Lianqiang Che

Changes in plasma amino acid profiles, growth performance and intestinal antioxidant capacity of piglets following increased consumption of methionine as its hydroxy analogue

The aim of the present study was to determine whether early weaning-induced growth retardation could be attenuated by increased consumption of methionine as DL-methionine (DLM) or DL-2-hydroxy-4-methylthiobutyrate (HMTBA) in both lactating sows and weaned piglets. Therefore, diets containing DLM and HMTBA at 25% of the total sulphur-containing amino acids (AA) present in the control (CON) diet were fed to lactating sows and weaned piglets and their responses were evaluated. Compared with the CON diet-fed sows, the HMTBA diet-fed sows exhibited a tendency (P<0·10) towards higher plasma taurine concentrations and the DLM diet-fed sows had higher (P<0·05) plasma taurine concentrations, but lower (P<0·05) isoleucine concentrations. Suckling piglets in the HMTBA treatment group had higher (P<0·05) intestinal reduced glutathione (GSH) content, lower (P<0·05) oxidised glutathione (GSSG):GSH ratio, and higher (P<0·05) plasma cysteine and glutathione peroxidase (GPx) activity than those in the CON and DLM treatment groups. The feed intake (P<0·05) and body weight of piglets averaged across post-weaning (PW) days were higher (P< 0·05) in the HMTBA treatment group than in the DLM treatment group and were higher (P<0·05) and tended (P<0·10) to be higher, respectively, in the HMTBA treatment group than in the CON treatment group. Increased (P<0·05) GSSG content and GSSG:GSH ratio and down-regulated (P<0·05) expression of nutrient transport genes were observed in the jejunum of piglets on PW day 7 than on PW day 0. On PW day 14, the HMTBA diet-fed piglets had higher (P<0·05) intestinal GSH content than the CON diet-fed piglets and higher (P<0·05) plasma GPx activity, villus height and goblet cell numbers than the CON diet- and DLM diet-fed piglets. In conclusion, early weaning-induced growth retardation appears to be attenuated through changes in plasma AA profiles and elevation of growth performance and intestinal antioxidant capacity in piglets following increased consumption of methionine as HMTBA.

Effects of maternal over- and undernutrition on intestinal morphology, enzyme activity, and gene expression of nutrient transporters in newborn and weaned pigs

OBJECTIVES It has been suggested that maternal nutrition during gestation is involved in the offsprings intestinal development. The aim of this study was to evaluate the effects of maternal nutrition on digestive and absorptive function of offspring at both birth and weaning with pig as model. METHODS Eighteen primiparous Landrace × Yorkshire gilts (ages 253 ± 9 d; body weight 148.6 ± 6.9 kg) were allocated to a normal nutrition (control) group as recommended by the National Research Council (NRC; 1998), an undernutrition (UN) group (75% of NRC recommendations), and an overnutrition (ON) group (150% of NRC recommendations); the nutritional treatments were introduced from day 1 of gestation to farrowing. RESULTS By comparison, the small intestine weight (+33%; P < 0.01) and the ratio of small intestine weight to length (+25%; P < 0.05) for the ON group were higher than those for the control group. Meanwhile, the maternal ON treatment had significant effect on the activity of brush border lactase in the jejunum (+125%; P < 0.05) at birth. Expression of mRNA for SGLT1, GLUT2, PEPT1, and GLP2R were significantly increased (+1.7∼9.6-fold; P < 0.05) in jejunum of newborn or weaned piglets from the ON group; whereas maternal UN significantly affected small intestine weight (-28%; P < 0.01), length, and the ratio of weight to length (-11% and -19%; P < 0.05, respectively), and villus height (-29% and -22%; P < 0.05, respectively) in jejunum and ileum. Furthermore, maternal UN enhanced the activity of brush border lactase in the jejunum of newborn piglets (P < 0.05). CONCLUSIONS Maternal ON enhanced intestinal function via up-regulating digestive enzyme activities and gene expression of transporters in both newborn and weaning piglets. Maternal UN impaired fetal intestinal development that could be partially compensated during the neonatal period.

Feeding prepubescent gilts a high-fat diet induces molecular changes in the hypothalamus-pituitary-gonadal axis and predicts early timing of puberty

OBJECTIVE The onset of puberty in females has been occurring earlier over the past decades, presumably as a result of improved nutrition in developed countries. However, the underlying molecular mechanisms responsible for the early attainment of puberty as a result of nutrition fortification remain largely unknown. The aim of this study was to evaluate the hormone and gene expression changes in prepubescent gilts fed a high-fat diet to investigate whether these changes could predict the early timing of puberty. METHODS Forty gilts were fed a daily basal diet (LE) or a basal diet with an additional 270 g/d or 340 g/d of fat (HE) during the prepubescent phase. Blood samples were collected during the prepubescent phase to detect hormone secretion changes in insulin-like growth factor-1, kisspeptin, estradiol, progesterone, and leptin. The gene expressions at the hypothalamus-pituitary-gonadal axis were examined on day 73 of the experiment (average age on day 177) during the prepubescent phase. RESULTS An HE diet resulted in accelerated body weight gain and back-fat thickness at the P2 point compared with LE gilts during the prepubescent phase. Gilts that were fed HE diets attained puberty 12 d earlier than LE gilts, and a larger proportion of HE gilts reached puberty at day 180 or 190 of age. A postmortem analysis revealed a promoted development of the uterus and ovary tissue that was characterized by a 53.7% and 29.5% increase in the uterine and ovary weight, respectively, and an increased length of the uterine horn and oviduct tissue in HE gilts. Real-time quantitative polymerase chain reaction revealed that HE gilts had higher Kiss-1, G protein-coupled receptor 54, gonadotropin-releasing hormone and estrogen receptor α mRNA expression levels in the hypothalamic anteroventral periventricular nucleus; the leptin receptor mRNA expression level was higher in the hypothalamic arcuate nucleus and ovary tissue; the insulin-like growth factor-1 receptor expression was higher in the pituitary and ovary tissues, and the follicle-stimulating hormone and luteinizing hormone mRNA expression levels were higher in the pituitary gland. CONCLUSION These data showed that the consumption of additional fat can facilitate early attainment of puberty, which can be predicted by the changes in secreted hormones and gene expression in the hypothalamus-pituitary-gonadal axis.

Maternal Methyl Donor Supplementation during Gestation Counteracts the Bisphenol A-Induced Impairment of Intestinal Morphology, Disaccharidase Activity, and Nutrient Transporters Gene Expression in Newborn and Weaning Pigs

This study was conducted to explore whether exposure to bisphenol A (BPA) during pregnancy could change intestinal digestion and absorption function in offspring using pigs as a model, and whether methyl donor (MET) could counteract the BPA-induced impacts. Fifty Landrace × Yorkshire sows were divided into four dietary groups throughout gestation: control diet (CON); control diet supplemented with BPA (50 mg/kg); control diet supplemented with MET (3 g/kg betaine, 400 mg/kg choline, 150 μg/kg vitamin B12, and 15 mg/kg folic acid); and control diet with BPA and MET supplementation (BPA + MET). Intestine samples were collected from pigs’ offspring at birth and weaning. Maternal BPA exposure during pregnancy significantly reduced the ratio of jejunum villus height to crypt depth, decreased the jejunum sucrase activity, down-regulated the mRNA expression of jejunum peptide transporter 1 (Pept1) and DNA methyl transferase 3a (DNMT3a), and decreased the DNA methylation level of jejunum Pept1 in offspring (p < 0.05). Maternal MET supplementation significantly raised the ratio of villus height to crypt depth in jejunum and ileum, improved the jejunum lactase activity, up-regulated the mRNA expression of jejunum Pept1, lactase (LCT), DNMT1, DNMT3a, and methylenetetrahydrofolate reductase (MTHFR), and increased the DNA methylation level of jejunum Pept1 in offspring (p < 0.05). However, the ratio of jejunum villus height to crypt depth was higher in BPA + MET treatment compared with CON and BPA treatment (p < 0.05). Meanwhile, there was no difference in the jejunum sucrase activity, the mRNA expression of jejunum Pept1 and DNMT3a, and the DNA methylation level of jejunum Pept1 between CON and BPA + MET treatment. These results indicated that maternal exposure to BPA during gestation might suppress offspring’s intestinal digestion and absorption function, whereas supplementation of MET could counteract these damages, which might be associated with DNA methylation.

Increased maternal consumption of methionine as its hydroxyl analog promoted neonatal intestinal growth without compromising maternal energy homeostasis

BackgroundTo determine responses of neonatal intestine to maternal increased consumption of DL-methionine (DLM) or DL-2-hydroxy-4-methylthiobutanoic acid (HMTBA), eighteen primiparous sows (Landrace × Yorkshire) were allocated based on body weight and backfat thickness to the control, DLM and HMTBA groups (n = 6), with the nutritional treatments introduced from postpartum d0 to d14.ResultsThe DLM-fed sows showed negative energy balance manifested by lost bodyweight, lower plasma glucose, subdued tricarboxylic acid cycle, and increased plasma lipid metabolites levels. Both villus height and ratio of villus height to crypt depth averaged across the small intestine of piglets were higher in the DLM and HMTBA groups than in the control group. Piglet jejunal oxidized glutathione concentration and ratio of oxidized to reduced glutathione were lower in the HMTBA group than in the DLM and control groups. However, piglet jejunal aminopeptidase A, carnitine transporter 2 and IGF-II precursor mRNA abundances were higher in the DLM group than in the HMTBA and control groups.ConclusionIncreasing maternal consumption of methionine as DLM and HMTBA promoted neonatal intestinal growth by increasing morphological development or up-regulating expression of genes responsible for nutrient metabolism. And increasing maternal consumption of HMTBA promoted neonatal intestinal antioxidant capacity without compromising maternal energy homeostasis during early lactation.

Effect of High Fat Dietary Intake during Maternal Gestation on Offspring Ovarian Health in a Pig Model

Excessive fat intake is a global health concern as women of childbearing age increasingly ingest a high fat diet. We therefore determined the association of a maternal high fat diet in pregnancy with offspring ovarian health during the gestation and postnatal female offspring in pig a model. Thirty-two Yorkshire gilts with similar bodyweights mated at the third estrus were randomly assigned to two nutrition levels of either a control (CON, crude fat: 7.27%) or a high fat diet (HFD, crude fat: 11.78%). Ovary samples were collected during the fetal (Day 55 (g55) and Day 90 of gestation (g90)) and offspring (prepuberty Day 160 (d160) and age at puberty) period to detect ovary development, antioxidant status and apoptosis cells. Maternal HFD did not influence notch signaling gene expression, which regulates primordial follicle formation and transformation, and ovarian histological effect at g55 and g90. However, maternal HFD reduced the numbers of large follicles at d160 and small follicle numbers upon puberty compared to CON in offspring. The results also revealed that the antioxidant index of total antioxidative capability (T-AOC), cytoplasmic copper/zinc superoxide dismutase (CuZn-SOD), glutathione peroxidase (GPx) activities and mRNA expression were higher in the CON than the HFD at g90 and d160, whereas, malondialdehyde (MDA) concentration was decreased in the CON. Maternal HFD increased the inhibitor of the apoptosis-related gene of B-cell lymphoma-2 (bcl2) mRNA expression at g90 and d160, whereas, pro-apoptotic-related gene bcl-2 assaciated X protein (bax) was reduced. These data show that the maternal high fat diet does not delay fetal ovarian development, but it changes ovarian health by the induction of oxidative stress and accelerating cell apoptosis in offspring.

Effect of intra-uterine growth restriction on long-term fertility in boars

The present study assessed the effect of birthweight on reproductive performance, including a possible mechanism, in male pigs. Ten newborn male piglets, including five normal birthweight (NBW) piglets and five intra-uterine growth restricted (IUGR) piglets, were used in the study. All piglets were weaned on Day 28 and fed the same diet during the experiment (10 months). Average daily weight gain, feed intake and the feed conversion ratio were higher in NBW than IUGR piglets. Similarly, testis volume and the number of Leydig and Sertoli cells in the distal portion of the testes were higher in NBW than IUGR piglets (P<0.05). Semen volume (P<0.05) and the total number of spermatozoa per ejaculate (P=0.08) were lower in IUGR boars. Testosterone concentrations on Day 141 and prostaglandin E2 concentrations on Days 82 and 141 were higher in IUGR than NBW boars (P<0.05). The malondialdehyde content of seminal plasma was higher in IUGR boars, whereas sperm glutathione peroxidase activity was lower in IUGR versus NBW boars (P<0.05). Expression of DNA methyltransferase (Dnmt) genes Dnmt1, Dnmt3a, histone-lysine N-methyltransferase (Suv39h2), and lysine (K)-specific demethylase Kdm4a was upregulated in testes from IUGR boars. These findings suggest that growth restriction affects sperm production via reproductive organ development and epigenetic regulation.

Proteomic Analysis of Fetal Ovary Reveals That Ovarian Developmental Potential Is Greater in Meishan Pigs than in Yorkshire Pigs.

Time-dependent expression of functional proteins in fetal ovaries is important to understand the developmental process of the ovary. This study was carried out to enhance our understanding of the developmental process of porcine fetal ovaries and to better address the differences in fetal ovary development of local and foreign pigs. The objective of the present study is to test the expression of key proteins that regulate the growth and development of fetal ovaries in Meishan and Yorkshire porcine breeds by using proteomics technology. Six Meishan and 6 Yorkshire pregnant gilts were used in this experiment. Fetal ovaries were obtained from Yorkshire and Meishan gilts on days 55 and 90 of the gestation period. Using 2D-DIGE (two dimensional-difference in gel electrophoresis) analysis, the results showed that there are about 1551 and 1400 proteins in gilt fetal ovaries on days 55 and 90, respectively of the gestation. Using MALDI TOF-TOF MS analysis, 27 differentially expressed proteins were identified in the fetal ovaries of the 2 breeds on day 55 of gestation, and a total of 18 proteins were identified on day 90 of gestation. These differentially expressed proteins were involved in the regulation of biological processes (cell death, stress response, cytoskeletal proteins) and molecular functions (enzyme regulator activity). We also found that alpha-1-antitrypsin, actin, vimentin, and PP2A proteins promote the formation of primordial follicles in the ovaries of Yorkshire pigs on day 55 of gestation while low expression heat shock proteins and high expression alpha-fetoproteins (AFP) may promote Meishan fetal ovarian follicular development on day 90 of gestation. These findings provide a deeper understanding of how reduced expression of heat shock proteins and increased expression of AFP can significantly reduce the risk of reproductive disease in obese Meishan sows. Our study also shows how these proteins can increase the ovulation rate and may be responsible for the low reproductive efficiency reported in other obese breeds. The ovarian developmental potential was found to be greater in Meishan pigs than in Yorkshire pigs.

Effect of different amino acid patterns on semen quality of boars fed with low-protein diets

The objective of the present study was to determine the effect of different amino acid patterns on the semen quality of boars fed with low-protein diets. Twenty-four boars were randomly divided into 4 groups (HP, LP1, LP2, and LP3). HP boars received 17% crude protein diet with a lysine:threonine:tryptophan:arginine (Lys:Thr:Trp:Arg) ratio of 100:50:20:104. Other boars received 13% CP and similar Lys levels (0.84%) with Lys:Thr:Trp:Arg ratios of 100:50:20:71, 100:76:38:71, and 100:76:38:120 for LP1, LP2, and LP3, respectively. These results showed sperm motility in the LP3 group was higher than in HP group during the 13-22 week period. The total sperm number, acrosome integrity ratio, and the effective total sperm number in LP3 and LP2 was higher than in other groups, and the abnormality ratio was lower than in other groups during the 13-18 week period. During 19-22 week period, in LP1 and LP3 groups, total sperm number and effective total sperm number were higher than in other groups, abnormality ratio was lower, and acrosome integrity ratio was higher than in the HP group. Nitric oxide synthase activity of seminal plasma and nitric oxide concentration of spermatozoa were significantly higher in the LP3 group than in other groups. Furthermore, mRNA expression of androgen receptor in testes was up-regulated in LP3. In conclusion, we suggest that the optimum ratio of Lys:Thr:Trp:Arg in a 13% CP diet for boars is 100:76:38:120, which results in similar or better reproductive performances than a 17% CP diet.

Proteomic Analysis of Fetal Ovaries Reveals That Primordial Follicle Formation and Transition Are Differentially Regulated

Primordial follicle formation represents a critical phase of the initiation of embryonic reproductive organ development, while the primordial follicle transition into primary follicle determines whether oestrus or ovulation will occur in female animals. To identify molecular mechanism of new proteins which are involved in ovarian development, we employed 2D-DIGE to compare the protein expression profiles of primordial follicles and primary follicles of fetal ovaries in pigs. Fetal ovaries were collected at distinct time-points of the gestation cycle (g55 and g90). The identified proteins at the g55 time-point are mainly involved in the development of anatomical structures [reticulocalbin-1 (RCN1), reticulocalbin-3 (RCN3)], cell differentiation (actin), and stress response [heterogeneous nuclear ribonucleoprotein K (HNRNPK)]. Meanwhile, at the g90 stage, the isolated proteins with altered expression levels were mainly associated with cell proliferation [major vault protein (MVP)] and stress response [heat shock-related 70 kDa protein 2 (HSPA2)]. In conclusion, our work revealed that primordial follicle formation is regulated by RCN1, RCN3, actin, and HNRNPK, while the primordial follicle transformation to primary follicle is regulated by MVP and HSPA2. Therefore, our results provide further information for the prospective understanding of the molecular mechanism(s) involved in the regulation of the ovarian follicle development.