Guanyu Hou

Effects of curcumin on growth performance, jejunal mucosal membrane integrity, morphology and immune status in weaned piglets challenged with enterotoxigenic Escherichia coli

The aim of this study was to evaluate the effect of dietary curcumin supplementation on growth performance and intestinal mucosal barrier function of weaned piglets. Fifty piglets, weaned at 21±2 days of age, were randomly allotted to five treatments for 21 days. The dietary treatments were the control (basal diet), and the basal diet supplemented with 50mg/kg quinocetone, or 200 mg/kg, 300 mg/kg or 400mg/kg curcumin. The piglets were housed in individual pens and orally challenged with enterotoxigenic Escherichia coli (ETEC) during the preliminary trial period. The jejunal morphology and histology analysis were detected under light microscope. The plasma D-lactate and diamine oxidase (DAO) were determined by using enzymatic spectrophotometric assay. Immunohistochemistry assays were used to examine secretory immunoglobulin (sIgA) protein expression. Real-time PCR was used to determine mRNA levels of cytokine and Toll-like receptor 4 (TLR4) in jejunal mucosa. The results showed that, compared with the control, dietary addition of 300 mg/kg or 400 mg/kg curcumin decreased (P<0.05) feed/gain ratio and crypt depth, improved (P<0.05) villus height and villus height:crypt depth ratio, reduced (P<0.05) plasma D-lactate and DAO activity, up-regulated the protein expression of sIgA (P<0.05), increased (P<0.05) the number of goblet cells (GCs) and reduced (P<0.05) the number of intraepithelial lymphocytes (IELs). The mRNA levels of interleukin 1β (IL-1β) and TLR4 and tumor necrosis factor α (TNF-α) were also decreased (P<0.05), but mRNA level of interleukin 10 (IL-10) was increased (P<0.05). There was no difference in the above parameters between the 300 mg/kg and 400 mg/kg curcumin groups. Pigs fed with 50 mg/kg quinocetone also decreased (P<0.05) feed/gain ratio, increased villus height:crypt depth ratio (P<0.05), and reduced (P<0.05) crypt depth and mRNA levels of TLR4. In conclusion, curcumin and the quinocetone have similar effects in improving piglet growth, but dietary addition of 300 mg/kg or 400 mg/kg curcumin was more effective than quinocetone in improving intestinal mucosal barrier integrity, morphology, and immune status of weaned pigs. This indicates that curcumin could be used as a potential feed additive replacing quinocetone in weaned piglets.

Seroprevalence, risk factors and genotyping of Toxoplasma gondii in domestic geese (Anser domestica) in tropical China

BackgroundLittle information is available about the seroprevalence of Toxoplasma gondii infection in geese (Anser domestica) in China. In the present investigation, the seroprevalence, risk factors and genotyping of T. gondii in geese were investigated in Hainan province, tropical China.FindingsA total of 600 serum samples and 150 brain tissue samples were collected from six administrative regions in tropical China, and assayed for T. gondii antibodies by Indirect Haemagglutination (IHA) test. Genomic DNA was extracted from the 30 brain tissues of seropositive geese and T. gondii B1 gene was amplified using a semi-nested PCR. DNA samples giving positive B1 amplification were then genetically characterized using multi-locus PCR-RFLP. Overall, 17% (95% CI: 14–20) of the animals were positive for T. gondii antibodies. Presence of cats in the household (odds ratio, OR 3), hygiene (OR 2.3) and presence of stray cat around the house (OR 2.3) were considered as main risk factors associated with T. gondii infection. Of 30 DNA samples, three were positive for the T. gondii B1 gene, two showed complete genotyping results. Only one genotype (type II) was identified.ConclusionsThe results of the present survey indicated the presence of T. gondii infection in geese in tropical China. Therefore, it is imperative that improved integrated measures be carried out to prevent and control T. gondii infection in geese in this province. This is the first report documenting the occurrence of T. gondii genotype in geese in China.

Dual Functions in Response to Heat Stress and Spermatogenesis: Characterization of Expression Profile of Small Heat Shock Proteins 9 and 10 in Goat Testis

Small heat shock proteins 9 and 10 (HSPB9 and HSPB10) are two testis-specific expressed sHsps. The objective of this study was to investigate the mRNA expression profile of HSPB9 and HSPB10 in goat testis among the different seasons, ages, and environmental temperatures. Allocation of the two sHsps was also performed by immunohistochemistry. The results showed that the transcript levels of HSPB9 and HSPB10 were extremely high in the testis (P < 0.01). The relative expression of HSBP9 and HSPB10 in testis showed a tendency to increase with age and then is maintained at the constant level after sexual maturity. HSPB9 and HSPB10 have significantly higher expression in the breeding season  (P < 0.05) and hot season (P < 0.01). Both HSPB9 and HSPB10 were found to be upregulated by high-temperature stress in testis (P < 0.05), and the expressions of Hsp70 and Hsp90 were also increased simultaneously (P < 0.01). Immunohistochemistry analysis localized HSPB9 expressed in spermatogonia, spermatocytes, and round spermatids and HSPB10 expressed in the elongate spermatids. In epididymis, strongly staining signal of HSPB10 was detected in pseudostratified columnar epithelium. In conclusion, the two testis-specific sHsps are closely related to male reproduction and heat tolerance. The results could provide valuable data for the further studies on HSPB9 and HSPB10.

Effects of nutritional level of concentrate-based diets on meat quality and expression levels of genes related to meat quality in Hainan black goats

The present study investigated the effects of the nutritional levels of diets on meat quality and related gene expression in Hainan black goat. Twenty-four goats were divided into six dietary treatments and were fed a concentrate-based diet with two levels of crude protein (CP) (15% or 17%) and three levels of digestive energy (DE) (11.72, 12.55 or 13.39 MJ/kg DM) for 90 days. Goats fed the concentrate-based diet with 17% CP had significantly (P < 0.05) higher average daily gains (ADG) and better feed conversion rates (FCR). The pH 24h value tended to decrease (P < 0.05) with increasing DE levels. The tenderness of Longissimus dorsi muscle (LD) and Semimembranosus muscle (SM) reduced with increasing CP levels (P < 0.05). With increasing DE levels, tenderness was increased (P < 0.05). The heart fatty acid-binding protein (H-FABP) mRNA expression levels in LD and SM increased with increasing DE levels (P < 0.05), but decreased with increasing CP levels (P < 0.05). The calpastatin (CAST) and μ-calpain mRNA expressions levels in LD and SM were affected significantly (P < 0.05) by CP and DE levels in the diet. Therefore, the nutritional levels of diets affect meat quality and expression levels of genes associated with meat quality in Hainan black goats.

Seroprevalence and genetic characterization of Toxoplasma gondii in masked palm civet (Paguma larvata) in Hainan province, tropical China

In the present study, the seroprevalence, risk factors and genotyping of Toxoplasma gondii in masked palm civet were investigated in tropical China. A total of 500 serum were collected from five administrative farms in tropical China, and assayed for T. gondii antibodies by modified agglutination test (MAT). The brain samples of 20 aborted fetuses were examined by semi-nested-PCR, and positive aborted fetuses (50%) were necropsied to collect the brain tissue for molecular and bioassay examinations. Genomic DNA was extracted from the 29 brain tissues of infected mice and T. gondii B1 gene was amplified using multilocus PCR-RFLP. Overall, 27.6% (95% CI: 23.682-31.518) of the animals was positive for T. gondii antibodies. Ages of masked palm civet was considered as a main risk factor associated with T. gondii infection. 4 DNA samples (13.8%) were positive for the T. gondii B1 gene. Three samples belong to ToxoDB#9, and one belongs to genotype the type II variant (ToxoDB genotype#3). Our results indicated that ToxoDB Genotype#9 has a distribution in masked palm civet that could be potential reservoirs for T. gondii transmission, which may pose a threat to human health.

Effects of dietary supplementation with turmeric rhizome extract on growth performance, carcass characteristics, antioxidant capability, and meat quality of Wenchang broiler chickens

Our study aimed to determine the effect of increasing dietary levels of turmeric rhizome extract (TRE) on performance, carcass characteristics, antioxidant capability and meat quality of Wenchang broiler chickens. Three hundred, 1-day-old Wenchang broiler chickens were brooded together for 2 weeks, then randomly allocated into four treatments with five replicates of 15 birds each. Birds were fed a corn-soybean basal diet supplemented with TRE at 0, 100, 200 and 300 mg/kg for 12 weeks. The results revealed that a TRE-supplemented diet had no significant effect (P>0.05) on the body weight, although birds fed a diet with TRE at 100 and 200 mg/kg had higher average daily weight gains and average daily feed as compared to controls from 9 to 12 week (P<0.05). Also, the addition of TRE at 100 to 300 mg/kg had a better feed conversion ratio compared to controls from week 9 to 12 (P<0.05). Dietary supplementation with TRE at 300 mg/kg increased the breast muscle weight ratio (P<0.05). Meanwhile, dietary supplementation with TRE at 100 to 300 mg/kg reduced the abdominal fat ratio (P<0.05), compared to that of the control group. TRE increased enzymatic activities of superoxide dismutase and glutathione peroxidase, and reduced malondiadehhyde concentrations, compared to the control group. Dietary TRE supplementation at 300 mg/kg decreased the drip loss in both breast muscle and thigh muscles, compared with the control group (P<0.05). In conclusion, dietary TRE supplementation enhanced antioxidant capability, growth performance, breast muscle weight ratio, and reduced the abdominal fat ratio of Wenchang broiler chickens.

Effect of rapid freezing-thawing techniques on the sperm parameters and ultrastructure of Chinese Taihang black goat spermatozoa.

Supercooling sperm in liquid nitrogen vapour is a feasible and economic technique for the practical production. The study aimed to reveal the negative effects of this rapid freezing and thawing processes on Taihang black goat spermatozoa and to find out the changing of spermatozoa motility and ultrastructure by using CASA and TEM. Qualified semen samples, which collected from twenty Chinese Taihang black goats using artificial vagina were pooled and investigated the kinematics parameters and ultrastructural morphology. The results showed that freezing-thawing caused a significant reduction in the spermatozoon total motility (P<0.001), in rapid and medium cell numbers (P<0.001) and motility parameters (VAP, VSL, VCL, ALH and BCF) (P<0.01). Immotile spermatozoa number was increased significantly after freezing-thawing (P<0.001). In the ultrastructural analysis, the shape with a sperm nucleus characterized by ruptures, bend and deformity was observed. The plasma membranes were broken, and nucleoplasm erupted. The mitochondria in the middle piece were disturbed by partial absence or additional accumulations. Swelling, coiling, vacuolization and structural disorganization of mitochondria were also observed. In conclusion, Freezing-thawing procedure has a detrimental effect on motility, membrane integrity and mitochondria of goat spermatozoa. Transmission electron microscopy provides an intuitive observation to investigate deformity spermatozoa.

Seroprevalence and risk factors of Chlamydia psittaci infection in domestic geese Anser domestica, in Hainan province of China

Chlamydia psittaci, the agent of psittacosis in humans, infects a wide range of bird species. To assess the risk of psittacosis posed by domestic geese in China, the seroprevalence of C. psittaci infection in domestic geese in Hainan province, tropical China was examined using indirect hemagglutination assay (IHA). The overall seroprevalence was estimated at 25.6% (461/1800; 95% CI: 23.6-27.6). The C. psittaci seroprevalence ranged from 19% (95% CI: 14.6-23.4) to 34% (95% CI: 28.6-39.4) among different regions in Hainan province, and the differences were statistically significant (P<0.01). The risk factors significantly associated with C. psittaci seroprevalence were the presence of hygiene conditions, age, gender, and environment of geese in the farms. The results of the present investigation indicated the high seroprevalence of C. psittaci infection in geese in Hainan province, tropical China. Close contact with these geese is associated with a risk of zoonotic transmission of C. psittaci. Public education should be implemented to reduce the risk of avian to human transmission of such a pathogenic agent. To the best of our knowledge, this is the first report documenting the occurrence of C. psittaci seroprevalence in geese in China.

Effects of dietary α-lipoic acid on carcass characteristics, antioxidant capability and meat quality in Hainan black goats

Abstract The effects of α-lipoic acid (LA) on the carcase characteristics, antioxidant capability and meat quality of Hainan black goat were investigated in the present study. Thirty goats (10.71 ± 0.42 kg) were randomly assigned with three levels of LA in the concentration diet (0, 300, 600 mg/kg). The goats fed for 70 days. The results showed that goats fed the diet containing 600 mg/kg LA had a significantly (p < .05) higher ADG and better feed conversion rate (FCR) compared with goats offered the basal diet without LA. There were no differences in carcase characteristics among the three treatments. For antioxidant enzymes, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), total antioxidant capacity (T-AOC) and catalase (CAT) in serum significantly increased (p < .05) in goats fed with 600 mg/kg LA at day 70. The concentration of malondiadehhyde (MDA) was significantly lower (p < .05) in serum of goats that received 600 mg/kg LA than in the goats fed diet without LA. Addition level of LA had no significant impact on pH and intramuscular fat (IMF) of longissimus dorsi muscle tissue (LM) and semimembranosus muscle tissue (SM) in the goats (p > .05). However, increasing additional LA in the diet caused a decrease on drip loss and WBSF (p < .05). Treatment of goats with 600 mg/kg of LA has the lowest drip loss and WBSF. These results indicate that diet supplementation with LA may enhance antioxidant capability, improved the growth performance and meat quality in Hainan black goats.

Effect of rare earth elements on feed digestibility, rumen fermentation, and purine derivatives in sheep

The experiment was conducted to evaluate the effect of rare earth elements (REE) on feed digestibility, rumen fermentation, and urinary purine derivatives (PDs) in sheep. Eight sheep (44.58±2.9 kg of body weight) fitted with ruminal cannulas were used in a replicated 4×4 Latin square design 20-day experiment. Sheep were fed a basal diet containing 100, 200 and 300 mg REE-citrate per kg dry matter (DM). Mixture of REE mainly consisted of cerium (56.8%), lanthanum (35.0%) and praseodymium (6.5%). Ruminal pH value was linearly (P<0.01) and quadratically (P<0.01) decreased, and ammonia N concentration (9.73 to 11.83 mg/100 mL) was quadratically (P<0.05) decreased, whereas total volatile fatty acids concentration was linearly increased with increasing REE supplementation (P<0.05). The ratio of acetate to propionate was linearly (P<0.01) and quadratically (P<0.01) decreased due to increase of propionate concentration (P<0.05). In situ ruminal neutral detergent fibre (aNDF) degradation of Leymus chinensis was improved (P<0.01), but the in situ ruminal crude protein (CP) degradation of soybean meal was decreased by feeding REE (P<0.01). Moreover, digestibility of DM, organic matter, aNDF, acid detergent fibre and CP in the total tract and urinary excretion of PD were also linearly (P<0.01) and quadratically (P<0.01) increased with increasing REE addition. In conclusion, supplementation of the basal diet with REE improved rumen fermentation and feed digestion in sheep. It was suggested that REE stimulated rumen microbial activity, digestive microorganisms or enzyme activity in a dose-dependent manner. The optimum supplemental dose of REE was about 200 mg/kg dietary DM in sheep.