Assessment of test–retest reliability of animal-based measures on growing pig farms

Measures taken on animals are subject to variations and their reliability may represent one of their main limitations when used in a welfare assessment tool. Test–retest reliability refers to the likelihood that the same results will be obtained if the assessment is repeated by the same observer. This study discusses the test–retest reliability of quantitative and qualitative animal-based measures included into the Welfare Quality^® protocol on a sample of 15 intensive conventional farms of growing pigs. An average of 12 months elapsed between the two visits and no changes in management routines or housing conditions were made by the farmers during this interval. A Wilcoxon signed rank test was used to test whether the mean results obtained during the two visits were significantly different. Different methods were used to assess repeatability of mean prevalences at farm level: Spearman's correlation coefficient (rs), intra class correlation coefficient (ICC) and limits of agreement (LoA). Moderate bursitis, widespread skin discolouration and positive social behaviour presented mean results significantly different between the two visits (P<0.05). From a discriminative point of view, only moderately soiled body (rs=0.7; ICC=0.8) and the panic response (rs=0.7; ICC=0.5) were consistent the 12 month period. However, inconsistencies between Spearman's correlation and ICC were found when interpreting the reliability of several quantitative measures such as severely wounded animal and severely soiled body. The Qualitative Behaviour Assessment (QBA) was subject to a significant effect of visit, however, the two sets of scores were moderately related on the first axis of the principal component analysis (rs=0.5). A more evaluative approach such as the limits of agreement can be useful to guide the interpretation of test–retest reliability of quantitative measures based on farm averages and to detect farms that present a persistent welfare problem. Unless the assessment relates only to the relative ranking of a farm within the same visit, the QBA is not consistent over the 12 month period.     

Interobserver reliability of canine urine specific gravity assessed by analog or digital refractometers

Refractometry is utilized routinely to evaluate canine urine specific gravity (USG) in veterinary clinical settings. We aimed to determine if the magnitude of interobserver reliability when assessing canine USG via refractometry could impact clinical judgment. USG was determined in 38 dogs by 3 registered veterinary technicians (RVTs) using both an optical analog refractometer and a digital refractometer. Summary statistics were reported, interobserver reliability was assessed via intraclass correlation coefficient (ICC) analysis through a 2-way mixed-effects model, and agreement between RVT pairs was compared through Bland–Altman plots. The median analog refractometer USG measurement was 1.018 (range: 1.004–1.040) and for the digital refractometer was 1.0176 (1.0035–1.0357). The analog refractometer average measure ICC was 0.995 (95% CI: 0.992, 0.997; p < 0.001). The digital refractometer average measure ICC was 0.999 (95% CI: 0.999, 1.000; p < 0.001). Strong agreement between all pairs of RVTs was seen via Bland–Altman plots for both analog and digital refractometers, with 95% CIs spanning no more than 0.002 in either the positive or negative direction for all pairings. The interobserver variability in canine USG measurements by RVTs was trivial and did not impact clinical judgment and decision-making.     

Impact of rank position on fertility of sows

The investigations were carried out with 484 sows from two farms (farm A: housing the sows in small groups of 8 animals each, farm B with a large group of 100 sows) and a total number of 982 inseminations. The number of agonistic interactions was registered for each sow during 48 h after mixing soon after weaning the piglets at farm A. The individual rank place in the social hierarchy was calculated on the basis of wins and defeats and the sows were divided in high and low ranking sows. At farm B the rank position was estimated on the basis of the daily feeding order at two electronic feeding stations (first half of the sows in the feeding order = high ranking, second half = low ranking). Additionally, the following parameters were recorded for each sow: parity, genotype, farrowing rate and litter size (total and alive born piglets). The analysis showed that sows with a high rank position had a significantly higher farrowing rate (88.8%) compared to group-mates with low rank places (82.8%, p = 0.051) (farm A). Sows with a high rank position reached a significantly higher litter size of total born piglets (12.66, 16.14 piglets per litter respectively) than the low-ranking group-mates (12.13, 14.83 piglets/litter respectively — farms A and B). When mixing sows, the time and the conditions (e.g. group size, space allowance per sow) have to be considered to prevent the negative influence of low rank order on fertility.     

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 material

The online version of this article (doi:10.1186/s13567-014-0089-4) contains supplementary material, which is available to authorized users.     

Potential effect of two Bacillus probiotic strains on performance and fecal microbiota of breeding sows and their piglets

The effect of long-term administration of two Bacillus strains was tested on 98 breeding sows and their litters allotted into three treatments: a control group (CON); supplemented with 5 × 10⁸ cfu/kg B. subtilis − 541 (BSU); or with 5 × 10⁸ cfu/kg B. amyloliquefaciens − 516 (BAM). Reproductive and performance variables were recorded over three cycles with 56 dams remaining through the third lactation. Blood and fecal samples were taken longitudinally from 12 sows per treatment on days 8 and 21 of the third lactation and milk samples were taken on day 21. Feces from one piglet per litter was sampled on days 21 and 33 and jejunal gene expression was assessed in two piglets on day 21. Changes in fecal microbiota were assessed by 16S rRNA gene sequencing (Illumina MiSeq) and gene expression by Open-Array technology. Metabolomic responses were analyzed in milk by NMR and Ig-G and Ig-A specific antibodies were determined by ELISA. No significant differences were observed on feed intake, body weight, or fat mobilization of the sows. However, a significant increase in the total number of piglets born was observed in supplemented sows. Although the increase was seen from the first cycle with BAM, improvements were not seen with BSU until the third cycle. BAM also increased the number of born-alive and weaned piglets. NMR analysis showed an impact of BAM on milk composition. No differences were found in milk or blood immunoglobulins. A different structure of the fecal microbiota was found in supplemented sows, with changes across phylum, family, and genus. These changes were greater at day 8, suggesting a relevant role of probiotics establishing a new intestinal balance after labor. Shifts in the microbiota were also seen in the piglets, with a clearer impact post-weaning than in suckling. In this regard, correlations between microbial groups of sows and piglets showed a higher link with weaned (d33) than with suckling pigs (d21), reinforcing the idea of an early maternal carry-over. No changes due to treatment in jejunal gene expression were detected; however, piglet size had a clear impact on different genes. In summary, the addition of both probiotics, and particularly Bacillus amyloliquefaciens, demonstrated potential benefits on the prolificacy of sows. Daily feeding of Bacillus amyloliquefaciens resulted in an increase in the number of weaned piglets. The high correlations between the compositions of the microbiota of sows and their piglets are evidence of maternal imprinting, with effects lasting beyond weaning.     

Preventing transmission of Sarcoptes scabiei var. suis from infested sows to nursing piglets by a prefarrowing treatment with doramectin injectable solution

Studies were conducted at swine facilities in Illinois and North Carolina to evaluate the effect of treatment with doramectin injectable solution on transmission prevention of Sarcoptes scabiei var. suis from sows to nursing piglets. Approximately 42 days prefarrowing, 58 mange-free sows were experimentally infested with 200 S. scabiei in each ear. Seven to fourteen days prior to farrowing, 22 sows were given doramectin injectable intramuscularly at a dose of 300 microg/kg of body weight. A total of 21 sows served as untreated controls. Skin scrapings for mite counts and lesion scoring were performed on sows before treatment on day 21, and on either day 35 or 42. Each sow was observed on days 0, 7, 14, 21, 28, and 35 or 42 for the incidence of scratching/rubbing. Skin scrapings, lesion scoring, and observation of scratching/rubbing were performed on the piglets after weaning and at the end of the nursery stage. Geometric mean mite counts of the untreated sows were 0.70 and 0.26 on days 21 and 35 or 42, respectively, and 0.00 for doramectin-treated sows over the same time periods (P<0.05). Lesions scores and the incidence of scratching/rubbing were both higher in the untreated sows as compared to the doramectin-treated sows during the same time periods (P<0.05). Geometric mean mite counts of piglets farrowed by untreated sows were 0.50 and 0.60 after weaning and at the end of the nursery stage, respectively, and 0.00 for piglets from doramectin-treated sows over the same time periods (P>0.05). Lesion scores and the incidence of scratching/rubbing were both higher in piglets from untreated sows as compared to those piglets from doramectin-treated sows (P<0.05). Treating S. scabiei-infested sows with doramectin injectable solution before farrowing eliminated mite infestation and prevented the transmission of S. scabiei to piglets.     

Influences on the assessment of resource- and animal-based welfare indicators in unweaned dairy calves for usage by farmers

Consumers, industrial stakeholders, and the legislature demand a stronger focus on animal welfare of all livestock at the farm level by using suitable indicators in self-assessments. In order to deduce farms’ animal welfare status reliably, factors that influence indicators’ results need to be identified. Hence, this study aimed to apply possible animal welfare indicators for unweaned dairy calves on conventional dairy farms with early cow–calf separation and evaluate influencing factors such as age and sex of calves or climatic conditions on the applied indicators’ results. An animal welfare assessment using 7 resource-based and 14 animal-based indicators was conducted at 42 typical Western German dairy farms (844 calves) in 2018 and 2019 by two observers. The effect of influencing factors was calculated by binary and ordinal logistic regressions and expressed as odds ratios. Although every unweaned calf was assessed during the farm visits, most farms had relatively few unweaned calves (average number of calves ± standard deviation = 20.1 ± 6.7 calves), with six farms having not more than 10 calves. The small sample sizes question the usage of those indicators to compare between farms and to set thresholds at the farm level. Only one assessed indicator (cleanliness core body) was not statistically affected by the evaluated influencing factors. Calf age was identified as the most decisive factor, as it affected 16 of 21 evaluated indicators, and calf age distribution on-farm varied greatly. Climatic conditions (ambient temperature and rainfall) influenced resource-based indicators such as access to concentrate and water or the cleanliness of feeding implements and bedding as well as animal-based cleanliness indicators and the occurrence of health-related impairments such as coughing and diarrhea. The authors found differences between calves on farms assessed by the different observers not only in resource-based hygiene indicators but also in animal-based indicators such as hyperthermia or hypothermia, highlighting the need for further evaluation of quality criteria in dairy calf welfare assessments. Nevertheless, animal welfare assessments by farmers themselves could be useful tools to sensitize farmers to animal welfare and thereby improve calves’ welfare.     

Mammary Secretion of IgG in Sows

The IgG-concentration was determined in serum of 3 pregnant sows before and after partus and in colostrum of 7 sows 0–6 days post partum. The IgG-concentration decreased in serum before partus and increased after partus. The lowest value (1.5 g/100 ml) was observed at partus. The results indicate that IgG is transmitted from serum to colostrum.The concentration of IgG in colostrum was found to be 2.1–10.4 g/100 ml at partus. The concentration decreased very fast during the first day post partum. During 3–6 days post partum the IgG concentration was rather constant (0.3–0.5 g/100 ml). The importance of the results for the passive immunization of piglets is discussed.     

Investigation on the Production Performance of gE Antibody Positive Sows in Pig Farms Infected with Wild Type Pseudorabies Virus

Pseudorabies (PR) is caused by the Pseudorabies virus (PRV). It is an acute and hot highly contagious disease infecting livestock and a wide range of wild animals. In order to investigate the relationship between latent infection of Pseudorabies virus and sow production performance,this study collected production parameters of first-parity sows with wild virus gE positive and negtive in a Pseudorabies positive stable intensive farm, including total litter size, healthy litter size, weak litter size, stillbirths, mummified fetus, litter weight, number of weaning live, number of weaning qualified and weaning weight. And compared the production performance of PRV gE antibody negative and positive sows in the same intensive pig farm. The study showed that each PRV gE antibody negative sow could produce 11.96 live piglets per parity. Additionally, PRV gE antibody negative sow could provide more alive, weaning and weaning qualified piglets per parity than infection sows, which were 0.63, 0.18 and 0.28, respectively. Although the average birth weight and average weaning weight of piglets produced by PRV gE antibody positive sows were higher than those produced by negative sows, the weaning qualified rate of antibody negative sows was higher than that of antibody positive sows, indicating that the weaning live piglets produced by antibody negative sows had higher uniformity. In summary, the production performance of PRV gE antibody positive sows was lower than that of the negative sows. Eradication of PR can bring higher profit to the pig farm. Pig farm should actively eradicate the PR.     

伪狂犬病病毒野毒感染猪场的gE抗体阳性头胎母猪生产成绩调查

伪狂犬病（Pseudorabies，PR）是由伪狂犬病病毒（Pseudorabies virus，PRV）感染多种野生动物及家畜引起的急性、热性的高度接触性传染病。为掌握PRV隐性感染对头胎母猪生产成绩的影响，本研究跟踪调查某一PRV野毒阳性稳定万头母猪场中野毒gE抗体阴性和阳性的头胎母猪总产仔数、健仔数、弱仔数、死胎数、木乃伊胎数、仔猪初生窝重以及断奶活仔数、断奶合格仔数、仔猪断奶重等不同生产成绩指标，探索相同饲养条件下伪狂犬病对头胎母猪各生产指标的影响。结果发现，每头PRV野毒gE抗体阴性头胎母猪每窝平均可产11.96头活仔猪，比gE抗体阳性母猪每胎次多产活仔0.63头，以及每胎次可多提供0.18头断奶活仔，每胎次多提供0.28头断奶合格仔。虽然PRV野毒gE抗体阳性母猪所产仔猪初生均重及断奶均重均高于gE抗体阴性母猪所产仔猪，但gE抗体阴性母猪所产仔猪断奶合格率高于gE抗体阳性母猪，表明其断奶活仔整齐度更高。综上，PRV野毒gE抗体阳性的头胎母猪生产成绩低于gE抗体阴性母猪，伪狂犬病的净化可为猪场带来更高的经济效益，表明伪狂犬病的净化至关重要。     

Prevalence of infection with porcine circovirus-2 (PCV-2) and porcine reproductive and respiratory syndrome virus (PRRSV) in an integrated swine production system experiencing postweaning multisystemic wasting syndrome

The objective of this study was to evaluate the prevalence of infection with porcine circovirus-2 (PCV-2) and porcine reproductive and respiratory syndrome virus (PRRSV) through a longitudinal study in an integrated swine production system (7 farms) experiencing postweaning multisystemic wasting syndrome (PMWS). Risk factors for PCV-2 infection and for PCV-2 and PRRSV coinfection were also evaluated. Fifteen sows from each herd and 4 non-cross-fostered piglets from each sow were randomly selected at farrowing and ear-tagged at birth. Serum samples were analyzed for antibodies to PCV-2 and for detection of the PCV-2 and PRRSV genomes. Statistical analyses involved 2 approaches. The 1st approach characterized the dynamics of PCV-2 infection and their relationship with PRRSV infection. The 2nd approach analyzed the probability of being infected by PCV-2 or by both PCV-2 and PRRSV through a generalized linear mixed model incorporating sow and farm characteristics. At the 1st sampling time (1 wk of age), there was a significant relationship between sow PCV-2 infection and piglet PCV-2 infection (P < 0.0001). The risk of PCV-2 and PRRSV coinfection was 1.85 times greater in piglets from a sow with low titers of PCV-2 antibodies than in piglets from sows with medium to high titers (P = 0.03) and was 2.54, 2.40, and 2.02 times greater, respectively, in piglets from primiparous sows, PCV-2-infected sows, and farms in an area of high pig density than in piglets from sows of higher parity (P = 0.004), noninfected sows (P = 0.04), and farms in a low-density area (P = 0.09).     

Antibody response in sows and piglets following vaccination against Mycoplasma hyopneumoniae, toxigenic Pasteurella multocida, and Actinobacillus pleuropneumoniae

The aim of the experimental study was to compare the humoral immune response and occurrence of adverse effects following single or multiple simultaneous vaccination of sows against Mycoplasma hyopneumonia, toxigenic Pasteurella multocida, and Actinobacillus pleuropneumoniae. In addition, passively transferred antibodies to piglets were studied until weaning at 3 weeks of age. Fever was seen in a few sows within the first 12 hours after the 1st and 2nd vaccination. No difference in the occurrence of other adverse effects was observed between groups. Antibody levels were significantly higher in vaccinated sows and their offspring compared with the control group. This was found to be independent of single or simultaneous vaccinations with the 3 vaccines. In conclusion, applying multiple vaccines simultaneously to sows appeared not to influence the occurrence of adverse effects or the sow’s serum levels of antibodies at the time of farrowing, nor the offspring’s serum levels up to 3 weeks of age.     

Exposure to maternal feces in lactation influences piglet enteric microbiota,growth, and survival preweaning

It is known that gilt progeny performance is reduced compared with sow progeny. Previous research suggests that the presence of maternal feces in early life improves the health and survival of offspring. Therefore, we aimed to determine whether contact with feces from multiparous (MP) sows would improve the growth and survival of piglets born and reared on primiparous (P1) sows and if so, whether these differences are associated with the gut microbiota. Four treatments were applied for 10 days: Donor (n = 29) piglets had limited access to maternal feces as, each morning, sow feces were removed and placed in the crate of a P1 sow (P1-FT; n = 30 piglets) and P1-Con (n = 29) and MP-Con (n = 33) piglets had access to their own mothers’ feces. All piglets were weighed on days 1, 3, 10, and 18. Fecal samples were collected from a subset of sows (n = 10/treatment) 3 days post farrow and from two female piglets/litter on days 10 and 18 (n = 20/treatment) and subject to 16S rRNA amplicon analysis. Escherichia, Clostridium, Campylobacter, and Treponema were more abundant in MP sows, while P1 sows had a higher abundance of Lactobacillus and Prevotella. At 10 days, P1 progeny fecal microbiota differed, and growth and survival were reduced when compared with MP progeny. No treatment effect was observed for P1-FT piglets (P > 0.05). Donor piglets had a different fecal microbiota and improved weight and survival then all other treatments (P < 0.05). Overall, the removal of sow feces from the farrowing crate improved piglet microbiota development, growth, and survival.     

Effect of Prolactin Suppression on the Ovarian Activity in the Lactating Sow

The effect of prolactin suppression during lactation was studied in 6 sows nursing 5–10 piglets. In order to inhibit prolactin secretion a dopamin agonist (bromocriptine, Parlodel® “Sandoz”) was given per os from about 4 weeks after parturition until weaning 9–17 days later. Plasma prolactin and plasma progesterone were determined by radioimmunoassays. In all animals plasma prolactin was suppressed during the bromocriptine treatment. Two sows resumed ovarian activity during treatment as indicated by elevated plasma progesterone, probably as a result of the low plasma prolactin levels. The results suggest that the elevated plasma prolactin levels during lactation is one of the factors responsible for lactational an oestrus in the sow.     

Compensatory feeding during early gestation for sows with a high weight loss after a summer lactation increased piglet birth weight but reduced litter size

Sows mated in summer produce a greater proportion of born-light piglets (<1.1 kg) which contributes to increased carcass fatness in the progeny population. The reasons for the low birth weight of these piglets remain unclear, and there have been few successful mitigation strategies identified. We hypothesized that: 1) the low birth weight of progeny born to sows mated in summer may be associated with weight loss during the previous summer lactation; and 2) increasing early gestation feed allowance for the sows with high lactational weight loss in summer can help weight recovery and improve progeny birth weight. Sows were classified as having either low (av. 1%) or high (av. 7%) lactational weight loss in their summer lactation. All the sows with low lactational weight loss (LLStd) and half of the sows with high lactational weight loss received a standard gestation feeding regime (HLStd) (2.6 kg/d; day 0–30 gestation), whereas the rest of the sows with high lactational weight loss received a compensatory feed allowance (HLComp) (3.5 kg/d; day 0–30 gestation). A comparison of LLStd (n = 75) versus HLStd sows (n = 78) showed that this magnitude of weight loss over summer lactation did not affect the average piglet or litter birth weight, but such results may be influenced by the higher litter size (P = 0.030) observed in LLStd sows. A comparison of HLStd versus HLComp (n = 81) sows showed that the compensatory feeding increased (P = 0.021) weight gain of gestating sows by 6 kg, increased (P = 0.009) average piglet birth weight by 0.12 kg, tended to reduce (P = 0.054) the percentage of born-light piglets from 23.5% to 17.1% but reduced the litter size by 1.4 (P = 0.014). A subgroup of progeny stratified as born-light (0.8–1.1 kg) or -normal (1.3–1.7 kg) from each sow treatment were monitored for growth performance from weaning until 100 kg weight. The growth performance and carcass backfat of progeny were not affected by sow treatments. Born-light progeny had lower feed intake, lower growth rate, higher G:F, and higher carcass backfat than born-normal progeny (all P < 0.05). In summary, compensatory feeding from day 0 to 30 gestation in the sows with high weight loss during summer lactation reduced the percentage of born-light progeny at the cost of a lower litter size, which should improve growth rate and carcass leanness in the progeny population born to sows with high lactational weight loss.     

Campylobacter from sows in farrow-to-finish pig farms: risk indicators and genetic diversity

Sows have been identified as a source of Campylobacter contamination in piglets. We carried out a one-year study, in 2008, at 53 farrow-to-finish farms in Brittany, France, to determine the proportion of sows excreting Campylobacter. We also determined the genotypes of the Campylobacter isolates. Moreover, Generalized Estimating Equations including repeated effects were used to assess the association between management practices and farm characteristics, and risk of Campylobacter shedding by sows. Per farm, 10 feces samples from sows were collected from selected sites (maternity, service area, gestation area) on the farms. Campylobacter isolates were identified by PCR and typed by PFGE. Campylobacter was detected in 25.1% of the 530 samples from sows, and 67% of the 53 pig farms had at least one positive sample (of 10 taken). All the Campylobacter isolates belonged to the Campylobacter coli species. They displayed a very high level of genetic diversity, also inside farms and few genotypes were common to several farms. Warmer months, large farms, and individual housing for sows were identified as risk indicators of Campylobacter shedding by sows. A short delay between sampling and treatment of the samples should be considered, to improve the detection of the bacterium in the feces samples.     

Program of vaccination and antibiotic treatment to control polyserositis caused by Haemophilus parasuis under field conditions

The present study investigated the effects of vaccinating sows and piglets or piglets alone against Haemophilus parasuis on the prevalence of H. parasuis in nasal swabs, on the humoral and cellular immune responses, and on the production parameters of piglets at 3 Korean farms with a clinical history of polyserositis caused by H. parasuis. Piglets born to vaccinated or non-vaccinated sows were subdivided into 3 groups: vaccinated sows and vaccinated pigs (VS-VP), non-vaccinated sows and vaccinated pigs (NVS-VP), and non-vaccinated sows and non-vaccinated pigs (NVS-NVP). The proportion of piglets with positive nasal swabs was significantly lower (P < 0.05) in the vaccinated animals (VS-VP and NVS-VP groups) than in the non-vaccinated animals (NVS-NVP group) at 35 and 60 d of age at the 3 farms. The overall growth performance (from 7 to 60 d of age) of the vaccinated piglets was significantly better (P < 0.05) than that of the non-vaccinated piglets at the 3 farms. Piglets in the VS-VP group had significantly higher levels (P < 0.05) of H. parasuis-specific IgG antibodies, lymphocyte proliferation, and interferon-γ-secreting cells than piglets in the NVS-VP and NVS-NVP groups on days 1, 7, 21, 35, and 60 after birth at the 3 farms.     

Plasma ferritin of sows during pregnancy and lactation

We studied a set of indicators of iron metabolism in sows and new-born piglets: hemoglobin, plasma iron, total iron binding capacity and plasma ferritin. Iron status of seventy-two sows was studied throughout pregnancy and lactation. The results point to mobilization of iron from its storage sites up to the second month of gestation, but no appreciable decrease during the second half of pregnancy. No appreciable mobilization of the iron stores of sows was observed during the lactation period. Nine sows and their 78 piglets were used to compare the status of iron in the sows and the end of gestation with the iron status of the piglets at birth; there was a positive correlation between the mean values of plasma ferritin concentration in the piglets and the levels of plasma ferritin in their mothers.     

Effect on Perinatal Mortality of a Single Selenium Injection To Sows and Gilts

Selenium treatment of pregnant sows and gilts was conducted as a double-blind placebo-controlled study in 5 commercial herds with a total of 350 sows and gilts (Danish Landrace, Yorkshire and Landrace-Yorkshire crossbreeds). At 3–6 weeks before farrowing the animals were injected once intramuscularly with either Na-selenite (0.05 mg Se per kg) or placebo. Blood samples were taken immediately before treatment and once again at 3–6 weeks after farrowing, to evaluate the Se status. The productivity of the sows and gilts was recorded.Within herds there was no pretreatment difference in Se status between the two treatment groups, while a considerable variation was seen among herds. After farrowing there were only minor differences in Se status between the treatment groups, whereas the variation among herds persisted.Overall, no effect of the Na-selenite injection was seen, in that there was no difference in number of liveborn, stillborn, and weaned piglets between the treatment groups. The number of days from weaning to oestrus and the number of oestrous cycles per pregnancy were not influenced by the Na-selenite treatment.