Early-weaned Piglets Research Articles

Physiological aspects and ileal gene expression profile of early-weaned piglets fed a low threonine diet

Abstract High dietary threonine extraction by the digestive tract suggests that threonine contributes to maintain gut physiology. The aims of this study were to investigate both the physiological disturbances and the molecular events caused by an inadequate dietary threonine supply to the ileum of piglets. We compared paracellular permeability and gene expression, using porcine cDNA microarrays, of the ileum of piglets weaned at 7 days of age fed either a low (LT; n = 7) or a control (C; n = 7) well balanced threonine diet for 2 weeks. At slaughter, the ileal paracellular permeability, measured by FD4 flux in Ussing chambers, increased in piglets fed a LT diet compared with C piglets ( P = 0.017). Furthermore, 170 genes had their expression significantly modified in the ileum of the LT piglets: 64 were down regulated and 106 were up regulated. These genes are involved in immune response, apoptosis, energy metabolism, cell migration, epithelial permeability, RNA processing or protein translation. In conclusion, dietary threonine deficiency induced alteration of the ileal barrier and the ileum seems to respond by increasing its metabolic activity.

Effects of Chinese herbal ultra-fine powder as a dietary additive on growth performance, serum metabolites and intestinal health in early-weaned piglets

Abstract This study was conducted to determine the effects of dietary supplementation with a Chinese herbal ultra-fine powder on growth performance, serum metabolites and intestinal health in early-weaned piglets. Sixty piglets weaned at 21 days of age were randomly assigned to one of the 3 treatment groups, representing supplementation with 0 or 2 g/kg of the powder, or 0.2 g/kg of colistin to maize- and soybean meal-based diets (n = 20 per group). Dietary supplementation with the powder increased ADFI and ADG, improved the gain/feed ratio, and reduced the incidence of diarrhea in the weaned piglets (P

Dietary supplementation with polysaccharides fromSemen cassiae enhances immunoglobulin production and interleukin gene expression in early-weaned piglets

Forty piglets were used to determine the effect of 14-day dietary supplementation with polysaccharides from Semen cassiae (PSSA) on the immunity and interleukin (IL) gene expression in early-weaned piglets. Piglets were weaned at 21 days of age and four pigs were euthanized to provide the data at initial point. The remaining 36 pigs were fed the following corn- and soybean meal-based diets: the control diet (non-PSSA), the low-level PSSA diet (the control diet supplemented with 0.04% of PSSA), and the high-level PSSA diet (the control diet supplemented with 0.08% PSSA). Blood samples were collected on days 0 and 14, and lymph nodes on day 14 of the experimental period for the following measurements: IL-1β gene expression in blood mononuclear cells and jejunal mucosa; IL-2 gene expression in lymphatic nodes; serum levels of cytokines (IL-1β, IL-2, and IL-6); serum concentrations of immunoglobulins (IgA, IgG and IgM). Weaning stress resulted in decreases in serum antibody levels and cytoimmunity. Compared with the control group, dietary supplementation with a high level of PSSA increased: (1) serum concentrations of IL-1β, IL-2 and IL-6, as well as IgG, IgA and IgM; (2) expression of the IL-1β and IL-2 genes in blood mononuclear cells and lymphatic nodes; and (3) expression of the IL-1β gene in the jejunal mucosa. These novel findings suggest that polysaccharides from Semen cassiae enhance both the cell-mediated immune response and the humoral immunity in the early-weaned piglets. Copyright © 2007 Society of Chemical Industry

Intestinal development and growth performance of early-weaned piglets fed a low-threonine diet

High dietary threonine extraction by the digestive tract suggests that threonine contributes to maintain gut integrity. The aims of this study were to investigate the intestine development and the growth performance of early-weaned piglets pair-fed either a control well-balanced (C: 9.3 g threonine/kg diet) or a low-threonine diet (LT: 6.5 g threonine/kg diet) for 2 weeks. As expected, LT piglets presented lower plasma free threonine compared with C piglets (118 v. 356 ± 12 μmol/l, P < 0.001). Dietary threonine supply altered neither growth performance nor growth of the intestine and of the other portal-drained viscera (stomach, spleen and pancreas). Nevertheless, villus height was reduced in the ileum of the LT piglets compared with C piglets (446 v. 714 ± 74 μm, P < 0.05). This was also associated with a decrease in crypt width (P < 0.05) and villus height-to-crypt depth ratio (P < 0.05). Whereas maltase and lactase activities did not change between the two groups, aminopeptidase nitrogen activity was decreased in the ileum of LT piglets (269 v. 374 ± 27 IU/mg protein, P < 0.05). The number of mucin-containing goblet cells was not modified in the ileum and in the proximal part of the large intestine of the LT piglets compared with the C piglets. In conclusion, despite no alteration of intestinal growth, villus hypotrophy associated with a reduction of aminopeptidase nitrogen activity suggest an alteration of the structure of the ileum in early-weaned piglets fed a diet supplying inadequate dietary threonine.

In Vivo and In Vitro Effects of Tea Extracts on Enterotoxigenic Escherichia coli‐induced Intestinal Fluid Loss in Animal Models

Enterotoxigenic Escherichia coli (ETEC) infection is a major cause of dehydrating diarrhoea in infants and early-weaned piglets living under subhygienic conditions. We studied the effect of different tea types and subfractions on the intestinal fluid and electrolyte losses involved in ETEC diarrhoea. Jejunal segments of anaesthetised piglets were infected with ETEC or ETEC heat-labile toxin (LT) and subsequently perfused for 8 hours with control or tea solutions containing green or black tea extract (BTE) or 3 different BTE subfractions containing small-size, large-size or no phenolics. Changes in intestinal fluid and electrolyte net absorption were measured. To assess the antisecretory effects of tea, BTE was incubated before or after administration of the secretagogue forskolin in rat jejunal tissue placed in Ussing chambers and Cl- secretion measured as changes in short-circuit current (I(SC)). Enterotoxigenic E. coli infection of piglet jejunal segments significantly reduced net absorption of fluid, Na+ and Cl- and increased net secretion of K+ compared with controls. Perfusion of the ETEC-infected segments with both 3 g/L green tea extract and BTE significantly inhibited these disturbances in fluid and electrolyte balance. The BTE subfraction rich in polymeric phenolics but not the other subfractions improved the fluid and electrolyte balance. Addition of forskolin to rat jejunal tissue induced a significant increase in I(SC). Pretreating but not posttreating the jejunal tissue with BTE inhibited the forskolin-induced increase in I(SC). Tea may inhibit net fluid and electrolyte losses involved in secretory diarrhoea from ETEC.

The performance of early-weaned piglets following transport: Effect of season and weaning weight

Two groups of 48 Cotswold piglets weaned at 17 ± 1 d of age were assigned to road or simulated transport during summer or winter. Following transport [Control (&lt;20 min), 6 h, 12 h or 24 h], piglets were grouped by weaning weight (light, medium and heavy) in pens of four. Body weights were recorded on days 1–8, 10, 12 and 14. From an average weaning weight of 6.28 ± 0.09 kg, piglets lost on average 0.4 ± 0.1 kg. The minimum weight of 5.88 ± 0.1 kg was reached 2.24 ± 0.13 d post weaning and weaning weight was recovered at 3.55 ± 0.16 d post weaning. As transport duration increased from 6 to 24 h, total weight loss increased from 0.33 to 0.45 ± 0.022 kg (P &lt; 0.01). Piglets transported by road in winter had a longer growth check (4.08 vs. 3.18 ± 0.18 d, P &lt; 0.05) showed reduced percent ADG (5.37 vs. 6.61 ± 0.26%, P &lt; 0.05) and lower feed conversion efficiency (FCE) (0.87 vs. 0.96 ± 0.01 kg, P &lt; 0.01) than piglets transported by road in summer. Heavy piglets continued to lose weight longer than light piglets (2.26 vs.1.7 ± 0.16 d, P &lt; 0.02), although relative weight loss was not affected. During winter piglets exposed to road transport required more time to recover their weaning weight than piglets exposed to simulated transport (4.08 vs. 3.04 ± 0.18 d, P &lt; 0.05). While weaning is a confounding effect, these results suggest that longer transport (&gt;12 h) and transport in winter may cause additional stress to early-weaned piglets. Some factors of road transport in winter, possibly driving differences or fluctuating temperatures also negatively affected piglet recovery from weaning. Key words: Early weaning, transport, pigs, season

Effects of Biocom as a Replacement of Glutamine on Performance and Blood Biochemical Indexes of Early Weaned Piglets

The objective of this study was to evaluate Biocom (a protein source containing a high level of glutamine and alanyl- glutamine) as a replacement for glutamine (Gln) in nursery pig diets. Forty-two pigs (fourteen pigs per treatment) weaned at 28 d of age were used in a 28-d performance trial using three dietary treatments: control (no Gln), control supplemented with Gln or Biocom. The control diet was composed of corn, soybean meal, whey and fish meal. Individual body weight, pen feed disappearance and diarrhea were monitored. On d 0, 2, 7 and 14 postweaning, respectively, five pigs per treatment were selected and bled from the anterior vena cava to obtain five replicate samples of blood on each dietary treatment for determination of blood biochemical index. Dietary supplementation of Gln and Biocom did not influence performance, plasma Gln and total serum protein concentration (p>0.05). However, the addition of Gln and Biocom could prevent serum urea nitrogen and serum cortisol from increasing on d 2 postweaning (p 0.05) in any of the examined parameters between Gln- and Biocom-supplemented diets. In conclusion, dietary Gln did not influence the performance of early-weaned piglets owing to the complex diet containing whey, but could prevent the increase of serum urea and cortisol. Biocom could be used as a replacement for free pure Gln without any negative effect on early-weaned piglets. (Asian-Aust. J. Anim. Sci. 2006. Vol 19, No. 6 : 872-876)

Effects of season on the behaviour of early-weaned piglets during and immediately following transport

In North America commercial transport of piglets occurs without supplemental heat, over long durations (24 h) and without feed and water. Scan sampling was used to compare behaviour across seasons (summer, fall, winter) and over representative durations (Control, 6, 12 or 24 h) to help assess welfare. Six groups of 48 Cotswold piglets (17 ± 1 d) were weaned and transported along highways in a van equipped for video and temperature recording. Following transport, piglets were studied in groups of four, in weanling pens with free choice feed and water. Resting during transport increased in frequency from 59.8% (1–12 h) to 91.5% (13–24 h). This pattern was more defined in winter and fall implicating cold as a causal factor. Fatigue, as observed in slaughter hogs, may also be a factor. Higher levels of post-transport resting in transported (81.4%) compared to control piglets (77.5%) supported this interpretation. Habituation to transport conditions may also have affected behaviour as piglet interactions commonly associated with dominance hierarchy establishment, were more frequent, and sitting, a behaviour associated with stress post-weaning decreased in the last 12 h of transport. As the duration of transport increased, post-transport drinking frequency increased, although significance was reached between control (2.4%) and 24 h of transport (3.7%) only. Long transport durations may thus delay hierarchy development, require additional coping strategies with respect to cold and increase the risk for dehydration. However, indications for habituation to some aspects of transport after 12 h are also apparent. During winter transport the frequency of piglet interactions (three piglets) was much lower than in summer (39 piglets) and fall (18 piglets) indicating that the cold temperatures may have affected establishment of a dominance hierarchy. Summer and winter transport differed from fall transport, with less resting (5.5% versus 9.2%) and standing (5.5% versus 9.25%), and more sitting (0.52% versus 0.28%) during the fall, a pattern consistent with increased stress during fall transport. Higher levels of resting for 3 days in winter and 2 days in summer could indicate more post-transport fatigue in these seasons. Transport, irrespective of season, resulted in behaviour indicative of coping strategies. It is important to determine which stressors have the greatest impact in each season and develop strategies to reduce the effects of transport on welfare.

Effects of supplementation of xylanase, phospholipase or combination of both to a wheat-based diet on digestive function in early-weaned piglets

The effect of enzyme supplementation was studied in a balanced three-period (3 x 13 days) crossover trial with 16 male piglets weaned on day 11 post-natum. On days 15 and 16 of age the piglets were fitted with a simple T-cannula at the distal ileum. Starting on day 21 post-natum, piglets were fed the basal diet (22.1% CP and 14.5 MJ ME/kg as fed) without or with the addition of xylanase (endo-1,4-β-xylanase, EC 3.2.1.8) at a level of 5600 EXU/kg (as fed) or phospholipase (phospholipase A2, EC 3.1.1.4) at a level of 1000 IU/kg (as fed), or a combination of both. Activities of maltase, lactase, leucine aminopeptidase (LAP), lipase and α-amylase were measured in ileal digesta. The supplementation with exogenous feed enzymes had no significant (P>0.05) effect on the activities of maltase, LAP, lipase and α-amylase. The activity of lactase tended (P=0.1) to be higher in piglets fed the diet supplemented with the combination of both enzymes compared to the basal diet. In conclusion, the addition of exogenous feed enzymes had only minor effects on the activity of piglets’ own enzymes in the chyme entering the hindgut.

Feed composition in herds with or without postweaning Escherichia coli diarrhea in early-weaned piglets

Objective: To conduct a preliminary screening of possible risk factors associated with water and feed composition for postweaning Escherichia coli diarrhea (PWECD) in early-weaned piglets. Methods: A case-control study was conducted in Québec, Canada, including 34 herds with weaning age less than 22 days: 17 herds in which PWECD did not occur (Control; Group C) and 17 affected herds (Diarrhea; Group D). Diagnoses of PWECD with colibacillary shock were confirmed by a provincial diagnostic laboratory. Information on rations used in the nursery was collected during a farm visit. Each ration was analyzed, and electrolytic balance was calculated. Rations fed the day before the first occurrence of diarrhea in Group D herds were compared to median values for rations fed on the same postweaning days in Group C herds. Drinking water samples were also analyzed. Results: Higher levels of soybean and canola products (sources of vegetal proteins) were used in Group D herds the day before the first occurrence of diarrhea. Calcium and magnesium levels were higher and zinc concentrations and electrolytic balance were lower in the feeds of Group D herds than in the feeds of Group C herds. There was no relationship between water composition and PWECD status. Implications: Feed content may play a role in the occurrence of PWECD. Protein of animal origin should be included in the feed for the first 3 weeks post weaning, and high calcium levels should be avoided for 1 week. Zinc oxide supplementation is beneficial in reducing incidence of PWECD.

Investigation of changes in global gene expression in the frontal cortex of early-weaned and socially isolated piglets using microarray and quantitative real-time RT-PCR

We hypothesize that early-weaned piglets experience aberrant expression of stress-responsive genes in the frontal cortex, a key brain area involved in cognitive function and behavior organization. To test this hypothesis, female early-weaned piglets (EW; n = 6) were weaned 10 days after birth, while non-weaned piglets (NW; n = 6) were left with their dams. Half of EW ( n = 3) and NW ( n = 3) animals were socially isolated (SI) for 15 min at 12 days of age, when all animals ( n = 12) were euthanized and tissue collected. The effects of EW and SI were examined by gene expression profiling using cDNA microarray hybridizations, generated from a porcine brain cDNA library. A total of 103 genes were differentially expressed ( P < 0.05, fold change >1.25) among four direct comparisons. Forty-two genes had known functions, from which 24 showed relevant brain-related functions. Quantitative real-time polymerase chain reaction (Q-RT-PCR) was used to confirm regulation of expression of a subset of 6 genes with important brain functions, selected from the microarray outcomes. In non-weaned animals, a significant suppression of mRNA abundance for carboxypeptidase E, 14-3-3 protein and phosphoprotein enriched in astrocytes 15 kDa was observed in response to SI. Also, in early-weaned animals, diazepam binding inhibitor and actin-related protein 2/3 complex mRNA levels were suppressed in response to SI. Results suggest that social isolation of non- and early-weaned piglets may impact expression of genes involved in regulation of neuronal function, development, and protection in the frontal cortex of young pigs.

Assessment of the effects of the season of transport on the performance of early-weaned piglets

Six groups of 48 Cotswold piglets, weaned at 17 ± 1 d of age, were transported during three seasons (summer, winter or fall) and for four durations (0, 6, 12 or 24 h). As in commercial transport, feed and water were not available and supplemental heat was not provided. During transport, truck temperatures and piglet skin and rectal temperatures were recorded. At the end of transport piglets were placed in groups of four, in weanling pens. Body weights were recorded daily for 7 d and at 14 d.

Expression of porcine epidermal growth factor in Pichia pastoris and its biology activity in early-weaned piglets

Early-weaned piglets often have abnormalities in intestinal morphology and function. Epidermal growth factor (EGF) is critical in the development and in the repair of the gastrointestinal tract in pigs. This study investigated the effects of dietary EGF supplementation on growth performance and small intestinal morphology of early-weaned piglets. The functional domain of porcine EGF (pEGF) was cloned after RT-PCR amplification. The recombinant protein was expression by the Pichia pastoris expression system and the construct pPIC9K–pEGF was transformed into host GS115. The secretary recombinant protein in the supernatants was analyzed by SDS-PAGE. The gel indicated that the extra band at 6 kDa in the transformant, which corresponds to the standard hEGF, were both reactive to anti-pEGF antibody by Western blotting. The expression level of pEGF in the culture supernatant was 870 μg/mL. An animal feeding test was conducted to identify the effects of pEGF supplementation on growth performance and the development of digestive tracts of 14-day weaned piglets. The dietary treatment was a corn–soybean meal basal diet either with or without 1.5 mg/kg recombinant pEGF from the transformant fermentative supernatant. Dietary treatments enhanced the daily gain during 0–7 days postweaning ( p < 0.05), but did not affect the performance throughout the entire test period. Dietary supplemental pEGF significantly increased serum IgA levels on day 18 postweaning, and increased the mucosa IgA levels and crypt depth at jejunum on day 28 postweaning ( p < 0.05). The experimental results showed that the recombinant pEGF could be secreted by P. pastoris. The trophic effects of pEGF on growth performance, immune response, and small intestine development were determined by feeding recombinant pEGF to early-weaned piglets.

Some aspects of the pyridoxine (vitamin B6) requirement in weanling piglets

Four trials were carried out to determine the optimal level of dietary pyridoxine (vitamin B6) and its interaction with riboflavin (vitamin B2) in early-weaned piglets. In Trial 1, twelve piglets were tube-fed graded supplements of B6, 0, 10, 50 or 100 mg/kg. The level of 50 mg/kg maximized B6 in red blood cells (P<0.05). In Trial 2, thirty-six piglets were tube-fed with four combinations of B6 (0 v. 50 mg/kg) and B2 (0 v. 25 mg/kg). The B6 supplement increased (P<0.01) B6 in red blood cells. C-peptide and insulin responses to intravenous glucose tended (P<0.08) to or decreased (P<0.03) with B2 while no effect was observed on glucose. After gastro-enteral glucose, dietary B2 depressed C-peptide and insulin responses in B6-unsupplemented piglets and increased them in B6-supplemented piglets (P<0.03). The glucose response tended to be higher in B6-supplemented piglets (P<0.06). Trials 3 and 4 were carried out in commercial conditions using either B6 and/or B2 supplements given during 2 weeks after weaning (Trial 3) or a B6 supplement alone (50 mg/kg) given between 2 (weaning) and 10 weeks of age. Despite a marked and persistent increase (P<0.01) of B6 in red blood cells in B6-supplemented piglets, the effect on growth performance was either none (P>0.39; Trial 3) or marginally lower (<-2 %; P<0.03; Trial 4). In conclusion, it appears that a dietary supplement of 50 mg/kg B6 saturated the red blood cell pool in B6 and influenced, along with B2, the glucose homeostasis through the entero-insular axis. Nevertheless, such metabolic effects are not reflected on growth performance.

Effect of dietary supplementation of chitosan and galacto-mannan-oligosaccharide on serum parameters and the insulin-like growth factor-I mRNA expression in early-weaned piglets

The study was to determine effects of dietary supplementation of chitosan (COS) and galacto-mannan-oligosaccharids (GMOS) on some serum biochemical indices, serum growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels, and hepatic and long gissimus muscle IGF-I mRNA expression in early-weaned piglets. Twenty six Duroc × Landrace × Yorkshire piglets at the age of 15 days were used. The piglets had access to creep feed during the suckling. Six piglets were sacrificed for sampling at the beginning of the study. The other 20 piglets were individually housed in metabolic cages and randomly allotted to four corn and soybean meal-based diets including the control group, the antibiotic group with 110 mg lincomycin/kg diet, the COS group containing 0.025% COS, and the GMOS group with 0.20% GMOS, respectively, in a 2-week feeding experiment. Blood urea nitrogen (BUN) level was reduced whereas serum total protein concentration was increased ( P < 0.05) in responses to the COS and GMOS supplementation. Dietary supplementation of COS and GMOS also increased ( P < 0.05) the serum GH and IGF-I levels along with enhanced hepatic and the muscle IGF-I mRNA abundance. Dietary supplementation of oligosaccharides such as COS and GMOS may improve growth and feed conversion efficiency by increasing plasma GH and IGF-I levels, in the early-weaned piglets.

Impact of Feeding High-Iron Rice on Plasma Iron, Hemoglobin and Red Blood Cell Variables of Early-Weaned Piglets

Severe iron deficiency is a major nutritional problem encountered throughout the world. We assessed the effect of a conventionally bred, high-iron rice variety on plasma iron, hemoglobin, and red blood cell variables of early-weaned piglets during a 33-day feeding trial. 26-day-old male piglets were assigned to 3 treatment groups: group 1 = low-iron rice + low-iron supplementary feed; group 2 = high-iron rice + low-iron supplementary feed, and group 3 = low-iron rice + high-iron supplementary feed. Plasma iron, hemoglobin and red blood cell variables were measured on days 8, 16, 23, 30, and 33. Feed intake and weight gain were not significantly different between study groups. No significant differences in the iron-related parameters analyzed were found between the piglets of groups 1 and 2, except in red blood cells. Modifications regarding study design, study duration and subject’s growth rate are recommended to increase the possibility of detecting changes in the iron status triggered by diets having small differences in dietary iron.

7일령 조기 이유자돈에 대한 액상사료 자동급이기 이용효과

축산기술연구소에서 개발한 액상사료 자동급이기의 성능을 검사하고 이를 이용하여 조기 이유자돈의 사육 가능성을 알아보기 위하여 본 연구를 실시하였다. 포유중인 자돈 60두를 공시하여 대조구 자돈들은 21일령 까지 모돈에게 포유시켰다. 나머지는 생후 7일령에 모돈으로 부터 이유시킨 다음 액상사료 자동급이기를 이용하여 21일령까지 액상사료를 자동으로 인공급여 하였다. 그 이후 모든 자돈을 70일령 까지 단계적으로 같은 가루사료를 급여하였다. 그리고, 미국으로부터 수입되어 사용되고 있는 액상사료 자동급이기를 새로이 개발한 액상사료 자동급이기와 비교하여 사용하였다. 자돈들의 성장과 사료이용, 그리고 설사발생과 소장의 융모 변화 등을 조사하였다. 그 결과는 다음과 같다. 생후 7일에 모돈으로 부터 이유한 다음 액상사료 자동급이기를 이용하여 액상사료를 급여한 자돈들의 21일령 체중은 모두 포유를 지속한 자돈들에 비해 모두 유의하게(P〈0.05) 낮았다(5.55 vs 4.97 & 4.98 kg/head). 그 이후 액상사료 급여 자돈들의 성장이 빨라 70일령에 이르러서는 체중이 모돈으로 부터 포유하였던 자돈들에 비해 오히려 유의적으로(P〈0.05) 증가하는 결과를 보여 주었다(24.82 vs. 30.17 & 29.42 kg/head). 시험 전기간 동안의 일당증체량은(346.7 vs 425.8 & 416.1g/head) 모돈으로 부터 포유한 자돈보다 인공 포유 자돈들이 유의하게 증가하였다(P〈0.05). 사료요구율은 시험 전기간 동안 차이가 없었다(1.67 vs 1.78 and 1.84). 자돈들의 설사발생 빈도에 있어 액상사료 자동급이기 간에 차이가 없었다. 소장의 융모 변화를 비교한 결과 액상사료 인공포유 3일째(10일령) 십이지장 융모 높이가 크게 낮아진 것으로 나타났으나 7일째(14일령) 부터 융모가 회복되는 것으로 나타났다. 공장의 융모높이는 7일째(14일령) 크게 낮아진 것으로 나타났으나 14일째(21일령) 부터 융모가 회복되는 것으로 나타났다. 회장의 융모 높이는 처리간에 어떠한 경향을 보이지 않았다. 축산기술연구소에서 개발한 액상사료 자동급이기(NLRI)와 수입한 액상사료 자동급이기(IALF)에서 자돈 성장의 차이는 보이지 않았다. 이상의 결과 새로이 개발한 NLRI로 생후 7일만에 조기이유 시킨 자돈들도 성공적으로 육성할 수 있음을 보여주었다. This study was conducted to test the efficacy of the automatic liquid feeder(designated as NLRI) developed by National Livestock Research Institute, Korea for 7-day old early-weaning piglets. The other automatic liquid feeder imported from USA(designated as IALF) was used for a comparative purpose. A total of sixty piglets of 7 days of age were allotted to three treatments. The control group of 20 piglets was raised by their own sows until 21 days of age, while others were shifted to automatic liquid feeders of either NLRI or IALF on 7 days of age and reared during 14 days post-weaning. After then, all the piglets were fed nutritionally identical mash diets until 70 days of age. Compared with control group, body weight of piglets reared on automatic liquid feeders were lighter(P〈0.05) at 21 days of age [5.55kg (control) vs 4.97 (NLRI) and 4.98kg (IALF)], while heavier(P〈0.05) at 70 days of age(24.82kg vs 30.17 and 29.42kg). The results indicated that pigs reared on liquid feeding showed higher(P〈0.05) average daily gain than control pigs during the whole experimental period [346.7g (control) vs 425.8 (NLRI) and 416.1g (IALF)], while no difference was found in feed/gain (1.67 vs 1.78 and 1.84). There was no difference in growth performance and incidence of diarrhea between two automatic liquid feeders, NLRI and IALF. Compared with control group, intestinal villi tended to be shorter in liquid feeding group during the first week, but were recovered within two weeks. The results suggest that the automatic liquid feeder newly developed by National Livestock Research Institute, Korea can be successfully used for rearing young piglets weaned at very early age.

Response of early weaned piglets to graded levels of dietary cobalamin

The water-soluble vitamin cobalamin plays a central role as a co-factor in key pathways of energy and protein metabolism. The dietary requirement of this vitamin for the young pig (5–10 kg) has been estimated at 17.5 μg kg-1, but it is derived from estimates made over 40 yr ago. In light of changes in swine production, including the selection for high lean potential genotypes and the move to earlier weaning times, a reassessment of the adequacy of current cobalamin estimates is warranted. To this end, two trials were conducted to test the following alternate hypothesis: The current National Research Council (NRC 1998) estimated cobalamin requirement for the 5- to 10-kg early-weaned piglet is inadequate to maintain optimal cobalamin status, as reflected by growth, feed conversion efficiency, plasma cobalamin and plasma homocysteine concentrations. In trial 1, 60 Cotswold pigs (17 ± 1 d, equal males and females) were randomly assigned to receive diets, formulated with ingredients essentially devoid of cobalamin, and containing either 0, 35, 70, 105, or 140 g crystalline cobalamin kg-1. After 15 d, growth, feed intake and feed conversion efficiency were not significantly different (P &gt; 0.05) between the dietary cobalamin levels. However, plasma cobalamin was significantly lower (49.9 vs 186.7, 168.0, 164.7, and 178.7 pg mL-1; SEM 17.3; P &lt; 0.05) and homocysteine was significantly higher (34.5 vs. 22.5, 26.0, 24.7, and 23.4 μmol L-1; SEM 2.9; P &lt; 0.05) in piglets consuming diets containing 0 vs. 35, 70, 105 and 140 μg crystalline cobalamin kg-1, respectively. Trial 2 retained the same study design as trial 1, but added dietary cobalamin concentrations were equivalent to 0, 10, 20, 30, and 40 g kg-1. The observed pattern of responses in plasma cobalamin and homocysteine support a requirement of added cobalamin in excess of 30 μg kg-1 of diet. Taken together, the data support a requirement for the addition of 35 μg crystalline cobalamin kg-1 of a diet formulated with ingredients essentially devoid of natural cobalamin for the early-weaned piglet between 5 and 10 kg, a value that is double the current NRC requirement. In addition, the current study uses changes in the plasma concentration of the metabolite homocysteine as a novel approach for the estimation of the dietary requirement for cobalamin in animals. Key words: Cobalamin, early weaned pig, homocysteine, dietary requirement

Energy and economic analysis of biogas heated livestock buildings

The possibility to cover the annual space-heating requirements of a typical swine nursery by the methane produced using a solar-assisted anaerobic digester of innovative design, is studied for two Greek areas. Simulation is used to predict the hourly temperature and relative humidity inside the early-weaned piglet unit, along with the heating energy requirements to keep indoor conditions within pigs’ production space. The methane produced by the solar-assisted anaerobic digester is also calculated using a detailed simulation algorithm. The results showed that the methane produced from the solar-assisted anaerobic digester completely ensures not only full coverage of the annual space-heating requirements of the described piglet unit for both Greek areas, but also large methane surplus which could be used in various other ways. A simple sensitivity analysis concerning the economics of the solar-assisted anaerobic digester indicated that its profitability strongly depends on to what extent the produced methane is used.

Erythrocyte glutathione reductase activity and riboflavin nutritional status in early-weaned piglets.

The reliability of erythrocyte glutathione reductase activity (EGRAC) as an indicator of riboflavin (vitamin B2) status was determined in 36 piglets weaned at two weeks of age. Total B2 metabolites determined by high-performance liquid chromatography (HPLC) in plasma, red blood cells, and liver were used as reference values. There was no correlation between EGRAC values and total B2 metabolites either in circulation (r < 0.15, p > 0.08) or in liver (r < 0.01, p > 0.95). EGRAC does not appear to be a reliable biochemical indicator of vitamin B2 status in the pig.