The selection of single-chain Fv antibody fragments specific to Bhlp 29.7 protein of <Emphasis Type="Italic">Brachyspira hyodysenteriae</Emphasis>

Single-chain antibodies (scFv) specific to Brachyspira hyodysenteriae were isolated from a phagemid library. Recombinant Bhlp 29.7 protein was used for scFv selection and individual clones were tested by ELISA and immunofluorescent test; four unique clones were isolated. One of selected clones was able to bind specifically B. hyodysenteriae in ELISA and immunofluorescence test. This is the first report of species-specific recombinant antibodies against B. hyodysenteriae.     

Genetic Diversity of Bile Salt Hydrolases Among Human Intestinal Bifidobacteria

Attachment of Brachyspira hyodysenteriae to intestinal epithelial cell lines and its possible mediation by outer membrane proteins (OMPs) of the spirochete were examined. Different B. hyodysenteriae serotypes were shown to adhere to rat and swine intestinal epithelial cells (IEC-18 and IPEC-J2) in vitro but not to the human rectal tumor cell line (HRT-18). Adherence of strain B204 to IPEC-J2 cells was reduced by rOMP-specific antisera in amounts of 29 % (anti-rBhlp29.7), 59 % (anti-rBhlp16), 70 % (anti-rBhmp39h), and 74 % (anti-rBhmp39h), respectively. By use of pooled antisera against Bhlp16 and Bhmp39f inhibition rates of the other serotypes ranged from 53 to 91 %. In a western blot assay OMPs of all serotypes but one were detected by the respective rOMP antisera. Altogether the results indicated that OMPs of B. hyodysenteriae displayed a serotype overlapping antigenicity and mediated adherence of the spirochetes to animal cell cultures.     

A whole genome sequence association study for puberty in a large Duroc × Erhualian F2 population

A large proportion of gilts and sows are culled from reproduction populations because of anestrus and pubertal reproductive failure. Selecting early onset of puberty gilts has a favorable effect on sows’ reproductivity. However, age at puberty is hard to be routinely measured in commercial herds. With molecular genetic predictors, identifying individuals that have a propensity for early onset of puberty can be simplified. We previously performed genome scanning and a genome‐wide association study for puberty in an F2 resource population using 183 microsatellites and 62 125 SNPs respectively. The detection power and resolution of identified quantitative trait loci were very low. Herein, we re‐sequenced 19 founders of the F2 resource population in high coverage, and whole genome sequences of F2 individuals were imputed to perform an association study for reproductive traits. A total of 2339 SNPs associated with pubertal reproductive failure were identified in the region of 30.94–40.74 Mb on SSC7, with the top one, positioned at 33.36 Mb, explaining 16% of the phenotypic variances. We improved the magnitude of the P‐value by 10E+5 to 10E+7 using the whole genome sequence rather than using low/middle density markers as in previous studies, and we narrowed down the QTL confidence interval to 5.25 Mb. Combining the annotation of gene function, RAB23 and BAK1 were perceived as the most compelling candidate genes. The identified loci may be useful in culling sows failing to show estrus by marker‐assisted selection to increase reproductive efficiency of swine herds.     

A genetic comparison of pig, cow and trout isolates of Lactococcus garvieae by PFGE analysis

Aims: Genetic comparison of Lactococcus garvieae isolated from mammals and fish. Methods and Results: One hundred and ninety‐seven L. garvieae isolates obtained from trout (n = 153), cow (n = 7) and pigs (n = 37) were genetically characterized by determining their pulsed‐field gel electrophoresis (PFGE) profiles after macrorestriction with Bsp120I. Overall, L. garvieae isolates from pigs, cow and trout exhibited distinct PFGE patterns, with a low genetic relationship between them. Isolates from trout generated two pulsotypes [Genetic diversity (GD) 0·01] showing that the fish isolates were more genetically homogenous than the others. The L. garvieae isolates from cows displayed five (GD 0·71) different pulsotypes, while the swine isolates displayed 13 different pulsotypes (GD 0·35). Twenty‐one of the 37 swine strains (56·8%) were grouped in a single cluster that included two closely related (93% similarity) pulsotypes. These pulsotypes exhibited a high frequency of isolation from different organs of the animals, and they were also broadly distributed among herds, suggesting a wide distribution across the swine population. This suggests that L. garvieae might be able to colonize different organs of the swine cardio‐respiratory system. Conclusions: Results indicate that most L. garvieae isolates from pigs and trout exhibited a distinct genetic background. Significance and Impact of the Study: The present study describes the isolation of L. garvieae from both diseased and healthy pigs for the first time, and the findings suggest that pigs could be a previously unknown reservoir of this pathogen.     

Association of swine influenza HIN1 pandemic virus （SIV- HINlp） with porcine respiratory disease complex in sows from commercial pig farms in Colombia

Porcine respiratory disease complex （PRDC） is a serious health problem that mainly affects growing and finishing pigs. PRDC is caused by a combination of viral and bacterial agents, such as porcine reproductive and respiratory syndrome virus （PRRSV）, swine influenza virus （SIV）, Mycoplasma hyopneumoniae （Myh）, Actinobacillus pleuropneumoniae （APP）, Pasteurella multocida and Porcine circovirus 2 （PCV2）. To characterize the specific role of swine influenza virus in PRDC presentation in Colombia, 11 farms from three major production regions in Colombia were examined in this study. Nasal swabs, bronchial lavage and lung tissue samples were obtained from animals displaying symptoms compatible with SIV. Isolation of SIV was performed in 9-day embryonated chicken eggs or Madin-Darby Canine Kidney （MDCK） cells. Positive isolates, identified via the hemagglutination inhibition test, were further analyzed using PCR. Overall, 7 of the 11 farms were positive for SIV. Notably, sequencing of the gene encoding the hemagglutinin （HA） protein led to grouping of strains into circulating viruses identified during the human outbreak of 2009, classified as pandemic H1N1-2009. Serum samples from 198 gilts and multiparous sows between 2008 and 2009 were obtained to determine antibody presence of APP, Myh, PCV2 and PRRSV in both SIV-H1Nlp-negative and -positive farms, but higher levels were recorded for SIV- HI Nlp-positive farms. Odds ratio （OR） and P values revealed statistically significant differences （p〈0.05） in PRDC presentation in gilts and multiparous sows of farms positive for SIV-HINlp. Our findings indicate that positive farms have increased risk of PRDC presentation, in particular, PCV2, APP and Myh.     

Development of a modified selective medium to enhance the recovery rate of Brachyspira hyodysenteriae and other porcine intestinal spirochaetes from faeces

Aims: The aim of this study was to develop a modified selective medium to improve the recovery rate of Brachyspira hyodysenteriae and other clinically significant intestinal spirochaetes from porcine faeces. Methods and Results: The susceptibility of five Brachyspira spp. type strains and five Thai field isolates of B. hyodysenteriae to the antimicrobials halquinol and flavomycin was determined by in vitro susceptibility tests in the agar dilution method, and optimal incorporation rates were confirmed by broth dilution. All the spirochaetes were susceptible to halquinol at ≤1 μg ml^?1, while 16 μg ml^?1 of flavomycin (F) allowed their growth, and therefore, only the latter was selected for further use. F and different combinations of colistin (C), spectinomycin (S) and rifampacin (R) were incorporated into pre‐enrichment broths and/or agar plates, and growth of the spirochaetes from seeded faeces was determined. Two solid media were selected for further testing using faeces from 90 finishing pigs on 10 farms. A previously recommended method of pre‐enrichment did not increase the recovery rate. The use of blood agar modified medium (BAM) containing F (16 μg ml^?1), S (400 μg ml^?1), R (30 μg ml^?1) and colistin (C, 100 U ml^?1) (assigning as BAM‐CSRF) reduced the growth of contaminating intestinal microbiota and resulted in a significantly higher rate of spirochaete recovery than the previous recommended medium. Conclusion: BAM‐CSRF is a useful new selective medium for the isolation of B. hyodysenteriae and other intestinal spirochaetes from pig faeces. Significance and Impact of the Study: The new selective medium for isolating B. hyodysenteriae and other Brachyspira spp. from pig faeces will improve their recovery and subsequent disease diagnosis.     

Culling intervals and culling risks in four stages of the reproductive life of first service and reserviced female pigs in commercial herds

The objectives of this study were to measure culling intervals and culling risks in the four stages of the reproductive life of female pigs and to compare culling intervals between the number of services and between herd groups, based on herd productivity. We also compared survival patterns of females pigs between these herd groups. Our data set included lifetime records of 52,792 females born between 2001 and 2004 in 101 commercial herds. Two herd groups were selected on the basis of the upper 25th percentile of pigs weaned per mated female per 5 yr between 2002 and 2006, namely the high-performing herds, and ordinary herds. Culled females were also allocated into four groups based on the stages of their reproductive life when culled: unmated gilts, mated gilts, unmated sows, and mated sows. Culling intervals in unmated gilts and mated gilts were defined as the number of days from birth to culling and from first mating to culling, respectively. Culling intervals in unmated sows and mated sows were the number of days from weaning to culling. The number of services was categorized into two groups: first service and reservice groups. Multilevel linear mixed-effects models and survival analysis were performed. Culling intervals (±SEM) in unmated gilts, mated gilts, unmated sows, and mated sows were 302.9 ± 1.16, 98.4 ± 0.92, 14.3 ± 0.12, and 89.6 ± 0.42 d, respectively. Culling risks in the four groups were 5.6%, 7.1%, 58.0%, and 29.3%, respectively. In unmated gilts, mated gilts, and mated sows, the culling intervals in the high-performing herds were 43.0, 18.9, and 16.0 d shorter than those in ordinary herds, respectively (P < 0.05), but no difference was found between the herd groups for the culling interval of unmated sows. For mated sows in the reservice group, culling intervals of high-performing herds were ≥13.7 d shorter than those of the ordinary herds (P < 0.05), but for mated sows in the first service group, there was no difference in the culling interval between the herd groups. The culling hazard from 8 wk postweaning for mated sows in high-performing herds increased more rapidly than that in ordinary herds. In conclusion, to reduce culling intervals and improve herd productivity, we recommend implementing a strict culling policy for mated gilts and mated sows, especially reserviced females.     

Effect of a disinfection strategy on the methicillin‐resistant Staphylococcus aureus CC398 prevalence of sows,their piglets and the barn environment

Aims

To assess, in a cleaned and disinfected barn environment, the efficacy of an animal disinfection strategy to reduce the livestock‐associated methicillin‐resistant Staphylococcus aureus (LA‐MRSA) prevalence in sows, their offspring and the barn environment.

Methods and Results

On each farm, six sow rounds were sampled; sows were divided into either a test or control group. Per round, 20 sows and 40 of their piglets were sampled at different time points together with the barn environment. The disinfection strategy of the test groups consisted of washing the sows with a shampoo followed by disinfection of the skin with a solution containing chlorhexidine digluconate and isopropanol. On the first day of disinfection and 6 days after stopping the disinfection, a significant decrease (P < 0·01) of on average 68 and 66% in sow MRSA prevalence was observed on both farms, whereas no decrease was seen in the control groups. Just before weaning, 21–28 days after the end of the disinfection strategy, the difference in MRSA prevalence between both groups was reduced to 4% and no longer significant (P = 0·20). The MRSA prevalence of the piglets in the test groups was significantly lower (26%; P < 0·01) 6 days after the end of disinfection. Just before weaning, this difference was reduced to 5% but still significant (P < 0·01). In the swine nursery unit, no significant difference (P = 0·99) was seen between both groups. Based on semi‐quantitative counts, a relationship (r² > 0·6; P < 0·01) was seen between MRSA contamination in the barn environment and the MRSA prevalence in pigs.

Conclusion

Results show that the tested disinfection strategy reduces temporarily the sow and piglet MRSA status, but does not result in a final reduction in MRSA at weaning or in the nursery unit.

Significance and Impact of the Study

First report on the efficacy of an animal disinfection strategy to reduce LA‐MRSA prevalence in sows, their offspring and the barn environment.     

Within-farm variability in age structure of breeding-female pigs and reproductive performance on commercial swine breeding farms

This study investigated relationships between herd age structure and herd productivity in breeding herds; it also investigated a pattern in parity proportions of females over 2 years and its relationship with herd productivity in commercial swine herds. This study was based on data from 148 commercial farms in North America stored in the swine database program at the University of Minnesota. The primary selection criterion was fluctuations in breeding-female pig (female) inventories over a 2-year interval. Productivity measurements and parity proportions of females were extracted from the database. A 24-month time-plot in proportions of Parity 0 and Parities 3-5 females (mid-parity) was charted for each farm. Using these charts, a change in proportions of Parity 0 and mid-parity for each farm was categorized into patterns: FLUCTUATE (Parity 0 and mid-parity proportion lines crossed) or STABLE (the two proportion lines never crossed). Higher proportions of mid-parity sows were correlated with greater pigs weaned per female per year (PWFY; P < 0.01). Farms with a FLUCTUATE (73% of the 148 farms) pattern had lower PWFY than those with a STABLE pattern (P < 0.01). The STABLE farms had higher proportions of mid-parity sows, higher parity at culling, higher frequency of gilt deliveries per year, and lower replacement rate than the FLUCTUATE farms (P < 0.01). In conclusion, maintaining stable subpopulations with mid-parity and Parity 0 are recommended to optimize herd productivity.     

The Brachyspira hyodysenteriae ftnA Gene: DNA Vaccinationand Real-Time PCR Quantification of Bacteria in a Mouse Modelof Disease

The nucleotide sequence of the Brachyspira hyodysenteriae ftnA gene, encoding a putative ferritin protein (FtnA), was determined. Analysis of the sequence predicted that this gene encoded a protein of 180 amino acids. RT-PCR and Western blot showed that the ftnA gene was expressed in B. hyodysenteriae, and evidence suggests that FtnA stores iron rather than haem. ftnA was delivered as DNA and recombinant protein vaccines in a mouse model of B. hyodysenteriae infection. Vaccine efficacy was monitored by caecal pathology and quantification of B. hyodysenteriae numbers in the caeca of infected mice by real-time PCR.     

Experience of Vaccination against Porcine Parvovirus in Pig-Breeding Herds: Serological Status and Reproductive Performance

Blood samples from 77 gilts were examined for HI-antibody titers to PPV, all gilts belonged to the same herd and PPV-induced reproductive failure had previously occurred in the herd. Thirty-three gilts were vaccinated twice 5 and 2 weeks before mating while 44 gilts served as non-vaccinated controls. Only 3 % of the vaccinated gilts were seronegative at the time of mating compared to 14 % of the non-vaccinated gilts and 32 % of the non-vaccinated gilts had a serum titer lower than 1:64. The second part of the study comprised 4 herds with 50–70 sows in each herd. All of the herds had previously had reproductive problems caused by PPV infection. During the last 2 years, all gilts in these herds were vaccinated against PPV at 6.5 months of age with a revaccination 3–4 weeks later. There was a marked variation in serum titer levels among the 4 herds. In two herds the titers were overall rather low. In the third herd all had high PPV-titers at both sampling occasions and in the fourth herd the titers varied among animals but were rather consistent within animals at the two sampling occasions. In the herd with high titer, a PPV-outbreak was confirmed during January-March 1984. During that period all sows, vaccinated as gilts, farrowed normal litters. The results indicate that even in PPV-infected herds a large number of gilts are seronegative at the time of breeding and vaccination of gilts is therefore recommended. Furthermore it does not seem necessary to revaccinate sows, vaccinated as gilts, in herds where PPV is still present.     

Antimicrobial resistance and toxin gene profiles of Staphylococcus aureus strains from Holstein milk

Isolation of Staphylococcus aureus (Staph. aureus) from Holstein milk samples with mastitis and nonmastitis was conducted to estimate its prevalence, antimicrobial resistance and toxin genes. A total of 353 milk samples were collected from three Chinese Holstein herds. Fifty‐three Staph. aureus isolates collected from 29 Staph. aureus‐positive samples were characterized via antimicrobial susceptibility, toxin genes and Pulsed‐field Gel Electrophoresis (PFGE) profiles. The prevalence of Staph. aureus was 4·0–9·5% in mastitic and 7·3–11·5% in nonmastitic samples in the analysed herds. Approximately 61·0% of Staph. aureus strains isolated from mastitis cows were resistant to ≥10 antimicrobials compared with 0% of isolates with nonmastitis. The most frequently observed super antigenic toxin gene was pvl (41·5%) followed by seh + pvl (13·2%). We did not find mecA‐positive methicillin‐resistant Staph. aureus (MRSA) strains, while mecA‐negative MRSA strains were identified in the three herds. PFGE results suggested potential transmission of Staph. aureus strains in different farms. These results open new insights into Staph. aureus transmission and antimicrobial resistance of Holstein dairy cows and into developing strategies for udder health improvement of dairy cattle.     

Porcine reproductive and respiratory syndrome virus (PRRSV) in GB pig herds: farm characteristics associated with heterogeneity in seroprevalence

Background

The between- and within-herd variability of porcine reproductive and respiratory syndrome virus (PRRSV) antibodies were investigated in a cross-sectional study of 103 British pig herds conducted 2003–2004. Fifty pigs from each farm were tested for anti-PRRSV antibodies using ELISA. A binomial logistic model was used to investigate management risks for farms with and without pigs with PRRSV antibodies and multilevel statistical models were used to investigate variability in pigs' log ELISA IRPC (relative index × 100) in positive herds.

Results

Thirty-five herds (34.0%) were seronegative, 41 (39.8%) were seropositive and 27 (26.2%) were vaccinated. Herds were more likely to be seronegative if they had < 250 sows (OR 3.86 (95% CI 1.46, 10.19)) and if the nearest pig herd was ≥ 2 miles away (OR 3.42 (95% CI 1.29, 9.12)). The mean log IRPC in seropositive herds was 3.02 (range, 0.83 – 5.58). Sixteen seropositive herds had only seropositive adult pigs. In these herds, pigs had -0.06 (95% CI -0.10, -0.01) lower log IRPC for every mile increase in distance to the nearest pig unit, and -0.56 (95% CI -1.02, -0.10) lower log IRPC when quarantine facilities were present. For 25 herds with seropositive young stock and adults, lower log IRPC were associated with isolating purchased stock for ≥ 6 days (coefficient -0.46, 95% CI -0.81, -0.11), requesting ≥ 48 hours 'pig-free time' from humans (coefficient -0.44, 95% CI -0.79, -0.10) and purchasing gilts (coefficient -0.61, 95% CI -0.92, -0.29).

Conclusion

These patterns are consistent with PRRSV failing to persist indefinitely on some infected farms, with fadeout more likely in smaller herds with little/no reintroduction of infectious stock. Persistence of infection may be associated with large herds in pig-dense regions with repeated reintroduction.

     

Cloning of exoinulinase gene from Penicillium janthinellum strain B01 and its high-level expression in Pichia pastoris

Aims: The aim of this study is to improve exoinulinase production by expression of a cloned exoinulinase gene inuA1 (GenBank accession no. JF961344 ) from Penicillium janthinellum strain B01 in Pichia pastoris. Methods and Results: A full‐length cDNA of exoinulinase gene (inuA1) was cloned from P. janthinellum strain B01 using RACE PCR. An open reading frame (ORF) of 2115 bp is interrupted by a single intron of 67 bp. The fragment encodes a signal peptide with 20 amino acids and a mature protein with 684 amino acids. The inuA1 was subcloned to the pPICZαC expression vector and succesfully over‐expressed in Pichia pastoris X‐33. The highest activity of exoinlinase reached 272·8 U ml^?1 in the fermentation liquid. It was c. 11‐fold of that produced by wild‐strain B01. A large amount of fructose was identified after the hydrolysis of inulin with the crude recombinant exoinulinase. The recombinant exoinulinase was purified and characterized. The molecular weight of the purified recombinant exoinulianse was 100 kDa. The mass spectrometry result indicated that the purified protein was indeed recombinant exoinulinase. The optimal pH and temperature of the purified recombinant exoinulianse were 4·5 and 50°C, respectively. Conclusions: An exoinulinase gene of P. janthinellum strain B01 was cloned, sequenced and over‐expressed successfully in P. pastoris. Significance and Impact of the Study: Only a few genes have been cloned from P. janthinellum because its molecular biology is poorly understood. In this study, we cloned and over‐expressed inuA1 gene of P. janthinellum in P. pastoris. This recombinant exoinulinase can be used to hydrolyse inulin to produce fructose and facilitate the biofuel production from inulin resources.     

Maternal vaccination as a Salmonella Typhimurium reduction strategy on pig farms

Aims

The control of Salmonella in pig production is necessary for public and animal health, and vaccination was evaluated as a strategy to decrease pig prevalence.

Methods and Results

The study examined the efficacy of a live Salmonella Typhimurium vaccine, administered to sows on eight commercial farrow‐to‐finish herds experiencing clinical salmonellosis or Salmonella carriage associated with S. Typhimurium or its monophasic variants. Results of longitudinal Salmonella sampling were compared against eight similarly selected and studied control farms. At the last visit (~14 months after the start of vaccination), when all finishing stock had been born to vaccinated sows, both faecal shedding and environmental prevalence of Salmonella substantially declined on the majority of vaccinated farms in comparison to the controls. A higher proportion of vaccine farms resolved clinical salmonellosis than controls. However, Salmonella counts in positive faeces samples were similar between nonvaccinated and vaccinated herds.

Conclusions

The results suggest that maternal vaccination is a suitable option for a Salmonella Typhimurium reduction strategy in farrow‐to‐finish pig herds.

Significance and Impact of the Study

Salmonella vaccines have the potential to reduce the prevalence of Salmonella in pigs and result in a reduction of human cases attributed to pork.     

A quantitative TaqMan PCR assay for the detection of Mycoplasma suis

Aim: To develop a TaqMan probe‐based, highly sensitive and specific quantitative PCR (qPCR) assay for the detection and quantification of Mycoplasma suis in the blood of pigs. Methods and Results: Primers and probes specific to Myc. suis 16S rRNA gene were designed. The qPCR assay’s specificity, detection limit, intra‐ and inter‐assay variability were evaluated and its performance was compared with a Myc. suis conventional PCR assay (cPCR). Blood of two experimentally infected pigs, 40 Indiana pigs, 40 Brazilian sows and 28 peccaries were tested. The assay detected as few as ten copies of Myc. suis plasmids and was 100‐fold more sensitive than the cPCR. No cross‐reactivity with nontarget pig mycoplasmas was observed. An average of 1·62 × 10¹¹ and 2·75 × 10⁸ target copies ml^?1 of blood were detected in the acutely and chronically infected pigs, respectively. Three (7·5%) pigs and 32 (80·0%) sows were positive while all peccaries were negative for Myc. suis. Conclusion: The developed qPCR assay is highly sensitive and specific for Myc. suis detection and quantification. Significance and Impact of the Study: TaqMan qPCR is an accurate and quick test for detection of Myc. suis infected pigs, which can be used on varied instrumentation platforms.     

Association of swine influenza H1N1 pandemic virus(SIV-H1N1p) with porcine respiratory disease complex in sows from commercial pig farms in Colombia

Porcine respiratory disease complex(PRDC) is a serious health problem that mainly affects growing and finishing pigs. PRDC is caused by a combination of viral and bacterial agents, such as porcine reproductive and respiratory syndrome virus(PRRSV), swine influenza virus(SIV), Mycoplasma hyopneumoniae(Myh), Actinobacillus pleuropneumoniae(APP), Pasteurella multocida and Porcine circovirus 2(PCV2). To characterize the specific role of swine influenza virus in PRDC presentation in Colombia, 11 farms from three major production regions in Colombia were examined in this study. Nasal swabs, bronchial lavage and lung tissue samples were obtained from animals displaying symptoms compatible with SIV. Isolation of SIV was performed in 9-day embryonated chicken eggs or Madin-Darby Canine Kidney(MDCK) cells. Positive isolates, identified via the hemagglutination inhibition test, were further analyzed using PCR. Overall, 7 of the 11 farms were positive for SIV. Notably, sequencing of the gene encoding the hemagglutinin(HA) protein led to grouping of strains into circulating viruses identified during the human outbreak of 2009, classified as pandemic H1N1-2009. Serum samples from 198 gilts and multiparous sows between 2008 and 2009 were obtained to determine antibody presence of APP, Myh, PCV2 and PRRSV in both SIV-H1N1p-negative and-positive farms, but higher levels were recorded for SIV-H1N1p-positive farms. Odds ratio(OR) and P values revealed statistically significant differences(p0.05) in PRDC presentation in gilts and multiparous sows of farms positive for SIV-H1N1 p. Our findings indicate that positive farms have increased risk of PRDC presentation, in particular, PCV2, APP and Myh.     

Effects of dietary menhaden oil on growth and reproduction in gilts farrowed by sows that consumed diets containing menhaden oil during gestation and lactation

In sows, n-3 fatty acids increase litter sizes, however, effects on gilt reproductive development have not been adequately studied. Moreover, not determined are effects of feeding n-3 fatty acids to sows on reproduction in offspring. The objective here was to determine effects of 4% dietary menhaden oil on growth and puberty in gilts farrowed by sows fed menhaden oil. Sows (n = 44) were assigned to: (1) control gestation and lactation diets, or (2) diets including menhaden oil. For primiparous sows only, total litter size and born alive were greater (P < 0.05) in females fed menhaden oil. Conversely, pigs from primiparous controls were heavier (P < 0.05) than pigs from primiparous sows fed menhaden oil (parity by diet interactions, P < 0.01). Diet did not affect (P > 0.20) other sow and litter characteristics. At weaning, 84 gilts from control- or menhaden oil sows were placed three gilts per pen and provided control diets or diets containing menhaden oil. Nursery and grow-finish feed intake and feed efficiency were similar (P > 0.21) for gilts from the different sows and weight gain was similar (P > 0.24) for gilts fed control or menhaden diets. Gilts fed menhaden oil tended to eat less in the nursery (1.18±0.08 kg v. 0.98±0.08 kg; P = 0.09) and overall (1.83±0.04 kg v. 1.72±0.04 kg; P = 0.06). Thus, overall feed to gain was greater (2.52±0.03 v. 2.33±0.03; P < 0.01) and nursery (2.12±0.04 v. 1.80±0.04; P = 0.10) and grow-finish (3.07±0.19 v. 2.58±0.19; P = 0.08) feed to gain tended to be greater, for control gilts. Age at puberty was greater (P = 0.02) for gilts from menhaden oil-fed sows (205.1±3.2 days) compared to gilts from controls (193.9±3.2 days) and tended to be greater (P = 0.09), for controls (203.5±3.2 days) compared to gilts fed menhaden oil (195.5±3.2 days). A tendency existed (P = 0.09) for greater follicular fluid in gilts fed menhaden oil, however, ovulation rate and ovarian, luteal and uterine weights were not affected by sow diet, gilt diet or the interaction (P > 0.23). Feeding gilts menhaden oil enhanced feed efficiency and hastened puberty onset. Gilts from sows consuming menhaden oil exhibited delayed puberty and retaining females from sows fed this feedstuff may be ill advised.     

A retrospective study on the preserving capacity of a commercial boar semen extender

The objective of this study was to evaluate the preserving capacity of a commercial, long-term boar semen extender beyond 4 days in terms of farrowing failure and total born per litter in sows and gilts. Data from 21 farms were subjected to logistic and linear regression analyses to assess the effect of parity (2-5, > 5 and gilts), wean-to-service interval (/= 6 days) and number of AI (1, 2, or 3) on the association between semen age (/=10 days) and fertility. As the semen age increased, the likelihood of farrowing failure increased and total born per litter decreased in sows and gilts. The effect of semen ageing on farrowing failure was more pronounced in sows than in gilts as in the latter it became significant only after 8 days. The effect of semen ageing on total born per litter was similar in both sows and gilts. A lower parity and wean-to-service interval were associated with a reduction in farrowing failure and increase in total born per litter in sows. Increasing the number of inseminations up to two was beneficial in reducing farrowing failure in sows and gilts. A third insemination increased the likelihood of farrowing failure in sows. The number of total born per litter in sows increased with number of inseminations and the effect was not significant in gilts.