低蛋白质日粮对断奶仔猪生长相关激素和肠道微生物区系的影响

【目的】在饲喂低蛋白质日粮条件下,探究断奶仔猪生长相关激素、回肠和盲肠微生物组成及其代谢产物的变化。【方法】选取体重相近杜长大断奶仔猪54头,随机平均分为3组,每组18头,分别饲喂含20%(NP组)、17%(MP组)和14%(LP组)粗蛋白日粮,平衡日粮中的赖氨酸、蛋氨酸、苏氨酸和色氨酸,于试验第10、25和45天每组屠宰6头,采血测定血常规和生长相关激素;于第45天采集回肠和盲肠食糜,分析微生物及其代谢产物。【结果】与NP组相比,第25和45天时MP和LP组尿素氮水平显著降低(P0.05),第25天时LP组甘油三脂含量、第45天时LP组胆固醇含量显著增加(P0.05)。各时间点血液胰高血糖素、胰岛素、生长激素、T3和T4在3组之间差异均不显著。门水平上,回肠和盲肠中的微生物均以厚壁菌门占主导地位,但各组间差异不显著;随日粮蛋白质含量降低,乳酸杆菌属呈上升趋势,严格梭菌属呈下降趋势,但差异不显著。降低日粮蛋白质含量显著减少了回肠和盲肠中氨氮的产量(P0.05)。【结论】断奶仔猪日粮蛋白质降低3或6个百分点不影响机体生长相关激素的分泌,但能降低血液尿素氮和肠道内氨氮的浓度,对肠道有益菌乳酸杆菌属的相对丰度有一定的提高作用。这说明低蛋白质日粮能提高断奶仔猪对饲料氮源的利用率,且有利于肠道健康。     

Effects of feeding a Lactobacillus plantarum JL01 diet on caecal bacteria and metabolites of weaned piglets

Currently, knowledge is limited concerning the impact of a Lactobacillus plantarum JL01 diet for weaned piglets on caecal bacteria and metabolite profiles. In our experiments, 24 weaned piglets were randomly divided into two groups; each piglet in the treatment groups (Cec-Lac) was fed a basic diet and administered 10 ml of L. plantarum JL01 (1·0 × 10⁹ CFU per ml) every day. The control group (Cec-Con) was fed a basic diet. After feeding for 28 days, we analysed the parameters of the caecal digesta of weaned piglets. We used 16S rDNA gene sequencing and mass spectrometry (MS)-based metabolomics techniques to investigate the effect of a L. plantarum JL01 diet on intestinal microbial composition and its metabolite profiles in the caecum contents of weaned piglets. The results showed that the richness estimators (ACE and Chao indices) in the caecal bacteria increased in the Cec-Lac group. Prevotella_2 and Desulfovibrio decreased significantly, while Pantoea and Rectale_group increased in the caecum of weaned piglets in the Cec-Lac group. Furthermore, Pearson's correlation analysis revealed that the genus Rectale_group was positively correlated with indole-3-acetic acid (P < 0·05), and the genus Pantoea had the same correlation with 1-palmitoyl lysophosphatidic acid. The metabolomics analysis revealed that the L. plantarum JL01 diet supplementation had significant effects on tryptophan metabolism and fat digestion and absorption. The results indicated that the L. plantarum JL01 dietary supplementation not only altered the microbial composition but also mediated tryptophan metabolism and fat digestion and absorption in the caecum, factors that may further affect the health of the host.     

Effects of dietary supplementation with grape seed procyanidins on nutrient utilisation and gut function in weaned piglets

Grape seed procyanidins (GSPs), widely known for their beneficial health properties, fail to bring about the expected improvement in piglets’ growth performance. The effects of dietary supplementation with GSPs on nutrient utilisation may be a critical influencing factor. Hence, the purpose of this study was to investigate the effects of dietary supplementation with GSPs on nutrient utilisation and gut function in weaned piglets. One hundred and twenty crossbred piglets were allocated randomly to four treatment groups, with three replicate pens per treatment and 10 piglets per pen. Each group was given one of the four dietary treatments: the basal diet (control group) or the basal diet with the addition of 50-, 100- or 150-mg/kg GSPs. The trial lasted 28 days. Faeces were collected from d 12 to 14 and from d 26 to 28 for measuring the coefficient of total tract apparent digestibility (CTTAD) of the nutrients. Blood samples were collected on d 14 and 28 for detecting the blood biochemical parameters. Two piglets per pen were slaughtered to collect the pancreas and intestinal digesta for evaluating the digestive enzyme activity and the coefficient of ileal apparent digestibility (CIAD) of the nutrients. On d 14 and 28, supplementation with 150-mg/kg GSPs significantly decreased the CTTAD of DM and CP in piglets. On d 14, GSPs supplementation at a concentration of 150 mg/kg led to a remarkable decrease in the CIAD of CP and gross energy (GE). On d 28, GSPs supplementation at a dose of 150 mg/kg generated a marked decline in the CIAD of DM, GE, CP and ether extract. Grape seed procyanidins supplementation at concentrations of 100 or 150 mg/kg inhibited the activities of lipase and amylase. In contrast, the jejunum mucosa maltase and sucrase activities increased due to the inclusion of GSPs at a concentration of 100 mg/kg in the piglet diet. Compared with the levels of the control group, the serum glucose and total protein levels were enhanced significantly by supplementation with GSPs at 100 mg/kg and reduced dramatically at 150 mg/kg. The serum diamine oxidase activity and endotoxin levels were decreased by GSPs supplementation in piglet diets. In conclusion, higher concentrations of GSPs in weaned piglet diets attenuated nutrient digestion and inhibited digestive enzyme activity; however, suitable concentrations of GSPs could promote brush-border enzyme activity, enhance serum glucose and total protein concentrations and decrease epithelial permeability.     

Effects of a dietary crude fibre concentrate on growth in weaned piglets

Many fibre sources can help the adaptation of piglets at weaning, improving the growth. In this study, the effects of a dietary crude fibre concentrate (CFC) on piglet’s growth was investigated. From 31 to 51 days of age, 108 weaned piglets (D×(Lw×L)), had access to two isofibrous, isoenergetic and isonitrogenous diets, supplemented with 1% of CFC (CFC group) or not (control (CON) group). From days 52 to 64 all piglets received the same starter diet. During the dietary treatment period the CFC group showed higher average daily gain, average daily feed intake and feed efficiency (P<0.001) than CON group. At 64 days of age, BW was higher in CFC group compared with CON group (P<0.001). Blood samples were collected at days 31, 38, 45 and 52 of age. From days 31 to 52 significant differences in the somatotropic axis between groups were observed. In particular, growth hormone levels were higher only at the end of the 1^st week of dietary treatment (P<0.05) in CFC group animals compared with CON group animals. The IGF-I trend was similar between groups even if the IGF-I levels were higher in the CFC group than CON group 1 week after starting treatment (P<0.01). The IGF-binding protein 3 (IGFBP-3) levels were higher in the first 2 weeks of dietary treatment and lower in the 3^rd week in CON group compared with CFC group (P<0.01). Specifically, the IGFBP-3 profile was consistent with that of IGF-I in CFC group but not in CON group. At the same time, an increase of leptin in CFC compared with CON group was observed (P<0.05). Piglets fed the CFC diet showed a lower diarrhoea incidence (P<0.05) and a lower number of antibiotic interventions (P<0.05) than CON diet from 31 to 51 days of age. Pig-major acute-phase protein plasma level (P<0.01) and interleukin-6 gene expression (P<0.05) were higher in CON group than CFC group at the end of 1^st week of dietary treatment. In conclusion, this study showed that CFC diet influences the hormones related to energy balance enhancing the welfare and growth of piglets. Furthermore, the increase in feed intake during 3 weeks of dietary treatment improved the feed efficiency over the entire post-weaning period.     

Effects of dietary supplementation with freshwater microalgae on growth performance,nutrient digestibility and gut health in weaned piglets

In pigs, digestive disorders associated with weaning lead to antibiotic use to maintain intestinal health. Microalgae have been studied in humans and rodents for their beneficial effects on health. The nutritional value of microalgae in animal diets has been assessed, but results were not conclusive. Dietary supplementation with microalgae as an alternative to antibiotic use was studied in two trials (72 piglets with initial BW=9.1±1.1 kg in trial 1 and 24 piglets with initial BW=9.1±0.9 kg in trial 2). All piglets were weaned at 28 days of age and then housed in individual cages. Piglets were randomly allocated to one of the four diets during 2 weeks after weaning: a standard diet with no supplementation (NC) or the standard diet supplemented with 1% Spirulina (SP), with 1% Chlorella (CV), or with 0.2% of colistin as positive control (PC). Trial 1 was performed to determine the effect of microalgae supplementation from 28 to 42 days on performance and incidence of diarrhoea. Animals received then a standard diet from 42 to 56 days of age. Trial 2 was performed from 28 to 42 days of age to assess nutrient digestibility of the experimental diets and to determine inflammatory status and intestinal morphology at 42 days of age. In trial 1, 94% of the pigs had diarrhoea in the 1st week after weaning with no beneficial effect of colistin on diarrhoea incidence, average daily feed intake (ADFI), average daily gain (ADG), and gain : feed (G : F) ratio. This suggests that the diarrhoea was due to digestive disorders that did not result from enterotoxigenic Escherichia coli infection. Supplementation with either Spirulina or Chlorella did not affect ADFI, ADG and G : F in trials 1 and 2 (P>0.10). Diarrhoea incidence was reduced in CV pigs compared with NC, SP and PC pigs (P<0.05). Total tract digestibility in pig receiving microalgae was greater for gross energy (P<0.05), and tended to be greater for dry matter, organic matter and NDF (P<0.10) compared with NC and PC pigs. Villus height at the jejunum was greater in SP and CV pigs compared with NC and PC pigs (P<0.05). This study shows a potential effect of both Spirulina and Chlorella supplementation on intestinal development and a potential of Chlorella supplementation to manage mild digestive disorders. Further investigation is necessary to determine the mechanism action of Spirulina and Chlorella on gut health and physiology.     

Effects of alternative feed additives to medicinal zinc oxide on productivity,diarrhoea incidence and gut development in weaned piglets

The use of medicinal zinc oxide (ZnO) must be phased out by 2022, thus prompting an urgent need for alternative strategies to prevent diarrhoea in weaner piglets. The objectives of this study were to assess the impact on weaner piglet performance, diarrhoea incidence and gut development, when (1) dietary ZnO supplementation was substituted by alternative commercial products based on macroalgae, specific probiotics or synbiotics, or (2) dietary ZnO inclusion was reduced from 2500 to 1500 ppm. A total of 4680 DLY piglets (DanBred, Herlev, Denmark), weaned around 35 days of age, were randomly assigned according to sex and BW to six different dietary treatment groups. A basal diet was supplemented with no ZnO (NC= negative control), 2500 ppm ZnO (PC= positive control), 1500 ppm ZnO (RDZ= reduced dose of ZnO) or commercial macroalgae (OceanFeed™ Swine =OFS), probiotic Miya-Gold or synbiotic GærPlus products. The piglets entered and exited the weaner unit at ~7.0 and 30 kg BW, respectively. In-feed ZnO was provided the first 10 days post-weaning, while the alternative supplements were fed throughout the weaner period. As expected, the average daily feed intake, average daily weight gain (ADG), feed conversion ratio (FCR) and diarrhoea incidence were improved in the PC compared to NC group (P< 0.05) during phase 1 consistent with improved indices of villi development observed in subgroups of piglets sacrificed 11 days post-weaning. Reduction of ZnO to 1500 ppm lowered ADG (P< 0.05) and slightly increased incidence of diarrhoea during the first 10 days after weaning (but not later) without affecting FCR. None of the three alternative dietary additives, including a 10-fold increased dose of GærPlus than recommended, improved piglet performance, gut health and gut development above that of NC piglets. The OFS piglets sacrificed 11 days after weaning had significantly lower weights of hindgut tissue and contents compared to the PC group, consistent with antimicrobial activity of the product, which was detected from anaerobicin vitrofermentation. In conclusion, dietary ZnO supplementation during the first 10 days post-weaning may be reduced from 2500 to 1500 ppm without major negative implications for weaner piglet performance and health in herds under a high management level. However, none of the alternative dietary supplements were able to improve piglet performance or gut health, when ZnO was omitted from the diet.     

Impaired translation initiation activation and reduced protein synthesis in weaned piglets fed a low-protein diet

Weanling mammals (including infants) often experience intestinal dysfunction when fed a high-protein diet. Recent work with the piglet (an animal model for studying human infant nutrition) shows that reducing protein intake can improve gut function during weaning but compromises the provision of essential amino acids (EAA) for muscle growth. The present study was conducted with weaned pigs to test the hypothesis that supplementing deficient EAA (Lys, Met, Thr, Trp, Leu, Ile and Val) to a low-protein diet may maintain the activation of translation initiation factors and adequate protein synthesis in tissues. Pigs were weaned at 21 days of age and fed diets containing 20.7, 16.7 or 12.7% crude protein (CP), with the low-CP diets supplemented with EAA to achieve the levels in the high-CP diet. On Day 14 of the trial, tissue protein synthesis was determined using the phenylalanine flooding dose method. Reducing dietary CP levels decreased protein synthesis in pancreas, liver, kidney and longissimus muscle. A low-CP diet reduced the phosphorylation of eukaryotic initiation factor (eIF) 4E-binding protein-1 (4E-BP1) in skeletal muscle and liver while increasing the formation of an inactive eIF4E.4E-BP1 complex in muscle. Dietary protein deficiency also decreased the phosphorylation of mammalian target of rapamycin (mTOR) and the formation of an active eIF4E.eIF4G complex in liver. These results demonstrate for the first time that chronic feeding of a low-CP diet suppresses protein synthesis in animals partly by inhibiting mTOR signaling. Additionally, our findings indicate that supplementing deficient EAA to low-protein diets is not highly effective in restoring protein synthesis or whole-body growth in piglets. We suggest that conditionally essential amino acids (e.g., glutamine and arginine) may be required to maintain the activation of translation initiation factors and optimal protein synthesis in neonates.     

Incorporation of galactomannans in the diet of newly weaned piglets: effect on bacteriological and some morphological characteristics of the small intestine

In search of substances replacing antibiotics as growth promoters for farm animals, non-digestible oligosaccharides (NDO) or non-starch polysaccharides (NSP) have been proposed as possible alternatives. In this context, the influence of galactomannans on bacteriological and morphological aspects of the gastrointestinal tract in weanling pigs was investigated. Four groups of five newly weaned piglets received one of the following diets: control feed (C), C supplemented with guar gum (1%), C supplemented with locust bean gum (1%) and C supplemented with 10% of carob tree seeds meal as source of locust bean gum. The animals were euthanized after 11-12 days and digesta were sampled in stomach, jejunum (proximal and distal) and caecum, while mucosal scrapings and ring shaped tissue samples were taken of proximal and distal jejunum. On these samples bacteriological, biochemical and morphological determinations were carried out. Total count of bacteria in digesta and mucosal scrapings was not influenced by the different diets, with the exception of the proximal jejunum where a small decrease (0.5 log10 CFU) was noted with the guar gum and carob tree seeds diet. The number of E. coli increased by feeding both gums and carob tree seeds. With the latter diet, higher counts of streptococci were observed. In agreement with the lower concentration of lactic acid in jejunal contents, guar gum decreased the number of lactobacilli. Locust bean gum decreased the molar proportion of acetate in caecal contents while butyrate and valerate were augmented. Feeding the carob tree seeds resulted in shorter villi and a lower villus height/crypt depth ratio in the jejunum mucosa, which was an indication for a faster renewal rate of the epithelium. Both locust bean gum feeds significantly lowered the mitotic index in the crypts of the small intestine. Only with the carob tree seeds diet, viscosity of jejunal contents was increased. In conclusion, the effects of the addition of 1% of pure guar gum or locust bean gum were inconsistent and not very outspoken, whereas 10% of carob tree seeds meal in the diet resulted in influences on intestinal characteristics at the bacteriological and morphological level.     

Incorporation of galactomannans in the diet of newly weaned piglets: Effect on bacteriological and some morphological characteristics of the small intestine

In search of substances replacing antibiotics as growth promoters for farm animals, non-digestible oligosaccharides (NDO) or non-starch polysaccharides (NSP) have been proposed as possible alternatives. In this context, the influence of galactomannans on bacteriological and morphological aspects of the gastrointestinal tract in weanling pigs was investigated. Four groups of five newly weaned piglets received one of the following diets: control feed (C), C supplemented with guar gum (1%), C supplemented with locust bean gum (1%) and C supplemented with 10% of carob tree seeds meal as source of locust bean gum. The animals were euthanized after 11?–?12 days and digesta were sampled in stomach, jejunum (proximal and distal) and caecum, while mucosal scrapings and ring shaped tissue samples were taken of proximal and distal jejunum. On these samples bacteriological, biochemical and morphological determinations were carried out. Total count of bacteria in digesta and mucosal scrapings was not influenced by the different diets, with the exception of the proximal jejunum where a small decrease (0.5 log₁₀ CFU) was noted with the guar gum and carob tree seeds diet. The number of E. coli increased by feeding both gums and carob tree seeds. With the latter diet, higher counts of streptococci were observed. In agreement with the lower concentration of lactic acid in jejunal contents, guar gum decreased the number of lactobacilli. Locust bean gum decreased the molar proportion of acetate in caecal contents while butyrate and valerate were augmented. Feeding the carob tree seeds resulted in shorter villi and a lower villus height/crypt depth ratio in the jejunum mucosa, which was an indication for a faster renewal rate of the epithelium. Both locust bean gum feeds significantly lowered the mitotic index in the crypts of the small intestine. Only with the carob tree seeds diet, viscosity of jejunal contents was increased. In conclusion, the effects of the addition of 1% of pure guar gum or locust bean gum were inconsistent and not very outspoken, whereas 10% of carob tree seeds meal in the diet resulted in influences on intestinal characteristics at the bacteriological and morphological level.     

Changes of gut microbiota structure and morphology in weaned piglets treated with fresh fermented soybean meal

This study investigated the effects of dietary fresh fermented soybean meal (FSM) on the intestinal microbiota and metabolites, bacterial enzyme activity and intestinal morphology of weaning piglets. A total of 64 weaned piglets were randomly allocated into two treatments. A corn-soybean-based diet was used as the control and other treatment was fed the same basal diet containing 15% fresh FSM. The feeding trial lasted for 21 days. Bacterial community structure and diversity in the cecum and colon were assessed using pyrosequencing-based analysis. The results showed that the phylum level, Firmicutes, Bacteroidetes, Proteobacteria and Tenericutes were dominant in the cecum or colon. Gut Firmicutes increased, while Bacteroidetes and Proteobacteria decreased in the fresh FSM-fed piglets. At the genus level, the relative abundances of butyrate-producing bacteria, Lactobacillus and Prevotella were higher in both cecum and colon of fresh FSM fed piglets. Meanwhile, fresh FSM could promote the development of intestinal morphological and reduce the incidence of diarrhea. The results indicated that fresh FSM might change intestinal function by influencing intestinal microenvironment.     

Effects of beta-glucan extracted from Saccharomyces cerevisiae on humoral and cellular immunity in weaned piglets

Twenty-four barrows were used to investigate the effects of beta-glucan on immune function in weaned piglets. Pigs (8.09 +/- 0.20 kg, 28 d of age) were fed a diet without or with supplemented beta-glucan (50 mg/kg feed). All pigs were injected with ovalbumin (OVA) on day 14 to investigate their humoral immune response. On day 28, lymphocytes were isolated from all pigs to determine the effects of beta-glucan on cellular immunity of pigs in vitro. Lymphocytes from six pigs of each group were incubated with 16 microg lipopolysaccharide (LPS) per ml culture medium, the remainder with an equivalent volume of culture medium alone. Samples were collected at 0, 3, 6, 12, 18, 24, and 48 h after LPS addition for determination of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interleukin-10 (IL-10). On day 31, six pigs of each group were injected with either LPS (25 microg/kg BW) or an equivalent amount of sterile saline. Blood samples were collected at 3 h after LPS injection for analysis of IL-6, TNF-alpha, and IL-10 in plasma. The results indicated that dietary beta-glucan enhanced pig antibody response to OVA only in the first week after injection. In vitro, the increases of IL-6 and TNF-alpha in culture medium were partially dampened in pigs supplemented with beta-glucan when their lymphocytes were incubated with LPS, whereas the increase of IL-10 was potentiated. In vivo, dietary beta-glucan attenuated the increase of plasma IL-6 and TNF-alpha, and enhanced the increase of plasma IL-10 when pigs were challenged with LPS. These results demonstrate that beta-glucan can improve the humoral immunity of pigs and modulate cellular immunity of pigs by mitigating the elevation of pro-inflammatory cytokines and enhancing the increase of anti-inflammatory cytokines after an immunological challenge.     

Growth performance and gut function of piglets weaned at four weeks of age and fed protease-treated soya-bean meal

Two experiments were carried out to investigate the effects of the protease-treatment of soya-bean meal (SBM) on its composition and nutritive value when fed to piglets weaned at 4 weeks of age in cereal-based diets. In experiment 1, two proteases, active at either alkaline (protease P1) or acid pH (protease P2), were compared with alkali or acid treatment alone. In experiment 2, treatment with protease P2 at acid pH was compared with untreated-SBM, acid-treated SBM, a soya protein concentrate or skim milk powder+fishmeal. Protease treatment increased SBM alpha amino nitrogen concentrations and reduced in vitro SBM antigenicity. Protease P1 reduced in vitro antigenicity to a greater extent than protease P2. However, protease P1 hydrolysed SBM polypeptides non-specifically whereas protease P2 preferentially hydrolysed a high molecular weight polypeptide. In experiment 1, piglets (12 diet⁻¹) fed alkali-treated SBM gained more weight than piglets fed acid-treated SBM in the first 7 days after weaning. Protease P1 did not improve live-weight gain compared with alkali-treatment whereas protease P2 did improve live-weight gain compared with acid treatment. In experiment 2, piglets (24 diet⁻¹) fed protease P2-treated SBM or skim milk powder+fishmeal gained significantly more weight over the first 7 days post-weaning than piglets fed untreated SBM. In neither experiment were there significant differences between diets in piglet serum anti-SBM specific antibodies. There were no consistent changes in small intestine enzyme specific activities in response to the diets fed. Histopathological examination of the small intestine of piglets in experiment 2 revealed no evidence of enteric disease. Neither were there any differences between diets in villus height or crypt depth.     

地衣芽孢杆菌对脂多糖诱导的仔猪肝脏炎症及抗氧化功能的影响

[目的]本文旨在研究地衣芽孢杆菌(Bacillus licheniformis HJ0135)对脂多糖(lipopolysaccharide,LPS)应激断奶仔猪肝脏指数、炎症因子、抗氧化功能及相关基因表达的影响。[方法]选择24头28日龄健康状况良好的三元杂交断奶仔猪(杜×长×大),随机分成4个试验组:对照组(control,CON),500 mg/kg地衣芽孢杆菌HJ0135组(BL)、LPS应激组(LPS)以及LPS+500mg/kg地衣芽孢杆菌HJ0135组(BL-LPS),在试验第28天,给LPS组和BL-LPS组仔猪腹腔注射1.5 mL浓度为1 mg/mL的LPS,给CON组和BL组仔猪注射等量生理盐水,1.5 h后屠宰并采样。[结果]与CON组相比,BL组血清谷草转氨酶(aspartate aminotransferase,AST)和谷丙转氨酶(alanine aminotransferase,ALT)的含量降低,肝脏的总抗氧化能力(total antioxidant capacity,T-AOC)提升且过氧化氢酶(catalase,CAT)和总超氧化物歧化酶(total...     

The effects of L-carnitine on some hematological parameters in rats fed a cholesterol-rich diet

We evaluated the effects of L-carnitine on the hematological characteristics of rats fed a cholesterol-rich diet. Healthy male Wistar Albino rats were assigned to four equal groups. During the 40 day experiment, group 1 was fed standard rat pellets, group 2 was fed standard rat pellets containing 7.5 % cholesterol powder, group 3 was fed standard rat pellets and water that contained 75 mg/l L-carnitine, and group 4 was fed standard rat pellets that contained 7.5% cholesterol and water that contained 75 mg/l L-carnitine. Blood samples were analyzed for red (RBC) and white (WBC) blood cells, hemoglobin, hematocrit, granulocytes, lymphocytes, monocytes, mean cell volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) using an automated cell counter. The RBC count in the group that received the 7.5% cholesterol diet was decreased significantly compared to the other groups. The hematocrit of the cholesterol group was lower than for the L-carnitine + cholesterol and L-carnitine groups. The MCV in the cholesterol group was significantly higher than the control group. The MCH in the cholesterol group was higher than for the other groups. There was no significant difference among the groups with regard to hemoglobin, MCHC, WBCs and leukocyte types. L-carnitine appears to have beneficial effects on erythrocyte stability, erythropoiesis and hyperlipidemia.     

Effects of dietary grape pomace on the intestinal microbiota and growth performance of weaned piglets

ABSTRACT

Grape pomace (GP) is an abundant by-product from wine production and is rich in phenolic compounds, unsaturated fatty acids, dietary fibre and beneficial bacteria. In this study, weaned piglets were fed a basic diet supplemented with 5% GP for 4 weeks. Compared with those in the control (CON) group, it was found that the proportion of Lactobacillus delbrueckii, Olsenella umbonata and Selenomonas bovis in the caecum and the villus height and villus height/crypt depth ratio (VCR) of the jejunum were both significantly increased in the GP group (p < 0.05). Meanwhile, at the mRNA expression level, several proinflammatory cytokines (IL-1β, IL-8, IL-6 and TNF-α) were significantly downregulated (p < 0.05) in piglet caecal tissue, and the short-chain fatty acid receptors (GPR41 and GPR43) were not significantly upregulated. In contrast, the levels of IgG was significantly increased (p < 0.05) in the sera of weaned piglets in the GP group. However, no difference in growth performance between the two groups of piglets was detected. These results show that GP had no adverse effects on the growth performance of piglets, but GP can promote the content of some beneficial bacteria in the caecum; this effect is conducive to improving the disease resistance potential of piglets.     

Effects of dose and formulation of carvacrol and thymol on bacteria and some functional traits of the gut in piglets after weaning

Two trials were conducted to study the effects of dose and formulation of carvacrol and thymol on bacterial counts, metabolites and functional traits of the gut in weaned piglets. In the first experiment (Exp. I), 25 piglets (28 d, 6.59 ± 0.48 kg BW) were allocated to five dietary treatments: a control diet, or the same diet supplemented with either carvacrol or thymol at doses of 500 and 2000 mg kg^?1. In the second experiment (Exp. II), 35 piglets (28 d, 7.99 ± 0.73 kg BW) were assigned to seven dietary treatments: the same control diet as in Exp. I, or this diet supplemented with thymol in one of three formulations (on celite, on alphacel or microencapsulated) at doses of 500 and 2000 mg kg^?1. At 11/12 days post-weaning piglets were euthanised, and digesta from stomach, proximal and distal small intestine were sampled for bacteriological and biochemical analysis. Small intestinal tissue was sampled for histo-morphological determinations. In none of the experiments or sections of the gut was the number of bacteria lowered by the carvacrol or thymol supplementation. In Exp. I, the villus/crypt ratio at the distal small intestine for the experimental diets (1.30–1.32) was higher than for the control diet (1.24) (p < 0.05). Thymol fed animals in Exp. II had a lower number of intra-epithelial lymphocytes at the proximal (p < 0.05) and at the distal (p < 0.1) small intestine as compared to control animals. Mean concentration of the active ingredient in the stomach and proximal small intestine for the 2000 mg kg^?1 carvacrol diet was 521 and 5 mg kg^?1 fresh digesta, respectively, and for the 2000 mg kg^?1 thymol diets it ranged between 475 and 647 and between 13 and 24 mg kg^?1 fresh digesta, respectively. Cumulative absorption in the proximal small intestine was higher than 90% for all treatments and was not affected by formulation type. These data suggest that carvacrol and thymol can improve gut health, but evidence for clear antimicrobial effects towards the major culturable bacteria of the pig foregut is limited.     

Prevention and treatment of tail biting in weaned piglets

The aims of this study were to evaluate four preventive measures and two curative treatments of tail biting. The preventive measures were: chain, rubber hose, straw rack (5 g/pig/day) and the provision of straw on the floor twice daily by hand (2 × 10 g/pig/day). The two curative treatments, which were applied following the onset of tail biting in a pen were: straw twice daily (as in the fourth preventive measure) and the removal of the biter. In total, 960 undocked weaned piglets (10 piglets per pen) were observed during 5 weeks. Tail lesions (none, bite marks and wounds) were recorded daily. The incidence of pens with wounded pig tails was significantly lower when straw was provided twice daily (8% of pens) compared to the chain (58% of pens) and rubber hose (54% of pens) treatment, but did not differ significantly from the straw rack treatment (29% of pens). Tails with bite marks were significantly less common in pens with twice daily straw (16% of pens) compared to chain (88% of pens), rubber hose (79% of pens) and straw rack (75% of pens). No significant difference was found between the curative treatments. Both treatments showed a reduced incidence of red fresh blood on the tails at days 1–9 following curative treatment, compared to day 0. However, neither curative treatment eliminated tail biting entirely. In conclusion, this study indicates that tail biting is best prevented with a small amount of straw, provided twice daily, and to a lesser extent with a straw rack, compared to providing a chain or a rubber hose. Once tail biting has occurred, providing a small amount of straw twice daily and removing the biter appears to be equally effective.