RSS 1.0Pig Development
Challenges facing the pig industry including environmental and animal welfare legislation as well as high production costs and poor pig prices means that there is increasing demand for new knowledge and solutions to problems at farm level. The research aspect of the Pig Production Development Unit based at Moorepark Research Centre, Fermoy, Co. Cork is equipped to meet this demand.
Recent Submissions
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Effects of pen faeces and feed contamination in biomarkers determination in oral fluid of pigsThe present study aims to evaluate the possible effects of the presence of pen faeces and feed on the measurement of a panel of biomarkers in porcine oral fluid. For this, clean porcine oral fluid was pooled and incubated with two different concentrations of pen faeces or feed representing a high or low level of contamination with each material. In addition, these pools were aliquoted and subjected to centrifugation, filtration or chemical clarification to evaluate if these techniques could revert the effects of those contaminants in biomarker evaluation. A panel of 21 biomarkers that assessed stress, inflammation, immune system and redox homeostasis among others, were measured for all aliquots. Changes of statistical relevance (p < 0.05) in oral fluid contaminated with pen faeces or feed versus untreated samples were observed for all methods employed with the exception of adenosine deaminase (ADA) and creatine kinase (CK) in oral fluid contaminated with pen faeces or feed. Pen faeces did not affect the measurement of haptoglobin, superoxide dismutase, CK, lactate dehydrogenase (LDH), ADA and cortisol (when the latter is measured by chemiluminescence); while uric acid, LDH, CK, ADA, and hydrogen peroxide methods were not affected by the presence of feed in oral fluid. The effects of centrifugation, filtration or chemical clarification with chitosan in these contaminated samples were modest and for most cases did not caused baseline levels on the measured biomarkers. In conclusion, the presence of pen faeces or feed in porcine oral fluid can interfere with the results obtained when analytes are measured.
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Use of infrared thermography to noninvasively assess neonatal piglet temperatureHypothermia is risk factor for piglet neonatal mortality, especially for low birth weight piglets. Piglets with intrauterine growth retardation (IUGR) also have a higher mortality risk at birth. This study aimed to validate infrared thermography (IRT) as an alternative to rectal temperature (RT) to measure piglet temperature in the hour postpartum, and to identify piglets with thermoregulation difficulties. At birth (6.3 ± 0.35 min postpartum), 67 piglets were dried, weighed, scored for growth retardation (IUGR; 0–3), and isolated in a plastic box where IRT images were taken, followed by RT. Piglets were then returned to the farrowing pen, and the process repeated at 15, 30, and 60 min postpartum. Piglets were ranked according to their weight (quartiles: 0.57–1.27 kg, 1.27–1.5 kg, 1.5–1.74 kg, 1.74–2.44 kg). Temperatures (ear base and tip; minimum, maximum and average of back) were extracted from IRT images (Thermacam Researcher Pro 2.0). Pearson correlations between temperature measures were calculated, and the effect of time, IUGR score, and weight were included in linear mixed models (SAS 9.4). RT was correlated with all IRT data across time points (P < 0.05); correlations were strongest with the ear base, and weakest with the ear tip and minimum back temperature. Both IUGR score and weight rank affected ear base (P < 0.05) and RTs (P < 0.05). The lightest piglets, and piglets with severe IUGR had the lowest temperature, relative to their counterparts. Indeed, differences between all weights categories were significant for RT. Piglets with the lowest weight (0.27–1.27 kg) had lower ear base temperatures than piglets in the third quartile (1.5–1.74 kg; 35.2 ± 0.36 °C vs. 36.5 ± 0.35 °C, t64.9 = −4.51, P < 0.001) and the heaviest piglets (1.74–2.44 kg; 35.2 ± 0.36 °C vs. 36.4 ± 0.36 °C, t70.4 = −3.97, P < 0.005). Overall, piglets with severe IUGR (score 3) had a lower RT than normal piglets (score 0; 35.8 ± 0.46 °C vs. 37.2 ± 0.42 °C, t43.1 = 3.16, P < 0.05) and piglets with mild IUGR (score 1; 35.8 ± 0.46 °C vs. 37.1 ± 0.40 °C, t45.3 = 2.92, P < 0.05); and they also had lower temperature at the base of the ear than normal piglets (35.1 ± 0.42 °C vs. 36.3 ± 0.36 °C, t63.1 = 3.01, P < 0.05). These results confirmed that IRT is an interesting noninvasive tool for assessing neonatal piglets’ thermoregulatory abilities and could be used in research investigating successful interventions for piglets at risk of hypothermia.
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Optimisation of a bead-beating procedure for simultaneous extraction of bacterial and fungal DNA from pig faeces and liquid feed for 16S and ITS2 rDNA amplicon sequencingEfficient cell lysis is critical for the extraction of DNA from difficult-to-lyse microorganisms such as Gram-positive bacteria and filamentous fungi. A bead-beating (BB) step is usually included in DNA extraction protocols to improve cell lysis. However, there is no consensus on the duration of BB that is necessary for complete lysis of the microbial communities present in complex microbial ecosystems, but which will still maintain the integrity of DNA released from easy-to-lyse microbes. Another consideration is that most protocols are tailored to one particular target group of microbes, typically either bacteria or fungi, in a given sample matrix. In this study, we investigated the impact of five BB durations (0, 3, 10, 15 and 20 min) during DNA extraction with the QIAamp® Fast DNA Stool Mini Kit, on the bacterial and fungal communities of single pig faecal and liquid feed samples, extracted in triplicate, with the objective of determining a suitable ‘catch-all’ method. Both sample types were subjected to the BB durations in triplicate, followed by 16S (bacterial) and ITS2 (fungal) rDNA amplicon sequencing. The performance of the different BB durations was assessed based on the quantity of total DNA extracted, alpha- and beta-diversity analyses of the resultant microbial communities and differential abundance of bacterial and fungal taxa. Our results suggest that 20 min of BB is most appropriate for maximising the lysis of difficult-to-lyse bacteria and fungi in both pig faeces and liquid feed, while minimising the negative impact on easier-to-lyse microbes. Total DNA yield increased with BB duration for both sample types; however, the yield from faeces decreased after 20 min of BB. Despite this, DESeq2 analysis indicated that changes in the differential abundances of the dominant taxa at this point were limited, which was supported by the Shannon diversity results. Maximising the BB duration appeared to be necessary in order to obtain a representative profile of the Gram-positive bacteria, particularly in liquid feed, and of the filamentous fungi present in both sample types. However, considering the small sample size, along with the reliance on differential as opposed to absolute abundances to validate increases or decreases in taxa, a larger-scale study is necessary to verify the findings of the present study.
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Mixing aggression intensity is associated with age at first service and floor type during gestation, with implications for sow reproductive performanceAggression resulting from mixing to establish a dominance hierarchy is a major welfare concern for group-housed sows. The associated stress can negatively impact aspects of reproductive performance. Objectives of this study were to investigate associations between 1) age at first service (AFS) and mixing aggression intensity in first parity sows, 2) mixing aggression intensity and reproductive performance within and between parity one and parity two, and 3) mixing aggression intensity, floor type during gestation and reproductive performance. Gilts (n =160, hereafter referred to as sows) were mixed into stable groups of eight unfamiliar individuals approximately 4 days after artificial insemination, housed on fully slatted concrete (CON; n =80) floor uncovered or covered with rubber slat mats (RUB; n =80), and followed through two parities. Skin lesions (SLMIX; a proxy for the intensity of mixing aggression), were scored post mixing in each parity according to severity (0=no lesions to 5=severe lesions) on five body regions (ear, neck, hindquarter, rump, and belly) on the left and right sides, and at the tail/anogenital region. Total SLMIX score was calculated for each sow. Data on reproductive performance traits were acquired retrospectively from farm records for both parities. Two analyses were performed: 1) data from each parity were analysed separately and 2) SLMIX score in parity one was used to predict reproductive performance in parity two. Lower AFS was associated with a lower SLMIX score in parity one (P =0.031). There was no association between SLMIX score and reproductive performance in parity one, while sows with higher SLMIX score in parity two had a higher proportion of piglets dead during lactation (P =0.027) and a longer cycle length (P =0.003) in parity two. Sows with higher SLMIX scores in parity one had more non-productive days (P <0.001) in parity two. Concrete sows had a higher SLMIX score than RUB sows in parity one (P =0.015), but not in parity two. In addition, CON sows had a higher proportion of piglets born dead (P =0.013) compared with RUB sows in parity two. Mixing aggression has a negative influence on reproductive performance within parities, and it may also have a long-term negative carry-over effect on reproductive performance in subsequent parities. Serving gilts at younger ages could help to minimize the intensity of aggression at mixing, while housing on rubber flooring has beneficial implications for their reproductive performance.
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Effect of multicarbohydrase enzymes containing α-galactosidase on the growth and apparent metabolizable energy digestibility of broiler chickens: a meta-analysisExogenous enzyme supplementation is a valid strategy to improve nutrient availability and growth performance in broilers. Traditional carbohydrases, such as xylanase and β-glucanase, are well-researched solutions to increase the nutritional value of cereal grains, whilst reducing any negative impact of associated viscous polysaccharides. The feeding value of soybean meal and other protein rich oilcakes may not be fully exploited with traditional enzymes, as structures such as galacto-oligosaccharides and pectins require specific α-galactosidase, mannanase and other hemicellulolytic enzymes. This study aimed to summarize, in a meta-analysis, the results from independently run randomized controlled studies in various global locations that evaluated the effect of two distinct multicarbohydrase formulations, in which an α-galactosidase was combined with either xylanase (AGX) or β-glucanase (AGB). Through meta-regression analysis, the mean difference effects of AGX and AGB supplementation on broiler final body weight (BW), feed conversion ratio (FCR) and nitrogen-corrected apparent metabolizable energy (AMEN) were calculated for each relevant study. Fixed and random-effects models were used to compute the standardized mean difference (SMD) and confidence intervals, with corrective actions taken to ensure compliance with publication bias and heterogeneity by the Egger test and the Cochran Q test. Adjusted models showed that the AGX supplementation increased broiler BW (SMD=+30 g; 95 % CI: 0.08_0.48; P = 0.006) and improved FCR (SMD=−0.01 g/g; 95 % CI: -0.51_-0.11; P = 0.002). A composite evaluation of independent studies showed increased AMEN in broilers supplemented with AGX (SMD=+58 kcal/kg; 95 % CI: 0.45_1.10; P < 0.001). Furthermore, meta-analysis confirms that AGB supplementation increased BW (SMD=+56 g; 95 % CI: 0.32_0.91; P < 0.001), improved FCR (SMD=−0.04 g/g; 95 % CI: −0.76_−0.20; P = 0.006) and increased AMEN (SMD=+49 kcal/kg; 95 % CI: 0.30_1.07; P < 0.001). Overall, this meta-analysis found that dietary supplementation of broiler diets with the multicarbohydrases containing α-galactosidase considered in this evaluation, improved broiler growth during rearing periods of 35 days or more. These improvements may be supported by increases in energy utilization, as found in this study.
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Effect of multicarbohydrase enzymes containing α-galactosidase on the growth and apparent metabolizable energy digestibility of broiler chickens: a meta-analysisExogenous enzyme supplementation is a valid strategy to improve nutrient availability and growth performance in broilers. Traditional carbohydrases, such as xylanase and β-glucanase, are well-researched solutions to increase the nutritional value of cereal grains, whilst reducing any negative impact of associated viscous polysaccharides. The feeding value of soybean meal and other protein rich oilcakes may not be fully exploited with traditional enzymes, as structures such as galacto-oligosaccharides and pectins require specific α-galactosidase, mannanase and other hemicellulolytic enzymes. This study aimed to summarize, in a meta-analysis, the results from independently run randomized controlled studies in various global locations that evaluated the effect of two distinct multicarbohydrase formulations, in which an α-galactosidase was combined with either xylanase (AGX) or β-glucanase (AGB). Through meta-regression analysis, the mean difference effects of AGX and AGB supplementation on broiler final body weight (BW), feed conversion ratio (FCR) and nitrogen-corrected apparent metabolizable energy (AMEN) were calculated for each relevant study. Fixed and random-effects models were used to compute the standardized mean difference (SMD) and confidence intervals, with corrective actions taken to ensure compliance with publication bias and heterogeneity by the Egger test and the Cochran Q test. Adjusted models showed that the AGX supplementation increased broiler BW (SMD=+30 g; 95 % CI: 0.08_0.48; P = 0.006) and improved FCR (SMD=−0.01 g/g; 95 % CI: -0.51_-0.11; P = 0.002). A composite evaluation of independent studies showed increased AMEN in broilers supplemented with AGX (SMD=+58 kcal/kg; 95 % CI: 0.45_1.10; P < 0.001). Furthermore, meta-analysis confirms that AGB supplementation increased BW (SMD=+56 g; 95 % CI: 0.32_0.91; P < 0.001), improved FCR (SMD=−0.04 g/g; 95 % CI: −0.76_−0.20; P = 0.006) and increased AMEN (SMD=+49 kcal/kg; 95 % CI: 0.30_1.07; P < 0.001). Overall, this meta-analysis found that dietary supplementation of broiler diets with the multicarbohydrases containing α-galactosidase considered in this evaluation, improved broiler growth during rearing periods of 35 days or more. These improvements may be supported by increases in energy utilization, as found in this study.
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Intestinal microbiota modulation and improved growth in pigs with post‑weaning antibiotic and ZnO supplementation but only subtle microbiota efects with Bacillus altitudinisThe objective was to evaluate the efect of dietary Bacillus altitudinis spore supplementation during day (D)0–28 post-weaning (PW) and/or D29–56 PW compared with antibiotic and zinc oxide (AB+ZnO) supplementation on pig growth and gut microbiota. Eighty piglets were selected at weaning and randomly assigned to one of fve dietary treatments: (1) negative control (Con/Con); (2) probiotic spores from D29–56 PW (Con/Pro); (3) probiotic spores from D0–28 PW (Pro/Con); (4) probiotic spores from D0–56 PW (Pro/Pro) and (5) AB+ZnO from D0–28 PW. Overall, compared with the AB+ZnO group, the Pro/Con group had lower body weight, average daily gain and feed intake and the Pro/Pro group tended to have lower daily gain and feed intake. However, none of these parameters difered between any of the probiotic-treated groups and the Con/Con group. Overall, AB+ZnO-supplemented pigs had higher Bacteroidaceae and Prevotellaceae and lower Lactobacillaceae and Spirochaetaceae abundance compared to the Con/Con group, which may help to explain improvements in growth between D15–28 PW. The butyrate-producing genera Agathobacter, Faecalibacterium and Roseburia were more abundant in the Pro/Con group compared with the Con/Con group on D35 PW. Thus, whilst supplementation with B. altitudinis did not enhance pig growth performance, it did have a subtle, albeit potentially benefcial, impact on the intestinal microbiota.
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Microbial Quality of Liquid Feed for Pigs and Its Impact on the Porcine Gut MicrobiomeThere is evidence that spontaneous fermentation frequently occurs in liquid pig feed that is intended to be delivered as fresh liquid feed, often with a resultant deterioration in the microbial and nutritional quality of the feed, which can negatively affect pig health and growth. Strategies including controlled fermentation with microbial inoculants, pre-fermentation or soaking of the cereal fraction of the diet, enzyme supplementation and dietary acidification have been employed to inhibit pathogens and prevent deterioration of feed nutritional quality, with promising results obtained in many cases. This review evaluates the impact of these strategies on the microbial quality of liquid feed and discusses how they can be further improved. It also investigates if/how these strategies impact the pig gut microbiota and growth performance of liquid-fed pigs. Finally, we review liquid feed system sanitisation practices, which are highly variable from farm to farm and discuss the impact of these practices and whether they are beneficial or detrimental to liquid feed microbial quality. Overall, we provide a comprehensive review of the current state of knowledge on liquid feed for pigs, focusing on factors affecting microbial quality and strategies for its optimisation, as well as its impact on the pig gut microbiome.
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Risk Factors for Antimicrobial Use on Irish Pig FarmsThe threat to public health posed by antimicrobial resistance in livestock production means that the pig sector is a particular focus for efforts to reduce antimicrobial use (AMU). This study sought to investigate the risk factors for AMU in Irish pig production. Antimicrobial use data were collected from 52 farrow-to-finish farms. The risk factors investigated were farm characteristics and performance, biosecurity practices, prevalence of pluck lesions at slaughter and serological status for four common respiratory pathogens and vaccination and prophylactic AMU practices. Linear regression models were used for quantitative AMU analysis and risk factors for specific AMU practices were investigated using logistic regression. Farms that milled their own feed had lower total AMU (p < 0.001), whereas higher finisher mortality (p = 0.043) and vaccinating for swine influenza (p < 0.001) increased AMU. Farms with higher prevalence of pericarditis (p = 0.037) and lung abscesses (p = 0.046) used more group treatments. Farms with higher prevalence of liver milk spot lesions (p = 0.018) and farms practising prophylactic AMU in piglets (p = 0.03) had higher numbers of individual treatments. Farms practising prophylactic AMU in piglets (p = 0.002) or sows (p = 0.062) had higher use of cephalosporins and fluoroquinolones. This study identified prophylactic use and respiratory disease as the main drivers for AMU in Irish pig production. These findings highlight areas of farm management where interventions may aid in reducing AMU on Irish pig farms.
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Exploratory study of the effects of intra-uterine growth retardation and neonatal energy supplementation of low birth-weight piglets on their post-weaning cognitive abilitiesThe present study investigated the effects of intra-uterine growth retardation (IUGR, score 0–3; i.e., “normal” to “severe”) level at birth, and the effects of neonatal energy supplementation (dosed with 2 ml of coconut oil, commercial product or water, or sham-dosed), on post-weaning cognitive abilities of low birth-weight piglets (<1.1 kg). In total, 184 piglets were recruited at weaning (27±0.1 days) for habituation to the test procedures, and were either tested for spatial learning and memory in a T-maze (n=42; 37±0.5 days) or for short-term memory in a spontaneous object recognition task (SORT; n=47; 41±0.3 days). Neonatal supplementation did not affect performances of pigs in the T-maze task or SORT. IUGR3 pigs tended to be faster to enter the reward arm and to obtain the reward in the reversal step of the T-Maze task, suggesting a better learning flexibility, compared to IUGR1 (entry t72.8=2.9, P=0.024; reward t80=3.28, P=0.008) and IUGR2 (entry t70.3=2.5, P=0.068; reward t73.9=2.77, P=0.034) pigs. However, a higher percentage of IUGR1 pigs tended to approach the novel object first (DSCF-value=3.07; P=0.076) and to interact with it more (t40=2.19, P=0.085), relative to IGUR3 pigs. IUGR1 pigs showed a strong preference for the novel object, as they had a greater percentage time difference interacting with the objects when the novel object was presented (t81=−3.41, P=0.013). In conclusion, some low birth-weight piglets are able to perform a spatial task and an object recognition test, but performances in these tests may be modulated by IUGR level.
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Effect of l-carnitine supplementation and sugar beet pulp inclusion in gilt gestation diets on gilt live weight, lactation feed intake, and offspring growth from birth to slaughterThis study evaluated the effects of l-carnitine (CAR) and sugar beet pulp (SBP) inclusion in gilt gestation diets on gilt live weight, cortisol concentration, lactation feed intake, and lifetime growth of progeny. Eighty-four pregnant gilts (Large White × Landrace) were randomly assigned to a treatment at day 38 of gestation until parturition; Control (0% SBP, 0 g CAR), CAR (0.125 g/d CAR), SBP (40% SBP), and SBP plus CAR (40% SBP, 0.125 g/d CAR). Gilts were weighed and back-fat depth was recorded on day 38, day 90, and day 108 of gestation and at weaning. Gilt saliva samples were collected pre-farrowing and fecal consistency was scored from entry to the farrowing room until day 5 post-partum. The number of piglets born (total, live, and stillborn) and individual birth weight was recorded. Piglet blood glucose concentration was measured 24 h post-partum and pigs were weighed on day 1, day 6, day 14, day 26, day 76, day 110, and day 147 of life. Carcass data were collected at slaughter. There was no interaction between CAR and SBP for any variable measured. The SBP-fed gilts were heavier on day 90 and day 108 of gestation (P < 0.05) and lost more weight during lactation (P < 0.05) than control gilts. They also had a greater fecal consistency score (P < 0.01). Total farrowing duration, piglet birth interval, and lactation feed intakes were similar between treatments (P > 0.05). The number of piglets born (total, live, and stillborn) and piglet birth weight was likewise similar between treatments (P > 0.05). Piglets from CAR-fed gilts had lower blood glucose concentrations (P < 0.01), while piglets from SBP-fed gilts had greater blood glucose concentrations (P < 0.01). Piglets from CAR gilts had a lower average daily gain between day 1 and day 6 (P < 0.05) and day 14 and day 26 post-partum (P < 0.05) compared to piglets from control gilts. However, CAR gilts weaned a greater number of pigs (P = 0.07). Live weight and carcass weight at slaughter were heavier for pigs from CAR gilts (P < 0.05) and from SBP gilts (P < 0.05). Pigs from CAR gilts (P < 0.01) and SBP gilts (P < 0.05) had increased carcass muscle depth. In conclusion, no benefit was found from the combined feeding of CAR and SBP. Fed separately, CAR increased the live weight, carcass weight, and muscle depth of progeny at slaughter. Feeding a high SBP diet increased fecal consistency in gilts pre-farrowing and increased live weight and carcass muscle depth of progeny.
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Influence of sows’ parity on performance and humoral immune response of the offspringBackground Primiparous sows (PP) have higher nutrient requirements, fewer piglets born with lower birth weight and growth performance than multiparous sows (MP). The aim of the current study was to investigate the effect of parity of sow (PP or MP) on the growth performance and humoral immune response of piglets. A total of 10 PP and 10 MP (3rd to 5th parity) sows were used. There were 4 treatments in a 2 × 2 factorial arrangement, with piglets from PP sows suckled by PP or MP sows, and piglets from MP sows suckled by PP or MP sows. Average daily gain (ADG) of piglets during the lactation period, and ADG, average daily feed intake (ADFI) and gain:feed ratio (G:F) from weaning to 144 days of age were controlled, and concentrations of immunoglobulins G (IgG) and major acute phase protein (Pig-MAP) were measured as markers of humoral immune response throughout the study. Results Total ADG was higher in piglets born from MP than in those born from PP (669 vs. 605 g/day; standard error of the mean (SEM) = 15.5, n = 5; P = 0.001) and in piglets suckled by MP than in piglets suckled by PP (655 vs. 620 g/day; SEM = 15.5, n = 5, P = 0.037). Total ADFI was higher for pigs born from MP than for those born from PP (1592 vs. 1438 g/d, SEM = 42.2, n = 5, P < 0.001). Total G:F tended to be higher for pigs suckled by MP than for those suckled by PP (0.43 vs. 0.41, SEM = 0.006, n = 5, P = 0.076). At weaning, IgG serum concentration was higher (30.0 vs. 17.8 mg/mL, SEM = 4.98, n = 15, P = 0.013) in pigs suckled by MP than in piglets suckled by PP. However, IgG concentrations were higher for pigs born from PP than for pigs born from MP on days 116 (P < 0.001) and 144 (P = 0.088). Pig-MAP tended to be lower in pigs suckled by MP than in pigs suckled by PP on days 40 and 60 of age (P < 0.10). Conclusions The research indicates that the growth performance and humoral immune response of the offspring of PP is improved by cross-fostering with MP. These results open the possibility of an interesting strategy for improving the growth of litters from PP, that is easier to apply than current programs based on parity segregation, which implies a separate building site to house gilts, first parity sows and their offspring.
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Farmer Perceptions of Pig Aggression Compared to Animal-Based Measures of Fight OutcomeSeveral animal welfare issues persist in practice despite extensive research which has been linked to the unwillingness of stakeholders to make changes. For example, most farmers do not perceive pig aggression to be a problem that requires action despite the fact that stress and injuries are common, and that several solutions exist. Frequent exposure to animal suffering could affect farmer responses to distressed animals. This study investigated for the first time whether this occurs, using pig aggression as a focus. Using video clips, 90 pig farmers judged the severity of aggression, level of pig exhaustion and the strength of their own emotional response. Their judgments were compared to objective measures of severity (pigs’ skin lesions and blood lactate), and against control groups with similar pig experience (10 pig veterinarians) and without experience (26 agricultural students; 24 animal science students). Famers did not show desensitization to aggression. However, all groups underestimated the outcome of aggression when they did not see the fight occurring as compared to witnessing a fight in progress. We suggest that farmers be provided with evidence of the economic and welfare impact of aggression as indicated by lesions and that they be advised to score lesions on affected animals.
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Feed Restriction Modifies Intestinal Microbiota-Host Mucosal Networking in Chickens Divergent in Residual Feed IntakeDifferences in chickens’ feed intake may be the underlying factor influencing feed-efficiency (FE)-associated variation in intestinal microbiota and physiology. In chickens eating the same amount of feed, quantitative feed restriction may create similar intestinal conditions and help clarify this cause-and-effect relationship. This study investigated the effect of ad libitum versus restrictive feeding (85% of ad libitum) on ileal and cecal microbiota, concentrations of short-chain fatty acids, visceral organ size, intestinal morphology, permeability, and expression of genes related to nutrient uptake, barrier function, and innate immune response in broiler chickens with divergent residual feed intake (RFI; metric for FE). On day 30 posthatch, 28 low-RFI (good FE) and 29 high-RFI (poor FE) chickens across both feedinglevel groups (n 112) were selected. Supervised multigroup data integration and relevance network analyses showed that especially Lactobacillus (negative) in ileal digesta, Turicibacter (positive) in cecal digesta, and Enterobacteriaceae (positive) in both intestinal segments depended on chicken’s feed intake, whereas the level of Anaerotruncus in cecal digesta was most discriminative for high RFI. Moreover, shallower crypts and fewer goblet cells in ceca indicated host-related energy-saving mechanisms with low RFI, whereas greater tissue resistance suggested a stronger jejunal barrier function in low-RFI chickens. Values corresponding to feed intake level RFI interactions indicated larger pancreas and lower levels of ileal and cecal short-chain fatty acids in restrictively fed high-RFI chickens than in the other 3 groups, suggesting host physiological adaptations to support greater energy and nutrient needs of high-RFI chickens compensating for the restricted feeding.
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The effect of group composition and mineral supplementation during rearing on the behavior and welfare of replacement giltsSow longevity supported by good health and reproductive performance is necessary to optimize sow lifetime performance. In some countries, replacement gilts are reared with finisher pigs destined for slaughter, so they are exposed to sexual and aggressive behaviors performed by males. This is associated with stress and injury. Moreover, diets formulated for finishers are not designed to meet the needs of replacement gilts and may not supply the necessary minerals to promote limb health, optimal reproduction, and, thus, sow longevity. In this 2 × 2 factorial design experiment with 384 animals (32 pens [12 animals per pen]), we investigated the effect of female-only (FEM) or mixed-sex (MIX) rearing, with (SUPP) or without (CON) supplementary minerals (copper, zinc, and manganese) on locomotion, salivary cortisol levels, behavior, body lesions (BL), and hoof health of gilts. The experimental period began at transfer to the finisher stage (day 81.3 ± 0.5 of age; day 0) until breeding age (day 196 ± 0.5 of age; day 115). Locomotion was scored (0–5) biweekly from day 0 until slaughter day 67 or breeding age day 115 for the remaining gilts. Saliva samples were taken monthly from four focal gilts per pen. All counts of aggressive, harmful, sexual, and play behavior were recorded by direct observation 1 d biweekly (5- × 5-min observations/pen/d). BL scores were recorded on focal pigs biweekly from day 1 until day 99 on the back, neck, shoulder, flank, and hind quarter on each side of the body. Hind hooves were scored for eight disorders (heel erosion [HE], heel sole separation [HSS], and white line separation [WLS], dew claw length and dew claw cracks, toe length and both vertical and horizontal toe cracks) by severity, and a total hoof lesion score was calculated by summing individual scores. General linear mixed models were used to analyze cortisol, behavior, BL, and total hoof scores. Generalized linear mixed models were used for locomotion, bursitis and individual hoof disorders. There was less aggression (P < 0.05) and sexual behavior in the FEM compared to the MIX groups with more play behavior in MIX compared to FEM groups (P < 0.01). Gilts in the MIX groups had higher BL scores than gilts in the FEM groups (P < 0.001). Total hoof scores were higher in MIX (8.01 ± 0.15) than FEM (7.70 ± 0.12; P < 0.02) gilts. CON diet gilts had higher HE scores than SUPP gilts (P < 0.05). HSS (P < 0.05) and WLS (P < 0.05) scores were higher in MIX than FEM gilts. Rearing gilts in FEM groups had benefits for hoof health likely mediated through lower levels of activity due to male absence, and minerals helped reduce HE.
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RNA-Seq of Liver From Pigs Divergent in Feed Efficiency Highlights Shifts in Macronutrient Metabolism, Hepatic Growth and Immune ResponseLiver is a metabolically complex organ that influences nutrient partitioning and potentially modulates the efficiency of converting energy acquired from macronutrients ingestion into a muscle and/or adipose tissue (referred to as feed efficiency, FE). The objective of this study was to sequence the hepatic tissue transcriptome of closely related but differently feed efficient pigs (n = 16) and identify relevant biological processes that underpin the differences in liver phenotype between FE groups. Liver weight did not significantly differ between the FE groups, however, blood parameters showed that total protein, glucose, cholesterol and percentage of lymphocytes were significantly greater in high-FE pigs. Ontology analysis revealed carbohydrate, lipid and protein metabolism to be significantly enriched with differentially expressed genes. In particular, high-FE pigs exhibited gene expression patterns suggesting improved absorption of carbohydrates and cholesterol as well as enhanced reverse cholesterol transport. Furthermore, the inferred decrease in bile acid synthesis in high-FE pigs may contribute to the observed greater levels of serum glucose, which can be then delivered to cells and utilized for growth and maintenance. Gene ontology analysis also suggested that livers of more efficient pigs may be characterized by higher protein turnover and increased epithelial cell differentiation, whereby an enhanced quantity of invariant natural killer T-cells and viability of natural killer cells could induce a quicker and more effective hepatic response to inflammatory stimuli. Our findings suggest that this prompt hepatic response to inflammation in high-FE group may contribute to the more efficient utilization of nutrients for growth in these animals.
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Influence of the Intestinal Microbiota on Colonization Resistance to Salmonella and the Shedding Pattern of Naturally Exposed PigsSalmonella colonization and infection in production animals such as pigs are a cause for concern from a public health perspective. Variations in susceptibility to natural infection may be influenced by the intestinal microbiota. Using 16S rRNA compositional sequencing, we characterized the fecal microbiome of 15 weaned pigs naturally infected with Salmonella at 18, 33, and 45 days postweaning. Dissimilarities in microbiota composition were analyzed in relation to Salmonella infection status (infected, not infected), serological status, and shedding pattern (nonshedders, single-point shedders, intermittent-persistent shedders). Global microbiota composition was associated with the infection outcome based on serological analysis. Greater richness within the microbiota postweaning was linked to pigs being seronegative at the end of the study at 11 weeks of age. Members of the Clostridia, such as Blautia, Roseburia, and Anaerovibrio, were more abundant and part of the core microbiome in nonshedder pigs. Cellulolytic microbiota (Ruminococcus and Prevotella) were also more abundant in noninfected pigs during the weaning and growing stages. Microbial profiling also revealed that infected pigs had a higher abundance of Lactobacillus and Oscillospira, the latter also being part of the core microbiome of intermittent-persistent shedders. These findings suggest that a lack of microbiome maturation and greater proportions of microorganisms associated with suckling increase susceptibility to infection. In addition, the persistence of Salmonella shedding may be associated with an enrichment of pathobionts such as Anaerobiospirillum. Overall, these results suggest that there may be merit in manipulating certain taxa within the porcine intestinal microbial community to increase disease resistance against Salmonella in pigs.
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Fecal Microbiota Transplant from Highly Feed-Efficient Donors Shows Little Effect on Age-Related Changes in Feed-Efficiency-Associated Fecal Microbiota from ChickensChickens with good or poor feed efficiency (FE) have been shown to differ in their intestinal microbiota composition. This study investigated differences in the fecal bacterial community of highly and poorly feed-efficient chickens at 16 and 29 days posthatch (dph) and evaluated whether a fecal microbiota transplant (FMT) from feed-efficient donors early in life can affect the fecal microbiota in chickens at 16 and 29 dph and chicken FE and nutrient retention at 4 weeks of age. A total of 110 chickens were inoculated with a FMT or a control transplant (CT) on dph 1, 6, and 9 and ranked according to residual feed intake (RFI; the metric for FE) on 30 dph. Fifty-six chickens across both inoculation groups were selected as the extremes in RFI (29 low, 27 high). RFI-related fecal bacterial profiles were discernible at 16 and 29 dph. In particular, Lactobacillus salivarius, Lactobacillus crispatus, and Anaerobacterium operational taxonomic units were associated with low RFI (good FE). Multiple administrations of the FMT only slightly changed the fecal bacterial composition, which was supported by weighted UniFrac analysis, showing similar bacterial communities in the feces of both inoculation groups at 16 and 29 dph. Moreover, the FMT did not change the RFI and nutrient retention of highly and poorly feedefficient recipients, whereas it tended to increase feed intake and body weight gain in female chickens. This finding suggests that host- and environment-related factors may more strongly affect chicken fecal microbiota and FE than the FMT.
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Feed Restriction Modulates the Fecal Microbiota Composition, Nutrient Retention, and Feed Efficiency in Chickens Divergent in Residual Feed IntakeThere is a great interest to understand the impact of the gut microbiota on host’s nutrient use and FE in chicken production. Both chicken’s feed intake and gut bacterial microbiota differ between high and low-feed efficient chickens. To evaluate the impact of the feed intake level on the feed efficiency (FE)-associated variation in the chicken intestinal microbiota, differently feed efficient chickens need to eat the same amount of feed, which can be achieved by feeding chickens restrictively. Therefore, we investigated the effect of restrictive vs. ad libitum feeding on the fecal microbiome at 16 and 29 days posthatch (dph), FE and nutrient retention in chickens of low and high residual feed intake (RFI; metric for FE). Restrictively fed chickens were provided the same amount of feed which corresponded to 85% of the ad libitum fed group from 9 dph. FE was determined for the period between 9 and 30 dph and feces for nutrient retention were collected on 31 to 32 dph. From the 112 chickens (n = 56 fed ad libitum, and n = 56 fed restrictively), 14 low RFI and 15 high RFI ad libitum fed chickens, and 14 low RFI (n = 7 per sex) and 14 high RFI restrictively fed chickens were selected as the extremes in RFI and were retrospectively chosen for data analysis. Bray-Curtis dissimilarity matrices showed significant separation between time points, and feeding level groups at 29 dph for the fecal bacterial communities. Relevance networking indicated positive associations between Acinetobacter and feed intake at 16 dph, whereas at 29 dph Escherichia/Shigella and Turicibacter positively and Lactobacillus negatively correlated to chicken’s feed intake. Enterobacteriaceae was indicative for low RFI at 16 dph, whereas Acinetobacter was linked to high RFI across time points. However, restrictive feeding-associated changes in the fecal microbiota were not similar in low and high RFI chickens, which may have been related to the higher nutrient retention and thus lower fecal nutrient availability in restrictively fed high RFI chickens. This may also explain the decreased RFI value in restrictively fed high RFI chickens indicating improved FE, with a stronger effect in females.
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Surveillance Data Highlights Feed Form, Biosecurity, and Disease Control as Significant Factors Associated with Salmonella Infection on Farrow-to-Finish Pig FarmsAmong the zoonotic pathogens affecting pigs, Salmonella stands out due to the high number of human cases linked to pork consumption. In the last two decades many countries have put considerable effort into the control of the infection by surveillance and control strategies on farm. Despite this effort, many herds still have a high Salmonella prevalence and they require guidance to address this problem. The present study, using the serological surveillance data of finishing pigs from the Irish National pig Salmonella Control Programme, aimed to highlight factors associated with increased risk or that might mitigate Salmonella occurrence on farm. A questionnaire with 33 questions regarding herd characteristics, management, feeding, biosecurity, and health was completed for 61 individual herds. After the multivariate analysis by linear regression, nine variables were retained in the final model and linked to herd seroprevalence. Home produced-feed linked to the use of meal showed an eight points reduction in Salmonella prevalence compared to purchased feed (p = 0.042). Different biosecurity measures were associated to lower seroprevalence. Changing of footwear from outside to inside the farm decreased seroprevalence nearly 20 units (p = 0.014) and policies not permitting access to the farmyard to feed trucks (p = 0.048) or avoiding the presence of cats on the farm (p = 0.05) were estimated in 10 units less of seroprevalence. In contrast, the lack of perimeter fence increased the chance to have higher seroprevalence in five units (p = 0.05). Finally, intestinal diseases such as swine dysentery (p = 0.044) and E. coli diarrhea (p = 0.1) were estimated to increase Salmonella prevalence in ∼20 and 10 units, respectively, demonstrating the importance of controlling other enteric pathogens in an on-farm Salmonella control programme. These results show the usefulness of surveillance data to improve on-farm control and confirm that Salmonella infection in pigs is multi-factorial and the approach to its control should be multifaceted.
