Response of piglets weaned from sows fed diets supplemented with conjugated linoleic acid (CLA) to an Escherichia coli K88+ oral challenge

Seventy-eight Cotswold piglets weaned from sows receiving 0% or 2% conjugated linoleic acid (CLA)-supplemented rations from day 85 of gestation through lactation were allocated to nursery diets (ND) according to their dam's lactation ration (LR) as follows (1) 0%-0% (0% CLA LR: 0% CLA ND, n = 17); (2) 0%-2% (0% CLA LR: 2% CLA ND, n = 17); (3) 2%-0% (2% CLA LR: 0% CLA ND, n = 23); and (4) 2%-2% (2% CLA LR: 2% CLA ND, n = 21). At 28 ± 2 days of age all piglets received an oral Escherichia coli K88+ (enterotoxigenic Escherichia coli, ETEC) challenge and were subsequently monitored for scour development and overall health until 36 ± 2 days of age, after which blood and tissue samples were collected. Piglet BW was not affected by dietary CLA supplementation to LR (P > 0.05). However, by day 36 piglets receiving 2% CLA-supplemented ND were significantly lighter (P < 0.05) than piglets receiving control diets. Average daily gain and feed efficiency were not affected by CLA supplementation. Average daily feed intake (ADFI) was greater for piglets weaned from 2% CLA-supplemented sows from day 17 to 28 (P < 0.05), otherwise ADFI was unaffected by dietary CLA supplementation (P > 0.05). The development of scours was less severe in piglets weaned from 2% CLA-supplemented sows at 8, 24, 48 and 56 h after ETEC challenge (P < 0.05). Intestinal coliform and lactic acid bacteria populations post challenge were not affected by CLA supplementation. However, cecal ammonia-N was numerically greatest in 0%-0% piglets compared to the other treatment groups, and the total volatile fatty acid production was numerically lower in 0%-0% and 0%-2% piglets compared to 2%-0% and 2%-2% piglets. In addition, piglets weaned from 2% CLA-supplemented sows had increased serum immunoglobulin A (P < 0.001) and G (P < 0.05) levels and reduced (P < 0.05) intestinal mucosal inflammation compared to piglets weaned from control sows. Although there were no obvious additional health effects observed when CLA was provided in ND, supplementing sow rations with 2% CLA from mid-gestation through weaning appears to have immune-stimulating carry-over effects post weaning. Thus, supplementing sow rations with CLA may be a practical strategy for enhancing passive immune transfer and improving the immune status and overall gut health of nursery piglets.     

Castration of piglets under CO2-gas anaesthesia

It has become common practice in pig fattening production systems to castrate young boar piglets without the use of anaesthesia. In this study, we examined whether or not CO2 gas is capable of inducing an acceptable anaesthetic state during which castration can be performed. The first step was to identify the most promising CO2/O2 mixture. Based on the results from this first experiment, a mixture of 70% CO2 + 30% O2 was chosen for further investigation as a potential anaesthetic during the castration of young piglets. Thereby, it was established whether the duration and depth of anaesthesia were acceptable for castration where the animal has to be insensible and unconscious. Physiological effects were assessed based on electroencephalogram (EEG) and electrocardiogram (ECG) measurements, blood gas values and behavioural responses. During the induction phase, the only typical behaviour the piglets exhibited when exposed to the 70/30 gas mixture was heavy breathing. All piglets (n = 25) lost consciousness after approximately 30 s according to the EEG. Heart rate decreased slowly during the induction phase, a serious drop occurred when piglets lost their posture. Immediately after this drop, the heart rate neared zero or showed a very irregular pattern. Shortly after loss of posture, most animals showed a few convulsions. None of the animals showed any reaction to castration in behaviour and/or on the EEG and ECG. On average, the piglets recovered within 59 s, i.e. EEG returned to its pre-induction pattern and piglets were able to regain a standing position. After 120 s, heart rate returned to pre-induction levels. In order to explore the usage range of CO2 concentration, 24 piglets were exposed to 60% CO2 + 20% O2 + 20% N2 for up to 30 s after loss of consciousness (as registered on EEG), and castrated after removal from the chamber. Sixteen of the 24 animals showed a reaction to the castration on the EEG. To establish the maximum time piglets survive in 70% CO2 + 30% O2, five piglets were placed in this mixture for 3 min. Two of them died. After that, four piglets were placed in this mixture for 2 min after unconsciousness, one died after 2 min. It was concluded from this study that it is possible to anaesthetise piglets with a mixture of 70% CO2 + 30% O2, but that there are limits to its safety in terms of CO2 concentration and duration of exposure. Before implementation for practical use, further research is essential to assess the limits of gas concentration and exposure times.     

Effects of dietary addition of heat-killed Mycobacterium phlei on growth performance,immune status and anti-oxidative capacity in early weaned piglets

The contradiction between high susceptibility of early weaned piglets to enteric pathogens and rigid restriction of antibiotic use in the diet is still prominent in the livestock production industry. To address this issue, the study was designed to replace dietary antibiotics partly or completely by an immunostimulant, namely heat-killed Mycobacterium phlei (M. phlei). Piglets (n = 192) were randomly assigned to one of the four groups: (1) basal diet (Group A), (2) basal diet + a mixture of antibiotics (80 mg/kg diet, Group B), (3) basal diet + a mixture of antibiotics (same as in Group B, but 40 mg/kg diet) + heat-killed M. phlei (1.5 g/kg diet) (Group C) and (4) basal diet + heat-killed M. phlei (3 g/kg diet) (Group D). All piglets received the respective diets from days 21 to 51 of age and were weaned at the age of 28 d. Compared with the Control (Group A), in all other groups the average daily gain, average daily feed intake, small intestinal villus height:crypt depth ratio and protein levels of occludin and ZO-1 in the jejunal mucosa were increased. A decreased incidence of diarrhoea in conjunction with an increased sIgA concentration in the intestinal mucosa and serum IL-12 and IFN-γ concentrations was found in groups supplemented with heat-killed M. phlei (Groups C and D), but not in Group B. Groups C and D also showed decreased IL-2 concentrations in the intestinal mucosa with lower TLR4 and phosphor-IκB protein levels. The antioxidant capacity was reinforced in Groups C and D, as evidenced by the reduction in malondialdehyde and enhanced activities of antioxidant enzymes in serum. These data indicate that heat-killed M. phlei is a promising alternative to antibiotic use for early weaned piglets via induction of protective immune responses.     

Effects of soybean glycinin on performance and immune function in early weaned pigs

Glycinin, a major storage protein in soybean, has been identified as an important food allergen. The present study was conducted to investigate the effects of soybean glycinin on the local and systemic immune responses using a swine model specific for glycinin allergy. Performance, peripheral blood lymphocyte proliferation and CD4⁺ and CD8⁺  subsets in the plasma of naive and sensitised piglets were determined. In addition, the concentrations of IgA, IgG, IgM, interleukin-4 and interleukin-6 in the jejunum mucosa were measured. Our results showed that dietary supplementation of glycinin reduced piglet performance (p < 0.05), while increasing lymphocyte proliferation and CD4⁺/CD8⁺  ratio (p < 0.01). Intestinal mucosal immune responses to glycinin were enhanced with high levels of IgA (p < 0.01) as well as interleukin-4 and interleukin-6 in the jejunum mucosa in glycinin-treated piglets compared with the control (p < 0.01). There were no differences due to treatment in the densities of IgG and IgM. In conclusion, it was found that glycinin stimulated local and systemic immune responses in allergic piglets and had negative effects on piglet performance. The severity of the immune reactions depends on the dose of glycinin with higher doses causing more severe symptoms.     

Review: Assessment of completeness of reporting in intervention studies using livestock: an example from pain mitigation interventions in neonatal piglets

Accurate and complete reporting of study methods, results and interpretation are essential components for any scientific process, allowing end-users to evaluate the internal and external validity of a study. When animals are used in research, excellence in reporting is expected as a matter of continued ethical acceptability of animal use in the sciences. Our primary objective was to assess completeness of reporting for a series of studies relevant to mitigation of pain in neonatal piglets undergoing routine management procedures. Our second objective was to illustrate how authors can report the items in the Reporting guidElines For randomized controLled trials for livEstoCk and food safety (REFLECT) statement using examples from the animal welfare science literature. A total of 52 studies from 40 articles were evaluated using a modified REFLECT statement. No single study reported all REFLECT checklist items. Seven studies reported specific objectives with testable hypotheses. Six studies identified primary or secondary outcomes. Randomization and blinding were considered to be partially reported in 21 and 18 studies, respectively. No studies reported the rationale for sample sizes. Several studies failed to report key design features such as units for measurement, means, standard deviations, standard errors for continuous outcomes or comparative characteristics for categorical outcomes expressed as either rates or proportions. In the discipline of animal welfare science, authors, reviewers and editors are encouraged to use available reporting guidelines to ensure that scientific methods and results are adequately described and free of misrepresentations and inaccuracies. Complete and accurate reporting increases the ability to apply the results of studies to the decision-making process and prevent wastage of financial and animal resources.     

Untersuchungen über den Abbau von Nicht-Protein-Stickstoff-Verbindungen im Pansen der Wiederkäuer

Absetzferkeln wurden im Starterfutter 1 % Lactitol oder 0,2 % Fructo‐, Isomalto‐ bzw. Galacto‐Oligosaccharide zugesetzt. Nach 2 Wochen Anpassung erfolgte die Schlachtung 3 Stunden nach der Morgenmahlzeit. In den Versuchsgruppen waren die Blutharnstoff‐Konzentrationen und Magenfer‐mentierungen gegenüber der Kontrolle gesenkt und die Magenentleerungen beschleunigt. Im Colon ergaben sich durch die Zusätze erhöhte Volumina und Inhalte bei höher en Laktatanteilen besonders im vorderen Teil.     

Effects of soybean isoflavones on the growth performance,intestinal morphology and antioxidative properties in pigs

Soybean meal is rich in soybean isoflavones, which exhibit antioxidant, anti-inflammatory, antiviral and anticancer functions in humans and animals. This study was conducted to investigate the effects of soybean isoflavones on the growth performance, intestinal morphology and antioxidative properties in pigs. A total of 72 weaned piglets (7.45 ± 0.13 kg; 36 males and 36 females) were allocated into three treatments and fed corn-soybean meal (C-SBM), corn-soy protein concentrate (C-SPC) or C-SPC supplemented with equal levels of the isoflavones found in the C-SBM diet (C-SPC + ISF) for a 72-day trial. Each treatment had six replicates and four piglets per replicate, half male and half female. On day 42, one male pig from each replicate was selected and euthanized to collect intestinal samples. The results showed that compared to pigs fed the C-SPC diet, pigs fed the C-SBM and C-SPC + ISF diets had higher BW on day 72 (P < 0.05); pigs fed the C-SBM diet had significantly higher average daily gain (ADG) during days 14 to 28 (P < 0.05), with C-SPC + ISF being intermediate; pigs fed the C-SBM diet tended to have higher ADG during days 42 to 72 (P = 0.063), while pigs fed the C-SPC + ISF diet had significantly higher ADG during days 42 to 72 (P < 0.05). Moreover, compared to pigs fed the C-SPC diet, pigs fed the C-SBM diet tended to have greater villus height (P = 0.092), while pigs fed the C-SPC + ISF diet had significantly greater villus height (P < 0.05); pigs fed the C-SBM and C-SPC + ISF diets had significantly increased villus height-to-crypt depth ratio (P < 0.05). Compared with the C-SPC diet, dietary C-SPC + ISF tended to increase plasma superoxide dismutase activity on days 28 (P = 0.085) and 42 (P = 0.075) and reduce plasma malondialdehyde (MDA) content on day 42 (P = 0.089), as well as significantly decreased jejunal mucosa MDA content on day 42 (P < 0.05). However, no significant difference in the expression of tight junction genes among the three groups was found (P > 0.05). In conclusion, our results suggest that a long-term exposure to soybean isoflavones enhances the growth performance, protects the intestinal morphology and improves the antioxidative properties in pigs.     

Comparative studies on the effect of ergot contaminated feed on performance and health of piglets and chickens

Two dose response trials were conducted with piglets and chickens to study the effects of increasing amounts of ergot (Claviceps purpurea) with a defined alkaloid content and pattern on performance, biochemical serum characteristics and organ weights (of chickens). The ergot was mixed into the cereal-soybean meal based diets at levels of 0, 0.5, 1, 2 and 4?g/kg. The total alkaloid content of the ergot was analysed to be 2775?mg/kg and showed the following composition: ergometrine 8.1%, ergotamine 5.4%, ergocornine 3.2%, α-ergocryptine 1.9%, ergocristine 14.9% and residue 66.5%. Each treatment was tested with eight castrated male and eight female piglets over a period of 35 days (8?kg initial live weight) and 28 male chickens for 21 days (43?g initial live weight). Cumulative daily dry matter intake and live weight gain [g/d] were 595, 535, 560, 577 and 490 and 413, 399, 420, 443 and 347 for the piglets fed the unsupplemented control diet and the diets containing 0.5, 1, 2 and 4?g ergot per kg, respectively. Feed intake and live weight gain of the piglets fed the highest ergot supplemented diet were significantly decreased. Serum aspartate aminotransferase activity of the 4?g ergot treatment was significantly increased. Also serum albumin concentrations showed significant linear alterations. Serum activities of glutamate dehydrogenase, γ-glutamyltransferase, total protein and porcine growth hormone were not significantly influenced by dietary treatment. The experiment with chickens demonstrated no significant effects on performance due to dietary ergot exposure. The serum activities of glutamate dehydrogenase and alanine aminotransferase were not significantly influenced by dietary treatment while serum activities of γ-glutamyltransferase and aspartate aminotransferase and the concentrations of albumin and total bilirubin were significantly affected. Heart weights showed a significant linear decrease due to ergot feeding. According to these results, piglets seemed to react more sensitively on the occurrence of ergot in the diet as compared to chickens. The critical level of total ergot alkaloids for piglets seemed to be in the range from 5.6?mg to 11.1?mg/kg diet for the present study. Ergot effects on signs of inflammation in the proximal duodenum occurred in chickens fed diets containing 2.8?mg and 11.1?mg total ergot alkaloids/kg although live performance remained unaffected. Further studies are necessary to define the critical level of ergot alkaloids in dependence on alkaloid pattern.