec typing to study the genetic diversity of LA-MRSA isolates and to determine possible MRSA sources for pig(let)s. PFGE, spa typing, and SCCmec typing revealed the presence of one or few dominant genotype(s) per farm. In contrast, 212 MLVA types were detected on the four farms, forming one cluster on farm A, three on farm B, four on farm C and two on farm D. The genotype, found on farm A was unique for this farm. Farms B, C and D shared one cluster. In general, MLVA types from these clusters were isolated from piglets, sows, and the environment on various sampling events. Piglets carried MLVA types both related and unrelated to their mother sows’ MLVA types at farrowing and onwards. In conclusion, molecular typing revealed that within a farm one or a few dominant strain(s) are widespread. Potential MRSA sources for piglets were mother sows, the environment and other piglets.Electronic supplementary materialThe online version of this article (doi:10.1186/s13567-014-0089-4) contains supplementary material, which is available to authorized users.

Genetic diversity of livestock-associated MRSA isolates obtained from piglets from farrowing until slaughter age on four farrow-to-finish farms

During a previous longitudinal study, performed on four farrow-to-finish farms (A to D), samples were taken from twelve sows, their offspring, and the environment on various occasions over six months to study the MRSA presence. During the present study, a selection of the obtained MRSA isolates were typed by multiple-locus variable-number tandem-repeat analysis (MLVA), Pulsed Field Gel Electrophoresis (PFGE), spa typing, and SCCmec typing to study the genetic diversity of LA-MRSA isolates and to determine possible MRSA sources for pig(let)s. PFGE, spa typing, and SCCmec typing revealed the presence of one or few dominant genotype(s) per farm. In contrast, 212 MLVA types were detected on the four farms, forming one cluster on farm A, three on farm B, four on farm C and two on farm D. The genotype, found on farm A was unique for this farm. Farms B, C and D shared one cluster. In general, MLVA types from these clusters were isolated from piglets, sows, and the environment on various sampling events. Piglets carried MLVA types both related and unrelated to their mother sows' MLVA types at farrowing and onwards. In conclusion, molecular typing revealed that within a farm one or a few dominant strain(s) are widespread. Potential MRSA sources for piglets were mother sows, the environment and other piglets.

Individual responses of mother sows to a probiotic Enterococcus faecium strain lead to different microbiota composition in their offspring.

Pregnant gilts were fed the probiotic Enterococcus faecium NCIMB10415 (SF68) one month before birth of piglets. DNA extracts of sow faeces taken in weekly intervals as well as extracts from the intestine of their offspring during the suckling period at 12 and 26 days of life were analysed by denaturing gradient gel electrophoresis (DGGE) and quantitative PCR. DGGE profiles of faecal bacterial communities from three out of six probiotic-fed sows were distinctly different from the control and other probiotic-fed sows at all time points after probiotic supplementation. The probiotic-fed sows and their offspring were therefore divided into non-responder (n=3) and responder (n=3) groups. The probiotic strain significantly increased faecal lactobacilli cell numbers in mother sows, which could be assigned to a significant increase of Lactobacillus amylovorus and Lactobacillus acidophilus. Responding sows showed a more pronounced increase than non-responding sows. Similarly, suckling piglets from non-responding and responding sows showed numeric and significant differences for different bacterial groups and species. DGGE profiles of suckling piglets from responding sows also grouped more closely than profiles from control animals. Non-metric multiscaling of suckling piglets showed the same tendency for suckling piglets, but not for post-weaning piglets. This study showed that the probiotic E. faecium strain modified the faecal microbiota of sows. This modification is carried over to their offspring, but leads to changes that do not mirror the quantitative composition in the mother sow. Individual variations in the bacterial composition of mother sows before probiotic feed intake may influence the impact of a probiotic in sows and their offspring.

Transfer of Cystoisospora suis-specific colostral antibodies and their correlation with the course of neonatal porcine cystoisosporosis

Cystoisospora suis is the most pathogenic species of coccidia in suckling piglets, affecting them predominantly within their first three weeks of life. The clinical signs of neonatal cystoisosporosis include watery diarrhea and wasting, leading to significant economic losses for the farmer. Since neonatal piglets have an immature immune system, colostral transfer of maternal factors such as immune cells or antibodies is essential for controlling infections at that age. However, the role of C. suis-specific antibodies transferred from the sow to the piglets and possible correlations between antibody levels in the piglets acquired from colostrum with the clinical outcome of disease are currently not understood. To address this issue, 12 non-infected piglets and 14 piglets experimentally infected with C. suis on the third day of life were examined during their first four weeks of life. IgG, IgA, and IgM titers in the blood serum specific for sporozoites and merozoites of C. suis were evaluated, along with oocyst excretion and fecal consistency. Additionally, the antibody content in the colostrum and milk of three mother sows was determined. A transfer of naturally acquired C. suis-specific antibodies from sows to piglets with the colostrum could be demonstrated. Maternal antibodies in piglets’ blood sera did not persist for longer than 14–21 days except for IgG which was present in high titers until the end of the study. Within 2–3 weeks after birth the onset of endogenous antibody production was noticed. Titers in blood serum showed a correlation with the severity of diarrhea which was positive for IgG and IgM (possibly due to increased consumption or loss of these antibodies) and negative for IgA. C. suis-specific mucus antibodies isolated from infected and non-infected piglets (n=6/group) on the 28th day of life were present in both groups, showing significantly higher titers of IgA and IgM in infected piglets. Maternally transferred antibodies acquired by natural infections of sows as observed in this study did not provide protection against the clinical manifestation of disease. The level and effect of transferrable maternal factors necessary for protection still need to be elucidated. However, correlations between antibody titers and fecal consistency in the piglets indicate that C. suis-specific antibodies might be useful markers for the expectable clinical severity of cystoisosporosis.

Dietary inulin alters the intestinal absorptive and barrier function of piglet intestine after weaning

An experiment was conducted to study the effects of dietary inulin supplementation on the electrophysiological properties of small intestine of suckling and weaned piglets as indicators for glucose absorption and barrier function. Ten sows were divided into two groups, receiving either a control diet, or a diet with 3% inulin. The diets were fed from 3weeks ante partum to 6weeks post partum. In the first 2weeks of life, piglets received only sow’s milk. Irrespective to sex and without castration of males, four piglets (one piglet of each litter) from each group were selected and sacrificed on day 10 of age. The gastrointestinal tract of each piglet was removed and segments were immediately taken from the mid-jejunum and mounted in Ussing chambers. Furthermore, at weaning (6weeks old) 8 piglets were randomly selected irrespective to sex and males were un-castrated (4 animals from sows received control diet and 4 animals from sows received 3% inulin supplemented diet) and fed for 2weeks either control weaning diet or inulin supplemented diet. Thereafter segments of the mid-jejunum were used to investigate the effect of inulin on the gut electrophysiology of weaned piglets. The increase in short-circuit current (Isc) after the addition of glucose is an indicator of higher glucose absorption and the higher tissue conductance (Gt) of the epithelium suggested a higher intestinal permeability to paracellular Na+. In suckling piglets, the addition of d-glucose on the luminal side of the isolated jejunal mucosa increased (P<0.001) the Isc in the inulin-supplemented and control groups compared to basal values. Electrogenic glucose transport (ΔIsc) was similar in suckling piglets from sows fed inulin or control diet, suggesting that feeding of inulin to the mother sows had no effect on glucose absorption across the jejunal mucosa of suckling piglets. However, the dietary inulin supplementation after weaning increased the ΔIsc (P<0.001) compared with the controls, suggesting that the inulin supplementation increased the electrogenic transport of glucose across the jejunal mucosa of weaned piglets indicating higher glucose absorption. Furthermore, the Gt was higher in the inulin-supplemented weaned piglets than in control piglets, which could be due to the increased paracellular permeability to Na+. In conclusion, dietary inulin increased the glucose transport and altered the intestinal barrier by increasing the intestinal permeability in the jejunal mucosa of post-weaned piglets. Furthermore, the results indicated that inulin has a positive effect on glucose absorption in the piglet small intestine after weaning and subsequently the dietary inulin offers a promising approach to avoid post-weaning gastrointestinal tract disorders in pigs.

No effect of the plant growth regulator, chlormequat, on boar fertility

Chlormequat is a commonly used plant growth regulator in agriculture. Defined levels of chlormequat residue are allowed in food and an acceptable daily intake is defined for humans. However, there are results in the literature suggesting that a daily intake below the acceptable level for human is detrimental for mammalian reproduction. In the present experiment we investigated the effect of chlormequat at levels up to that acceptable for humans on reproduction in male pigs. Chlormequat (also known as chlorocholine chloride (CCC)) was mixed into the diet and given to the experimental animals at three levels (three treatment groups), i.e. 0 mg CCC/kg BW per day (Control), 0.025 mg CCC/kg BW per day and 0.05 mg CCC/kg BW per day. Eight mother sows per treatment group were used in the experiment. From the day of insemination, the mother sows received the experimental diets. The piglets were weaned at 4 weeks of age and two boar littermates continued on the same treatment as the dam until maturity and delivery of semen for in vitro fertilization (IVF) and in vivo fertilization. Semen volume, sperm concentration and fraction of live sperms were not (P ⩾ 0.46) detrimentally affected by chlormequat intake. The fraction of oocytes developing to more than the one-cell stage at day 5 after IVF was not (P = 0.88) detrimentally affected by chlormequat intake. Chlormequat intake did not detrimentally affect the fraction of gilts being pregnant after one insemination (P = 0.65) or the number of embryos in the pregnant gilts (P = 0.36). Serum chlormequat concentration was 0.9 μg/kg in the 0.025 mg CCC/kg BW per day group and 1.8 μg/kg in the 0.05 mg CCC/kg BW per day group, but was below the detection limit in control animals. In conclusion, the plant growth regulator chlormequat could not be proven to be detrimental to the selected reproduction traits in male pigs. This is in contrast to existing results from the male mouse.

RESEARCHES ON THE SURVIVAL OF THE SUCKLING PIGS IN CORELATION WITH BODY WEIGHT

The researches were made on 482 suckling pigs from 40 mother sows belonging to Landrace and Large White race. The sows were in third and fourth lactation and they were breed in industrial system. In average there were 12.2 suckling pigs. Considering the weight of the first suckling pig 100% this gradual decrease till the last one to 65-85%. The medium weight of the 4 suckling pigs was 1.270kg and the medium mortality 0.70% and to the last 4 was 1.100 kg and the mortality 7.02%. The mortality of the first 5 suckling pigs is 2.5% and gradual increase reaching in the last evaluated pig to 66_100%. The increasing of the mortality is explained by hypoxia and hypoglicemia of the new born evacuated during the second part of the parturition

Prevalence of Isospora suis and Eimeria spp. in suckling piglets and sows in Poland

The aim of this investigation was to determine the prevalence of coccidian infections in suckling piglets and sows in Poland. The research was carried out in 14 out of 16 Polish provinces in the years 2003–2005. The investigation was conducted on three types of farms: large farms (>100 sows), medium farms (25–100 sows) and small farms (<25 sows). Diarrhoea of unweaned piglets was observed on all the examined farms. Overall, 780 litters of suckling piglets from 104 farms and 267 mother sows were examined. The faeces were analyzed with the modified McMaster method. Isopsora suis was found in 217 (27.8%) litters from 70 (66.7%) farms. Eimeria spp. was detected only in 20 (2.6%) litters from 12 (11.5%) farms. On the large farms I. suis infection was detected in 31.7% of litters whereas Eimeria spp. in 1.4% of them. On the medium sized farms I. suis was found in 18.1% of litters and Eimeria spp. in 0.6%. On the small farms I. suis was detected in only 13.2% of litters, whereas Eimeria spp. in as many as 28.9%. I. suis and Eimeria spp. oocysts were found in 18 (6.7%) and 16 (6%) sows respectively. From 72 sows producing I. suis infected piglets only 12 (16.7%) shed I. suis oocysts and as little as 4 (5.6%) shed Eimeria oocysts. In the remaining 56 sows (77.8%) no cases of coccidian infections were detected. The results of this investigation demonstrate the high prevalence of I. suis in suckling piglets on the large swine farms in Poland.

A novel method for the production of transgenic cloned pigs: electroporation-mediated gene transfer to non-cultured cells and subsequent selection with puromycin.

Puromycin N-acetyl transferase gene (pac), of which the gene product catalyzes antibiotic puromycin (an effective inhibitor of protein synthesis), has been widely used as a dominant selection marker in embryonic stem (ES) cell-mediated transgenesis. The present study is the first to report on the usefulness of puromycin for production of enhanced green fluorescent protein (EGFP) transgenic piglets after somatic cell cloning and embryo transfer. Somatic cells isolated from porcine fetuses at 73 days of gestation were immediately electroporated with a transgene (pCAG-EGFPac) carrying both EGFP cDNA and pac. This procedure aims to avoid aging effects thought to be generated during cell culture. The recombinant cells were selected with puromycin at a low concentration (2 microg/ml), cultured for 7 days, and then screened for EGFP expression before somatic cell cloning. The manipulated embryos were transplanted into the oviducts of 14 foster mother sows. Four of the foster sows became pregnant and nine piglets were delivered. Of the nine piglets, eight died shortly after birth and one grew healthy after weaning. Results indicate that puromycin can be used for the selection of recombinant cells from noncultured cells, and moreover, may confer the production of genetically engineered newborns via nuclear transfer techniques in pigs.

Application of the E‐screen assay to test for oestrogenically active substances in swine feed

A pig breeder in central Hesse (Germany) noticed the occurrence of enlarged vulvae in female piglets. Intoxication with oestrogenically active substances by contamination of two feed mixes ingested by the mother sows appeared to be a possible cause. Using a combined technique of the DFG analytical method S19 and the E-screen assay, two feed samples were found to contain powerful oestrogenically active compounds. By co-incubation with the anti-oestrogen tamoxifen it could be clearly demonstrated that the oestrogenic activity was mediated by the oestrogen receptor. These results demonstrate that use of the E-screen assay in combination with the DFG analytical method S19 provides a simple and readily usable prescreening method for the routine detection of oestrogenically active compounds in animal feed. The results from the E-screen assay show that the sows ingested 10-80 microg oestradiol equivalents per day in their feed. Because of the bioavailability of these substances, the oestrogenic active compounds seem to be transferred into the milk and passed to the piglets via suckling. The milk of the dam appears to contain this substance in biologically active form and at such high concentrations that the female piglets had enlarged vulvae.

最近の養豚領域における大腸菌の化学療法剤耐性とRプラスミドの分布

A survey on antibiotic resistance and R plasmids was carried out in 9, 696 Escherichia coli strains isolated from swine and their environment. Resistant strains and R plasmids were isolated at a high frequency from swine, flies and drainage from pig breeding houses. Of these strains, 95.0% was resistant and 34.7% of them had R plasmids was isolated from mother sows; 98.1% was resistant and 27.4% of them had R plasmids isolated from growing pigs; 93.6% was resistant and 30.4% of them had R plasmids isolated from newborn piglets. CL- or NA-resistant strains were not detected from any material.

A serological survey on hemagglutinating encephalomyelitis virus infection in pigs in Japan.

A serological survey was carried out to detect hemagglutination-inhibition (HI) antibody against hemagglutinating encephalomyelitis virus (HEV) from the serum of pig. A total of 6, 797 porcine serum samples were collected from 45 prefectures in Japan. As a result, 3, 393 samples (49.9%) had the antibody. Of them, 1, 992 samples (58.7%) had an HI titer of 1:1280 or high. The positive rate varied from 39.6 to 72.0% in each age-group. It was 53.7, 47.0, 39.6, 52.5, 54.4, and 72.0% in the 0-2, 2-4, 4-6, 6-8, 8-l2, and over-12-month groups, respectively. In short, the positive rate became higher in accordance with the advance in age. The occurrence of such a high positive rate as 53.7% in the 0-2 month group, and the same HI titers of suckling piglets as those of their mother sows may be due to the absorption of antibodies from colostrum. The breed of pigs may not be a factor to induce HEV infection. The positive rate was high in the Kinki and Chugoku districts (66.1 and 65.1%, respectively) and low in the Tohoku and Kanto districts (26.6 and 27.8%, respectively). Antibodies against HEV were proved in Japan in 1965 and confirmed in every subsequent year. In 1973, more than 60.0% of the pigs examined were found to possess those antibodies. Therefore, it is concluded that HEV infection may be widespread in Japan.

哺乳子豚の血液学的研究

A total of 91 serum samples from suckling piglets and 14 colostric serum samples from mother sows were examined for protein contents by means of paper electrophoresis. The results obtained are summarized as follows.A. Serum protein of piglets.1. Immediately after birth.(See table)2. Twelve hours after the beginning of suckling.(See table)3. The albumin/globulin ratio was the highest in suckling piglets at four weeks of age, when the ratio was 1.14±0.47.B. Colostric serum protein. The paper-electrophoretic pattern of colostric serum protein was divided into four peaks according to mobility. The fourth peak showed a value of 66.06±7.69 per cent immediately after parturition. It seemed that this peak might be related to gamma-globulin of the serum protein of piglets.

Organisation of Agriculture

IT used to be said that the greatest public benefactor was the man who could make two blades of grass grow where one grew before. Not so to-day, when the nations are considering agreements to restrict output and even destroying the products of the soil. The man of science must take up an apologetic attitude at the present time with regard to agriculture. For two generations he has been entreated to make the land more productive and to reduce costs; but as an American professor of agriculture writes to me: “Ten million acres of cotton and some thousands of tobacco have been ploughed under. The latest move is the killing of some 5 million pigs weighing under 100 Ib. and the slaughter of some 200,000 prospective mother sows. If this will bring national prosperity I have wasted my life.” The man of science may be forgiven if he concludes that he is no longer wanted and may retire to his ivory tower, but whatever food for irony the world spectacle presents he will not be allowed to enjoy it in detachment, for if the deluge comes he will be swept down with the rest.