首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 734 毫秒
1.
The study aimed to investigate the effects of maternal dietary methyl donors on the performance of sows and their offspring, and the associated hepatic insulin‐like growth factor‐1 (IGF‐1) expression of the offspring. A total of 24 multiparous sows were randomly fed the control (CON) or the CON diet supplemented with methyl donors (MD) at 3 g/kg betaine, 15 mg/kg folic acid, 400 mg/kg choline and 150 μg/kg VB12, from mating until delivery. After farrowing, sows were fed a common lactation diet through a 28‐days lactation period and six litters per treatment were selected to be fed until at approximately 110 kg BW. Maternal MD supplementation resulted in greater birthweight (p < 0.05) and increased the piglet weights (p < 0.01) and litter weights (p < 0.05) at the age of day 28, compared with that in CON group. The offspring pigs in the MD group had greater ADG (p < 0.05) and tended to lower F:G ratio (p = 0.07) compared with that of CON group from day 28 to 180 of age. The offspring pigs from MD group had greater serum IGF‐1 concentrations and expressions of hepatic IGF‐1 gene and muscular IGF‐1 receptor (IGF‐1r) protein at birth (p < 0.05), and greater hepatic IGF‐1 protein (p = 0.03) and muscular IGF‐1r gene expressions (p < 0.05) at slaughter, than that from the CON group. Moreover, the methylation at the promoter of IGF‐1 gene in the liver of newborn piglets and finishing pigs was greater in the MD group than that of the CON group (p < 0.05). In conclusion, maternal MD supplementation throughout gestation could enhance the birthweight and postnatal growth rate of offspring, associated with an increased expression of the IGF‐1 gene and IGF‐1r, as well as the altered DNA methylation of IGF‐1 gene promotor.  相似文献   

2.
The effects of growth hormone (GH) and insulin‐like growth factor‐I (IGF‐I) on protein synthesis and gene expression of κ‐casein in bovine mammary epithelial cell in vitro were studied. The treatments were designed as follows: the growth medium without serum was set as the control group, while the treatments were medium supplemented with GH (100 ng/ml), IGF‐I (100 ng/ml), and GH (100 ng/ml) + IGF‐I (100 ng/ml). The quantity of κ‐casein protein was measured by ELISA, and the κ‐casein gene (CSN3) expression was examined by real‐time quantitative PCR (RT‐qPCR). Compared with the control group, all the experimental groups had greater (p < 0.05) expression of CSN3. The concentration of κ‐casein followed a similar response as CSN3, but the difference between the treatments and the control was not statistically significant (p > 0.05). Furthermore, no synergistic effect of GH and IGF‐I was observed for both the κ‐casein concentration and CSN3 expression. It is therefore concluded that GH or IGF‐I can independently promote the expression of CSN3 in bovine mammary epithelial cells in vitro.  相似文献   

3.
This study aimed to evaluate the effects of supplementing Saccharomyces cerevisiae (SC) during the pre‐ and post‐weaning periods on growth, metabolic and hormonal responses, and rumen fermentation in calves. Three‐week‐old Holstein calves were assigned to either control (n = 12) or SC group (n = 12), the latter of which received 2 × 109 cfu/day of SC. The experiment was conducted over a period of 7 weeks around weaning. Daily gain (DG) in the SC group was higher (p < .05) than that in the control group. In the SC group, plasma glucose, insulin, and growth hormone (GH) concentrations were higher (p < .05) and concentrations of glucagon and insulin‐like growth factor 1 (IGF‐1) tended to be higher (p < .1) than in the control group. Proportion of rumen propionate and concentration of rumen ammonia nitrogen at 10 weeks of age were greater (p < .05) in the SC group than that in the control group. Supplementation of SC around weaning may improve dietary nutrient and energy availability and increase plasma GH and IGF‐1 concentrations. These changes observed in SC‐supplemented calves could be closely related to the improvement of DG.  相似文献   

4.
Jatropha curcas is a drought‐resistant shrub or small tree widespread all over the tropics and subtropics. The use of J. curcas (L) kernel meal in fish feed is limited owing to the presence of toxic and antinutritional constituents. In this study, it was detoxified using heat treatment and organic solvent extraction method. The detoxification process was carried out for 60 min to obtain the detoxified meal. Cyprinus carpio L. fingerlings (n = 180; avg. wt. 3.2 ± 0.07 g) were randomly distributed in five treatment groups with four replicates and fed isonitrogenous diets (crude protein 38%) for 8 weeks. The inclusion levels of the detoxified Jatropha kernel meal (DJKM) and soybean meal (SBM) were as follows: control diet was prepared with fish meal (FM) and wheat meal, without any DJKM and SBM; diets S50 and J50: 50% of FM protein replaced by SBM and DJKM respectively; diets S75 and J75: 75% of FM protein replaced by SBM and DJKM respectively. Highest body mass gain and insulin‐like growth factor‐1 (IGF‐1) gene expression in brain, liver and muscle were observed for the control group, which were statistically similar to those for J50 group and significantly (p < 0.05) higher than for all other groups, whereas growth hormone gene expression in brain, liver and muscle exhibited opposite trend. Insulin‐like growth factor‐1 concentration in plasma did not differ significantly among the five groups. Conclusively, growth performance was in parallel with IGF‐1 gene expression and exhibited negative trend with GH gene expression.  相似文献   

5.
This study aimed to detect the genetic variability in Leptin and Pit‐1 genes using polymerase chain reaction–restriction fragment length polymorphism and DNA sequencing also to explore their possible associations with reproductive and productive traits of Egyptian buffaloes. Regarding Leptin gene, three genotypes (AA, AG and GG) were identified with frequency of 0.54, 0.40 and 0.06, respectively, and the genotypes were distributed according to the Hardy–Weinberg equilibrium. Allele A was comparatively higher than G with frequency of 0.74 and 0.26, respectively. For Pit‐1 gene, the association could not be performed due to the monomorphism (BB). The results showed that AA genotypes were found to be superior in most of production and reproduction traits. AA genotypes yielded more milk (2332.34 kg, p = 0.04) with higher fat% (6.10, p = 0.004) and fat yield (155.75 kg, p = 0.06), reach peak milk production at 42.19 days and required 2.19 services for conception in comparison with GG genotypes. Birthweight of animals with AA genotype was lesser than with GG genotype (39.35 and 43.67 kg, p = 0.02, respectively). The days open is numerically better in AA genotype animals (99.35 days), but the difference between the three genotypes was non‐significant. The distinct significant associations reported in this study suggested that Leptin is reputable candidate genetic marker, which might be used to enhance animals’ genetic potential for milk production in conjunction with reproduction.  相似文献   

6.
The effects of zinc–methionine (Zn‐Met) supplementation on growth, blood metabolites and gastrointestinal development were investigated in two experiments with sheep. The objective of Experiment 1 was to determine the effects of Zn‐Met supplementation on hormones and metabolites involved in growth and energy balance regulation, while Experiment 2 aimed to determine the effects of Zn‐Met on feed intake, body weight, gastrointestinal development and liver glycogen concentration in lamb. The animals were assigned to groups with different concentrations of dietary Zn‐Met (0, 0.4, 0.8 and 1.2 g/day) in both experiments. In Experiment 1, feeding different doses of Zn‐Met increased plasma insulin‐like growth factor 1 (IGF‐1) concentration, but it linearly decreased plasma growth hormone (GH). No differences were observed in blood cortisol, insulin and glucose concentrations among the treatments. In Experiment 2, addition of Zn‐Met to the diets did not lead to changes in the body weights of the lambs. Both average daily gain and dry matter intake (DMI) increased linearly with increasing concentrations of dietary Zn‐Met. Lambs receiving Zn‐Met showed higher liver glycogen concentrations than the control. While significant increases were observed in the villus height and crypt depth in the duodenum and jejunum as a result of Zn‐Met supplementation, no change was detected in blood glucose concentrations (p > 0.05). Our findings suggest that dietary Zn‐Met may improve growth, energy balance and gastrointestinal development in sheep.  相似文献   

7.
The objective of this study was to test the hypothesis that aspartame supplementation in starter diet accelerates small intestinal cell cycle by stimulating secretion and expression of glucagon‐like peptide ?2 (GLP‐2) in pre‐weaned lambs using animal and cell culture experiments. In vivo, twelve 14‐day‐old lambs were selected and allocated randomly to two groups; one was treated with plain starter diet (Con, n = 6) and the other was treated with starter supplemented with 200 mg of aspartame/kg starter (APM, n = 6). Results showed that the lambs received APM treatment for 35 d had higher (p < .05) GLP‐2 concentration in the plasma and greater jejunum weight/live body weight (BW) and jejunal crypt depth. Furthermore, APM treatment significantly upregulated (p < .05) the mRNA expression of cyclin D1 in duodenum; and cyclin A2, cyclin D1, cyclin‐dependent kinases 6 (CDK6) in jejunum; and cyclin A2, cyclin D1, CDK4 in ileum. Moreover, APM treatment increased (p < .05) the mRNA expression of glucagon (GCG), insulin‐like growth factor 1 (IGF‐1) in the jejunum and ileum and mRNA expression of GLP‐2 receptor (GLP‐2R) in the jejunum. In vitro, when jejunal cells were treated with GLP‐2 for 2 hr, the 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2‐H‐tetrazolium bromide (MTT) OD, IGF‐1 concentration, and the mRNA expression of IGF‐1, cyclin D1 and CDK6 were increased (p < .05). Furthermore, IGF‐1 receptor (IGF‐1R) inhibitor decreased (p < .05) the mRNA expression of IGF‐1, cyclin A2, cyclin D1 and CDK6 in GLP‐2 treatment jejunal cells. These results suggest that aspartame supplementation in starter accelerates small intestinal cell cycle that may, in part, be related to stimulate secretion and expression of GLP‐2 in pre‐weaning lambs. Furthermore, GLP‐2 can indirectly promote the proliferation of jejunal cells mainly through the IGF‐1 pathway. These findings provide new insights into nutritional interventions that promote the development of small intestines in young ruminants.  相似文献   

8.
The aim of this study was to evaluate the effects of methionine supplementation on energy metabolism and reproductive performance during the early post‐partum period in primiparous does. Forty nulliparous New Zealand White does were used. Females were randomized in two groups at calving: the control group (n = 20) was fed with the basal diet, and the methionine group (n = 20) was fed the basal diet plus 1 g/animal/day of methionine from the day of calving to 4 days post‐partum. Results showed that methionine supplementation increased (p = 0.032) the concentration of insulin‐like growth factor‐1 with respect to control group 4 days post‐partum. It similarly increased the prolificacy (p = 0.03), the number of kits born alive per litter (p = 0.06) and the body gain weight of the litter during supplementation (p = 0.035). These results were observed despite the does in the methionine group having a deeper negative energy balance than the does in the control group. Finally, methionine supplementation did not affect receptivity (p = 0.23), fertility (p = 0.49), the number of kits born dead per litter (p = 0.86) insulin and metabolites as glucose, non‐esterified fatty acids and triglycerides. In conclusion, our results show that methionine supplementation during the first 4 days of the post‐partum period in rabbits increases total litter size and the corporal weight of kits and is associated with an increase in blood concentration of IGF‐1.  相似文献   

9.
This study was aimed to investigate the effects of rumen‐protected γ‐aminobutyric acid (RP‐GABA) on apparent nutrient digestibility, growth performance and health status in heat stressed beef cattle. Fifty Jinjiang Yellow cattle were randomly assigned to 5 treatments (10 animals/treatment). Treatments 1 to 5 were basal diets affixed with 0 (control), 8, 16, 24 and 32 mg of RP‐GABA/kg of body weight (BW) respectively. The trial lasted 45 days. Apparent digestibility of crude protein (CP), crude fiber (CF) and calcium (Ca) quadratically increased with increasing RP‐GABA (p < .01), while apparent digestibility of phosphorus (P) tended to quadratically increase (p = .09). Dietary supplementation with increasing RP‐GABA linearly increased DM digestibility and average daily gain (ADG) (p < .01), whereas the feed to gain (F:G) ratio linearly decreased with increasing RP‐GABA (p < .01). The average daily feed intake (ADFI) value tended to linearly increase with RP‐GABA supplementation (p = .08). Total protein (TP), blood urea nitrogen (BUN) and malondialdehyde (MDA) levels quadratically decreased (p < .01) with increasing RP‐GABA, however albumin (ALB), glucose (GLU), superoxide dismutase (SOD), triiodothyronine (T3) and thyroxine (T4) levels quadratically increased (p ≤ .01). In conclusion, the present results indicated that dietary supplementation with RP‐GABA led to improved nutrient digestibility, growth performance and antioxidant status in heat stressed beef cattle.  相似文献   

10.
An experiment was conducted to investigate the effect of plasma concentrations of the metabolic hormones [Growth hormone (GH), insulin and insulin‐like growth factor –I (IGF‐I)] and nutritional metabolites (Glucose, cholesterol, total protein, albumin, globulin, urea and creatinine) on the resumption of post‐partum ovarian activity in sixteen Friesian–Sanga cows grazing extensively on native grassland. Blood samples were taken from cows from week 1 to 16 post‐partum. Cows were classified as having resumed ovarian activity when a plasma progesterone concentration of ≥ 1.0 ng/ml was recorded for two consecutive weekly samples. Based on the resumption of ovarian activity, cows were classified as early‐cycling, late‐cycling or non‐cycling. The concentrations of the metabolic hormones were measured from week 1 to 10, while those of the nutritional metabolites were measured during week 1, 3, 5, 7 and 9 during the study period. The concentrations of the metabolic hormones, GH and insulin were similar (p > 0.05) in the three ovarian activity groups, likewise the concentrations of the nutritional metabolites, glucose, total protein, globulin, urea and creatinine. Plasma IGF‐I concentration was higher (p < 0.001) in early‐cycling (18.7 ± 0.74 ng/ml) than in late‐cycling (12.4 ± 0.75 ng/ml) and non‐cycling (10.4 ± 0.91 ng/ml) cows. Plasma cholesterol concentrations were significantly lower (p < 0.05) in early‐cycling (1.94 ± 0.15 mmol/l) compared with late‐cycling (2.48 ± 0.12 mmol/l) and non‐cycling (2.61 ± 0.11 mmol/l) cows. For plasma albumin concentrations, the levels recorded for early‐cycling cows were higher (40.7 ± 2.85 g/l) than in late‐cycling (34.4 ± 1.97 g/l) and non‐cycling (33.6 ± 2.66) cows. The results suggest that cows with lower plasma concentrations of IGF‐I and albumin, but higher plasma cholesterol concentrations were at risk of delayed resumption of post‐partum ovarian activity.  相似文献   

11.
A study was conducted to assess comparatively the growth performance of three different indigenous goat breeds during exposure to summer heat stress. The primary objective of the study was to observe the heat stress impact on the growth performance based on the body weight changes, allometric measurements, growth hormone (GH) concentration and peripheral blood mononuclear cell (PBMC) Insulin‐like growth factor‐1 (IGF‐1) mRNA expression pattern during the summer season in comparison with the local breed (Osmanabadi). Thirty‐six ten‐month‐ to one‐year‐old female goats of Osmanabadi, Malabari and Salem Black breeds were randomly divided into six groups, OC (n = 6; Osmanabadi control), OHS (n = 6; Osmanabadi heat stress), MC (n = 6; Malabari control), MHS (n = 6; Malabari heat stress), SBC (n = 6; Salem Black control) and SBHS (n = 6; Salem Black heat stress). Body weight was recorded at weekly intervals, whereas other growth and allometric measurements and blood collection were carried out at fortnightly intervals. Breed factor significantly (p < .05) influenced only few growth variables such as body weight, body mass index (BMI) and body condition score (BCS). However, heat stress treatment significantly (p < .05) reduced all growth parameters expect BMI. Further, the heat stress significantly (p < .01) increased plasma GH concentration in goats with significantly higher (p < .05) concentration recorded in OHS. Among the stress groups, the lower (p < .05) PBMC IGF‐1 mRNA expression was recorded in OHS, while the higher (p < .05) expression was observed in SBHS indicating the extreme adaptive capability of Salem Black breed. Thus, the results indicated that the Salem Black breed performed much better compared to both Osmanabadi and Malabari breeds indicating the superior ability of this breed to adapt to heat stress challenges. The results also indicated that plasma GH and IGF‐1 gene may act as ideal biomarkers for assessing the heat stress impact on growth performance in indigenous goats.  相似文献   

12.
An experiment was conducted to determine the effects of different amounts of dietary methionine on growth performance, serum protein, growth hormone (GH), insulin‐like growth factor‐I (IGF‐I) concentrations and IGF‐I mRNA expression of growing meat rabbits. One hundred weaned growing meat rabbits were allocated to individual cages and randomly divided into five groups. The methionine addition concentrations of the five groups were 0, 2, 4, 6 and 8 g/kg diet (as‐fed basis) and sulphur amino acids (SAA) concentrations ranging from 3.8 to 11.6 g/kg diet, respectively. The results obtained were as follows: the average daily gain of 2, 4 and 6 g/kg diet groups was higher than that of 0 g/kg diet group (p < 0.01). The feed gain ratio of the 4 g/kg diet group was lower than those of 0 and 8 g/kg diet group (p < 0.01). Methionine concentrations did not affect serum urea nitrogen, total protein, insulin and IGF‐I concentration (p > 0.05). The quadratic effects of methionine on the serum concentration of albumin (Alb) and GH were obtained (p = 0.013, p = 0.018). The quadratic effect of methionine amount on IGF‐I mRNA expression was obtained (p = 0.045). The serum concentration of Alb of the 4 g/kg diet group was higher than those of 0 and 8 g/kg diet group (p < 0.01). The serum concentration of GH of 8 g/kg diet group was higher than that of the 0 g/kg diet group (p < 0.05). The liver IGF‐I mRNA expression of 4 g/kg diet group was higher than those of the 0 and 8 g/kg diet group (p < 0.05). Providing a diet mainly consisted of corn, wheat bran and peanut vine, the optimum dietary methionine addition concentration and SAA concentration for a weaner to 2‐month‐old growing meat rabbits were shown to be 2 and 5.7 g/kg diet respectively.  相似文献   

13.
The aim of this study was to identify factors that regulate ruminal epithelial insulin‐like growth factor‐binding protein (IGFBP) expression and determine its role in rumen epithelial cell proliferation. Primary bovine rumen epithelial cells (BREC) were incubated with short‐chain fatty acids (SCFAs) at pH 7.4 or 5.6, lactate, lipopolysaccharide (LPS), insulin‐like growth factor‐I (IGF‐I), ‐II (IGF‐II), or recombinant bovine IGFBP2 (rbIGFBP2). The mRNA expression levels of IGFBP in BREC were analyzed using quantitative real‐time polymerase chain reaction (qRT‐PCR). The proliferation rate of BREC was analyzed using a WST‐1 assay. IGFBP2 gene expression tended to be lower with SCFA treatment (p < .1), and IGFBP6 gene expression was significantly lower with SCFA treatment (p < .05). IGFBP3 and IGFBP6 gene expression tended to be higher with d ‐Lactate treatment (p < .1). IGFBP3 gene expression was significantly higher (p < .05) with LPS treatment. BREC treated with IGF‐I grew more rapidly than vehicle control‐treated cells (p < .01); however, recombinant bovine rbIGFBP2 inhibited IGF‐I‐induced proliferation. IGF‐II and/or rbIGFBP2 did not affect BREC proliferation. Taken together, SCFA treatment decreased IGFBP2 and IGFBP6 expression in rumen epithelial cells, and lower expression of these IGFBP might promote rumen epithelial cell proliferation by facilitating IGF‐I.  相似文献   

14.

Paratuberculosis (PTB) is a chronic infectious enteritis of ruminants, caused by Mycobacterium avium subspecies paratuberculosis (MAP) that brings huge economic loss to the dairy farmers. The study was conducted to explore the association of selected SNPs in IFNG, SLC11A1, ANKRA2 and PGLYRP1 genes with resistance to PTB disease in Indian cattle population. A case-control resource population was established based on the results of diagnostic tests used for detection of MAP infection status viz. ELISA, Johnin PPD test, faecal microscopy and IS900 blood PCR. The PCR-RFLP method was used for genotyping of SNPs. SNPs rs109453173 in SLC11A1, rs110853455 in IFNG and rs41933863 in ANKRA2 genes were significantly (P<0.05) associated with resistance to MAP infection. For SNP rs109453173, GG genotype and G allele was found to be associated with resistance against MAP infection than CC and CG genotypes and C allele, respectively. For SNP rs110853455, AG genotype was found to be associated with susceptibility to MAP infection than AA and GG genotype. For SNP rs41933863, the AG genotype provided three and six times more resistance against MAP infection than GG and AA genotype. The results of this study are suggestive of SNPs rs109453173, rs110853455 and rs41933863 as potential markers for screening MAP resistant cattle and a breeding programme favouring GG genotype and G allele for rs109453173, AG genotype for rs41933863 and against AG genotype for rs110853455 might confer resistance against MAP infection in Indian cattle. However, investigation of these SNPs in an independent and larger population will warrant the strength of association for resistance against MAP infection in cattle.

  相似文献   

15.
This study evaluated the effects of rumen‐protected folic acid (RPFA) supplementation and dietary protein level on growth performance, ruminal fermentation, nutrient digestibility and hepatic gene expression in calves. Forty Holstein male calves (161 ± 5.7 days of age and 192 ± 5.4 kg of body weight) were assigned to one of four groups in a randomized experimental design with a 2 × 2 factorial arrangement. Moderate crude protein (130.1 g CP/kg [MCP] or high crude protein (150.2 g CP/kg [HCP]) diets were fed without (RPFA?) or with 3.6 mg FA (RPFA+) as RPFA per kg dietary dry matter (DM). Calves were fed a total mixed ration with a corn silage to concentrate ratio of 50:50 on a DM basis. The CP×RPFA interaction was not significant for any of the studied variables. The unchanged DM intake, higher average daily gain and lower feed conversion ratio were observed for HCP or RPFA+. Ruminal pH was lower, and total volatile fatty acids (VFA) concentration was higher for HCP or RPFA+. Acetate proportion was higher, and propionate proportion was lower for HCP or RPFA+. As a result, the higher acetate to propionate ratio was observed. Ruminal ammonia N was higher for HCP, but was lower with RPFA supplementation. The higher digestibility of DM, OM, CP and NDF was observed. Blood glucose and insulin were unchanged, but albumin, total protein, GH and IGF‐1 were higher. Similarly, the higher hepatic expression of GH, IGF‐1, GHR, IGF‐1R, PI3K, mTOR and P70S6K was observed for HCP or RPFA+. The results indicated that increasing dietary CP content or supplementation with RPFA promoted growth performance of calves by improving nutrient utilization and up‐regulating hepatic expression of gene related to protein synthesis.  相似文献   

16.
This study aimed to characterize the relationship between the growth of rumen papillae in calves and the mRNA expression of insulin‐like growth factor‐binding proteins (IGFBPs) in the rumen papillae. The length of rumen papillae, the mRNA expression of IGFBPs in rumen papillae by quantitative real‐time PCR, and the presence of insulin‐like growth factors I and II (IGF‐I and II) by immunohistochemistry (IHC) were analyzed in nine Holstein calves divided into three groups: suckling (2 weeks, n = 3), milk‐continued (8 weeks, n = 3), and weaned (8 weeks, n = 3). The length of rumen papillae was greater (p < 0.01) in weaned calves than in suckling and milk‐continued calves, whereas the expressions of IGFBP2, IGFBP3, and IGFBP6 genes were lower (p < 0.05) in the rumen papillae of weaned calves than in milk‐continued calves. Thus, rumen papillae length and IGFBP2, 3, and 6 expressions were negatively correlated. The IHC analysis showed that IGF‐I and IGF‐II were present in the rumen epithelium of calves. These results suggested that the growth of rumen papillae after weaning is associated with the induction of IGFs by the low levels of IGFBP2, IGFBP3, and IGFBP6.  相似文献   

17.
The objective of this study was to assess the effects of genistein (GEN) on expression of insulin‐like growth factor 1 (IGF‐1) and insulin‐like growth factor binding protein 1 (IGFBP‐1) in young and aged rat ovary. Forty young female Sprague Dawley (SD) rats (200 ± 20 g) and forty aged female SD rats (490 ± 20 g) were selected and according to weight, they were divided into the following five groups with eight animals in each: negative control group (NC), low‐dose group (L), middle‐dose group (M), high‐dose group (H) and positive control group (PC). GEN group received GEN of 15, 30, 60 mg/kg respectively. It lasted 30 days. Concentrations of serum hormones, IGF‐1 and IGFBP‐1 were determined by enzyme‐linked immunosorbent assay (ELISA). Gene and protein expressions of IGF‐1 and IGFBP‐1 were determined by real‐time PCR and Western blot respectively. Compared with NC, GEN significantly increased oestradiol‐17β(E2) level in aged rat, reduced luteinizing hormone (LH) level in young and aged rat. Serum levels of IGFBP‐1 in young rats were significantly higher in GEN groups (p < 0.05). mRNA and protein expression levels of IGF‐1 and IGFBP‐1 were positively correlated with GEN dose. GEN could significantly reduce the ratio of IGF‐1/IGFBP‐1 of aged rats. Multivariate Cox regression analysis result showed IGF‐1 and IGFBP‐1 levels significantly correlated with GEN dose. We speculate that there is an association between the addition of GEN and expression of IGF‐1 and IGFBP‐1, and the relationship between them is different in young and aged rat.  相似文献   

18.
This study evaluated the effects of rice whole crop silage (RWCS) on growth, plasma levels of vitamin A, β‐carotene, vitamin E and IGF‐1, and expression of genes involved in muscle protein degradation and synthesis in Japanese Black calves. Eleven calves were divided into RWCS (fed RWCS ad libitum and concentrate, n = 5) and control groups (fed hay ad libitum and concentrate, n = 6). Final body weight and dairy gain were significantly larger in the RWCS group compared with the control group. Plasma β‐carotene and vitamin E concentrations were significantly higher in the RWCS group compared with control group. Although plasma vitamin E concentration in the RWCS group significantly increased from 4 to 9 months of age, it did not increase in the control group. At 6 months of age in the RWCS group, ubiquitin B (p < 0.05) and calpain 1 (p = 0.097) mRNA expression were lower than control group, but they were not different between groups at 9 months of age. These results indicate that RWCS increases plasma β‐carotene level and promotes muscle growth because of a decrease in the rate of protein degradation, but the effect is lost with the increase in plasma vitamin E level.  相似文献   

19.
The growth hormone receptor (GHR) gene is responsible for growth and carcass traits, and polymorphisms associated with the variation of meat production are thought to occur in the liver‐specific promoter of the GHR gene in cattle. The aim of this study was to analyse the structure of the liver‐specific promoter of GHR in Japanese Black cattle, as the relationship between GHR polymorphism and meat production is poorly understood in this breed. Typically in European cattle, the LINE‐1 element, a family of retrotransposons, is inserted in the liver‐specific promoter. However, a short GHR promoter without the LINE‐1 sequence was found in the Japanese Black breed as in Bos indicus cattle. The frequency of the short allele was approximately 60%. In addition, 24 of 29 Holstein/Japanese Black crosses carried the short allele from their sire. The present result suggests that the short allele for GHR may be a candidate marker for improving meat production of Japanese Black cattle.  相似文献   

20.
  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号