Microbiological assessment of liquid feed for finisher pigs on commercial pig units.

AIMS: To investigate the microbiological and nutritional quality of liquid finisher pig feed on commercial production units and the factors influencing this. METHODS AND RESULTS: Microbiological and physio-chemical analyses were performed on liquid feed sampled from the mixing tank and troughs of the finisher section of eight commercial pig units. Lactic acid bacteria, yeast and Escherichia coli counts, as well as lactic acid, ethanol and acetate concentrations were higher in residual feed sampled from the troughs compared with mixing tank samples (P < 0·001). Feed pH, as well as lysine, methionine and threonine concentrations and gross energy were all lower in the residual trough samples (P < 0·001). Liquid co-products reduced E. coli counts in the residual trough samples (P < 0·05), pH in the mixing tank (P < 0·01) and fresh trough samples (P < 0·05) and mould counts at all three sampling locations (P < 0·01) but sanitation practices had no impact. CONCLUSIONS: Even when considered unfermented, a considerable degree of spontaneous fermentation occurs in liquid feed, with resultant negative effects on nutritional quality. SIGNIFICANCE AND IMPACT OF THE STUDY: This is one of the first studies showing that uncontrolled fermentation of fresh liquid pig feed is commonplace on commercial units, highlighting the need for implementation of suitable control strategies.

Effect of dietary L-carnitine supplementation to sows during gestation and/or lactation on sow productivity, muscle maturation and lifetime growth in progeny from large litters.

Genetic selection for increased sow prolificacy has resulted in decreased mean piglet birth-weight. This study aimed to investigate the effect of L-carnitine (CAR) supplementation to sows during gestation and/or lactation on sow productivity, semitendinosus muscle (STM) maturity, and lifetime growth in progeny. Sixty-four sows were randomly assigned to one of four dietary treatments at breeding until weaning; CONTROL (0mg CAR/d), GEST (125mg CAR/d during gestation), LACT (250mg CAR/d during lactation), and BOTH (125mg CAR/d during gestation & 250mg CAR/d during lactation). The total number of piglets born per litter was greater for sows supplemented with CAR during gestation (17.3 v 15.8 ± 0.52; P<0.05). Piglet birth-weight (total and live) was unaffected by sow treatment (P>0.05). Total myofibre number (P=0.08) and the expression level of selected myosin heavy chain genes in the STM (P<0.05) was greater in piglets of sows supplemented with CAR during gestation. Pigs from sows supplemented with CAR during gestation had lighter carcasses at slaughter than pigs from non-supplemented sows during gestation (83.8 v 86.7 ± 0.86kg; P<0.05). In conclusion, CAR supplementation during gestation increased litter size at birth without compromising piglet birth-weight. Results also showed that the STM of piglets born to sows supplemented with CAR during gestation was more developed at birth. However, carcass weight at slaughter was reduced in progeny of sows supplemented with CAR during gestation. The CAR supplementation strategy applied during gestation in this study could be utilized by commercial pork producers to increase sow litter size and improve offspring muscle development.

An association analysis of sow parity, live-weight and back-fat depth as indicators of sow productivity.

Understanding how critical sow live-weight and back-fat depth during gestation are in ensuring optimum sow productivity is important. The objective of this study was to quantify the association between sow parity, live-weight and back-fat depth during gestation with subsequent sow reproductive performance. Records of 1058 sows and 13 827 piglets from 10 trials on two research farms between the years 2005 and 2015 were analysed. Sows ranged from parity 1 to 6 with the number of sows per parity distributed as follows: 232, 277, 180, 131, 132 and 106, respectively. Variables that were analysed included total born (TB), born alive (BA), piglet birth weight (BtWT), pre-weaning mortality (PWM), piglet wean weight (WnWT), number of piglets weaned (Wn), wean to service interval (WSI), piglets born alive in subsequent farrowing and sow lactation feed intake. Calculated variables included the within-litter CV in birth weight (LtV), pre-weaning growth rate per litter (PWG), total litter gain (TLG), lactation efficiency and litter size reared after cross-fostering. Data were analysed using linear mixed models accounting for covariance among records. Third and fourth parity sows had more (P0.05). Heavier sow live-weight throughout gestation was associated with an increase in PWM (P0.05). In conclusion, this study showed that sow parity, live-weight and back-fat depth can be used as indicators of reproductive performance. In addition, this study also provides validation for future development of a benchmarking tool to monitor and improve the productivity of modern sow herd.

Cyanotic Congenital Heart Disease Modes of Presentation and Prenatal Detection

Prenatal detection of structural congenital heart disease (CHD) optimises cardiovascular stability pre-operatively and post-operative outcomes. We compared prenatal detection rates of critical CHD in units offering universal fetal anomaly scans with those offering imaging to selected women. One hundred and thirteen infants met inclusion criteria. The overall pre-natal detection rate for critical CHD was 57% of liveborn infants. It was 71% (57/80) in hospitals who offered a universal anomaly scan and 29% (9/31) in centres offering a limited service. Postnatal diagnosis was associated with PICU admission (p=0.016) and preoperative mechanical ventilation (p=0.001). One-year mortality was 10 fold higher in the postnatally diagnosed group 15% vs 1.55% (p=0.0066). There is a significant disparity between centres offering universal anomaly versus selective screening. Prenatal detection confers advantage in terms of pre-operative stability and one year survival. Failure to deliver an equitable service exposes infants with CHD to avoidable risk.

Differences in intestinal size, structure, and function contributing to feed efficiency in broiler chickens reared at geographically distant locations.

The contribution of the intestinal tract to differences in residual feed intake (RFI) has been inconclusively studied in chickens so far. It is also not clear if RFI-related differences in intestinal function are similar in chickens raised in different environments. The objective was to investigate differences in nutrient retention, visceral organ size, intestinal morphology, jejunal permeability and expression of genes related to barrier function, and innate immune response in chickens of diverging RFI raised at 2 locations (L1: Austria; L2: UK). The experimental protocol was similar, and the same dietary formulation was fed at the 2 locations. Individual BW and feed intake (FI) of chickens (Cobb 500FF) were recorded from d 7 of life. At 5 wk of life, chickens (L1, n = 157; L2 = 192) were ranked according to their RFI, and low, medium, and high RFI chickens were selected (n = 9/RFI group, sex, and location). RFI values were similar between locations within the same RFI group and increased by 446 and 464 g from low to high RFI in females and males, respectively. Location, but not RFI rank, affected growth, nutrient retention, size of the intestine, and jejunal disaccharidase activity. Chickens from L2 had lower total body weight gain and mucosal enzyme activity but higher nutrient retention and longer intestines than chickens at L1. Parameters determined only at L1 showed increased crypt depth in the duodenum and jejunum and enhanced paracellular permeability in low vs. high RFI females. Jejunal expression of IL1B was lower in low vs. high RFI females at L2, whereas that of TLR4 at L1 and MCT1 at both locations was higher in low vs. high RFI males. Correlation analysis between intestinal parameters and feed efficiency metrics indicated that feed conversion ratio was more correlated to intestinal size and function than was RFI. In conclusion, the rearing environment greatly affected intestinal size and function, thereby contributing to the variation in chicken RFI observed across locations.

Salmonella in breeding pigs: Shedding pattern, transmission of infection and the role of environmental contamination in Irish commercial farrow-to-finish herds.

This study aimed to provide new insights into the epidemiology of Salmonella in pig production, focusing on potential shedding patterns in breeding pigs throughout a full production cycle and the risk of transmission of infection from the sow to her offspring. A longitudinal study was conducted on five farrow-to-finish commercial pig farms. In each herd, shedding of Salmonella in faeces was monitored in breeders through service, gestation and lactation. Swabs of the farrowing room floor and pools of faeces from piglets were collected on two occasions during lactation. Environmental pen swabs were also taken in the weaning and finisher houses. Salmonella isolates were serotyped, tested for antimicrobial resistance (AMR) and typed by Multiple-Locus Variable number tandem repeat Analysis (MLVA). Shedding by breeding pigs was low in all stages of the production cycle; 5% of sows shed at service, the production stage with highest risk of shedding (p < .01), 1.6% shed during gestation and 2.5% after farrowing. Salmonella was detected in 4% of piglet faecal pools in the second week post-farrowing and 5% in the fourth week. Serotyping and AMR profiles of Salmonella isolates revealed that strains in sows and gilts were mostly different from strains isolated in weaner and finisher facilities. MLVA typing confirmed that the source of infection in piglets was in most instances the contaminated environment rather than their dam. Based on the typing results, it appears that sows do not pose a major risk in the maintenance and transmission of Salmonella to their progeny but instead the contaminated pen environment is more significant in the perpetuation of the organism on farm.

Anaerobic co-digestion of pig manure and food waste; effects on digestate biosafety, dewaterability, and microbial community dynamics.

This study assessed the effect of varying pig manure (PM)/food waste (FW) mixing ratio and hydraulic retention time (HRT) on methane yields, digestate dewaterability, enteric indicator bacteria and microbial communities during anaerobic co-digestion. Three 10 L digesters were operated at 39 °C, each with a PM/FW feedstock composition of 85%/15%, 63%/37% and 40%/60% (volatile solids basis). While the PM/FW ratio was different among reactors, the organic loading rate applied was equal, and increased stepwise with reducing HRT. The effects of three different HRTs were studied: 41, 29, and 21 days. Increasing the proportion of FW in the feedstock significantly increased methane yields, but had no significant effect on counts of enteric indicator bacteria in the digestate or specific resistance to filtration, suggesting that varying the PM/FW feedstock composition at the mixing ratios studied should not have major consequences for digestate disposal. Decreasing HRT significantly increased volumetric methane yields, increased digestate volatile solids concentrations and increased the proportion of particles >500 µm in the digestate, indicating that decreasing HRT to 21 days reduced methane conversion efficiency High throughput 16S rRNA sequencing data revealed that microbial communities were just slightly affected by changes in digester operating conditions. These results would provide information useful when optimizing the start-up and operation of biogas plants treating these substrates.

Assessing serum metabolite profiles as predictors for feed efficiency in broiler chickens reared at geographically distant locations.

1. The objective of this study was to investigate differences in growth performance, serum intermediary metabolites, acute-phase proteins and white blood cells in low, medium and high-residual feed intake (RFI) chickens. It was also assessed if the environment affects the feed efficiency (FE) and FE-related performance and serum profiles of chickens. 2. Individual body weight (BW) and feed intake (FI) were recorded from d 7 of life. At 5 weeks of age, female and male broiler chickens (Cobb 500) were selected according to their RFI (L1: Austria; L2: UK; n = 9/RFI group, sex and locatity -45on) and blood samples were collected. 3. Chickens at L1 had similar FI but a 15% higher BW gain compared to chickens at L2. The RFI values of female chickens were -231, 8 and 215 g and those of male chickens -197, 0 and 267 g for low, medium and high RFI, respectively. 4. Location affected serum glucose, urea, cholesterol, non-esterified fatty acids (NEFA) and ovotransferrin in females, and serum glucose and triglycerides in male chickens. Serum uric acid and NEFA linearly increased from low to high RFI in females, whereas in males, cholesterol showed the same linear response from low to high RFI. Serum alpha-1-acid glycoprotein and blood heterophil-to-lymphocyte ratio linearly increased by 35% and 68%, respectively, from low to high RFI but only in male chickens at L1. 5. Regression analysis showed significant positive relationships between RFI and serum uric acid (R2 = 0.49) and cholesterol (R2 = 0.13). 6. It was concluded that RFI-related variation in serum metabolites of chickens was largely similar for the two environments and that serum metabolite patterns could be used to predict RFI in chickens.

Feed efficiency metrics in growing pigs.

The objective of the present study was to quantify the interrelationships between different feed efficiency measures in growing pigs and characterize pigs divergent for a selection of these measures. The data set included data from 311 growing pigs between 42 and 91 d of age from 3 separate batches. Growth-related metrics available included midtest metabolic BW (BW), energy intake (EI), and ADG. Ratio efficiency traits included energy conversion ratio (ECR), Kleiber ratio (ADG/BW), relative growth rate (RGR), residual EI (REI), and residual daily gain (RDG). Residual intake and gain (RIG; i.e., a dual index of both REI and RDG) and residual midtest metabolic weight (RMW) were also calculated. Simple Pearson correlations were estimated between the growth and feed efficiency metrics. In litters with at least 3 pigs of each sex, pigs were separately stratified on each residual trait as high, medium, and low rank. Considerable interanimal variability existed in all metrics evaluated. Male pigs were superior to females for all metrics ( < 0.001) except for both BW and EI, where no sex differences were evident. Feed efficiency metrics improved as birth BW increased ( < 0.05) except for RGR, where the contrary was observed. Correlations between most growth and feed efficiency metrics were strong to moderate ( < 0.05). Low-REI pigs (i.e., more efficient) had lower EI and ECR and were superior for RIG ( < 0.001) compared with high- and medium-REI pigs. High-RDG pigs (i.e., more efficient) had greater BW gain and better ECR ( < 0.001) compared with medium- and low-RDG pigs. Residual EI and RIG were both superior ( < 0.001) in high-RDG pigs compared with medium- and low-RDG pigs. Energy conversion ratio, REI, and RIG were superior ( < 0.05) in high-RMW pigs (i.e., more efficient) compared with medium-RMW pigs. High-RIG pigs (i.e., more efficient) had lower EI ( < 0.01) and superior ECR for RDG and REI compared with medium- and low-RIG pigs. In general, most of the correlations among the feed efficiency traits investigated in this study were different from unity, indicating that each trait is depicting a different aspect of efficiency in pigs, although the moderate to strong correlations suggest that improvement in one trait would, on average, lead to improvements in the others. Pigs ranked as more efficient on residual traits such as REI consumed less energy for a similar BW gain, which would translate into an economic benefit for pig producers.

Investigation of in-feed organic acids as a low cost strategy to combat Salmonella in grower pigs.

Salmonella carriage in pigs is a significant food safety issue. Dietary supplementation with organic acids has previously been shown to reduce shedding and transmission of Salmonella. Therefore, this study aimed to examine the effect of three commercially available organic acid-based products on Salmonella levels in grower pigs, using a model of experimental infection that closely mimics natural exposure to the organism. Seven week old trial pigs (n=40) with a mean weight of 14.7kg were placed in one of four pens with 10 pigs/pen. Pens had previously been contaminated with Salmonella Typhimurium 4,[5],12;i;- via seeder pigs. Trial pigs received one of four diets for 28days: 1, control diet; 2, sodium butyrate supplemented diet; 3, benzoic acid supplemented diet and 4, formic-citric acid supplemented diet. A further 10 pigs were placed in a Salmonella-free pen receiving the control diet. Pigs were weighed and blood sampled on days 0 and 28. Faeces was collected on day 0, 2, 3, 5, 7, 14, 21 and 28 and examined for Salmonella. On day 28, 5 pigs/group were euthanised and ileocaecal lymph nodes (ILN) and caecal contents sampled for culture. The remaining 5 pigs/pen were then fed the control diet and faeces were collected on days 35 and 42. On day 42 pigs were euthanised and ILN and caecal contents tested for Salmonella levels. The trial was repeated once. Within the first two days of exposure to the contaminated environment, 96% (77/80) of pigs became infected. Most pigs shed Salmonella at levels of between 100-103 CFU/g faeces for at least 7days post-exposure. A significant reduction in Salmonella faecal concentration was observed after supplementation with sodium butyrate (p=0.001) and a formic citric acid blend (p<0.0001). Average daily weight gain (ADWG) was significantly increased in all groups fed the supplemented feed when compared to the positive control group. The use of sodium butyrate or a blend of formic and citric acid in feed could be considered a cost-effective control measure to reduce Salmonella faecal shedding and improve ADWG in Salmonella infected herds.

Comparison of growth performance and excreta composition in broiler chickens when ranked according to various feed efficiency metrics.

Several feed efficiency (FE) metrics are currently used in livestock production to select for improved FE. Whether or not different FE metrics similarly estimate physiological characteristics in chickens of diverging FE has not been reported so far. This study aimed to assess potential differences in feed intake (FI), performance, and nutrient excretion in broiler chickens of diverging FE when ranked according to their residual FI (RFI), residual BW gain (RBG), RFI and BW gain (RIG), and G:F between d 7 and 35 of life. The FI was determined daily and BW was recorded once a week. The ranking of chickens into good, medium, and poor FE groups was completed separately for each FE metric. Freshly dropped excreta were collected for pH and DM measurements on d 30 to 32 of life and total excreta for determination of nutrient excretion was collected on d 34 to 36 of life. Relationships among FE metrics were evaluated using regression analysis showing that RFI, RIG, and G:F were more related to each other than to RBG. The FE values greatly varied among chickens for all FE metrics and chickens did not always cluster within the same FE group when using RFI, RIG, RBG, and G:F as the FE metrics because of the calculation approaches. Due to sex-related differences in performance, data of male and female chickens were analyzed separately. The RFI and RIG metrics showed a linear increase ( < 0.01) in total FI from good to poor FE in male and female chickens, whereas G:F showed this effect ( ≤ 0.011) only when BW gain was standardized to 1,500 g. The RBG did not clearly select chickens of enhanced total BW gain and only tended ( < 0.1) to select for greater BW gain from good to poor FE in female chickens. Excreta pH linearly decreased by 0.7 log units and DM content increased in males from good to poor FE when using RFI and RIG, respectively ( < 0.01). In both sexes, RFI ( < 0.05) and RIG metrics ( ≤ 0.06) showed a linear increase in daily nitrogen excretion from good to poor FE. In conclusion, results demonstrate that selection of the metric used to determine the FE of chickens modified the results obtained for comparison of production parameters and nutrient excretion among FE groups. Thereby, the RFI, RIG, and G:F metrics were beneficial in selecting the most feed efficient chickens to reduce feed costs, whereas the use of RFI and RIG may be better to select chickens with improved nitrogen retention and thus reduced excretion of an environmental pollutant.

An investigation into the removal of Salmonella and enteric indicator bacteria from the separated liquid fraction of raw or anaerobically digested pig manure using novel on-farm woodchip biofilters.

The objective was to investigate the removal of Salmonella and enteric indicator bacteria from the liquid fraction of raw and anaerobically digested (AD) pig manure in woodchip biofilters over a 14 week (98 day) period. Antibiotic susceptible Salmonella Infantis was detected in one influent material (liquid fraction of raw manure) on two occasions but was not found in the effluent at any time point. Furthermore, mean coliform reductions of 56% were observed in the biofilters treating the liquid fraction of raw manure. However, a mean increase of 228% was found in those treating the liquid from AD manure, despite the fact that the microbial challenge to these biofilters was lower. In addition, relatively high coliform counts were still present in the effluent from both biofilter treatments, especially in the systems treating the liquid fraction of AD manure. However, findings for Escherichia coli and Enterococcus were more promising, with reductions observed for both treatments (10 and 18.5% for E. coli and 71 and 87% for Enterococcus). Moreover, E. coli and Enterococcus were at, or just above, the limit of detection in the final effluents. Overall, although, there are no microbial limits for discharge or washwaters, the woodchip filter effluent would appear safe for discharge to waterways or use on-farm as regards Salmonella, E. coli and Enterococcus but not coliform. In conclusion, woodchip biofilters offer potential as a low-cost sustainable novel treatment option for the removal of pathogens from the liquid fraction of pig manure.

Oesophageal manometry: 10-year audit from a specialist centre, and early experience with high-resolution manometry.

BACKGROUND: Manometry is the gold standard investigation of innate or acquired motility disorders in the oesophagus. New technology in the form of high-resolution manometry (HRM) may supplant traditional water-perfused manometry and enhance standardisation of manometric interpretation and reporting. This study reports on a 10-year experience of 5,184 consecutive patients using the traditional methods, and an early experience with HRM. RESULTS: Of 5,184 patients assessed, 4,509 (87%) had both pH and manometry and 675 (13%) had manometry only. 3,523 (78%) of the pH /manometry group had normal motility, 635 (14%) showed ineffective motility (IM), 213 (5%) a non-specific motility disturbance (NSMD), 42 (0.9%) achalasia, 58 (1.3%) nutcracker oesophagus, 22 (0.5%) hypertensive LOS (HLOS), 8 (0.2%) diffuse oesophageal spasm (DOS) and 8 (0.2 %) had scleroderma. For those referred solely for manometry only, 324 (48%) had normal motility, 72 (11%) IM, 51 (8%) NSMD, 175 (26%) achalasia, 16 (2%) nutcracker oesophagus, 32 (5%) HLOS, 1 (0.1%) DOS and 4 (0.6%) had scleroderma. 92 patients to date have been studied with HRM, with enhanced definition of lower oesophageal sphincter (LOS) function. CONCLUSION: For patients referred for reflux related symptoms, motility disorders are present in 22% of the cases. Conversely, of the patients referred for dysphagia, motility disturbances are detected in 52% of the cases sent for manometry. Our initial experience shows that HRM technology is adding a valuable dimension and clearer understanding of motility patterns in the dysphagic patient.

Adenosine kinase, glutamine synthetase and EAAT2 as gene therapy targets for temporal lobe epilepsy.

Astrocytes are an attractive cell target for gene therapy, but the validation of new therapeutic candidates is needed. We determined whether adeno-associated viral (AAV) vector-mediated overexpression of glutamine synthetase (GS) or excitatory amino-acid transporter 2 (EAAT2), or expression of microRNA targeting adenosine kinase (miR-ADK) in hippocampal astrocytes in the rat brain could modulate susceptibility to kainate-induced seizures and neuronal cell loss. Transgene expression was found predominantly in astrocytes following direct injection of glial-targeting AAV9 vectors by 3 weeks postinjection. ADK expression in miR-ADK vector-injected rats was reduced by 94-96% and was associated with an ~50% reduction in the duration of kainate-induced seizures and greater protection of dentate hilar neurons but not CA3 neurons compared with miR-control vector-injected rats. In contrast, infusion of AAV-GS and EAAT2 vectors did not afford any protection against seizures or neuronal damage as the level of transcriptional activity of the glial fibrillary acidic promoter was too low to drive any significant increase in transgenic GS or EAAT2 relative to the high endogenous levels of these proteins. Our findings support ADK as a prime therapeutic target for gene therapy of temporal lobe epilepsy and suggest that alternative approaches including the use of stronger glial promoters are needed to increase transgenic GS and EAAT2 expression to levels that may be required to affect seizure induction and propagation.

Practice and documentation of palliative sedation: a quality improvement initiative.

BACKGROUND: Palliative sedation (ps), the continuous use of sedating doses of medication to intentionally reduce consciousness and relieve refractory symptoms at end of life, is ethically acceptable if administered according to standards of best practice. Procedural guidelines outlining the appropriate use of ps and the need for rigorous documentation have been developed. As a quality improvement strategy, we audited the practice and documentation of ps on our palliative care unit (pcu). METHODS: A pharmacy database search of admissions in 2008 identified, for a subsequent chart review, patients who had received either a continuous infusion of midazolam (≥10 mg/24 h), regular parenteral dosing of methotrimeprazine (≥75 mg daily), or regular phenobarbital. Documentation of the decision-making process, consent, and medication use was collected using a data extraction form based on current international ps standards. RESULTS: Interpretation and comparison of data were difficult because of an apparent lack of a consistent operational definition of ps. Patient records had no specific documentation in relation to ps initiation, to clearly identified refractory symptoms, and to informed consent in 60 (64.5%), 43 (46.2%), and 38 (40.9%) charts respectively. Variation in the medications used was marked: 54 patients (58%) were started on a single agent and 39 (42%), on multiple agents. The 40 patients (43%) started on midazolam alone received a mean daily dose of 21.4 mg (standard deviation: 24.6 mg). CONCLUSIONS: The lack of documentation and standardized practice of ps on our pcu has resulted in a quality improvement program to address those gaps. They also highlight the importance of conducting research and developing clinical guidelines in this area.

Treatment of separated piggery anaerobic digestate liquid using woodchip biofilters.

The Irish nitrates directive restricts the land area suitable for landspreading of pig manure, so anaerobic digestion warrants consideration. In this study, six identical Lodgepole pine woodchip biofilters were set up to treat the separated liquid fraction of digestate after anaerobic digestion of pig manure. Two hydraulic loading rates were examined: 5 L/m2/d (LLR) and 10 L/m2/d (HLR). Following a start-up period of 70 days, an average of 90% and 71% of NH4(+)-N was removed at LLR and HLR, respectively. LLR resulted in higher total nitrogen removals than HLR (p < 0.05). Efficient nitrification occurred at LLR as indicated by the lower NH4(+)-N (p < 0.05) and higher NO3(-)-N (p < 0.05) concentrations in the biofilter effluent. A batch experiment testing the capacity of saturated woodchips in removing total oxidized nitrogen (TON) from the effluent of the woodchip biofilters showed that TON was reduced by 323 mg/L from 663 mg/L in 360 h, indicating that the aerobic woodchip biofilters should incorporate a saturated layer ofwoodchips at the base ofthe biofilters to enhance nitrogen removal.

Assessing the biosafety risks of pig manure for use as a feedstock for composting.

The objective was to assess the biosafety risks of pig manure for use as a feedstock for composting. Salmonella was detected in the manure from half of the 30 pig farms sampled, with 52% of isolates recovered identified as multi-drug resistant S. Typhimurium. The highest prevalence (60%) was found on Salmonella category 2 and 3 farms i.e. those with medium and high Salmonella seroprevalence, respectively, although this was not statistically significant. Escherichia coli counts were, however, significantly higher in manure from Salmonella category 3 farms. Manure separation may be useful as a means of reducing/eliminating pathogens from manure prior to composting, as manure solids generated using a decanter centrifuge had lower E. coli and Enterococcus counts than manure. These findings should be taken into consideration when selecting pig manure for use as a feedstock for compost or other marketable manure by-products.

Transgenerational effects of feeding genetically modified maize to nulliparous sows and offspring on offspring growth and health.

This study assessed the effect of feeding genetically modified maize expressing a truncated form of the Cry1Ab protein from Bacillus thuringiensis (Bt MON810 maize) to sows during gestation and lactation and their offspring from weaning to 115 d postweaning on offspring growth and health. After weaning at approximately 28 d of age (d 0), individually penned, mixed sex pigs (approximately 8 kg BW) from sows fed isogenic or Bt maize diets were blocked by sow treatment, sex, and BW and randomly assigned to Bt or isogenic maize diets as follows: i) isogenic maize-fed sow/isogenic maize-fed offspring (iso/iso); ii) isogenic maize-fed sow/Bt maize-fed offspring (iso/Bt); iii) Bt maize-fed sow/isogenic maize-fed offspring (Bt/iso); and iv) Bt maize-fed sow/Bt maize-fed offspring (Bt/Bt). Growth performance was recorded at intervals to harvest at approximately 105 kg BW (n=15/treatment) and blood samples were taken for biochemical analysis on d 0, 30, 70, 100, and 115 postweaning (n=10/treatment). Pigs were harvested on d 115 postweaning (n=10/treatment), and carcass weight, backfat depth, and organ weights (heart, kidney, spleen, and liver) were recorded. Kidney, liver, lymph nodes, and small intestine were collected for histological analysis. Offspring from Bt maize-fed sows were heavier than offspring from isogenic maize-fed sows on d 30 (P<0.05), 100 (P<0.05), and 115 postweaning (P<0.05) and had greater overall ADG (P<0.05). Overall ADFI was greater for offspring from sows fed Bt maize (P<0.05) and for Bt maize-fed pigs (P<0.05). Offspring from Bt maize-fed sows had greater carcass (P<0.05) and lighter spleen (P<0.05) weights. Dressing percentage was greater for Bt maize-fed pigs than isogenic maize-fed pigs (P<0.05), and livers were lighter for pigs in the Bt/Bt group than pigs in the iso/Bt or Bt/iso group (P<0.05). Offspring from Bt maize-fed sows also had greater duodenal crypt depths (P<0.05) and lower villus height/crypt depth ratios (P<0.05). No pathology was observed in the organs, and serum biochemistry values generally remained within normal limits and no overall differences were observed, with the exception of overall γ glutamyltransferase, which was less for pigs on the Bt/Bt treatment than pigs on the iso/Bt and Bt/iso treatments. These results indicate that transgenerational consumption of Bt maize diets is not detrimental to pig growth and health.

Effect of feeding genetically modified Bt MON810 maize to ∼40-day-old pigs for 110 days on growth and health indicators.

A total of 72 male weaned pigs were used in a 110-day study to investigate the effect of feeding genetically modified (GM) Bt MON810 maize on selected growth and health indicators. It was hypothesised that in pigs fed Bt maize, growth and health are not impacted compared with pigs fed isogenic maize-based diets. Following a 12-day basal period, pigs (10.7 ± 1.9 kg body weight (BW); ∼40 days old) were blocked by weight and ancestry and randomly assigned to treatments: (1) non-GM maize diet for 110 days (non-GM), (2) GM maize diet for 110 days (GM), (3) non-GM maize diet for 30 days followed by GM maize diet up to day 110 (non-GM/GM) and (4) GM maize diet for 30 days followed by non-GM maize diet up to day 110 (GM/non-GM). BW and daily feed intake were recorded on days 0, 30, 60 and 110 (n = 15). Body composition was determined by dual energy X-ray absorptiometry (n = 10) on day 80. Following slaughter on day 110, organs and intestines were weighed and sampled for histological analysis and urine was collected for biochemical analysis (n = 10). Serum biochemistry analysis was performed on days 0, 30, 60, 100 and 110. Growth performance and serum biochemistry were analysed as repeated measures with time and treatment as main factors. The slice option of SAS was used to determine treatment differences at individual time points. There was no effect of feeding GM maize on overall growth, body composition, organ and intestinal weight and histology or serum biochemistry on days 60 and 100 and on urine biochemistry on day 110. A treatment × time interaction was observed for serum urea (SU; P < 0.05), creatinine (SC; P < 0.05) and aspartate aminotransferase (AST; P < 0.05). On day 30, SU was lower for the non-GM/GM treatment compared with the non-GM, GM and GM/non-GM treatments (P < 0.05). On day 110, SC was higher for the non-GM/GM and GM/non-GM treatments compared with non-GM and GM treatments (P < 0.05). Overall, serum total protein was lower for the GM/non-GM treatment compared with the non-GM/GM treatment (P < 0.05). The magnitude of change observed in some serum biochemical parameters did not indicate organ dysfunction and the changes were not accompanied by histological lesions. Long-term feeding of GM maize to pigs did not adversely affect growth or the selected health indicators investigated.